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July 21, 2016

MEMORANDUM TO THE NATIONAL ORGANIC STANDARDS BOARD

FROM: Miles V. McEvoy

Deputy Administrator

National Organic Program (NOP)

SUBJECT: Hydroponic and Aquaponic Task Force Report

The Hydroponic and Aquaponic Task Force Report is available for your review. 

In September 2015, AMS convened the Hydroponic and Aquaponic Task Force to further 

explore the issue. The task force was comprised of sixteen (16) diversely qualified individuals 

that represent both the soil-based organic and hydroponic communities. The objective of the task 

force was to develop a report for the NOSB that: 1) describes the current state of technologies 

and practices used in hydroponics and aquaponics; and 2) to examines how those practices align 

or do not align with the Organic Foods Production Act (OFPA) and the USDA organic 

regulations. 

Please use this report to make a recommendation to AMS. Based on your recommendation, 

AMS will take the necessary steps to establish clear standards for these production systems. The 

public will be invited to provide comments during your deliberations, as well as when AMS 

develops guidance or initiates rulemaking on this issue.

AMS greatly appreciates the time and effort that the Hydroponic and Aquaponic Task Force 

members volunteered in writing this report. Members of the task force include:

• Will Allen, Milwaukee, Wisconsin

• Colin Archipley, Esondido, California

• John Biernbaum, Ph.D., East Lansing, 

Michigan

• Angela Caporelli, Frankfort, Kentucky 

• Dave Chapman, East Thetford, Vermont

• Marianne Cufone J.D., New Orleans, 

Louisiana 

• Amy Lamendella, Santa Cruz, California

• Charlie Shultz, San Marcos, Texas

• Eric Sideman, Ph D., Strafford, New 

Hampshire

• Pierre Sleiman, Encinitas, California

• Stacy Tollefson, Ph.D., Tucson, Arizona

• Jose Edgardo Torres, Sahuarita, Arizona 

• Jessica Vaughan, Freedom, California

• Jeffry Evard, Plainfield, Indiana

• Sam Welsch, Lincoln, Nebraska

• Theresa Lam, East Brunswick, New 

Jersey
NOTE: This report was written by the National Organic Standards Board, Hydroponic and Aquaponic Task 

Force. This report has not been reviewed for approval by the U.S. Department of Agriculture (USDA), and, hence, 

the contents of this report do not represent the views and policies of the USDA, nor of other agencies in the 

Executive Branch of the Federal government, nor does mention of trade names of commercial products constitute 

a recommendation for use. Additionally, the information provided as part of this report, including photos, 

diagrams, videos, presentations, written content or otherwise belongs to the report authors. Outside of reading 

the report, none of the information provided should be used by others without permission from the individual who 

contributed the content.

National Organic Standards Board (NOSB)

Hydroponic and Aquaponic Task Force Report

July 21, 2016

Table of Contents

1. 2010 NOSB Recommendation Subcommittee Report

2. Hydroponic and Aquaponic Subcommittee Report

3. Alternative Labeling Subcommittee Report
1

1. 2010 Recommendation

Subcommittee Report

Subcommittee Members

John Biernbaum, MSU and MOFFA

Dave Chapman, Greenhouse Organic Farmer

Theresa Lam, NOFA-NJ

Amy Lamendella, CCOF

Eric Sideman, MOFGA

Sam Welsch, OneCert
2

Summary of 2010 Subcommittee Report 

In 2010 the National Organic Standards Board passed a recommendation onto the National 

Organic Program called Production Standards for Terrestrial Plants in Containers and 

Enclosures. This recommendation was the culmination of more than a decade of work by the 

NOSB, and was the final recommendation of the Board on this topic. Six years later, the NOP 

felt that there were a few points relating to hydroponic production that were left ambiguous, 

and so created the Hydroponic and Aquaponic Task Force. The Task force formed three

Subcommittees: one was to describe "organic hydroponic" production and discuss the ways in 

which it aligns with OFPA and the USDA organic regulations, one was to discuss alternative 

labeling, and we ("the 2010 Recommendation Subcommittee”) accepted the task of providing 

clarification and further support for the position taken in the 2010 NOSB recommendation and 

consider the alignment of soilless production systems with organic law and regulation.

The Federal Register Notice announcing the formation of this task force had simple objectives: 

"There are two main objectives of the task force: (i) To describe current hydroponic and 

aquaponic production methods used in organic production, and (ii) to assess whether these 

practices align with OFPA and the USDA organic regulations. The task force will prepare a report 

advising the NOSB on proposed standards or guidelines for hydroponic and aquaponic methods 

in organic agriculture. The report may be used to inform the NOSB on recommendations 

concerning hydroponic and aquaponic systems and for possible guidance or rulemaking by the 

NOP." 

Observing that the framework of organic farming is based on its foundation of sound 

management of soil biology and ecology, it became clear to the NOSB that systems of crop 

production that eliminate soil from the system, such as hydroponics, cannot be considered as 

acceptable organic farming practices. The 2010 Subcommittee of the Task force came to the 

same conclusion. Similar to the NOSB in 2010, we based our conclusion on historical founding 

principles of the organic farming movement, regulatory text in the Organic Foods Production 

act, Regulatory Text of the USDA National Organic Program, good soil management practices, 

and international organic standards.

The organic farming movement began in the early part of the twentieth century, pioneered by 

farmers and academics who were responding to obvious problems with "modern" agriculture 

(where little organic matter is added to the soil) such as depletion of soil fertility and structure, 

decline of livestock health caused by low feed quality, soil erosion, etc. The basic premise of 

organic farming was that agricultural soil needs continuous restoration by means of adding 

manure and/or compost, managing cover crops and crop residue, and adding natural rock 

powders. The earliest organic certification programs based their standards on this premise. 

OFPA and the NOP regulatory text did an excellent job of representing this heart of the early 

certification programs by using the word "must" or "shall" (rather than "may") in the sections 

regulating soil management. 
3

Organic farming practices are centered on the basic principle of feeding the soil rather than the 

crop. This simple slogan rests on the idea that the successful management of soil is all about 

taking care of the organic fractions; the living organisms, the recently dead and decomposing 

organisms, the slow to decay organic matter, and the very stable organic matter often referred 

to as humus. The key to an organic farming system is to build and maintain these interactions. 

It is through the interaction of the organic matter fractions with the mineral fractions that a 

productive and sustainable soil system is developed and maintained. In an organic farming 

system the bulk of the crop's nutrients comes from complex organic molecules being fed into 

these organic fractions, and some portion of the material and mineral fraction being converted 

to nutrient forms available for plant uptake. Some of the organic material becomes part of the 

organic fraction of the soil, building the soil. Section 6513 (b)(1) of OFPA states, "...foster soil 

fertility, primarily through the management of the organic content of the soil...". Our 

interpretation of this OFPA section is that direct crop feeding with available fertilizers is to be 

used only as a supplement when necessary.

The 2010 Task Force Subcommittee recognize that there are some parts of an organic system 

that do not directly link to the soil, for example production of transplants. Furthermore, there 

are some commodities produced that include a less than obvious link to soil, such as sprouts, 

crops grown in containers, etc. In this report, we discuss these and explain the link to the soil, 

and explain why some of these may not be applicable to the premise that organic production 

takes place in the soil. We discuss the continuum between “grown in the ground” and “grown 

in a nutrient solution” and how to draw the line between a system that feeds the soil, and a 

system that does not meet organic principles because it is based on simply feeding the crop.

The basic standard of all of the countries in Europe is that hydroponic production is prohibited. 

We believe, that although some international standards allow crops to be grown in containers 

of biologically active media mimicking a soil system, and also restrict the amount of crop 

nutrients coming from direct feeding, there is no international organic standard that allows the 

bulk of the crop nutrients to come from direct crop feeding. 

Conclusions

The NOSB in their 2010 recommendation made it clear that they support the historical premise 

that organic production should take place in soil. Our subcommittee of the 

Hydroponic/Aquaponic Task Force agrees, and has worked to clarify any ambiguities that we 

and/or the NOP recognized.

The crux of our conclusion is to clarify the distinction between organic fertility management 

and conventional fertility management. In organic management, the source of the bulk of the 

crop nutrients are from the biological activity decomposing complex organic molecules 

(compost, manures, seed meals, etc.) and the mineral fractions in the soil. In contrast, in non 

organic production the bulk of the plant nutrients are supplied in available forms. It is the 
4

management of the soil that is at the heart of organic production. In contrast, in a non organic 

system it is the management of the fertilizers.

The NOSB will ultimately have to recommend its clear intention for the role of soil. This will be a 

very important recommendation for the future of organic certification. No matter what one 

thinks about which path is best, we can all accept that many in the organic community are 

opposed to the inclusion of hydroponic as organic1. Failure to address that concern will inevitably 

undermine public and farmer support for the USDA Organic label. 

Container Growing, (including hydroponic production)

Based on the work of this subcommittee, there appear to be the following choices to satisfy both 

the language of OFPA and the intent of the 2010 recommendation:

● Limit organic certification to what is grown in the ground, with the exceptions of 

transplants, ornamental, and herbs (The common standard used in most European 

organic certification). This would be the single path that is in clear alignment with the 

language of OFPA. The majority of the subcommittee supports this option.

● If certification includes crops grown in containers, it will require additional standards to 

cover the practices that are not covered by existing regulations. The critical question is 

how to ensure that container grown plants get most of their fertility from the natural 

processes of the soil or compost based media in the containers. This could require a 

limitation on the percentage of nutrition that could be gained from additional fertilizers 

after planting, and the amount of fertility obtained from liquid feeding. We suggest a 

limitation of no more than 50% of the required fertility being added after planting, and 

no more than 20% to be added as a liquid fertilizer after planting. For perennials these 

limitations should be on an annual basis. A similar limitation suggested by IFOAM EU is 

intended for field crops as well as greenhouse crops. Another suggestion is to follow the 

recommendation of Dr. Martine Dorais of Laval University and the Agassiz Research and 

Development Centre to grow in 100 to 180 liters of soil per m2. At this volume she has 

demonstrated that no liquid fertilizing is necessary, and fertility can be provided by the 

biological activity of the growing medium in the beds. We recommend defining the 

growing area to include the paths between rows. This choice deviates from a strict 

interpretation of the language of OFPA, but is closer to the intention. 

Enclosures

 

1 A clear demonstration of the depth of this opposition was the Moratorium letter presented to Secretary Vilsack 

in April of 2016. This letter called for an immediate moratorium on all new hydroponic certification until final 

standards in accord with the 2010 recommendation could be completed. It was signed by 65 organic leaders, 15 

former NOSB members, and 40 organizations whose total membership exceeds 2.2 million people. (Appendix H)
5

● Greenhouses need to be more specifically defined as having transparent roofs and walls 

to permit the passage of sunlight. Controlled indoor environments without transparent 

roofs and walls can be used for transplant production but not for organic crops.

● Electric lighting may be used as a supplement to the sun, but not as a replacement for 

the sun when producing organic crops. Transplants can be produced with only electric 

lighting. 

Growing Media

● Regulations relative to container growing media for transplants and organic crops need 

to be refined and evolved to require compost based media. This will require expanded 

definitions and guidelines relative to the production and acceptable characteristics of 

compost. The primary goal is to align with the expectations regarding containers as 

outlined above. At a bare minimum, a substrate used in pots or containers should have a 

minimum of 20% compost.

Rotation of Crops

Regarding rotation of crops in greenhouses, there seem to be two choices:

● Require rotations for all annual crops. This may be accomplished by rotating the crops, or 

by rotating the soil in the beds on a schedule of once every number of years. Then the 

rotated soil should be removed and be renewed by cover cropping or composting before 

returning to the greenhouse.

● Accept that greenhouse crops are grown in a specialized environment, and may require 

that issues such as soil biodiversity and health can be treated in a similar way to a 

perennial crop, with liberal use of compost, mulch, and interplanting.
6

Table of Contents

Summary of 2010 Subcommittee Report.................................................................................... 2

Conclusions ............................................................................................................................... 3

Container Growing, (including hydroponic production)............................................................ 4

Enclosures ............................................................................................................................. 4

Growing Media ....................................................................................................................... 5

Rotation of Crops ................................................................................................................... 5

Table of Contents....................................................................................................................... 6

Introduction................................................................................................................................ 9

Section 1. Regulatory Issues: How OFPA and NOP Regulatory Text Address Soil..................13

Background ...........................................................................................................................13

Before OFPA: ....................................................................................................................13

OFPA, the USDA organic regulations, and the NOSB:.......................................................14

Organic Foods Production Act and National Organic Program Regulatory Text ....................16

OFPA Section §6513(b)(1).................................................................................................16

National Organic Program Regulatory Text Sections 205.202, 203, and 205.........................17

§205.202 Land requirements. ..........................................................................................17

§ 205.203 Soil fertility and crop nutrient management practice standard............................17

§205.205 Crop rotation practice standard. .......................................................................17

Hydroponics Task Force Regulatory Considerations .............................................................18

Exceptions That Need to be Addressed in Future Regulation (Applicability of OFPA and 

USDA organic regulations to various types of soil-less production systems) .........................19

Soil requirements are not applicable to four types of soil-less production: sprouts, 

mushrooms, wild aquatic plants, and annual seedlings......................................................20

Some soil-less growing systems are not in alignment with USDA organic regulations 

because their fertility does not come from soil....................................................................21

Some container grown systems that use a combination of soil/compost as the source of 

fertility may be close enough to soil-grown that they could be certified with some 

amendments to USDA organic regulations.........................................................................22

Consistent with OFPA and USDA organic regulations ...........................................................23

§6501. Purposes................................................................................................................23

§6506. General requirements.............................................................................................24

§6512. Other production and handling practices ................................................................24
7

§6513. Organic plan...........................................................................................................24

Section 2. Soil as the Foundation.............................................................................................26

The Science of Growing in the Ground..................................................................................26

Role of Soil in Organic Agriculture.........................................................................................30

Soil Physical Properties .....................................................................................................31

Soil Chemical Properties....................................................................................................32

Soil Biological Properties ...................................................................................................32

“Organic” Soil.....................................................................................................................32

Regarding Organic Hydroponics ........................................................................................33

Section 3. Containers and Growing Media ................................................................................35

The Challenge of the 2010 Recommendation........................................................................35

Assessment of Alignment with OFPA and USDA Organic Regulations..................................36

Photos of each type...............................................................................................................37

Type A Production System.................................................................................................38

Type B Production System.................................................................................................40

Type C Production System ................................................................................................42

Type D Production System ................................................................................................43

Type E Container production systems................................................................................44

Criteria Used for Characterizing Systems ..............................................................................46

1. Source of Fertility ...........................................................................................................46

2. Growing Media / Compost..............................................................................................46

3. Biological Activity of Growing Media...............................................................................46

4. Consumer Awareness of Growing Method .....................................................................47

5. Annual Seedling Transplants or Finished Crops.............................................................48

6. Container Size ...............................................................................................................48

7. Adherence to All Applicable Aspects of the USDA Organic Regulation ..........................48

Section 4. International Standards ...........................................................................................49

The Canadian Standards.......................................................................................................49

The EU Standards.................................................................................................................52

The Four Scandinavian Countries .........................................................................................55

Section 5. 2010 Recommendations Not Directly Related to Hydroponics.................................56

Eight Point Summary.............................................................................................................57
8

Eight Point Details .................................................................................................................58

1. Enclosures .....................................................................................................................58

2. Lighting ..........................................................................................................................59

3. Natural Resources .........................................................................................................61

4. Containers .....................................................................................................................62

5. Container Growing Media...............................................................................................64

6. Land Use and Soil management ....................................................................................66

7. Rotation .........................................................................................................................67

8. Compost ........................................................................................................................69

Section 6. Definitions ...............................................................................................................73

Section 7. Appendices ..............................................................................................................75

Appendix A: EGTOP Report on Greenhouse Production.......................................................75

Appendix B: IFOAM EU Position Paper on Organic Greenhouse Production.........................77

Appendix C: Canadian Soil Fertility and Crop Nutrient Management and Greenhouse 

Standards..............................................................................................................................81

Appendix D: Soil Association Greenhouse Standards ...........................................................86

Appendix E: Language for the EU rule on growing in the ground...........................................91

Appendix F: Bioland Standards on Soils and Substrates and Growing of Seedlings, 

Transplants, Sprouts and Potted Herbs in Greenhouses (Bioland - the leading association for 

organic farming in Germany) .................................................................................................93

Appendix G: 1980 USDA Report on Organic Agriculture ......................................................95

Appendix H: Moratorium Letter.............................................................................................98

Appendix I: USDA Regulations of the use of Chilean Nitrate in Organic Agriculture ............110

Appendix J: Letter from Michael Sligh..................................................................................111
9

Introduction

This report is intended to offer clarification of the 2010 NOSB recommendation on Terrestrial 

Plants in Containers and Enclosures Greenhouses. That recommendation took years of work, 

and received extensive public review. In our opinion, it was a strong statement in support of 

traditional organic principles continuing as the basis for standards in the NOP. However, there 

were a few points found by the NOP to be left ambiguous. So five years later, the task force is 

now reviewing the recommendation, and offering possible ways of going forward. It is the 

subcommittee’s mission to honor the intentions and conclusions of the 2010 recommendation 

as much as possible.

To understand the 2010 recommendation, it is necessary to understand the history of the 

organic movement. Long before the USDA became involved, there was a worldwide agricultural 

movement based on a simple idea: Feed the soil, not the plant2. This slogan became the 

mantra for the organic community (Kuepper, 2010). The organic movement grew in response to 

another movement; an industrial/agricultural revolution that began in the late 1930’s, and 

exploded in the 1940’s. At that time, it was becoming popular to use fertilizers that were 

chemically manufactured to make the nutrients in them soluble, and thus rapidly available to 

plants. These synthetic fertilizers were able to circumvent the natural biological processes that 

has been the basis for all plant nutrition for the last 350 million years. It was, indeed, a 

revolution.

There were several consequences of this agricultural revolution. First, yields immediately 

increased. Plants grew faster and bigger. Productivity, as measured in pounds per acre, went up 

(Pratt, 1965). Second, insect and disease challenges increased (Yepsen, 1976). This was not a 

problem for this agro/ industrial revolution as they also were developing many potent 

pesticides and fungicides to control these problems. As time went by, the chemical agriculture 

industry went even further, and developed herbicides to reduce the challenges of weed control.

However, there were also unintended consequences. Concerns of many over human illness as a 

result of pesticide residue have consistently increased since 1940 (Carson, 1962). Concerns also 

grew that food from this agricultural revolution no longer supplied everything that people and 

livestock needed for health (Howard, 1940: Howard, 1952).

Thus in the early 1940’s, a number of thinkers and farmers began the organic farming 

movement, based on the work of others who came before. The term “organic farming” was 

first coined by Lord Northbourne. It was quickly picked up by Sir Albert Howard, Lady Eve 

Balfour, J.I. Rodale, and others. These early organic pioneers were intently focused on the life in 

 

2

This was cited as a foundational belief of organic farming in the 1980 USDA Report and Recommendations on 

Organic Farming. See Appendix G.
10

the soil. These pioneers were the first proponents of what is sometimes called “Deep Organic”3, 

meaning that it is based on principles of soil systems that embrace the lessons of soil ecology 

which includes an understanding of soil microbiology, soil zoology, plant biology, nutrient 

cycling, and the system of animal, plant, and soil community. The farming techniques which 

they championed were intended to enhance and further develop these biological processes in 

the soil. 

Their concerns were not about finding natural substitutes for the chemically enhanced 

fertilizers. This approach of substitution is sometimes called “Shallow Organic”. The pioneers 

had a completely different approach to understanding the soil/plant system, which involved 

cultivating the complexity in that system in order to cultivate stability and health. It was their 

belief that a complex soil/animal system would produce food that had the greatest health 

benefits for both humans and other animals in a sustainable way.

The complexity of this soil system was based on the rich diversity of life in the soil. This varied 

web of organisms includes bacteria, fungi, protozoa, nematodes, springtails, mites, spiders, 

worms, and burrowing mammals. 

This system is powered by the sun, via the plants. Plants use the energy from the sun to drive 

photosynthesis. They feed the soil bacteria and fungi by exuding sugars and enzymes out 

through their roots. Plants will give somewhere between 30% to 60% of their photosynthates to 

the bacteria and fungi living in the rhizosphere, the area right around their root hairs (Jackson, 

L. et al., 2012; Kallenbach and Grandy, 2011). These bacteria and fungi, in turn, provide the 

plants with minerals which they have obtained from the mineral fraction of the soil. 

Additionally, as decaying plant matter is deposited in the ground, either as animal manure or as 

decaying plant material, that organic matter is eaten and digested by the many forms of life in 

the soil, both microbial and animal. These life forms are busy eating each other as well, but if 

we take away the organic matter (which includes manures and the plant roots), we are killing 

the life in the soil.

This complex system is the basis of all life on the planet. It has been evolving over the last 400 

million years. Organic agriculture is a movement that acknowledges this process, and that tries 

to participate in it by maintaining and building the soil on the farm. 

In our opinion, the 2010 recommendation refers to these principles. We believe that the 

recommendation stresses that the regulation of organic agriculture is much more than a list of 

permitted and prohibited materials. In our opinion the NOSB recommendation interprets the 

OFPA and the NOP Regulation as a reflection of the belief that organic farming was meant to be 

a way of growing healthful crops as part of a system that was based on healthy soil. To quote 

 

3

The terms “Deep Organic” and “Shallow Organic” were first coined by Dr. Stewart Hill in the 1980’s at a NOFA 

talk.
11

the first sentence of Sir Albert Howard’s book, An Agricultural Testament: “The maintenance of 

the fertility of the soil is the first condition of any permanent system of agriculture.”

Citations

Carson, Rachel (1962) Silent Spring. Houghton-Mifflin Co.

Kuepper, George (2010) A Brief Overview of the History and Philosophy of Organic Agriculture. 

Kerr Center for Sustainable Agriculture.

Howard, Albert (1940) An Agricultural Testament. Oxford University Press.

Howard, Albert (1952) The Soil and Health. The Devin-Adair Company.

Jackson, Louise, Bowles, T., Hodson, Amanda, and Lazcano, Cristina (2012) Soil microbial-root 

and microbial-rhizosphere processes to increase nitrogen availability and retention in 

agroecosystems. Current Opinion in Environmental Sustainability 4:1-6. 

Kallenbach C, Grandy AS (2011) Controls over soil microbial biomass responses to carbon 

amendments in agricultural systems: a meta-analysis. Agric Ecosyst Environ, 144:241-252.

Pratt, Christopher (1965) Chemical Fertilizers. Scientific American, June, 1965. Reprinted in 

Plant Agriculture: Readings from Scientific American (1970), 152-162.

Yepsen. Roger (1976) Organic Plant Protection. Rodale Press.
12
13

Section 1. Regulatory Issues: How OFPA and NOP Regulatory Text 

Address Soil

Background

Before OFPA:

The organic farming movement began in the early part of the twentieth century, pioneered by 

farmers and academics who were responding to obvious problems with "modern" agriculture 

such as depletion of soil fertility and structure, decline of livestock health caused by low feed 

quality, soil erosion, etc. The Pioneers (Sir Albert Howard, Lady Eve Balfour, Rudolf Steiner, 

Jerome Irving Rodale, Aldo Leopold, William Albrecht, and others) fostered the notion that the 

success and sustainability of farming relies on management of the soil's health (Kuepper, 2010; 

Lockeretz, 2007). Most at that time referred to this as humus farming. They recognized that 

the soil is a complex system composed of countless biological interactions, and that ordinary 

practices of crop production leads to weakening of these interactions and subsequent loss of 

fertility and health. The kingpin of what they termed "humus farming" - named after the very 

stable organic matter at the heart of healthy soil, later to be called "organic farming" (Paull, 

2014) - is that in order to maintain and increase productivity, continuous restoration of the soil 

is needed by means of "manuring", managing crop residue, composting, cover cropping, and 

adding natural rock powders (Howard, 1940).

During the 1960s the counterculture began to link the organic agriculture movement with the 

wider environmental movement, and it gained more and more recognition in the general 

public. A role in this growing recognition was played by the new generation of farmers that 

arose from what is now termed the "back-to-the-land" movement. These farmers marketed 

their products in farmers markets, from their own farm stands and to the growing number of 

"health food stores". As the demand grew for organic food and farmers began bringing the 

food from their communities to the cities, the distance between the producer and the customer 

grew. Third party certification emerged as a means of assuring customers, who were now far 

removed from their farmer, that the products they purchased were truly organic.

In 1971 Rodale Press's Organic Farming and Gardening Magazine initiated an organic 

certification program based upon standards developing at that time in Europe. In 1972 the 

Maine Organic Farmers and Gardeners Association ran their first organic certification program 

based on the Rodale Organic Certification Program. California Certified Organic Farmers was 

soon to follow in 1973. Many more certifiers organized during the next decade, and by the 

1980s farmers across the country could find an organic certifier close to home. Although there 

were minor variations in what practices and materials were allowed, the standards used by 

each certifier were remarkably similar. Farmers had to submit a plan to the certifier that gave 

detailed explanation of what practices and materials were used on the farm in production of 

the crops to be called organic. Of course most synthetic pesticides and fertilizers were not 

allowed by organic standards, but the real crux of the standards was not what was prohibited, 
14

but rather what was required. Organic certification standards required on-farm practices and 

use of materials that fostered soil health by means of managing crop residue, using livestock 

manures, composting, cover cropping and adding natural rock powders. In other words, these 

early organic certification programs reflected the farming practices suggested by the pioneers 

of organic farming.

OFPA, the USDA organic regulations, and the NOSB:

Later, these same farming practices were reflected in the federal regulations that arose. The 

writing of the Organic Foods Production Act (OFPA) was a grassroots effort. Although not 

everyone involved with the organic movement in the 1980s supported the idea of a federal 

regulation, those writing the regulation made a tremendous effort to include representatives 

from organic certifiers from coast to coast. As a result, OFPA represents the standards that 

guided organic production prior to its passage. And, the National Organic Program (NOP) 

attempted to carry this over when they wrote the regulatory text that implements the law, 

especially the sections on managing the soil (Section 205.203). Both OFPA and the USDA 

organic regulations were written with the understanding that the foundation of organic farming 

is soil management. The Preamble to the USDA organic regulations contains statements 

confirming the fundamental essentiality of soil in certified organic production, including, but 

not limited to:

● “The soil fertility and crop nutrient management practice standard in section 205.203 

establishes the universe of allowed materials and practices.” 

● “A producer of an organic crop must manage soil fertility, including tillage and 

cultivation practices, in a manner that maintains or improves the physical, chemical, and 

biological condition of the soil and minimizes soil erosion.” 

● “The producer must manage crop nutrients and soil fertility through rotations, cover 

crops, and the application of plant and animal materials.”

● “The fundamental requirement of the soil fertility and crop nutrient management 

practice standard, that tillage, cultivation, and nutrient management practices maintain 

or improve the physical, chemical, and biological condition of the soil and minimize 

erosion, remains unaltered.”

 

Soil is fundamental to organic agriculture. By using the word "must" or "shall" rather than 

"may" in the sections regulating soil management, both OFPA and the USDA organic regulations 

require those producing organic crops to do so in soil. 

The National Organic Standards Board (NOSB) came to this same conclusion after decades of 

working on standards for container and greenhouse growing. The NOSB worked on container 

growing standards because OFPA and the USDA organic regulations did not specifically address 

this aspect of farming and the NOP intended for such standards to be included. The Preamble 
15

to the USDA organic regulations published on Dec. 21, 2000 recognized the importance of 

greenhouse regulations: “The NOP intends to provide standards for categories where the Act 

provides the authority to promulgate standards. During the 18-month implementation period, 

the NOP intends to publish for comment certification standards for apiculture, mushrooms, 

greenhouses and aquatic animals. These standards will build upon the existing final rule and will 

address only the unique requirements necessary to certify these specialized operations.” The 

NOSB proposed regulations for greenhouse standards in 2001 (NOSB 2001). Hydroponic 

production was not mentioned in these, but that was not an oversight. Eric Sideman was on the 

NOSB at the time of this discussion. He writes, “Hydroponic production standards were 

presented for discussion, but we rejected them because such production was thought at that 

time (as it was again in the 2010 NOSB Recommendation) to not meet basic organic production 

principles. Jim Riddle was a fellow NOSB member at that time and he concurs with my memory. 

Although we on the NOSB at that time expected the NOP to reject hydroponic production as an 

organic method, they did not, and furthermore the NOP did not publish certification standards 

for greenhouse standard as intended by the end of the implementation period in October 

2002.”

In 2003, the NOSB published a discussion document that questioned whether or not 

hydroponics and other soil-less systems could be certified (NOSB 2003). The NOSB also made 

the statement, “The NOSB agrees with the NOP position that mushroom, apiculture, and 

greenhouse operations can be certified as organic, and that the products of such operations can 

be labeled “organic” and carry the USDA organic seal. Further, the NOP should proceed with 

regulatory amendments, using recommendations submitted by the NOSB. ... Though the issue 

has been discussed, the NOSB has not submitted a recommendation on hydroponic production 

standards since adoption of the final rule. NOSB recommends that the Crops Committee place 

the item on its work plan. Rulemaking for hydroponic standards should not proceed until the 

NOSB has submitted a final recommendation.” In response, the NOP wrote, “NOP concurs with 

the NOSB and agrees ... not to propose hydroponic standards until the NOSB has submitted a 

final recommendation (NOP 2005). 

The NOP maintained that hydroponic production is allowed if done in full compliance with the 

USDA Organic Regulations. The NOP did not provide any further guidance to certifiers how the 

provisions of OFPA could be met. Many certifiers do not certify hydroponics operations because 

they believe such operations do not fully comply with OFPA and USDA organic regulations.

The 1995 recommendation states: "Hydroponic production in soilless media to be labeled 

organically produced shall be allowed if all provisions of the OFPA have been met." Hydroponics 

were not mentioned in the final rule. According to Michael Sligh, founding member of the NOSB 

from 1992-1997 who also served as the founding chair, the NOSB discussion was very brief and 

represented a placeholder for future discussion. He writes, “my understanding of that 

statement, that ‘all provisions of OFPA have been met’, was the key to my voting for that very 

brief recommendation.... I understood OFPA to be about organic farming, which meant that the 
16

goal ... is to optimize the health and productivity of interdependent communities of soil life, 

plants, animals and people.” (See Appendix J for complete letter.) 

All of the NOSB’s discussion documents in 2008 and 2009 continued to examine “The overriding question of whether soil-less systems are compatible with organic production.” (NOSB 

2008, NOSB 2009a, NOSB 2009b) In 2010, the NOSB recommended greenhouse standards for 

the USDA organic regulations and concluded that “hydroponic and aeroponic systems are 

prohibited.” (NOSB 2010)

In response to the 2010 NOSB recommendation, the NOP wrote on September 30, 2010, “The 

NOP thanks the NOSB for their completion of work on greenhouse standards through their April 

2010 recommendation. The NOP will develop a proposed rule based on the NOSB final 

recommendations.” The NOP has not yet developed a proposed rule on this topic.

The 2010 NOSB recognized a few exceptions to the principle of growing only in soil, for example 

producing transplants, crops that do not naturally grow in soil, etc. We will discuss those later 

in our report, but first here is a summary of sections in OFPA and the USDA organic regulations 

that require that organic production takes place in soil. 

Organic Foods Production Act and National Organic Program Regulatory Text

OFPA Section §6513(b)(1)

§6513. Organic plan 

(b) Crop production farm plan

(1) Soil fertility

Soil Fertility: “An organic plan shall contain provisions designed to foster soil fertility, primarily 

through the management of the organic content of the soil through proper tillage, crop 

rotation, and manuring.” [emphasis added]

This section of OFPA does not list any exceptions and is applicable to all organic crop 

production. By using the word "shall" rather than "may", it is requiring that the organic plan 

describe farming practices designed to foster soil fertility, thus implicitly requiring that 

production takes place in the soil. The simple dictionary definition of soil is, “the upper layer of 

earth that may be dug or plowed and in which plants grow.”

By using the word “primarily” when it states that soil fertility must come “primarily through 

management of the organic content of soil...”, OFPA established the foundation of fertility in 

organic farming as coming from “management of the organic content of the soil through proper 

tillage, crop rotation, and manuring”. When those practices are implemented, other sources of 

fertility are only minor sources. 
17

This subcommittee sees only one conclusion: when other sources become the primary source 

of fertility, then that operation is violating this mandatory part of OFPA. This conclusion is 

supported by statements in the Preamble to the USDA organic regulations that emphasize that 

soil is the primary source of fertility: “A producer of an organic crop must manage soil fertility, 

including tillage and cultivation practices, in a manner that maintains or improves the physical, 

chemical, and biological condition of the soil and minimizes soil erosion. The producer must 

manage crop nutrients and soil fertility through rotations, cover crops, and the application of 

plant and animal materials.... Crop nutrient management. The fundamental requirement of the 

soil fertility and crop nutrient management practice standard, that tillage, cultivation, and 

nutrient management practices maintain or improve the physical, chemical, and biological

condition of the soil and minimize erosion, remains unaltered.... Additionally, we clarified that 

producers may manage crop nutrients and soil fertility by applying mined substances if they are 

used in compliance with the conditions established in the National List.”

National Organic Program Regulatory Text Sections 205.202, 203, and 205

The following sections of the USDA organic regulations reflect the mandatory soil fertility 

requirements in OFPA.

§205.202 Land requirements.

Any field or farm parcel from which harvested crops are intended to be sold, labeled, or 

represented as “organic,” must:

(a) Have been managed in accordance with the provisions of §§205.203 through 205.206;

§ 205.203 Soil fertility and crop nutrient management practice standard.

(a) The producer must select and implement tillage and cultivation practices that maintain or 

improve the physical, chemical, and biological condition of soil and minimize soil erosion.

(b) The producer must manage crop nutrients and soil fertility through rotations, cover crops, 

and the application of plant and animal materials.

(c) The producer must manage plant and animal materials to maintain or improve soil organic 

matter content in a manner that does not contribute to contamination of crops, soil, or water 

by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances....

§205.205 Crop rotation practice standard.

The producer must implement a crop rotation including but not limited to sod, cover crops, 

green manure crops, and catch crops that provide the following functions that are applicable to 

the operation:

(a) Maintain or improve soil organic matter content;

(b) Provide for pest management in annual and perennial crops;

(c) Manage deficient or excess plant nutrients; and
18

(d) Provide erosion control.

Similar to OFPA, by using the word "must" rather than "may” in these sections, the USDA 

organic regulations require these farming practices, thus implicitly requiring that production 

takes place in the soil.

In its 2010 recommendation, the NOSB identified the same sections listed above as the relevant 

areas of OFPA and USDA organic regulations that exclude hydroponic and other soil-less 

growing systems from certification. The NOSB recommendations of both 2010 (NOSB 2010) and 

2001 (NOSB 2001) indicated that a producer operating a greenhouse with crops grown in 

containers may need to be exempt from requirements of 205.202, 205.203(a) and 205.205 

along with the crop rotation and cover cropping requirements in section 205.203(b). By 

recommending these exceptions, the NOSB was proposing amendments to the USDA organic 

regulations that would “build upon the existing final rule and will address only the unique 

requirements necessary to certify these specialized operations.” (NOP Preamble 2000).

Hydroponics Task Force Regulatory Considerations

In a presentation to the Hydroponics Task Force in 2016, the NOP stated that it was “Unable to 

accept exemption from 3 year requirement” and that it would require “Justification for 

exempting operations from – Crop rotation – Cover cropping” requirements. (NOP 2016) The 

reasons for these exceptions seem obvious to this subcommittee. It appears that the NOSB 

thought the 3 year requirement would not be applicable to a greenhouse using containers that 

would be filled with soil that meets the 3 year requirement. Crop rotation and cover crops may 

also not be necessary for container growing in a greenhouse if the operator is able to meeting 

the functions of a crop rotation through other practices. The text of the NOSB’s proposed 

standards describes alternative practices that would be acceptable. 

According to the NOP, (NOP 2016) other challenges to drafting regulations based on the NOSB 

2010 recommendation include:

• Insufficient information to draw a line between hydroponics and other types of 

production in containers/enclosures. 

• Clarification of requirement for growing media that supports diverse soil 

ecology. 

• No mention of aquaponics

The NOP also said it needs answer to these questions:

• If hydroponic systems are not allowed to be considered organic: 

– Clarify and justify how to determine the line between hydroponic production 

and container grown crops 
19

– If soil ecology is the basis for not allowing hydroponics, how is soil ecology 

defined?

• If hydroponic systems are allowed to be considered organic, specify: 

– How these systems can integrate cultural, biological, and mechanical 

practices that foster cycling of resources, promote ecological balance, and 

conserve bio-diversity. 

– What would be required of organic hydroponic systems – key components of 

measurable and enforceable standards. 

– How these products would be labeled.

These questions point out the difficulty of trying to alter the definition of soil to justify 

container growing. Although the characteristics of soil vary considerably from place to place, it 

is always clear what the soil of any given place is. If the NOP found these challenges too great to 

promulgate regulations from the NOSB recommendation because of the inability to draw a line 

between difference types of container growing, it would appear that the requirements for soil 

in the OFPA and USDA organic regulations would prevent the certification of any container 

grown crop. It is the lack of greenhouse standards that created the confusion and inconsistency 

about certification of greenhouse operations that grow crops in containers. 

The NOSB proposed that it may be possible to certify container growing with a compost based 

growing media if it provides the beneficial symbiotic ecological relationships found in soil. 

However, this subcommittee recognizes that it may be difficult to develop standards that would 

enable the implementation of this recommendation. There are aspects of soil ecology that may 

not be able to be reproduced in containers. We discuss this in later sections of this report.

Exceptions That Need to be Addressed in Future Regulation (Applicability of 

OFPA and USDA organic regulations to various types of soil-less production 

systems)

Some agricultural products that may be deemed organic are not directly from soil production. 

We believe that the NOSB, in their 2010 recommendation, recognized that as OFPA and the 

USDA organic regulations are written now, there should be a link to soil in order that organic 

certification of such products be a sound and reasonable interpretation of the intent, or the 

product should be of a type that does not naturally need soil to live and grow. Furthermore, 

production practices of all agricultural products deemed organic should meet the Principles of 

Organic Production and Handling as described by the NOSB in their adopted guideline of 2001.

The 2010 NOSB recommendation (Production Standards for Terrestrial Plants in Containers and 

Enclosures) addressed exceptions to the premise that plants be grown in soil. Some exceptions, 
20

e.g., sprouts, mushrooms, etc., they said were outside the scope of the recommendation. From 

this subcommittee’s perspective, the recommendation could be bettered, and more easily 

accepted by the NOP, if it explained how each of these exceptions to the premise that crops be 

grown in soil; 1) are linked to soil, or 2) are not naturally living or growing in soil so there is no 

reason for farming them in soil. Furthermore, how each meets the Principles of Organic 

Production and Handling (NOSB, 2001) should be made clear. 

The following crops may or may not be considered exceptions to the premise that crops be 

grown in soil. We present an explanation as to why, if we think they should be exceptions, or 

we raise issues where we believe there is reasonable debate as to whether or not they should 

be exceptions.

Soil requirements are not applicable to four types of soil-less production: sprouts, 

mushrooms, wild aquatic plants, and annual seedlings. 

These four types of production are in alignment with USDA organic regulations.

Sprouts and wild harvest of aquatic plants are addressed by the USDA organic regulations. The 

Preamble to the final rule indicated that additional standards would be needed for production

of mushrooms and greenhouse production.

1) Sprouts (soil not applicable, in alignment with USDA organic regulations) Sprouting seeds 

does not need to take place in soil because sprouting should be considered a processing of an 

organic product. The seed is the certified organic product, and sprouting the organic seeds is 

simply processing. It is not analogous to growing a crop since no new crop production is 

occurring. The seed is the organic product; it is simply germinating. For the sprout to be 

considered organic the seed must have been produced on a farm according to the organic 

standards.

Sprout production requires only organic seed and water. Soil is not used, so the requirements 

for soil are not applicable. Sprout production can be certified as a handling operation, not as a 

farm because it does not require soil.

2) Mushrooms (soil not applicable, in alignment with USDA organic regulations) Mushrooms 

are not plants and so, similar to other non-plant agricultural products, should be exempt from a 

required direct link to soil. Mushrooms are in the kingdom Fungi. Unlike plants, mushrooms 

do not depend on minerals from soil. Rather, mushrooms are nourished by food fed to them by 

the producer. The key to the organic status of mushrooms should be that the food must be 

produced according to organic production standards. 

3) Wild Aquatic plants (soil not applicable, in alignment with USDA organic regulations) These 

species naturally occur in aquatic (soil-less) systems and so it is not unreasonable for NOP to 
21

accept an organic status without a soil link in their production, if all other criteria of OFPA and 

the USDA organic regulations are met.

The preamble to the USDA organic regulations in 2000, described changes that were included 

to specifically allow for the certification of wild aquatic plants: “Finally, we changed the 

definition of "wild crop" to specify that harvest takes place from a "site" instead of "from land," 

thereby allowing for aquatic plant certification.” However, this allowance was specifically for 

wild aquatic plant certification. The USDA organic regulations do not have any specific 

standards for non-wild aquatic plant certification.

4) Seedlings and planting stock raised in soil-less media (soil not applicable, in alignment with 

USDA organic regulations) The raising of these in a soil-less media is a short period of the whole 

production time. These crops will spend most of their time growing in the soil, and the short 

period of time in preparation for their field production should be an exception.

Seedlings are specifically mentioned in OFPA and USDA organic regulations. § 205.204(a) 

requires annual seedlings to be certified organic. Nonorganic annual seedlings may only be 

used if a temporary variance is granted in accordance with § 205.290(a)(2). The requirements 

for soil would apply to crops grown from seedlings, but may not be applicable to the seedling 

itself.

Some soil-less growing systems are not in alignment with USDA organic regulations 

because their fertility does not come from soil.

5) Fertigation as primary fertility source (Not aligned with OFPA and USDA organic regulations) 

Fertigation is the injection of fertilizers, soil amendments, and other water-soluble products 

into an irrigation system. Fertigation is not limited to greenhouse production or container 

growing. When fertigation becomes the primary source of fertility, it does not comply with the 

OFPA requirement that fertility come “primarily through the management of the organic 

content of the soil.” It would take a change in OFPA to allow systems that depend primarily on 

fertigation to be certified organic.

6) Hydroponic production of terrestrial plants (Not aligned with OFPA and USDA organic 

regulations) Hydroponics violates OFPA and USDA organic regulations because practices do not 

meet the requirements of the Sections noted above. Because fertility comes from water 

delivery of nutrients rather than soil, it appears that it would take a change in OFPA to certify 

hydroponic and aquaponics systems as organic.

The 2010 recommendation from the NOSB considered that such production does not meet the 

principles of organic production. They concluded that such production does not include the 

very basis of organic production, i.e., providing nourishment to the living fraction of the soil and 

this in turn providing available minerals to crops. 
22

Some operators of hydroponic systems claim to employ biological activity to reduce complex 

molecules to simple mineral components that plants can use. However, this subcommittee was 

not provided with sufficiently detailed information to determine whether or not this is the 

primary source of crop nutrition. Furthermore, even if it is, we question whether removing soil 

from the system meets the intent of the OFPA. The so called “bioponic” systems are so new 

that there is no published research data on how they actually function. Is such hydroponic 

production actually based on a system that bypasses the soil food web and fertilizes the plants 

directly using immediately available nutrients? 

Some container grown systems that use a combination of soil/compost as the 

source of fertility may be close enough to soil-grown that they could be certified 

with some amendments to USDA organic regulations.

7) Container production of crops to maturity (Debatable, not in full alignment with USDA 

organic regulations, but may be in alignment with 2010 NOSB recommendation) The media in 

containers may or may not contain soil and the corresponding biological activity creating 

available nutrients for plants. Furthermore, the amount of the media may or may not be large 

enough to supply the bulk of crop nutrients. This is fodder for debate in the NOSB and NOP. 

Options include:

 a) simply prohibiting the production of crops to maturity in containers, 

 b) or requiring containers of such size that the bulk of the crop nutrients comes from the soil 

in a container. In other words, limiting the amount of crop nutrients coming from soluble, plant 

available fertilizers. 

The NOP has previously addressed the issue of crop nutrients being from available form rather 

than resulting from the soil. For example, the amount of nitrogen for a crop from sodium 

nitrate is limited to 20% of the total nitrogen needs. Hence, a possible guideline that assures 

container production meets the intent of OFPA and the USDA organic regulations is to require a 

minimum amount of biologically active soil/compost capable of supplying the bulk of crop 

nutrients, and limiting the portion of nutrients coming from immediately available form, as was 

done for sodium nitrate.

8) Microgreens (debatable, not in full alignment with USDA organic regulations, but are in 

alignment with the 2010 NOSB recommendation). Microgreens are raised past the stage where 

the product would be considered processing an organic seed (sprouts). They grow a short 

period of time past germination, and can be grown in a compost based medium. Such 

production may, or may not be considered an exception. Hydroponic production of 

microgreens would be considered under the hydroponic production system discussed above 

(item 36). Similar to growing crops in containers (addressed above) microgreen production is 
23

trying to provide compost-based production by having ALL of the nutrients come from the seed 

and/or media. Because microgreens are raised for such a short period, this is truly possible.

Either type of container grown crops (microgreens or full maturity crops) may require changes 

to USDA organic regulations to be certified organic. On the other hand, perhaps the Rule as 

written would support a container system that mimics a soil system, i.e., one that contains 

appropriate media (compost) that decomposes and releases plant nutrients, and one that is 

large enough and contains enough media that the crop is primarily getting its minerals from the 

media.

Consistent with OFPA and USDA organic regulations

One of the key purposes of OFPA is “to assure consumers that organically produced products 

meet a consistent standard” (OFPA §6501). It is clear from the inconsistent way that 

hydroponic, aquaponics, and container systems are currently being certified that purpose is not 

being met. In its 2010 recommendation, the NOSB questioned the appropriateness of certifying 

soil-less systems and pointed out the need for exceptions from mandatory sections of OFPA 

and current regulations in order to certify container grown crops. “Although the regulations do 

not specifically state ‘soil only production’, the exclusion of soil from organic production of 

normally terrestrial, vascular plants violates the intent of the regulations. This intent can be 

seen in these sections of the rule that require proper stewardship toward improving and 

maintaining the soil ecology within an organic farming system.” (NOSB 2010). Although the 

NOSB did not explain the need for exceptions from mandatory sections of OFPA and current 

regulations in order to certify container grown crops, it seems obvious to this subcommittee 

that additional standards are necessary. It appears that the NOP is now requesting justification 

for those exceptions or alternate methods for meeting the requirements.

The statements from the NOP that hydroponics are covered by existing regulations (NOSB 

2003) was confusing to accredited certifiers. Such a statement by itself does not make 

hydroponic systems certifiable. Certifiers who have certified hydroponic operations can only do 

so by ignoring mandatory sections of OFPA and USDA organic regulations or designating such 

sections as "not applicable". This has led to inconsistent application of the regulations. Most 

certifiers do not certify hydroponics and many refuse to certify hydroponics because they have 

determined that these systems cannot comply.

Some people point to §6512 of OFPA as justification for certification of hydroponics, but other 

sections of OFPA preclude such certification because it is not consistent with the fundamental 

requirement for fertility to come primarily from management of organic content of the soil.

§6501. Purposes

It is the purpose of this chapter—
24

(1) to establish national standards governing the marketing of certain agricultural products as 

organically produced products;

(2) to assure consumers that organically produced products meet a consistent standard; and

(3) to facilitate interstate commerce in fresh and processed food that is organically produced.

§6506. General requirements

(a) In general

A program established under this chapter shall—

... (7) provide for appropriate and adequate enforcement procedures, as determined by the 

Secretary to be necessary and consistent* with this chapter;

§6512. Other production and handling practices

If a production or handling practice is not prohibited or otherwise restricted under this chapter, 

such practice shall be permitted unless it is determined that such practice would be 

inconsistent* with the applicable organic certification program.

§6513. Organic plan

... (b) Crop production farm plan

(1) Soil fertility

An organic plan shall* contain provisions designed to foster soil fertility, primarily* through the 

management of the organic content of the soil through proper tillage, crop rotation, and 

manuring.

...(g) Limitation on content of plan

An organic plan shall not include any production or handling practices that are inconsistent* 

with this chapter.

[*emphasis added]

Citations

Howard, Sir Albert (1940) An Agricultural Testament. Oxford University Press.

Kuepper, George (2010) A Brief Overview of the History and Philosophy of Organic Agriculture. 

Kerr Center for Sustainable Agriculture.

Lockeretz, W. (Ed.). (2007). Organic Farming: An International History. Wallingford, UK: CABI.

NOP (2005). USDA RESPONSE TO NOSB FEEDBACK ON ISSUE STATEMENTS: FISHMEAL, INERTS, 

ANTIBIOTICS, AND SCOPE OF AUTHORITY. (NOP-USDANOSBFeedback3_10_05.pdf).

NOP (2016). NOP Presentation, Task Force Meeting, San Diego, CA, January 2016

NOSB (2001). Principles of Organic Production and Handling. (Adopted October 17, 2001)

NOSB (2001). NOSB Final Recommendation Greenhouse Production Systems. (October 2001)

NOSB (2003). Crops Committee Recommendations for a Guidance Document Relative to 

Hydroponics and Other Soil-less Growing Systems: Prepared by Owusu Bandele- 2003

NOSB (2008). Crops Committee Discussions on Guidance Statements Relative to Soil-less 

Growing Systems. April, 2008.
25

NOSB (2009a). NOSB Crops Committee Soil-less Growing Systems Discussion Item. May 2009 

Meeting.

NOSB (2009b). NOSB- Crops Committee Recommendation Greenhouse Production Systems. 

September, 2009.

NOSB (2010). National Organic Standards Board (NOSB) Crops Committee Recommendation: 

Production Standards for Terrestrial Plants in Containers and Enclosures (Greenhouses). 

(January 23, 2010).

Paull, John (2014) Lord Northbourne, the man who invented organic farming, a biography. 

Journal of Organic Systems 9:1: 53.
26

Section 2. Soil as the Foundation

The Science of Growing in the Ground

There is an ongoing discussion about whether it is possible to replicate the complexity of a 

healthy soil system in a hydroponic system. The organic movement was built on maintaining 

and improving the soil in an effort to realize many benefits. The organic movement began as a 

belief system. In free ranging discussions with a number of soil scientists who have been 

longtime advocates of organic farming, we have come up with the following thoughts about the 

ways in which science has come to support that belief system. 4

Reliance on a complex soil system is the foundation of organic farming. This soil system is based 

on biological complexity. A biologically complex system is a stable system. A biologically simple 

system is an unstable system. Modern “conventional” farming has worked on a strategy of 

making simpler systems that are nonetheless more easily controlled by human intervention. 

The soil on a “conventional” farm is biologically simpler than the soil on a well-managed organic 

farm (Birkhofer et al 2008; van Geel et al 2015; Tuck et al 2015; Bedini et al 2013). Nonetheless, 

most “conventional” farms have soil that has significant biological diversity. A hydroponic 

system, even with “added biology” is much simpler biologically than almost any soil system, 

including those of “conventional” farms. It is important to understand that there is an active 

biology even in “conventional” hydroponics. It is just less complex, and thus more vulnerable to 

disease, than a complex soil biology.

As Dr. Larry Phelan has written, “It is a fundamental principle of ecology that ecosystems with 

greater biological diversity are more stable and less susceptible to invasion”. As an 

example, fungal, bacterial and total phospholipid fatty acid microbial biomass increased by over 

40% on both conifer and aspen litter types in mixture, and microbial community composition 

changed significantly when plant litter types were mixed. Microbial diversity also increased with 

increasing plant litter diversity (Chapman and Newman, 2009). As the complexity of the 

environment increases, more niches are created and variation in resources provides 

opportunities for partitioning, allowing more species to coexist by reducing competition. The 

relationship between complexity/diversity and stability and invasibility is discussed in any 

Introductory Ecology textbook. Hydroponics are by design more simple than a soil environment. 

It is absurd to suggest that a hydroponic system, irrespective of the matrix used, can match the 

complexity of soil in terms of the physical environment, the resource base, or the biological 

community. 5

 

4

Scientists included Dr John Spargo- Penn State University, Dr. Larry Phelan- Ohio State University, Dr. Will 

Brinton- Woods End Laboratories, Dr. Bill Liebhardt- UC Davis, Dr. Fred Magdoff -University of Vermont, Dr. John 

Reganold- Washington State university, Dr. Walter Jehne CSIRO, Healthy Soils Australia, Dr. Stuart Hill- University 

of Western Sydney.

5

Personal communication from Dr. Phelan with the task force subcommittee.
27

The complexity of the soil system is best understood as a soil food web, as it is not a simple 

causal chain, but rather is a series of many interconnected relationships. It is a food web 

because everything in it is eating and being eaten by something else. There is constant cycling 

and recycling of nutrients.

It is our opinion that this web cannot be replicated by simply “adding biology”, because we are 

not smart enough to know which biology to add, nor how much. The microbes that are cultured 

in a compost tea might not be the microbes that are needed by the plant. The mycorrhizal fungi 

that are added might not be the mycorrhizal fungi that are needed for the immediate 

challenges facing the plant. One strain of mycorrhizal fungi will help with disease suppression 

but hinder insect resistance. Another might do the opposite. We are not knowledgeable 

enough to get it right. The key to organic farming is to create the conditions in which the 

diverse biology will flourish.

The plant is a key part of the soil system. It actually is selective in cultivating the optimal 

bacteria and fungi in the soil to serve its own constantly changing needs. (Kallenbach and 

Grandy, 2011) It does this by feeding the appropriate microbes with root exudates that are up 

to 1/3 of the photosynthates it produces. It selectively feeds the microbes it needs. This 

process of the plant’s supplying necessary energy to the life of the soil has been a basic part of 

the coevolution of the plant/soil community. 6

Those microbes are intelligent in responding to the needs of the plants. There are many 

mycorrhizal fungi that are present in a healthy soil system. They are the living interface 

between the plants and the soil. They will selectively regulate which substances in the soil liquid 

stream will be permitted to be taken up by the plant. They allow beneficial substances in 

appropriate amounts and reject damaging substances.

The animals in the soil are also very critical in managing the microbiology. By animals, we mean 

the beetles, mites, protozoans, spiders, springtails, nematodes, worms, termites, slugs, and 

small mammals that live in a healthy soil system. These animals are critical in selectively 

influencing the makeup of the soil bacteria and fungi. 

The basis for organic farming is to positively influence the conditions on the land and in the soil 

to optimize the growth of a very diverse and vibrant soil community. The amount of life below 

the surface of the soil is greater in biomass than the amount of life above the surface.

The soil is critical in managing the resource of water as well. See Role of Soil in Organic 

Agriculture that follows. The soil’s ability to successfully manage the water is based on the 

activities of the entire soil food web, not just on the addition of organic matter. 

 

6

Personal communication with Dr. Walter Jehne.
28

The complex soil system is not just important for providing proper nutrients. It is also critical for 

supplying chemicals that protect the plant from both insects and diseases.

A healthy soil system is based on recycling. There are critical cycles that the soil is a key 

participant in. These cycles include the mechanisms whereby carbon is sequestered in the soil. 

A healthy soil is our greatest defense against climate change.

The soil system is the basis for our survival on the planet. Plants, humans, other animals (both 

above and below the surface of the soil), and microbes have coevolved over the last 350 million 

years. In that time very sophisticated, interrelated mechanisms have evolved whereby healthy 

plants thrive and supply the needed nutrition for healthy mammals. 

It is the opinion of this subcommittee that we do not fully understand most of these processes. 

What we know is much smaller than what we don’t know. We can participate in and influence 

this system, but we cannot control it.

As Dr. Stuart Hill has said, quoting an old phrase, “If the animal is sick, look to the plant. If the 

plant is sick, look to the soil. If the soil is sick, look to the farmer.”

Citations

Bedini, S, et al. 2013. Mycorrhizal activity and diversity in a long-term organic Mediterranean 

agroecosystem. BIOLOGY AND FERTILITY OF SOILS 49: 781-790. 

Birkhofer, K., Bezemer, T. M., Bloem, J., et al. 2008. Long-term organic farming fosters below 

and aboveground biota: Implications for soil quality, biological control and productivity. Soil 

Biology & Biochemistry 40: 2297–2308.

Chapman, S., and Newman, G. S. 2009. Biodiversity at the plant-soil interface: Microbial 

abundance and community structure respond to litter mixing. Oecologia 162:763-9. 

Kallenbach C, Grandy AS (2011) Controls over soil microbial biomass responses to carbon 

amendments in agricultural systems: a meta-analysis. Agric Ecosyst Environ, 144:241-252.

Tuck, S.L., Winqvist, C., Mota, F., Ahnstrom, J., Turnbull, L.A., and Bengtsson, J. 2015. Land-use 

intensity and the effects of organic farming on biodiversity: a hierarchical meta-analysis. 

JOURNAL OF APPLIED ECOLOGY 51: 746-755

van Geel, M., Ceustermans, A., van Hemelrijck, W., Lievens, B., Honnay, O. 2015. Decrease in 

diversity and changes in community composition of arbuscular mycorrhizal fungi in roots of 

apple trees with increasing orchard management intensity across a regional scale. MOLECULAR 

ECOLOGY. 24: 941-952.
29

 
30

Role of Soil in Organic Agriculture

The authors of the OFPA and NOP Regulatory Text, and the members of the 2010 NOSB 

recognized the importance of soil, organic matter, soil organic matter, and soil biology. A 

discussion of more details can help better understand how organic matter in the soil system not 

only feeds the microorganisms but also plays the key role in building better soil physical and 

chemical properties. Moreover, a better understanding of the role of organic matter and soil 

organic matter will lead to a better understanding of why OFPA, the NOP Regulatory Text, and 

the 2010 NOSB Recommendation are written to include soil management as a mandatory part of 

the Organic System Plan.

The USDA Organic Regulation definition of organic matter is incomplete in that it appears to refer 

only to recently decaying or fresh organic matter, for example, the organic matter added to the 

soil through the use of cover crops, animal manure and mulches. The term organic matter has 

also been used to describe the stable, long term humus in the soil, more accurately referred to 

as “soil organic matter” (SOM). Compost is an example of organic matter that can contain both 

recently decaying as well as long term stable humus forms (SOM). Fine dark lines or particles in 

soil aggregates are visible examples of SOM. (Madgoff and van Es, 2009)

Our current understanding of successful organically managed soil systems allows and requires 

more detailed and differentiated definitions of “organic matter”. The approach used in the 2010 

recommendation separates the living organisms and dead plant material as two separate and 

distinct things. However, in modern perspectives the living organisms are or can be characterized 

as one of the organic matter fractions. 

The success of a biologically active, productive soil under Organic management has been 

characterized as a balance of four organic matter fractions. (Snapp and Grandy, 2011)

1. Living Organisms

2. Recently dead micro and microorganisms and plant material up to several years old.

3. Slow decaying organic matter in the range of decades old (5 to 50 years)

4. Stable and humus organic matter that exists for decades to centuries (50 to 500 years) 

and has been identified as “soil organic matter” or “SOM”. 

The proportions or percentages of these four fractions have been characterized as:
31

The key to an organic farming system is to build and maintain the interactions of the organic 

matter fractions with the mineral fractions. It is through these interactions that a productive and 

sustainable soil system is developed and maintained (Magdoff and Van Es, 2009). These 

interactions build soil structure that provides and retains a balance of water and air holding 

capacity, as well as good water drainage, that is needed for healthy/diverse microbial 

populations, which in turn, retain and cycle nutrients, and for crop growth (Moebius-Clune et.al, 

2016).

Although the 2010 recommendation emphasizes the importance of soil biology, it did not address 

the essential water and air balance nor the nutrient cycling and retention that are dependent on 

organic matter and SOM. A biologically active soil comes from cultivating soil structure that 

provides adequate air and water holding capacity. Furthermore, the organic matter or carbon 

content of soils are now understood as short and long term carbon “pools” or reserves that are 

used by and composed of microorganisms; abiotic and biotic pools. In other words, the soil 

system is an interwoven balance of living organisms that not only build the soil structure, but 

depend on it for their own survival. 

Soil Physical Properties

In an agricultural context, mineral soils are often defined as a mixture of soil particles of varying 

textures/sizes (sand, silt, clay) in combination with organic matter (range of 1 to 5% by volume), 

with a desired composition of 50% solid and 50% pore space. The dry bulk density or weight of 

“typical” or “ideal” mineral soils is generally reported as 1.3 gram per cubic centimeter (~83 

pounds per cubic foot). When present in deep undisturbed/structured continuous columns of 

two feet or more and after an application of an excess of water and drainage of water by gravity, 

there is a desired mixture of approximately 50% air/large pore space and 50% water/small pore 

space. The biological and chemical activity in the organic matter fraction is the key to the 

development of the pore spaces by forming secondary aggregation of soil particles. This 

aggregation creates a crumb-like structure that creates large pores which allow water movement 

and available oxygen, and small pores for water and nutrient holding capacity. It is the 

decomposition of organic matter by microorganisms in soil that creates the glues and cements 

that build soil structure (Magdoff and Van Es, 2009).
32

Living, decaying and long term SOM are necessary for continued maintenance of water 

absorption into and retention by mineral soils. Water absorption is influenced by soil texture, 

structure, crusting and macropore channels from decaying roots or earthworms (living organic 

matter). Soil aggregate formation and stability are two measures of soil health (Moebius-Clune 

et.al, 2016).

Soil Chemical Properties

The longer term organic matter or “humus” fraction also provides electrical or “magnetic” 

negative charges important for retaining a reserve of essential cations for plant growth (Ca++, 

Mg++, K+, NH4+, Fe++, Mn++, Zn++, Cu++). A key to the regulation of the rate of plant growth (not 

too fast and not too slow) is the balance between readily available / soluble nutrients and a long 

term supply of nutrients either associated with charged soil particles or in the pools of living and 

decaying organic matter. Just as it is possible to over fertilize plants in non-organic systems with 

the over application of soluble nutrients, it is also possible to over fertilize plants in organic 

systems by over application of soluble nutrients from organic fertilizers, or building too large 

pools of organic matter from manure or compost. It is the size of both the biotic and abiotic 

nutrient retention potentials that impacts the success of an organic soil management system. 

Soil Biological Properties

The nutrient retention potential of soil is in part characterized as cation exchange capacity of the 

non-living soil, as well as the living organic matter fraction that rapidly responds to short term 

nutrient fluxes by increasing or decreasing populations. Soluble nutrients can result in increased 

biological activity/populations that can sequester the available pool of nutrients. In a healthy soil 

system, knowledge of how these cycles work allows farmers to match nutrient availability with 

peak crop growth rates. 

“Organic” Soil 

The key distinction between organic fertility management and conventional fertility 

management is that in organic the source of the bulk of the crop nutrients are from the biological 

activity decomposing complex organic molecules (compost, manures, seed meals, etc.) and the 

mineral fractions. In contrast, in non organic production the bulk of the plant nutrients are 

supplied in available forms. It is the management of the soil that facilitates this complex system 

in an organic system. In contrast, in a non organic system it is the management of the fertilizers.

When does a “soil” become “certified organic”? The short answer is never. Soil is not certified 

as organic. The organic systems plan (OSP) that characterizes all the management practices that 

allow a soil to be productive is what is certified as organic. These practices can include crop 

rotation, tillage, use of cover crops to prevent erosion, catch crops to prevent leaching of 

nutrients, application of manure, mulch or compost to provide living, decaying and stable forms 

of organic matter. These practices are also identified to prevent erosion / soil loss and to build 
33

soil through the formation of stable soil aggregates. Our knowledge and management of soil 

physical properties (water/air), chemical properties (CEC, pH) and biological properties (diversity, 

biomass) together define an organic agriculture management system. Without the multiple, 

integrated roles that soil provides, it is not possible to have organic agriculture.

The lack of a definition of soil from an organic farming perspective and the language used in the 

2009/2010 recommendation allowed certain certification agencies and hydroponic growers to 

conclude that it was microorganisms or biology alone that made a system organic. Organic 

Agriculture is rooted in the management of soils, not the presence or absence of soil biology. 

Regarding Organic Hydroponics

Lord Northbourne in the book Look to the Land (1940), often referenced as one of the first uses 

of the term “organic agriculture”, spoke of concerns about the then recently developed 

commercial hydroponic systems in the opening pages of the book (pg 4). He spoke of how 

hydroponics can be misleading if applied to field soil systems and of the need to see the soil as a 

living whole and not a dead medium. Northbourne also spoke of the essential interdependent 

cycle that connected plants, animals and humans to the soil (pg 34) and the importance of the 

cycle to human health. 

A question to ask in regards to hydroponic systems of any type is whether multiple generations 

of plants can be grown from seed to seed under continuous hydroponic production. Decades 

ago Sir Albert Howard (2007) questioned the reliability of the long term soil and nutrient 

management trials at Rothamsted Experiment Station (UK) in part because each year fresh seed 

was introduced. The trial did not include continuous seed to seed production over many 

generations that would provide a better test of the system viability. Northbourne (1940) also 

pointed out the same need for a “considerable number” of generations to be grown with 

hydroponics to produce multiple generations of plants to be tested by exclusively feeding to 

multiple generations of animals (pg 5). 

Hydroponics is presented as a sustainable alternative to soil, in part due to the potential for 

nutrient recycling and the conservation of limited water resources. Comparing water use 

efficiency of hydroponics in greenhouses or controlled environments to field soils seems less 
34

appropriate than comparing it to other containerized systems in greenhouses or controlled 

environments. Regarding water use and nutrient efficiency, well managed non-leaching 

containerized systems using compost based growing media suitable for use in an organic systems 

plan can be as good as hydroponic systems. 

Literature Cited

● Moebius-Clune, B.N., D.J. Moebius-Clune, B.K. Gugino, O.J. Idowu, R.R. Schindelbeck, A.J. 

Ristow, H.M. van Es, J.E. Thies, H. A. Shayler, M. B. McBride, D.W. Wolfe, and G.S.Abawi. 

2016. Comprehensive Assessment of Soil Health – The Cornell Framework Manual, Edition 

3.0, Cornell University, Geneva, NY. 137 pages. 

http://soilhealth.cals.cornell.edu/training-manual/ 

● Howard, A. 2007. The Soil and Health: A Study of Organic Agriculture (Clark Lectures). 

University Press of Kentucky. 352 pgs. 

● Madgoff, F. and H. van Es. 2009. Building Soils for Better Crops 3rd edition. Sustainable 

Agriculture Research and Education (SARE) Program. 294 pgs. 

http://www.sare.org/Learning-Center/Books/Building-Soils-for-Better-Crops-3rd-Edition 

● Northbourne, W.J. 1940. Look to the Land. Second Revised edition published by Sophia 

Perennis, Hillsdale NY in 2003. 114 pgs. 

● Snapp, S. and S. Grandy. 2011. Advanced Soil Organic Management. Michigan State 

University Extension Bulletin E-3137. 6 pgs. 

http://msue.anr.msu.edu/uploads/234/42589/Building_Soil_Organic_Matter.pdf 
35

Section 3. Containers and Growing Media

The Challenge of the 2010 Recommendation

The key question that the 2010 NOSB recommendation did not clearly address was exactly how 

to draw the line between “grown in the soil” and “hydroponic”. There are a few other questions 

that require clarification, such as the use of 100% artificial lighting and the requirement for crop 

rotation, but this section of the report will focus on the big question of how to define what is 

acceptable as “grown in the soil”. 

The 2010 Recommendation stated: 

“Observing the framework of organic farming based on its foundation of sound management of 

soil biology and ecology, it becomes clear that systems of crop production that eliminate soil 

from the system, such as hydroponics or aeroponics, can not be considered as examples of 

acceptable organic farming practices. Hydroponics, the production of plants in nutrient rich 

solutions or moist inert material, or aeroponics, a variation in which plant roots are suspended 

in air and continually misted with nutrient solution, have their place in production agriculture, 

but certainly cannot be classified as certified organic growing methods due to their exclusion of 

the soil-plant ecology intrinsic to organic farming systems and USDA/NOP regulations governing 

them.”

And further on:

“Although the regulations do not specifically state ‘soil only production’, the exclusion of soil 

from organic production of normally terrestrial, vascular plants violates the intent of the 

regulations. This intent can be seen in these sections of the rule that require proper 

stewardship toward improving and maintaining the soil ecology within an organic farming 

system. It is pointed out that naturally aquatic plant species and non-vascular plant species 

such as mushrooms come from different (non-soil) ecological niches and would be handled 

separately. Sprouts (the sprouted radicle and hypocotyl of seeds) are produced without soil by 

design and are not subject to this recommendation. 

In previous Crops Committee discussion documents, the question has been asked: “Should 

container culture based growing media (typically utilized in greenhouse systems) that are 

predominantly compost and compostable plant materials be considered ‘soil’. As highlighted in 

earlier portions of this document, a foundational principle of organic farming is the practice of 

maintaining and nurturing soil health so as to foster the proliferation of the proper soil biology 

with their accompanying ecologies. Since all typical soil dwelling organisms, such as 

earthworms, protozoa, fungi, bacteria, actinomycetes, etc. can thrive in a properly designed 

compost based growing media, producing the beneficial symbiotic ecological relationships 

found in soil, such growing media should be rightfully considered soil.”
36

These paragraphs set a high bar for what can legitimately be considered organic. The 2010 

Recommendation does not articulate which specific practices can or cannot be allowed, but it 

makes clear that to permit growing in containers the standards must satisfy these demands.

One question asked of the task force is how to clarify which systems should be considered 

hydroponic, and which systems should be considered as being based on “sound management of 

soil biology and ecology”. There is a confusing continuum between “grown in the ground” and 

“grown in a nutrient solution.” The task force has spent a lot of time trying to examine the large 

variety of growing systems, and to create a framework for differentiating these systems. There 

has been a frustrating shortage of specific information on the fertility programs being used in 

the currently certified hydroponic operations, but we have done our best with the information 

we have gotten. Below is this subcommittee’s perspective of the continuum that the NOSB 

should consider.

At the top of the continuum is “grown in the ground.” This is clearly not considered hydroponic 

production anywhere in the world. It is grown in the soil, and it is grown as an integral part of 

the soil system. Once we take a shovelful of that soil and put it in a container, we have entered 

a new and challenging arena.

Every organic standard in the world accepts grown in the ground as qualifying for certification. 

The controversy for organic certification comes when the plants are grown to maturity in some 

kind of containers, and then harvested. At this point, there is no longer world consensus. This is 

stepping onto a slippery slope. As we have seen above, adhering to the basic language of the 

NOP regulations, and OFPA is very challenging.

Assessment of Alignment with OFPA and USDA Organic Regulations

For crops that are not grown directly in the ground, there is a wide range of production 

systems. Each system uses different production methods which have unique implications in 

terms of their similarity or differences to traditional in-ground systems, and their alignment 

with organic regulations. All of these types of systems only use approved inputs. Our 

subcommittee concludes that A is certifiable, B could be certifiable, but C through E is not 

certifiable.

A. Indoor or outdoor production of perennial or annual plants grown in-ground, with 

nutrients primarily supplied by the soil. 

B. Indoor or outdoor perennial or annual container system using growing media 

containing compost or soil which may be regularly amended with nutrients primarily

supplied by the soil. 
37

---------------------------- the systems below this line are not certifiable ---------------------------

-

C. Indoor or outdoor perennial or annual container system using growing media 

containing compost or soil which may be regularly amended with plant nutrients

primarily supplied by liquid fertilizers. This may or may not include the addition of 

microbial inoculants such as compost tea.

D. Indoor or outdoor perennial or annual container system growing in plugs or totally soilless, relying exclusively on the liquid system for plant nutrition. Ammonifying and 

nitrifying bacteria may develop in these systems over time. Microbes are added (via 

sources such as compost tea) to possibly make nutrients plant available. These can also 

use liquid nutrients that are already plant available. This includes aquaponics with a raft 

or an NFT system. No or very little soil or compost. 

E. Indoor or outdoor perennial or annual container system growing in water or in an inert 

growing media (such as coconut coir, peat moss, vermiculite, perlite, etc.), relying 

exclusively on the liquid system for plant nutrition, but without the addition of microbes 

via sources such as compost tea.

Photos of each type

These photos may be from conventional production, as we have been unable to find organic 

producers who would allow us to use photos of their production, but the systems are identical 

in appearance. As with all of the certified hydroponic production systems we have approached, 

getting clear information about current fertilization practices has been difficult, as the growers 

we have asked, including those on the task force, are unwilling to publicly share these details. 

However, this has really not affected our ability to assess alignment with OFPA because these 

systems derive their fertility primarily from soluble fertilizers delivered through water and not 

primarily from organic content of soil as required by OFPA.
38

Type A Production System 

(Indoor or outdoor production of perennial or annual plants grown in-ground, with nutrients 

primarily supplied by the soil. )

In the ground using a high tunnel. This system has been in production for over 12 years, 

certified organic since 2003, amended semiannually with compost, gypsum, and sulfur based on 

soil analysis. No liquids. No leaching.
39

In the ground with a heated greenhouse. 
40

Type B Production System

(Indoor or outdoor perennial or annual container system using growing media containing 

compost or soil which may be regularly amended with nutrients primarily supplied by the soil.)

A large bed of amended soil placed over a gravel parking lot. This is in Detroit and has been 

very productive for several years with minimal fertilization. No Liquid. Not certified Organic.
41

Beds of compost 12” deep over gravel and landscape fabric. Installed July 2012 and certified 

organic following inspection in September 2012. Only compost, gypsum or sulfur added 

annually. Produces large crops culinary herbs, salad greens, tomatoes and cucumbers. 
42

Type C Production System 

(Indoor or outdoor perennial or annual container system using growing media containing 

compost or soil which may be regularly amended with nutrients with fertility primarily supplied 

by liquid fertilizers. This may or may not include the addition of microbial inoculants such as 

compost tea.)

As an example of Type C production systems, this photo shows a container operation growing 

tomatoes. The growing media is made from a dairy manure compost, peat, and a small amount 

of perlite. After a short growing period, it requires liquid feeding with regular applications of 

fish hydrolyzate. This growing system could not work as a Type B due to insufficient soil volume 

to provide adequate nutrition primarily from the soil.
43

Type D Production System

(Indoor or outdoor perennial or annual container system growing in plugs or totally soil-less, 

relying exclusively on the liquid system for nutrition. Ammonifying and nitrifying bacteria may 

develop in these systems over time. Microbes are added (via sources such as compost tea) to 

possibly make nutrients more plant available. These can also use liquid nutrients that are 

already plant available. This includes aquaponics with a raft or an NFT system. No or very little 

soil or compost.)

This photo shows a Nutrient Film Technique (NFT) system with seeds started in “plugs” of a 

growing medium containing compost. Compost may provide biological activity but the 

nutrients are primarily provided by allowed fertilizer sources added to the recirculating 

solution.
44

Type E Container production systems

(Indoor or outdoor perennial or annual container system growing in water or in an inert 

growing media (such as coconut coir, peat moss, vermiculite, perlite, etc.), relying exclusively 

on the liquid system for nutrition, but without the addition of microbes via sources such as 

compost tea.)

http://www.priva.ca/en/discover-priva/testimonials/2014/southland-sod-farms-a-trailblazer-for-the-next-generation-of-raspberry-producers/ 

The photo above shows a system that is now being used for perennial container blueberries 

and raspberries.

Nursery growing containers used for berries range in volume from 5 to 10 gallons (25-40 liter). 

The growing media components may consist of sphagnum peat, coconut coir and perlite and 

may also include some compost or composted wood chips. In the last ten years, coconut coir 

has become a standard substrate for “conventional” vegetable hydroponics (for crops like 

tomatoes, cucumbers, peppers, and berries). If compost is added to the growing media (even as 

little as 1%), this then becomes an example of a Type C production system. In Type E production 
45

systems, fertility is derived predominantly from liquid fertilizers provided through the irrigation 

lines. Examples are fish emulsion hydrolyzate and/or soy products. 

Biological activity is reported to be the result of ubiquitous microbial populations. Microbial 

products may or may not be added to encourage or speed up establishment of these 

populations but “adding biology” has not proven necessary in order to establish microbial 

populations in many container operations. This has proven that adequate crop results can be 

achieved in container growing without adding compost, compost tea, or any of the 

commercially available products alleged to contain beneficial microorganisms.
46

Criteria Used for Characterizing Systems

The first question is whether we can accept container growing as qualifying as organic. If we 

can accept the possibility of container growing, then a second question is how to ensure that 

container growing systems still adhere to the basic principles of organic farming. Following are 

seven criteria that were considered by the 2010 Subcommittee.

1. Source of Fertility

Even with a minimum soil volume requirement, without specific requirements for the source of 

fertility there is nothing to prevent a grower from running what is, in effect, a hydroponic 

growing system, in which virtually all of the nutrients are supplied in the liquid nutrient 

solution, thus bypassing the soil food web. The British Soil Association has implemented a rule 

to address this, limiting the amount of nutrients that can be added after planting to no more 

than 50% of the total nutrients required. The Soil Association requires all crops to be grown in 

the ground, so this requirement applies to soil grown crops in both field and greenhouse. These 

same requirements are recommended by the IFOAM EU 2010 Recommendation for 

Greenhouse Standards, as well as limiting the nutrients supplied in a liquid form to no more 

than 25% of the total nutrients supplied to the crop. While we will discuss other possible 

approaches, this is a verifiable way of insuring that fertility is coming from the soil mixture. We 

suggest that the NOSB develop this type of approach of limiting the plant available fertilization 

to 20% of a plant’s nutritional needs on an annual basis in an effort to follow the intent of the 

2010 recommendation (akin to the manner by which NOP regulates the use of sodium nitrate, 

which is an immediately available source of nitrogen fertility) (See Appendix I).

2. Growing Media / Compost

The type of growing media will help determine the amount of water and nutrients supplied by 

the growing media versus directly from water applied nutrients. The height of the growing 

media in a container will impact the proportion of the pore space filled with water or air; short 

containers hold more water than tall containers. The media in short containers (flats) used for 

transplants is made more porous to increase air space. The same high porosity media is used 

for larger/taller containers for finished crops, but doing so is not essential. One measure of 

growing media nutrient retention capacity and porosity is the bulk density or weight per unit 

volume. Non-organic peat-based or coir-based container growing media have approximately 

one-tenth the bulk density of mineral soils (0.13 gram/cubic centimeter compared to 1.3 gram 

per cubic centimeter). Using compost and composted mineral soils, growing media can be 

designed with both the capacity to provide adequate aeration and nutrient retention. With 

compost or high organic matter based media, as the bulk density increases (range of 0.3 to 0.9 

gram per cubic centimeter) typically so will the nutrient holding capacity. We recommend that 

the organic growing media must have a minimum of 20% composted plant and animal material.

3. Biological Activity of Growing Media

The presence of biological activity that allows conversion of ammonium to nitrate nitrogen and 

the digestion of organic nutrient sources, as is the case for bioponic and aquaponic systems, 
47

does not qualify the system as suitable for organic certification. The 2010 recommendation 

distinguishes hydroponic systems from allowed container systems, using the assumption that 

greenhouse and container systems use compost-based growing media, or soil in which “all 

typical soil-dwelling organisms can thrive”. The extent to which soils can support diverse soil 

ecology varies drastically based on texture, structure, density, temperature etc. This 

requirement would be very challenging for certifiers to apply consistently, so we are not 

recommending a standard based on the measured biological activity. This task force has not 

been provided evidence that biological activity contributes significantly to providing fertility in a 

system that primarily provides soluble nutrients to the crops. We also are finding that some of 

the currently certified container production systems feeding via approved organic liquid 

fertilizers do not find it necessary to “add biology”, and are still quite successful in producing 

crops. This would indicate that adding biology is not a necessity for producing crops with 

allowed organic fertilizers. It raises the question whether adding biology is a necessity. Without 

specific limits on the use of liquid fertility, a farm could add compost tea or small amounts of 

compost in order to satisfy the requirement of having an active biology while actually relying 

primarily on the liquid fertilizers to supply the needed nutrients. A more easily verified 

regulation could be based on the amount of added fertilizer. The amount of fertility needed to 

be added would reflect the amount of fertility not supplied by the soil (see The Soil Association 

Greenhouse Standards, Appendix D and the IFOAM recommendations, Appendix B).

A recent study by the Oregon Department of Agriculture discovered that many of the 

commercial products being sold to growers to supply microorganisms are failing to meet their 

claims. “Some products have met the claim [that they contained viable microorganisms] and 

have passed, but the percentage is very low,” says Oregon Dept. of Agriculture fertilizer 

enforcement specialist Toby Primbs.

4. Consumer Awareness of Growing Method

For many centuries, agriculture has included growing seedlings in containers for transplant into 

the field. It has also included growing plants, such as ornamentals and herbs, for taking into 

people’s houses for their pleasure and, in the case of herbs, for their consumption.

Organic farming around the world has always accepted these kinds of container growing, and

there is little controversy around this. In the European standards, permitting this kind of 

container growing is explicitly stated, and is justified on the basis that the consumer can always 

tell that the seedlings or herbs they are purchasing are grown in pots (See Appendix A). In the 

case of seedlings, it has been justified in that the plants will spend the majority of their lives 

growing in the ground as part of a full soil system. But to ensure that consumers are not 

mislead, even for the stated exceptions of seedlings, ornamentals and herbs, any products 

grown in containers must also be sold in the same containers. That way it will be clear how 

those plants were produced.
48

5. Annual Seedling Transplants or Finished Crops

Methods for organic annual seedling production have included the range of Growing Methods 

from Type A to E listed above since the start of the USDA organic regulations. Methods of using 

peat-based and other light weight media and water soluble fertilizer have been accepted for 

annual seedlings. Apparently what has been allowed to happen is that these methods of 

production for annual seedlings are now being used for full season organic crop production. In 

order to align with OFPA, either a clear distinction between transplants and crops needs to be 

made, or more restrictive methods for transplant production requiring compost-based growing 

media similar to Types A to B need to be required.

6.Container Size

By making the containers large enough, it is possible to rely on the nutrients contained in the 

soil and the complex soil biology therein to supply the majority of nutrients that a plant 

requires. These systems are an attempt to adhere to the organic principle of feeding the soil 

instead of the plant, while at the same time allowing growers to avoid some of the challenges 

of growing in the ground, such as a buildup of disease and growing on very infertile or stony 

ground, or, in urban settings, even on concrete. Requiring a minimum soil volume per ft2 of 

growing area is a step in the right direction. 

To go further we could follow the recommendation of Dr. Martine Dorais of Laval University 

and the Agassiz Research and Development Centre to grow in 100 to 180 liters of soil per m2. At 

this volume she has demonstrated that no liquid feeding is necessary, and fertility can be 

provided by the biological activity of the growing medium in the beds. 

However, container size alone does not ensure the soil and organic matter as the primary 

source of fertility and the necessary restriction on routine liquid nutrients.

7.Adherence to All Applicable Aspects of the USDA Organic Regulation

A significant problem with allowing a container system in America is its departure from the 

section §205.203(a) of the USDA organic regulations- “The producer must select and implement 

tillage and cultivation practices that maintain or improve the physical, chemical, and biological 

condition of the soil and minimize erosion.” Although it can be required to use soil as the 

growing medium in a container, it would be difficult to say that growing in a container is 

maintaining or improving the soil. It is our concern that if NOSB accepts growing a crop to 

maturity in containers, an amendment to the USDA organic regulation may be required.
49

Section 4. International Standards

It is helpful to look at the standards in the rest of the world, to see how they have addressed 

these certifying challenges. The US is alone in NOT having created rules around greenhouse 

growing for organic certification.

There are three basic groupings. 

1. The Canadian standards. 7In the first group, Canada and Sweden are the only countries 

that we know of which have taken the approach of permitting container growing while 

requiring minimum soil volumes based on growing area. Both countries prohibit 

hydroponic production. 

2. The standards for most European countries prohibit hydroponic production. They allow 

container production for very limited exceptions. They require that organic crops be 

grown in the ground except for transplants, ornamental potted plants, and potted 

herbs, which can be grown in containers.

3. The Scandinavian standards allow growing in containers. The four countries take 

different approaches to this, but all permit some kind of container growing to maturity. 

An approved biodegradable substrate is permitted, but they all prohibit soil-less growing 

such as NFT or aquaponics. 

The Canadian Standards

Discussion:

In November 2015, the Canadian greenhouse standards were amended. The standards were 

strengthened, greatly increasing the amount of soil mixture required per square foot of growing 

area for staked crops such as tomatoes, cucumbers, and peppers. This was a huge change 

which will have a strong impact on the Canadian greenhouse industry. Existing certified 

operations have been given one year grace period to change their growing practices in order to 

meet the new standards.

The new standards (see Appendix C) continue to prohibit hydroponic and aquaponic growing 

for organic certification, but they go much further in stating explicit requirements for container 

growing. The old standards had no minimum required soil volume, much like the Scandinavian 

standards.

The new standards require a minimum soil volume of 70 liters per m2 of growing area. They 

state:

 

7

 See Appendix C.
50

“7.5.4 Soil used in a container system, with the exception of transplants, shall provide nutrients 

to plants continuously. The soil (growth media) shall contain a mineral fraction (sand, silt or 

clay) and an organic fraction; it shall support life and ecosystem diversity.” 

They go on to have stricter requirements for long season, tall “staked” crops, such as tomatoes, 

cucumbers, and peppers:

“7.5.5 The following conditions apply to containerized, staked crops (for example, tomatoes, 

sweet peppers, cucumbers, eggplant):

● a) at the start of production, the total volume of soil shall consist of at least 

10% compost;

● b) compost shall be included in the fertility program;

● c) containers shall be at least 30 cm (12 in.) high; and

● d) the soil volume shall be at least 70 L/m2 (15.4 gal./10.8 ft2), based on the 

total growing area.”

To give an example of how much soil this would be, here is a description of a typical 

greenhouse set up for tomatoes. The plants are grown in a bed that is approximately 4 feet 

wide, with a path on each side. In the bed there will be two rows of plants. If 5 gallon buckets 

were used to hold the soil blend, there would be two rows of five gallon buckets, filled to the 

brim, pressed together bucket to bucket, for the length of the bed. The standards don’t specify 

the shape of the container or raised bed. If it is a raised bed, it can be demarcated from the 

ground underneath by a sheet of poly, or some other kind of barrier. 

As listed below, the current Canadian standards ban all NFT and hydroponic growing systems 

from organic certification.

● 7.5.3: “Hydroponic and aeroponic production are prohibited.”

● 7.5.4: “Soil used in a container system, with the exception of transplants, shall 

provide nutrients to plants continuously. The soil (growth media) shall contain a 

mineral fraction (sand, silt or clay) and an organic fraction; it shall support life and 

ecosystem diversity.”

● 7.5.12: “Soil regeneration and recycling procedures shall be practiced. The following 

alternatives to crop rotation are permitted: grafting of plants onto disease-resistant 

rootstock, freezing the soil in winter, regeneration by incorporating biodegradable 

plant mulch (for example, straw or hay), and partial or complete replacement of 
51

greenhouse soil or container soil, provided it is re-used outside the greenhouse for 

another crop.”

The way that the current Canadian standards are written, there is no limitation on artificial 

lighting, and if a grower could satisfy the soil requirements, they could technically be permitted 

to grow in 100% artificial lights. 

In the current Canadian standards, no rotation is required in a greenhouse crop, either in the 

ground or in a container. (See above 7.5.12).

Aquaponics can be certified as organic in Canada through a non-government certification 

program for Aquaculture. Products certified under this label do not qualify for export to the US, 

nor can they bear the official Canadian organic seal.

The following are some key challenges that this subcommittee sees with the current Canadian 

standard:

1. The way that the standard is written, there is no minimum requirement for % of compost 

in the soil mixture for a lettuce crop, and there is no minimum requirement for the % of a 

mineral fraction in the soil mixture in any kind of crop. So theoretically, an operation 

could throw in a handful of sand into their coconut coir mix and satisfy the letter (if not 

the spirit) of the law. The current Canadian standard requires at least 10% compost in a 

staked crop at the start of the crop.

2. The required minimum soil volume is only at the start of the crop, but this could easily be 

greatly reduced by breakdown and settling by the end of the crop, resulting in a reduced 

soil volume of up to 50%. There perhaps should be clear requirements for both mineral 

fraction and compost fraction. There perhaps should be a requirement to maintain 

minimum soil volumes during the growing season, to avoid a single measurement when 

the soil mixture is fluffy and filled with air at the beginning of the season. This might well 

require topdressing with compost during the crop cycle.

3. It is unclear how certifiers would measure these required soil mix fractions.

4. There is no limitation on the amount of nutrients that could be supplied as a liquid, so 

even though an operation might be growing in a container with 70 liters/m2 of growing 

area, it would still be quite possible to be running a 99% hydroponic operation, in which 

virtually all of the nutrients that the crop takes up are in fact supplied in a nutrient 

solution. 

5. They do not address the use of the newer hydrolyzed liquid fertilizers that, in effect, 

provide soluble N to the crops, thus bypassing the need for a complex soil microbiology 

to transform the N from a complex organic form into a mineral form. Hydrolyzed protein is 

protein that has been hydrolyzed or broken down into its component amino acids. While there are 

many means of achieving this, two of the most common are prolonged boiling in a strong acid (acidHVP) or strong base, or using an enzyme such as pancreatic protease to simulate the naturally 

occurring hydrolytic process.

6. If the goal is to require the producer to create a soil system which will provide the bulk of 

the nutrients through the normal biological interplay of a complete soil system, then 

there should be a limitation placed on the % of liquid feed that could be provided.
52

7. There is no clear definition of the “growing area”. “Growing area” needs to be clearly 

defined. In most greenhouse production, “growing area” includes the paths between the 

growing beds, and sometimes the concrete walkway at the end of the house is included 

as well. This should be defined if the NOSB chooses to go in this direction.

8. There is no restriction on swinging back and forth between conventional and organic. As 

no transition period is required, this opens the way to an operation choosing whichever 

system seems most profitable for that season. It even permits a grower to use a 

prohibited substance to “clean up” an insect problem at the end of the crop cycle, and 

then return a week later to “certified organic” production.

9. Certifiers struggle with certifying for “ecosystem diversity”. That is a statement of 

principle, but it is beyond the capabilities of most certifiers to evaluate such a criterion. 

Certifiers felt that this was obvious in an in-ground system, but had no idea how to 

evaluate it in a container system. Certifiers expressed to us the desire to have more clear 

criteria that reflected the principle of “ecosystem diversity”. There are mechanisms for 

evaluating ecosystem diversity, such as measuring the diversity of soil life (both microbes 

and animals).

10. Although the question of 100% artificial light is not addressed in the standards, 

inspectors that we spoke with felt it should be, as none of them accepted 100% artificial 

light as qualifying for organic certification. It is true that the Canadian standards 

insistence that crops must be grown in a soil mixture would make 100% artificial light 

unlikely, it still could happen, for example in a marijuana crop growing in a locked facility.

The EU Standards

Most of the European countries are members of the EU, and EU organic standards are set by 

the European Commission. These standards are the basis for the standards of the member 

countries, which can then create their own standards, based on the EU standards. Individual 

countries may make stricter standards, but cannot allow practices that are prohibited by the 

European Commission. 

The European Commission is advised by the EGTOP (Expert Group for Technical Advice on 

Organic Production) in creating standards. The EGTOP is composed of scientists, academics, and 

policy advisors from various member states. The EGTOP makes recommendations, which are 

then acted on by the European Commission. The EGTOP is respected in the European organic 

community as a sincere group of scientists who know a lot about their field of expertise, and 

are also connected to the organic sector. 

In 2013 the EGTOP released a report with proposed organic greenhouse standards. See 

Appendix A.

Earlier in 2013, the IFOAM EU also released a report on organic growing in greenhouses. This 

report was the result of years of work. On the question of soil and hydroponics, the EGTOP 
53

report agreed with the IFOAM report, concurring that organic production in greenhouses 

should be grown in the ground, with the allowed exceptions of seedlings, ornamentals, and 

herbs. To see this report, go to Appendix B.

The approach of the EU Commission is quite different from that taken by the NOP. The basic 

standard of ALL of the countries in Europe says that hydroponic production is prohibited. The 

basic EU rule is that organic means grown in the soil, and that growing hydroponically (in an 

inert substance (like rockwool, or in a Nutrient Film Technique) is clearly forbidden. But the 

definition of “soil” is up to each country. 23 (including England, Germany, Holland, France, 

Spain, Belgium, Austria, and Italy) out of 28 member states forbid growing on natural substrates 

(such as coconut coir and peat moss) as well as inert substrates. They require that organic 

growing happen in soil that is continuously connected with the subsoil and bedrock. This means 

that is must be grown in the ground. An accepted exception is that seedlings, ornamentals, and 

herbs are allowed to be grown and sold in containers. If herbs are harvested prior to sale, then 

they must also be grown in the ground. As an example, the Dutch interpretation of the EU 

standard, laid down in Article 4 of the Council Regulation (EC) No 834/2007 is that crops that 

are normally grown in the soil, must be cultivated in the soil. And soil is defined as the outer 

layer of the earth's crust.

The 23 EU countries are very clear that the exceptions are exceptions, and that all other organic 

production must happen in the ground. Some of these countries do not have explicit language 

in their standards describing that the production must be in the ground, as they take the 

approach that growing in the soil is self-evident for organic growing, and only the exceptions 

must be specified. Some other countries have language that clearly states that organic 

production must happen in the ground. 

For example, the language from Germany as stated is the Bioland standards:

5.1.2 Soils and Substrates

Growing vegetables on stone wool, hydroponics, nutritional film technology, thin layer culture 

and similar systems are not permissible neither the production in bags and containers.

Permissible is the growing of herbs in pots and similar products, whereas the container is sold 

together with the plant.

But in all of these 23 countries, the enforced standards are that organic produce must be grown 

in the ground.

The rationale for the exceptions are specified by some countries, such as Holland and 

Germany.8 We have discussed with policy advocates of European groups the rationale for 

 

8

This justification is put in official writing in some countries, for example in Germany on the webpage with the official 

explanations of the European regulation for organic production:https://www.oekolandbau.de/fileadmin/pah/loek_protokolle/

The same for the Dutch official interpretation of the regulation: http://www.skal.nl/assets/Wetgeving/Skal-R4.pdf
54

allowing exceptions for containers for seedlings, ornamentals, and herbs.9 They have said that 

as seedlings still spend most of their life in the soil before harvest, this is still in keeping with the 

principle of grown in the ground. This is the traditional way that growing has always happened. 

The containers are still required to be filled with acceptable potting mixture based on Annex 1. 

All countries allow soil in the potting mixture except Austria, which prohibits it because it 

means removing soil from the farm.

The justification for an ornamentals or herbs to be grown and sold in a pots is that then the 

consumer can see exactly how it was grown, and not mistake it for something grown into the 

soil. The standard is that organic produce harvested out of sight of consumers must always 

come from plants grown in soil, and not from horticultural substrate cultures. We have heard 

from policy advocates that the goal in Europe is complete transparency with the consumer. 

They want the consumer to understand and be able to trust what they are buying.

There is one Dutch group of growers that is certified only by the NOP, called Pura Natura. They 

grow somewhere between 8 and 15 hectares of hydroponic peppers and tomatoes. There has 

been some concern that they might try to sell their produce in Holland, using the equivalency 

agreement with the US, but that hasn’t been attempted so far. Of course, the substrate grown 

“organic” produce from Holland is not considered organic in Holland. It can only be certified 

organic by the NOP, not by the Dutch certifiers. It is all exported to the US.

At the moment aquaponics are not certified organic in Europe. Growing in the soil is a 

foundational principle of European organics. The belief system of organic is based on the 

principle of feeding the soil, and thus supporting the whole biological system that transforms 

the minerals in the soil into food for the plant in a very steady, slow-release way.

The EU makes an effort to limit the fertilization of crops to the natural process of a healthy soil. 

The British Soil Association specifies that at least 51% of the nutrition for the crop must come 

from the soil at the time of planting. The belief is that the major source of the fertility has to be 

the soil. This standard takes work to enforce, but all the certifiers are working with this. Almost 

all European countries have held fast on the question of growing only in the soil. 

Looking at the standard in England and Belgium, they do allow continuous cropping in a 

greenhouse of a single crop, as long as other soil health issues are addressed. In the rest of 

Europe there is a variety of approaches. Many growers in Holland have a very minimal rotation 

in the greenhouse. Perhaps tomatoes are followed by peppers, often grafted onto the same 

rootstock, and then back to tomatoes. 

 

9

Private conversations with Marian Blom, a Regulation Officer for Bionext and former Council member for IFOAM EU, Chris 

Atkinson of Soil Association, and Alan Schofield of Soil Association and Organic Growers Alliance.
55

The Four Scandinavian Countries

The three northern countries of the EU (Sweden, Finland, and Denmark) plus Norway allow 

“substrate growing,” meaning they allow growing in containers or isolated beds. They took a 

different approach from the rest of Europe in defining “grown in the soil.” 

In Sweden they follow the KRAV standards. Here is the relevant section regarding soil 

requirements for growing in a substrate:

4.6.2 When you Cultivate in a Delimited Substrate- A substantial portion of the plant nutrients 

a plant takes up must come from the soil the plant is grown in. Therefore, you cannot cultivate 

exclusively in biologically inactive material or cultivate in excessively minimal soil volumes. If 

you cultivate in a delimited substrate, e.g. in a pot, and you add plant nutrients after planting, 

each plant must have at least 30 litres of soil. This applies to annual vegetable crops with a long 

cultivation time, e.g. tomatoes, cucumbers, red peppers and eggplants. Other cultivations must 

have at least 0.2 litres substrate per pot. (K) Other cultivations include mainly herbs and lettuce, 

though berry cultivations such as strawberries can be included. For bedding-plants that are 

then cultivated on open land there are no size requirements for pots, but they must be grown 

in a biologically active material. 

4.6.3 Hydroponics- Hydroponic cultivation is when plants are grown in a water solution. You 

can only cultivate aquatic plants with this technique. Sprouts must be sprouted and rinsed in 

clean water. (EU)

So Sweden allows container growing on the Canadian model, with specific requirements on the 

minimum soil volume per plant. They do not permit aquaponic nor NFT style growing.
56

Section 5. 2010 Recommendations Not Directly Related to 

Hydroponics

“The charge of the task force is to inform the National Organic Standards Board (NOSB) of our 

findings and advise on what practices should be allowed or restricted in organic hydroponic and 

aquaponic production.” (Federal Register, March 9, 2015)) 

A key document that that was developed to provide guidance and context for hydroponic and 

aquaponic is the NOSB Crops Committee Recommendation for Production Standards for 

Terrestrial Plants in Containers and Enclosures (Greenhouses) published January 23, 2010. 

That recommendation for rulemaking addressed certain aspects of greenhouse production that 

are commonplace in indoor cropping methods, such as container based root media (potting 

mixtures), hydroponics, and aeroponics. 

If growing in containers is to be certified, the discussion points below should be included in 

development of additional standards to the USDA organic regulations. The information 

presented here is a summary of parts of the 2010 recommendation that were questioned and 

critiqued by this subcommittee as well as proposed revisions and discussion to include in any 

future recommendations and rulemaking. 

The document includes eight points of discussion including

1. Enclosures

2. Lighting

3. Natural Resources

4. Containers

5. Container Growing Media

6. Land Use and Soil management

7. Rotations

8. Compost
57

Eight Point Summary 

Clarification and proposed edits of the 2010 recommendation has been provided by addressing:

1. Enclosures: The term enclosure was more clearly defined by differentiating greenhouses and 

controlled indoor environments. Greenhouses have transparent roofs and walls to collect 

sunlight and are used for transplants, in-ground crop production and container crop 

production. Controlled indoor environments use electrical lighting and should only be 

considered acceptable for transplant production. 

2. Lighting: The term “electrical light” is proposed as a preferred term over artificial or fullspectrum light. The use of lighting for transplant production is differentiated from crop 

production. We suggest a clarification that electric light as a “sole source” may be allowed 

for transplant production, but electrical lighting should only be allowed for supplemental use 

in crop production. 

3. Natural Resources: It is the opinion of this subcommittee that if container production is 

permitted, then this must include management of both soil/growing media within the 

containers as well as soil underneath and surrounding the container system. This would 

ensure that land is maintained, or improved for future in-ground production and overall 

protection of natural resources. The NOSB should consider limiting use of land where crops 

could be grown in the soil from being converted to container production. This subcommittee 

rejects the notion that covering the soil with plastic is maintaining the fertility.

4. Containers: Proposed change to the definition for the term “container” by differentiating 

between container growing methods for transplants (seedling annuals, planting stock) and 

containers for crop production. 

5. Container Growing Media: The term “container growing media” is proposed to replace the 

current term “growing media”. To provide more clarity, container growing systems and 

container growing media are defined for 1) transplants and 2) food production in the context 

that the first is currently allowed and the second is currently allowed and under review. To 

be consistent with OFPA, container growing media fertility must primarily come from 

compost based growing media and not from liquid sources, which is contrary to / more 

restrictive than current interpretation and certification allowed by the NOP. We accept the 

recommendation of the 2010 Committee that compost is the equivalent of soil for container 

crop production. 

6. Land Use and Soil management: Transition and tillage issues.

7. Rotations: The 2010 recommendation allows for exemption of the use of rotations in 

greenhouses, containers and protected cultivation by allowing use of alternative methods of 

maintaining soil and plant health. Some members of the subcommittee propose rejection of 
58

this exemption on the grounds that the alternative methods could also be used for field 

production and no rationale or justification is given for why crop rotation is not economically 

viable in a greenhouse or container production system. Other members support it.

8. Compost: Compost was primarily defined in the OFPA and NOP regulation by how it must be 

made without providing characteristics of the final product. A more detailed description of 

required compost characteristics for container growing media is recommended with the 

intent of expanding and extending the various roles of compost beyond that as a soil 

amendment. Compost for use as a container growing media needs to be defined. Questions 

are raised about vermicompost and compost from anaerobic digestion. 

Eight Point Details

1. Enclosures 

Starting Point From the 2010 Recommendation:

Greenhouse- Permanent enclosed structure that allows for an actively controlled environment 

used to grow organic crops, annual seedlings or planting stock used in organic production. 

What are the questions?

● What is a greenhouse?

● What other types of permanent enclosed structures are allowed for transplant 

production and crop production?

● Do non-permanent high tunnel structures used for protected cultivation of in ground 

organic crops without heating need to be defined in the recommendation? 

Analysis and Clarification

To define a greenhouse, the term “transparent” is used to describe the roof and walls of the 

structure. The absence of the word transparent in the 2010 recommendation definition is not 

accurate and is allowing the consequence of organic crops to be grown in buildings with only 

electrical lighting (see the Lighting discussion). 

Currently a greenhouse can be used to produce: 1) organic annual seedlings or planting stock, 

2) organic crops grown in the ground, and 3) organic crops grown in containers.

Differentiation is needed between a Greenhouse and a Controlled Indoor Environment. Many 

smaller scale diversified vegetable producers do not have greenhouses and instead rely on 

electric lights above transplants growing on shelves or tables in homes, basements, garages or 

other places. Our committee perception is that use of controlled indoor environments to 

produce annual seedlings as transplants is a common and acceptable practice for an OSP.
59

Larger indoor production facilities with only lighting have been in use for over 30 years to grow 

crops such as leafy greens and herbs. The use of such facilities is likely increasing in response to 

changing transportation costs, food security concerns, and climate and water availability. Some 

of these facilities have succeeded in getting certified organic (approved OSP). The production 

of organic crops in controlled indoor environments is questionable in terms of alignment with 

OFPA, the organic regulations and the founding principles of organic agriculture. Our 

committee perspective based in part on historical organic practices and perceived consumer 

expectation is that use of controlled indoor environments for organic crop production is not an 

acceptable practice for an OSP.

Summary of Committee Recommended Revisions

Greenhouse- Permanent enclosed structure with transparent roof and walls that allow for 

sunlight as the primary source of light for plant growth and an actively controlled environment 

used to grow transplants (annual seedlings, planting stock) or organic crops. 

New Definition - Controlled Indoor Environment– Permanent enclosed structure, room or area 

with electrical lighting as the sole or primary source of light for plant growth. 

Controlled Indoor Environments are allowed for organic transplant production but not allowed 

for organic crop production. 

Currently no recommendation relative to non-permanent high tunnel structures. 

2. Lighting

Starting Point from the 2010 Recommendation:

(c) Producers may use full-spectrum light sources. 

What are the questions?

● What types of lights are allowed?

● How can the lights be used?

o Supplement photosynthetic lighting?

o Sole source photosynthetic lighting?

o Photoperiodic lighting to alter the day length for flower initiation out of season?

Analysis and Clarification

By definition, use of the term “full spectrum” lighting would imply a mixture of 

wavelengths/colors in the 400 to 700 nanometer visible light range. This definition would 

disallow the use of high pressure sodium lamps, currently the most commonly used lamp for 

greenhouse photosynthetic lighting, and metal halide or LED lights used for controlled (indoor) 

environments. Initially the term “artificial” lighting was used. “Artificial” lighting is an 

inaccurate or incorrect term. In some cases, the term “supplemental” lighting would be 
60

appropriate for use of lighting in a greenhouse setting. However, for the purpose here, lighting 

may also be used in a controlled environment with no additional sunlight. The term “electric” 

lighting encompasses all types. 

A member of the NOSB involved in development of the 2010 recommendation verbally 

confirmed at the Task Force San Diego meeting (January 2016) that the intention of the Crops 

Committee was for supplemental lighting in greenhouses or for transplant production but not 

for crop production in controlled indoor environments. 

Operations using 100% lighting from electrical light sources are being certified. For example, 

crops growing in a shipping container outfitted with electrical light sources. It is questionable 

whether this practice is consistent with the perceptions or expectations of production of 

organic crops in an OSP. 

European standards do not allow certification of crop production without sunlight. 

Summary of Committee Recommended Revision: 

(c) Producers may use electrical light sources such as high pressure sodium, metal halide, 

fluorescent or light emitting diodes (LED) as supplemental electric light sources in 

greenhouses for providing photosynthetic light or for photoperiod alteration for crops 

harvested for food. Transplants may be produced with complete electric lighting in 

controlled indoor environments. Organic crops are not to be produced in controlled indoor 

environments with electrical lighting as a single source of light. 

Electric lighting - fixtures and lamps used to provide photosynthetically active radiation (PAR) 

primarily in the visible light wavelengths (400 to 700 nm) for plant growth. Examples include 

but are not limited to high pressure sodium, metal halide, fluorescent, and light emitting diodes 

(LED).

For a more detailed discussion of lighting standards, review the EGTOP report in Appendix A.
61

3. Natural Resources

Starting Point from the 2010 Recommendation:

The 2010 recommendations do not specifically address natural resource requirements as they 

relate to crop production within containers and enclosures. The majority of this subcommittee 

feels that was an oversight, and that there should be specific requirements in order to have a 

robust certification process for these systems.

What are the Questions?

● What are the natural resource implications for an operation that does not grow in the 

ground?

● Is the soil underneath a container system impacted by production practices which occur 

in the containers?

○ If yes, how are those impacts assessed, monitored and mitigated to ensure 

natural resources are maintained or improved?

● Is soil impacted by covering with permeable or impermeable coverings such as weed 

cloth, plastic or pavement?

○ Should paving over soil be allowed as an ongoing management practice within an 

organic system?
62

Analysis and Clarification

Natural resources requirements under NOP § 205.200 state that “...Production practices ... must 

maintain or improve the natural resources of the operation, including soil and water quality.” 

Natural resources are defined under NOP § 205.2 as “the physical, hydrological, and biological 

features of a production operation, including soil, water, wetlands, woodlands, and wildlife.” 

Additionally, NOP Guidance 5020 “Natural Resources and Biodiversity Conservation” clarifies 

specific practices that can be included with an organic system plan in order to meet § 205.200 

and certifier responsibilities for ensuring compliance. It is the opinion of this subcommittee that 

for container production systems this includes management of both soil/growing media within 

the containers as well as soil underneath the container system. This would ensure that land is 

maintained or improved for future in-ground production and overall maintenance of natural 

resources.

Container systems could meet natural resource requirements in ways which are similar to 

perennial in-ground crops. Within an organic system, some of the many functions of crop 

rotation and cover cropping is to provide species diversity, creating habitat and food sources for 

beneficial insects. For container systems, this function could be achieved in ways similar to 

those practices utilized in perennial systems including cover cropping/interplanting between 

crop rows; adding hedgerows around the crop production area or enclosed growing 

area/greenhouse; utilizing insectary plantings, which can be interspersed with crop plants, etc.

Summary of Committee Recommended Revisions

In the opinion of some of this subcommittee, the land underneath the container system must 

be considered a natural resource which must be maintained or improved.

1) Impacts on soil due to use of weed cloth, other permeable cover, or application of any 

material must be considered and mitigated.

2) Although erosion may not be an issue for covered ground, a soil’s ability to regenerate 

biological activity and soil organism populations must be considered. It is important to 

consider impacts on a soil covered with weed cloth during, for example, the 3-10 year 

lifespan of some perennial crop container systems.

3) For enclosed or outdoor systems on impermeable surfaces such as concrete, cement or 

pavement, it is important to consider whether paving over soil in order to place a 

container system should ever be allowed as a regular practice within an organic system 

plan. 

4) The NOSB should consider limiting use of land where crops could be grown in the soil 

from being converted to container production. This subcommittee rejects the notion 

that covering the soil with plastic is maintaining the fertility.

4. Containers 

Starting Point from the 2010 Recommendation:
63

Containers- Any vessel and associated equipment used to house growing media and the 

complete root structure of terrestrial plants and to prevent the roots from contacting the soil or 

surface beneath the vessel, such as, but not limited to, pots, troughs, plastic bags, floor mats, 

etc.

Transplant. A seedling which has been removed from its original place of production, 

transported, and replanted. (From final rule, not 2010 recommendation) 

What are the Questions?

● Containers are allowed for transplants. Is any change or clarification needed regarding 

transplant production?

● Are organic food crops grown and sold in a container suitable for an OSP?

● Should containers be allowed for organic crops?

o If yes, should there be regulations or boundaries on size, volume, etc? 

o Are there different regulatory implications for the production of perennial crops 

in containers versus annual crops? 

Analysis and Clarification

For the current definition, it appears that there are no boundaries. A container for growing a 

plant or plants can range from a plastic flat composed of over 100 cells of 0.5” cubed volume or 

a raised bed covering some fraction of an acre up to 12” deep or more. 

The size of a growing container relative to the crop being grown should be regulated in order to 

meet the premise that organic crops be grown in a biologically active supportive soil. The 

expectation is to provide long term water and fertility without constant / routine applications.

Internationally, approval for the use of containers for organic certification varies by country. 

The majority of European standards allow containers for a) transplants and b) for sale of 

finished product still in the container to the consumer but not for organic crops. 

Canada and some Scandinavian countries allow organic crop production in containers. Canada 

provides a minimum container volume. 

Summary of Committee Recommended Revisions

Containers- Any vessel and associated equipment used to hold growing media and the 

complete root structure of terrestrial plants and to prevent the roots from contacting the soil or 

surface beneath the vessel, such as, but not limited to, pots, hanging baskets, boxes, buckets, 

barrels, plastic crates, troughs, plastic bags, floor mats. etc. If necessary landscape fabric, 

weed-cloth or polyethylene film may be required to prevent root contact with soil not 

approved for an OSP. 

If requirements related to compost-based container growing media expectations to provide 

long term soil biology, water and fertility without constant / routine applications of water 
64

soluble nutrient sources (see container growing media) are included, container growing of 

organic crops can continue to be allowed. 

5. Container Growing Media

Starting Points Extracted from the 2010 Recommendation:

Growing media- Material which contains sufficient organic matter capable of supporting the 

plant root system and a natural and diverse soil ecology. 

“Although the regulations do not specifically state ‘soil only production’, the exclusion of soil 

from organic production of normally terrestrial, vascular plants violates the intent of the 

regulations.”

“Since all typical soil dwelling organisms, such as earthworms, protozoa, fungi, bacteria, 

actinomycetes, etc. can thrive in a properly designed compost based growing media, producing 

the beneficial symbiotic ecological relationships found in soil, such growing media should be 

rightfully considered soil.”

What are the Questions?

● Should container growing media that are compost based be considered ‘soil’?

● Does the definition of and type of container growing media allowed need to change 

from what is currently allowed? If so, how?

● Should a minimum amount of media per plant be required to assure that the crop 

nutrients are coming from the soil based organic matter interactions rather than from 

periodic feeding of available nutrients? 

● If compost is a suitable substitution for soil, how do we amend the definition of compost 

to include what is acceptable as growing media?

Analysis and Clarification

Growing media are defined by approved component materials and the absence of non-allowed 

substances such as synthetic nutrients or wetting agents. Growing media should also be defined 

by required characteristics that must be present. Transplant and container growing methods 

would have more clarity if container growing media had a defined initial and temporal water 

and nutrient holding capacity and biology carrying capacity. 

An emphasis has been placed on soil organic matter and desired limitations on the amount of 

soluble or supplemental fertility added to soil during crop production. Therefore, it is 

recommended that container growing media for an OSP be specified to be the primary source 

of fertility for crop production without routine additions of water soluble fertility. Compost 

based growing media can be prepared with the necessary high porosity / low bulk density to 

provide adequate aeration and water holding capacity when used in containers of limited 
65

depth/height. The same growing media can also provide adequate fertility for weeks or months 

of annual plant growth or years of perennial plant growth. 

For a greenhouse, indoor or container plant system, there are farming practices that provide for 

long term container growing media fertility, water conservation and diverse microbiology. 

These practices are often dependent on the production and use of growing media containing 

compost that can include mineral soil as a component of the compost. The compost can also be 

produced with allowed mineral amendments. As with field soils, organic matter in a variety of 

forms and stages of decomposition are essential for maintaining water and air balance 

necessary for plant roots and microorganisms, and for nutrient retention (CEC), reserves and 

availability (primarily based upon pH management). 

The size of a growing container relative to the crop being grown can be defined as a function of 

expectations to provide long term water and fertility without constant applications of plant 

nutrients. A point of discussion has been that in ground systems with sandy soil may rely on 

routine applications of fertility. Perhaps the question should be asked whether such sandy soils 

should be allowed in or approved for an OSP?

An emphasis on the use of compost as the basis for container growing media will likely have a 

positive impact on cultivating a greater degree of recycling of on and off farm organic matter. 

The definition of compost can be expanded as a way to increase options for organic crop 

production. This topic is addressed separately in the compost section. 

Why should soil or compost based container growing media be used for transplant and crop 

production?

1. Source of diverse minerals for plant growth and health of those consuming the plants.

2. Microbiology interactions with plant roots that impact the biology of the plant and 

contribute to the resiliency of the system and the tolerance or resistance of the plant to 

insect infestation or disease infection. Based on recently published research from 

Cornell University, the biology present in compost used for transplant media was 

present in the root rhizosphere of roots distant from the original transplant roots. 

3. Recycling of on and off farm organic matter and resources. 

Two common plant based organic materials that meet the definition of “organic matter” are 

sphagnum peat moss and coconut husk residue (coir). Depending on the source and the 

handling of the material, the organic matter present is primarily of a type that will not support 

“natural and diverse soil ecology” for extended periods of time (months) unless blended with 

other organic matter or compost. The difference needs to be recognized. 

Currently a root medium made up of primarily sphagnum peat or coir mixed with perlite or 

vermiculite is allowed for transplant / annual seedling production with the fertility coming from 

routine application of liquid sources. Should such options no longer be acceptable for an 
66

organic systems plan for transplants? This is important if requirements for container crop 

production are put in place. Is consistency needed for transplant and crop production? 

One perspective is that container growing media need to be an exception / exemption to OFPA 

requirements related to soil properties and management for organic certification. Not all the 

methods described in the OFPA that “must” be used to maintain soil organic matter (cover 

crops, tillage, etc.) are necessary to maintain compost based container media. A field or 

perennial plant system that relies on constant use of mulch does not require tillage and hay 

mulch can provide many benefits of cover crops. Is it possible that compost based container 

growing media could meet the requirements without being an exception? 

Another perspective that has been offered is that not all crops are tolerant of or provide the 

desired quality grown in a nutrient rich environment generally associated with perceptions of 

compost. Compost based container media can be produced with a wide range of fertility levels 

including limited fertility. 

Summary of Committee Recommended Revisions

Container Growing media- Compost based organic material with sufficient water and nutrient 

holding capacity and living microorganisms capable of supporting normal plant growth without 

frequent applications of supplemental plant or microbial nutrients or food.

6. Land Use and Soil management

Starting Point from the 2010 Recommendation:

The 2010 Recommendation states that in §205.209 (a) that “Container and enclosure 

(Greenhouse) operations must meet all applicable requirements of subparts B (205.105) and C 

(205.200 - 205.206) except that: (1) The producer operating a greenhouse with crops grown in 

containers using a growing media that does not contain soil is exempt from 205.202 (b) and 

205.203 (a)...”. 

205.202 (b) refers to the requirement for 3 years of no prohibited materials applied in order to 

be eligible for organic certification. In addition to issues regarding the use of the word 

“exemption”, the 2010 recommendation does not address specific requirements or 

considerations for transition of the container crop itself. 

What are the Questions?

● Is there an allowance for transition of non-organic container crops to organic?

● Can a non-organic container crop be repotted into allowed media and be considered

organic without a 3 year transition?

● What happens to a container crop in the event of an unintended application of 

prohibited substance?
67

o Can the media retransition?

o Can the crop retransition?

Analysis and Clarifications

As per §205.202 Land management, soil within a growing media must meet the 3 year 

transition in order to be used to grow organic crops. The remaining components, such as 

compost, peat, perlite etc., must be allowed substances under the USDA organic regulations.

In the opinion of this subcommittee, when discussing transition, it is appropriate to consider 

that a container system, where applicable due to use of prohibited inputs or applications, must 

transition in the same manner as land. Plants themselves should not be allowed to be “upsized” from use of prohibited materials or media into allowed growing media in order to 

eliminate transition periods. This would be analogous to digging up a plant and putting in 

another field after an application of prohibited materials. The only exception that applies the 

same standard for containers and in ground systems is where transplants or planting stock 

(such as bare root, or allowed non-organic planting stock or equivalents) are placed in allowed 

media/soil. Transition requirements should be clear in cases of drift or application of prohibited 

materials. We see no distinction between prohibited materials used on the plant or in the 

media with respect to transition of containers.

Summary of Committee Recommended Revisions

In the opinion of this subcommittee, if container production systems are to be permitted, they 

must take into account impacts to the soil and land underneath and around their crops, 

including monitoring and mitigating impacts due to covering the soil, applying materials, and 

runoff from the container. This could include a prohibition or limitation on waste to drain 

systems. An application of a prohibited material to a container that is not on a closed loop 

system would affect the transition date of the underlying ground.

Suggested update to the wording in the 2010 Recommendation 205.209 (a) to state:

“For a producer operation a greenhouse or other location with crops grown in containers, any 

soil used as growing media must meet the requirements of 205.202 (b), 205.203(a).”

7. Rotation

Starting Point from the 2010 Recommendation:

205.209(2) “In addition, the growing container based producer is exempt from the crop 

rotation and cover cropping requirements in section 205.203(b) and 205.205. In lieu of crop 

rotation and cover cropping, soil regeneration and recycling practices shall be implemented and 

documented for the certification agent in order to demonstrate that the required 

functions/goals of crop rotation and cover cropping listed in 205.205(a, b, c, d) have been 

achieved through these alternate practices, as applicable to the operation.

What are the Questions?
68

● Should organic crops grown in native or amended soil covered by a greenhouse or a 

protected environment (high tunnel) be allowed without a requirement for rotation?

● Should container growing media reuse be allowed without a requirement for rotation? 

● Are there appropriate comparisons to be made between management of long term 

annual crops in a greenhouse and perennial crop production in a field setting? 

● Can container media recycled by composting be considered to have met a rotation 

requirement by essentially doing a restart? If yes, how?

● How many crops of different botanical family, genus or species must be grown before 

replanting a particular crop? Needs to not be based on “years” but on crops or cycles.

Analysis and Clarification

Crop rotation is considered essential to maintain a natural and diverse soil ecology. A number 

of alternatives to maintain natural and diverse soil ecology in a greenhouse setting were 

provided in the 2010 recommendation. Any of those alternatives could also be used in an 

outdoor field setting at a small scale. Does this open the door for loss of emphasis on crop 

rotation? 

A number of alternatives to maintain a diverse soil ecology were provided in the 2010 

recommendation. The justification for the exemption was that the economic cost of managing 

the structure could only be met by producing a very limited number of high value crops. The 

diverse soil ecology could be maintained by managing crop residues, ground covers, mulches, 

compost applications, intercropping, etc. The task force subcommittee is divided on this issue. 

Allowing greenhouses to only grow high value crops such as tomatoes in repeated succession 

with no rotation is in conflict with organic regulations, but is commonly permitted.

Long term perennial crops such as fruit and nut trees are maintained without crop rotation but 

are required to use practices such as alley cropping, mulching, intercropping, or hedgerows to 

meet the same intended benefits provided by crop rotation. Ground covers, mulches, and 

compost applications are used to increase the diversity of organic matter needed to support 

diverse soil biology. 

Summary of Committee Recommended Revisions 

We are divided on whether rotations for in-ground annual greenhouse production and for 

containers should be required.

Define how a container growing media can be recycled by composting to allow reuse in a 

container without crop rotation.

Define what constitutes appropriate or minimal rotation based on crop number and not based 

on years or the seasonal cropping cycle of a field production setting. 

Suggested update to the 2010 recommendation:
69

205.209 2) In lieu of crop rotation and cover cropping requirements in section 205.203 (b) and 

205.205, container producers shall implement soil building and recycling practices so that the 

required functions/goals of crop rotation and cover cropping listed in 205.205 (a,b,c,d) have 

been achieved through these alternative practices, as applicable to the operation...”

8. Compost 

Starting Point from the 2010 Recommendation:

Compost. The product of a managed process through which microorganisms break down plant 

and animal materials into more available forms suitable for application to the soil. Compost 

must be produced through a process that combines plant and animal materials with an initial 

C:N ratio of between 25:1 and 40:1. Producers using an in-vessel or static aerated pile system 

must maintain the composting materials at a temperature between 131°F and 170°F for 3 days. 

Producers using a windrow system must maintain the composting materials at a temperature 

between 131°F and 170°F for 15 days, during which time, the materials must be turned a 

minimum of five times.

What are the Questions?

● Is the definition of compost used in the 2010 recommendation adequate to allow 

certifiers to make necessary decisions relative to the use of compost based container 

growing media? Given compost guidelines that have been provided by the NOSB and 

NOP (5021), does more need to be said or referenced in the recommendation? 

● Can the “green waste” information in the Handbook be used to adequately provide 

certifiers with the necessary information for decision making?

● Is the NOP compost definition contrary to most other definitions of composting relative 

to whether nutrients become less or more available? If so, why? 

● Is the NOP aware that the vermicomposting recommendation does not provide any 

guidance for a required minimum worm population density for vermicomposting? 

● Is the NOP aware of the growing use of anaerobic digestion (wet and dry methods) that 

produces large volumes of solid and liquid output not addressed by current compost 

guidelines with potential for nutrient recycling for an OSP? 

● Does the NOP have plans to address any future review or changes relative to compost? 

Analysis and Clarification

The original definition of compost was perceived to be overly prescriptive and narrow since the 

introduction of the NOP rule. The NOSB and certifiers have attempted to address the issue 

through recommendations and Guidelines, many of which are available in the USDA Organic 

Handbook. The NOSB Compost Task Force Recommendation of April 2002 and Final Report 

provide important details about composting for an OSP that are not referenced. 
70

Compost based container growing media are currently allowed but not clearly defined. 

Additional clarification or expanded guidelines of allowed and prohibited methods of making 

compost and of finished compost characteristics would provide more consistency and 

confidence in the certification process. 

Defining the product compost by describing the composting process of how it can be made 

continues to be a limitation on more accurately describing and promoting organic agriculture

practices that use compost. 

The current definition states that the process of composting makes “materials into more 

available forms suitable for application to the soil”. Most all other definitions (Rynk, 1992; 

Cooperband, 2002) of composting emphasize that the process of composting takes available 

forms of nutrients such as in high moisture manure or food scraps for example and converts 

them to less available forms. 

Defining compost as only a thermophilic process limits the use of other successful methods of 

processing organic matter (manure, green waste) into less available/more stable forms suitable 

for application to soils. Perceptions of compost are often narrow and based on experience 

with either a dairy or poultry manure based compost high in nutrients or a municipal leaf and 

grass based compost low in nutrients. There are many other options or types of compost. 

Compost is most often defined as a soil amendment. It is also frequently pointed out that 

compost should not be considered a “fertilizer” or source of soluble nutrients. This line of 

presentation was necessary in the early decades of organic farming when academics tended to 

dismiss compost as a potential strategy for soil management based on applying NPK thinking. 

Compost can be produced to serve the function of a growing medium or a major component of 

growing media by intentionally formulating the feedstocks to achieve a desired final C:N ratio 

and a balanced nutrient profile. This can also be accomplished by mixing a variety of mature 

composts that are high or low in total nutrients. Doing so may require starting C:N ratios of 

higher than the 40:1 currently allowed for blended compost feedstocks. 

One approach to avoid the current limitations of the compost definition is to use the definitions 

associated with “green waste” in the Handbook. Decomposition of organic materials without 

animal manure are suitable for use as mulch and soil amendments without meeting the heating 

requirement. Can it also be assumed therefore that such non-manure organic matter is also 

allowed for container growing media assuming no prohibited substances are present?

Recommendations for mesophilic (low temperature) composting or vermicomposting have 

been published. The current recommendation defines oxygen, moisture and composting times 

but lacks any reference to a minimum necessary worm population or density, for example 

worm biomass/unit area or volume of feedstocks. 
71

Anaerobic digestion (AD) may prove to be a viable composting method to recover energy, 

organic matter and nutrients from organic materials. The rule currently does not address or 

define necessary characteristics to allow the use of AD solids and liquids in organic agriculture 

systems. 

The current rule has no guidance or description of target or acceptable range of end product 

C:N ratio, bulk density, particle size distribution, total or soluble nutrient content or biological 

profile. To define appropriate or acceptable compost based growing media will require or 

benefit from some expanded guidance or definitions related to characteristics of finished 

compost. These characteristics might include: 

● Dry Bulk Density, Particle size distribution

● Percent organic matter, Percent Nitrogen, C:N Ratio

● pH, soluble salts or electrical conductivity, mineral analysis

● Biological respiration (Solvita test), Biological Diversity 

Most of these characteristics have already been described as part of the Compost Quality 

Assurance program or seal. (Woods End Laboratory, US Composting Council).

Summary of Compost Related Committee Recommended Revisions 

Assuming the 2010 Recommendation will be amended or edited; the continued development of 

compost guidelines by the NOSB compost task force needs to be referenced so more than just 

the initial definition of compost is included. 

Guidelines describing characteristics of finished compost suitable for use in container growing 

media can be developed and provided. The compost guidelines can support or be a part of 

guidelines for compost based growing media that are also needed. 

At some point issues related to alternative methods of composting can be addressed by the 

NOSB or possibly a new compost task force. Some issues to be addressed might be: 

Vermicomposting: 

● The current guideline of 70 to 90% moisture during composting may be too high for onfarm composting methods. 

● Vermicompost final quality is influenced by the density of worms present during the 

active composting phase and some guideline as to desired worm density could be 

provided.

Anaerobic Digestion 

● Wet and dry anaerobic digestion methods are available for commercial and on-farm 

use.
72

● These additional composting methods can provide solid and liquid products that can be 

useful tools in an OSP that should be made available to organic farmers / producers. 

Cited Literature

Cooperband, L. 2002. The Art and Science of Composting; A resource for farmers and compost producers. Center 

for Integrated Agricultural Systems, University of Wisconsin, Madison. 17 pgs. 

Rynk, R. (editor) 1992. On-Farm Composting Handbook. Northeast Regional Agricultural Engineering Service, 

Cooperative Extension, Ithaca, NY. NRAES-54. 204 pages. 

USDA Organic Handbook 

Examples of other compost definitions: 

● Rynk, pg 1 Composting is a biological process in which microorganisms convert organic materials such as 

manure, sludge, leaves, paper, and food wastes into a soil-like material called compost. It is the same process 

that decays leaves and other organic debris in nature. Composting merely controls the conditions so that 

materials decompose faster.

● Rynk, pg 5 The nutrients in compost are mostly in a complex organic form and must be mineralized in the 

soil before they become available to plants. For example, less than 15% of the total nitrogen in compost is 

typically available in the first cropping season.

● Cooperband, pg1 Composting is controlled decomposition, the natural breakdown process of organic 

residues. Composting transforms raw organic waste materials into biologically stable, humic substances that 

make excellent soil amendments. Compost is easier to handle than manure and other raw organic materials, 

stores well and is odor-free.
73

Section 6. Definitions

Aeroponic Production--a variation of hydroponics in which plant roots are suspended in air and 

misted with nutrient solution

Aquaponic Production -- A system of growing plants in the water that has been used to 

cultivate aquatic organisms

Compost -- The product of a managed process through which microorganisms break down

plant and animal materials including allowed feedstock materials (either nonsynthetic 

substances not prohibited at § 205.602, or synthetics approved for use as plant or soil 

amendments), into more available forms suitable for application to the soil. Compost must be 

produced through a process that combines plant and animal materials with an initial C:N ratio 

of between 25:1 and 40:1 and processes it to a low final C:N ratio (in the range of 5:1 to 20:1). 

Producers using an in-vessel or static aerated pile system must maintain the composting 

materials at a temperature between 131 °F and 170 °F for 3 days. Producers using a windrow 

system must maintain the composting materials at a temperature between 131 °F and 170 °F 

for 15 days, during which time, the materials must be turned a minimum of five times. 

Compost tea -- A water extract of compost produced to transfer microbial biomass, fine 

particulate organic matter, and soluble chemical components into an aqueous phase, intending 

to maintain or increase the living, beneficial microorganisms extracted from the compost.

Vermicompost -- Vermicomposts are organic matter of plant and/or animal origin, consisting 

mainly of finely-divided earthworm castings, produced non-thermophilically with bio-oxidation 

and stabilization of the organic material, due to interactions between aerobic microorganisms 

and earthworms, as the material passes through the earthworm gut.

Diverse Soil Ecology -- An incredible diversity of organisms make up the soil food web. They 

range in size from the tiniest one-celled bacteria, algae, fungi, and protozoa, to the more 

complex nematodes and microarthropods, to the visible earthworms, insects, small 

vertebrates, and plants.

Ecology -- Agricultural ecology is the study of agricultural ecosystems and their components as 

they function within themselves and in the context of the landscapes that contain them. 

Application of this knowledge can lead to development of more sustainable agricultural 

ecosystems in harmony with their larger ecosystem and ecoregion.

Growing media -- Material which contains sufficient organic matter capable of supporting the 

plant root system.

Hydroponic production-- the production of normally terrestrial, vascular plants in nutrient rich 

solutions or in an inert, porous, solid matrix bathed in nutrient rich solutions.

Organic matter --The remains, residues, or waste products of any organism which may include 

living, recently dead microorganisms & plant materials, slowly decaying organic matter decades 

old and stable and humus organic matter that exists for decades to centuries.

Organic production--A production system that is managed in accordance with the ACT and 

regulations in this part to respond to site-specific conditions by integrating cultural biological 

and mechanical practices that foster cycling of resources, promote ecological balance and 

conserve biodiversity.
74

Soil -- The upper layer of earth that may be dug or plowed and in which plants can grow. Soil 

consists of four important parts: mineral solids, water, air, and organic matter. Mineral solids 

are sand, silt, and clay and mainly consist of silicon, oxygen, aluminum, potassium, calcium, and 

magnesium. A typical agricultural soil has 1% to 6% organic matter. It is the interaction between 

the soil organisms in the organic matter that release the mineral nutrients from the soil 

minerals in plant available forms.

Soil food web -- The soil food web is the community of organisms living all or part of their lives 

in the soil. A food web diagram shows a series of conversions (represented by arrows) of energy 

and nutrients as one organism eats another.

Thrive -- to grow vigorously
75

Section 7. Appendices

Appendix A: EGTOP Report on Greenhouse Production

http://ec.europa.eu/agriculture/organic/eu-policy/expert-advice/documents/finalreports/final_report_egtop_on_greenhouse_production_en.pdf

3.9.2. When should growing plants in substrate be authorized? In general, organic growing and

the production of organic plants should take place in soil, and ‘soil’ means that the upper soil is 

in contact with the subsoil, so that roots can grow into the subsoil. As an exception from this 

principle, the Group accepts cultivation in substrates for seedlings and transplants, and for 

plants which are sold to the consumer together with the pot/container in which they grow (e.g. 

herbs in pots, ornamentals). In these cases, production in horticultural substrate is obvious to 

consumers and there is no risk that they are misled regarding the production method of the 

plants. By contrast, organic produce harvested out of sight of consumers should always come 

from plants grown in soil, and not from horticultural substrate cultures. This would also be 

important if a shorter conversion period is established for substrate cultures to avoid unfair 

competition between substrate-grown and soil-grown crops (see Section 3.10.2). 

3.9.2.1. Growing organic vegetables in demarcated beds as an exception for growing in soil 

Authorities in Finland, Sweden, Norway and Denmark, have authorised a practice of growing 

organic vegetables in ‘demarcated beds’, which is a form of substrate culture, where the plants 

are grown in large containers, bags or beds surrounded by plastic sheets/fleece where the roots 

may or may not be in contact with the soil. The total area is very small (about 18 ha). The Group 

strictly opposes to any enlargement of such practices in organic farming because it is not in line 

with the objectives and principle of organic farming. Some urban organic production systems 

(e.g. rooftop production) may not comply with the requirement of growing in soil. These 

systems may be encouraged as private initiatives, they are outside the scope of the organic 

farming rules and will need to be addressed separately. 

3.9.2.2. Side remarks on special cases, where the principle of growing in soil is not applicable 

for biological / technical reasons 

There are some plants, fungi and algae which naturally do not grow in the soil. For such plants, 

the principle of growing crops in the soil obviously does not apply.

● Exceptions for mushroom culture are defined in Art. 6 of the Reg. (EC) 889/2008. 

● Sprouts are young seedlings, which are produced by moistening of seeds. Production of 

sprouts in the soil would raise hygienic concerns, and it would not make sense, because 

at this stage of development, seedlings utilize exclusively the reserves in the seed and 
76

do not take up nutrients from the environment. Sprout production therefore does not 

fall under the definition of ‘hydroponics’, given in Art. 2(g) of the Reg. (EC) 889/2008. 

The same argument applies also to the ‘forcing’ of vegetative materials, e.g. chive bulbs 

(Allium schoenoprasum). EGTOP/6/13 Final Report on Greenhouse Production 

(Protected Cropping) 31

● Freshwater plants such as watercress (e.g. Rorippa amphibia) and freshwater algae (e.g. 

Spirulina) naturally grow in water and are often certified as organic. However, there is 

some doubt as to whether freshwater plants and algae can strictly be grown organically, 

because under the Organic Regulation their cultivation may be considered as 

hydroponics, and they do not fall under the Reg. (EC) 710/2009. A distinction could be 

made between stream bed production and greenhouse production. In greenhouses, 

they could be used in combined systems, where freshwater plants or algae are used to 

recycle nutrients originating from freshwater fish production.

The Group concludes that the circumstances under which the production of such freshwater 

plants and algae can be authorized should be clarified, possibly in the framework of revision of 

the Reg. (EC) 710/2009. However, the Group does not want to set a precedent for any kind of 

hydroponic cultivation of plants which would normally grow in the soil. 

3.9.2.3. Conclusion on when growing plants in substrates should be authorized 

The Group recommends that growing in substrates is accepted for seedlings and transplants, 

and for plants which are sold to the consumer together with the pot/container in which they 

grow (e.g. herbs in pots, ornamentals), while harvested organic vegetables or fruits (e.g. 

strawberries) should come from plants grown in the soil, and not from substrate cultures. 

However, the Group recognised that in Finland, Sweden, Norway and Denmark a practice was 

authorised where vegetables are grown on growing media in demarcated beds but strictly 

opposes to any enlargement of such practices in organic farming because it is not in line with 

the objectives and principle of organic farming. Therefore, the Group recommends that only 

those farms which have used demarcated beds in the past (i.e. before 2013) should be allowed 

to use them in the future and that there should be no expansion of the use of demarcated beds 

neither on these holdings nor in the rest of the EU. The Group recommends that any excess or 

spent growing media or plastic used in organic greenhouse production and farming in general 

should be reused or recycled. 

As regards plants, fungi and algae which naturally do not grow in the soil, e.g. water plants (e.g. 

water cress), some mushroom species and sprouts, the Group recommends that the production 

of such organisms should be authorized
77

Appendix B: IFOAM EU Position Paper on Organic Greenhouse Production

http://www.ifoameu.org/sites/default/files/page/files/ifoameu_reg_greenhouse_production_position_201302.p

df

Growing in greenhouses is a longstanding horticultural practice. Greenhouses are used to 

lengthen the growing season and to protect vulnerable crops. Organic greenhouses exist in 

many Member states. Organic greenhouse production falls within the scope of Regulation EC 

834/2007. The general rules for plant production apply. 

This means in particular that also for organic greenhouses the basis is that: soil fertility is based 

on the use of crop rotations which include legumes and other green manures and the 

application of organic manures. If these methods are insufficient, products listed in annex 1 of 

Regulation EC 889/2008 may be used in addition. Rapidly soluble fertility amendments should 

be allowed only as a last resort when other fertilization techniques have proved insufficient. 

But in greenhouse production, due to its character, growing measures are applied that are not 

possible in arable farming or non covered cropping such as heating, lighting or cooling. 

Furthermore other growing measures that are common practice in arable farming are more 

difficult in greenhouse production, such as a wide crop rotation. 

Due to harmonization of organic rules and increase in demand for organic products, trade 

between Member states has increased. The producers that are confronted with different 

practices and interpretations in the Member states demand a level playing field. At the same 

time differences in climatic conditions and the demand for local produce should be respected. 

Finally, the energy input in greenhouses can be such a considerable part of that specific plant 

production system that it needs to be addressed in an organic regulation. 

Regulating organic production in greenhouses touches upon many issues. It should be noted 

that some of the issues addressed are relevant for more types of production than only for 

greenhouses but we are proposing the measures only for greenhouses. Next to production of 

food crops this does include seedling production and production of ornamentals. 

In this paper we have taken a position on conversion, soil, fertility, use of peat, CO2 use, water 

use, steam sterilization, energy use and urban farming. 
78
79
80
81

Appendix C: Canadian Soil Fertility and Crop Nutrient Management and 

Greenhouse Standards

National Standard of Canada Organic Production Systems

http://www.cog.ca/uploads/GeneralPrincipelsandManagemetnStandards_2015.pdf

5.4 Soil fertility and crop nutrient management

 

5.4.1 The main objective of the soil fertility and crop nutrient management program shall be to 

establish and maintain a fertile soil using practices that maintain or increase soil humus levels, 

that promote an optimum balance and supply of nutrients, and that stimulate biological activity 

within the soil.

5.4.2 Where appropriate, the soil fertility and biological activity shall be maintained or 

increased, through: a) crop rotations that are as varied as possible and include plough-down, 

legumes, catch crops and deep-rooting plants; b) incorporation of plant and animal matter in 

compliance with this standard and with Table 4.2 of CAN/CGSB-32.311, including the following: 

1) composted animal and plant matter; 2) non-composted plant matter, specifically legumes, 

plough-down crops or deep-rooting plants within the framework of an appropriate multiyear 

rotation plan; and 3) unprocessed animal manure, including liquid manure and slurry, subject to 

the requirements of 5.5.1. 
82

5.4.3 Tillage and cultivation practices shall maintain or improve the physical, chemical and 

biological condition of soil, and minimize damage to the structure and tilth of soil, and soil 

erosion. 

5.4.4 Plant and livestock materials shall be managed to maintain or improve soil organic matter 

content, crop nutrients, and soil fertility, and in a manner that does not contribute to the 

contamination of crops, soil or water, by plant nutrients, pathogenic organisms, heavy metals 

or prohibited substances residue. 

5.4.5 The organic matter produced on the operation shall be the basis of the nutrient cycling 

program. It may be supplemented with other organic and non-organic nutrient sources. Nonorganic sources shall be listed in Table 4.2 of CAN/CGSB-32.311. Manure is also subject to the 

requirements of 5.5.1.

7.5 Greenhouse crops

7.5.1 In a permanent, in-ground soil system, prohibited substances shall not have been used for 

at least 36 months before the harvest of an organic crop.

7.5.2 In a container system, soil shall be free of prohibited substances.

Note: The Canadian Organic Products Regulations require operators to document that 

they have not used prohibited substances. The Regulations also require that, in the case 

of an initial application for organic certification of crops grown in greenhouses with a 

permanent, in-ground soil system, the application for certification must be filed 15 

months before the day on which the product is expected to be marketed. During that 

period of time, compliance with this standard will be assessed by the certification body 

and this assessment must include at least one inspection of the production unit, during 

production, in the year before crops may be eligible for certification and one inspection, 

during production, in the year crops are eligible for certification. This requirement does 

not apply to greenhouses built on land that is part of an existing organic operation.

7.5.3 Hydroponic and aeroponic productions are prohibited.
83

7.5.4 Soil used in a container system, with the exception of transplants, shall provide 

nutrients to plants continuously. The soil (growth media) shall contain a mineral fraction 

(sand, silt or clay) and an organic fraction; it shall support life and ecosystem diversity.

7.5.5 The following conditions apply to containerized, staked crops (for example, tomatoes, 

sweet peppers, cucumbers, eggplant):

● a) at the start of production, the total volume of soil shall consist of at least 

10% compost;

● b) compost shall be included in the fertility program;

● c) containers shall be at least 30 cm (12 in.) high; and

● d) the soil volume shall be at least 70 L/m2 (15.4 gal./10.8 ft2), based on the 

total growing area.

7.5.6 Supplemental heat, with proper exhaust of burnt gasses, and supplemental lighting, 

are permitted. Supplemental nutrition with substances listed in Table 4.2 of CAN/CGSB32.311, is permitted.

7.5.7 Plants and soil, including potting soil, shall not come into contact with prohibited 

substances, including wood treated with prohibited substances.

7.5.8 For crop production, the operator shall:

● a) use reusable and recyclable pots and flats whenever possible;

● b) use substances listed in Tables 4.2 and 4.3 of CAN/CGSB-32.311;

● c) use appropriate equipment cleaners, disinfectants and sanitizers listed in 

Tables 7.3 and 7.4 of CAN/CGSB-32.311.

7.5.9 Full-spectrum lighting is permitted.

7.5.10 The following procedures, processes or substances are permitted to:
84

● a) enrich carbon dioxide levels:

● 1) flaming;

● 2) fermentation;

● 3) composting; and

● 4) compressed gas (CO2);

● b) clean and disinfect plant containers, pots and flats:

● 1) substances listed in Tables 7.3 or 7.4 of CAN/CGSB-32.311; 

and

● 2) steam-heat sterilization;

● c) stimulate growth or development:

● 1) substances listed in Tables 4.2 or 4.3 of CAN/CGSB-32.311; 

and

● 2) control of daily temperature and light levels;

● d) prevent damping-off:

● 1) low-temperature baking;

● 2) hot-water treatment; and

● 3) steam treatment.

7.5.11 The following procedures or substances are permitted for the prevention and control 

of disease, insects or other pests:

● a) substances listed in Table 4.3 of CAN/CGSB-32.311;

● b) pruning;

● c) rouging;

● d) vacuuming;

● e) pest exclusion from greenhouses with air filters, screens or other physical 

devices; and

● f) biological control methods.

7.5.12 Soil regeneration and recycling procedures shall be practiced. The following 

alternatives to crop rotation are permitted: grafting of plants onto disease-resistant 

rootstock, freezing the soil in winter, regeneration by incorporating biodegradable plant 
85

mulch (for example, straw or hay), and partial or complete replacement of greenhouse soil 

or container soil, provided it is re-used outside the greenhouse for another crop.

7.5.13 Greenhouse crop product preparation

Wherever organic product preparation takes place, 8.1 and 8.2 apply.

7.5.14 Facility pest management

Subclause 8.3 applies to pest management practices in and around crop facilities.
86

Appendix D: Soil Association Greenhouse Standards

Soil Association Organic Standards Farming and Growing

https://www.soilassociation.org/media/1220/sa-farming-and-growing-standards.pdf

4.6 Managing soil (p. 65)

4.6.1 You should maintain a protective cover of vegetation, such as green manure or growing 

crops, to protect surface-living organisms and soil structure from exposure to dry conditions, 

heavy rain or strong winds. 

4.6.2 Your cultivation for crop production should: 

● be well-timed to get a suitable tilth whilst avoiding damage to the soil structure 

● cause minimal disruption of the soil profile by shallow ploughing or no-till systems, and 

● enable deep loosening of the sub-soil to break plough or compaction pans. 

4.6.3 You should monitor the levels of organic matter, available plant nutrients and nutrient 

reserves in your soil by analysing them and nutrient budgeting. You should try to do this at the 

same time each year. 

4.6.4 You must manage your soil to prevent erosion. 

4.6.5 You must manage your soil with the aim of developing and protecting an optimum soil 

structure, biological activity and fertility. To do this you must: 

● maintain humus levels, biological activity and plant nutrients for instance by regularly 

applying organic manure or compost and plant remains

● make sure your soil has enough microbial activity to start the decay of organic materials 

● make sure your soil has enough microbial activity to breakdown non-soluble minerals to 

make them available to plant roots, and 

● make sure your soil conditions encourage the continual activity of soil fauna and other 

soil stabilising agents. They will improve and stabilise soil structure by producing 

granular casts, deep burrows and mixing the organic matter.

5.1.13 If your rotation does not meet the requirements of standard 5.1.10 above and relies on 

brought-in inputs for crop production, you must:

● show us you are balancing your fertility building and fertility depleting management

● make optimum use of legumes, green manures and/or composted materials, and 

● reduce or minimise your reliance on brought-in inputs. 
87

5.1.14 When you cannot produce crops within a rotation your methods of nutrient supply, 

weed, pest and disease control must still comply with sections 4.6 - 4.11. Below are the main 

examples of such production systems: 

● permanent pastures, including upland habitats 

● perennial crops such as orchards, vineyards and plantation crops 

● wild harvested plants growing naturally in uncultivated areas (please see chapter 9). 

5.1.15 You must not use: 

● any cropping system we have not defined in standard 5.1.14 or 5.2.1 that relies on 

outside inputs for nutrient supply, weed, pest and disease control, or 

● continuous arable rotations.

5.2 Additional standards for protected cropping (p. 96)

5.2.1 You may produce crops without a rotation in a protected cropping system (polytunnel or 

glasshouse). You must: 

● demonstrate that your system builds and maintains the health of your soil and crops; 

● demonstrate that your system is not reliant upon routine use of restricted products for 

pest, disease and weed control, and; 

● comply with standard 5.1.13. 

5.2.2 You must produce a fertility management plan for your protected cropping system. The 

plan must demonstrate that your system: 

● maximises the efficient use of nutrients 

● builds soil health and fertility, and 

● optimises sustainability of fertility inputs. 

The table below outlines steps to best practice to inform your fertility management plan. Your 

plan must outline your options for movement towards more sustainable fertility sources over 

time. 
88

Note - your fertility management plan will help you to comply with standard 

5.2.3 If you use fuel or electricity to heat your protected cropping structure, you must record 

the energy you use for heating in kWh per metre2 per week. You must also record the type and 

source of energy used. 

5.2.4 If you heat your protected cropping structure and use more than 100kWh per metre2 per 

year for heating, you should produce an energy plan outlining how you will progress towards 

renewable energy or combined heat and power over the next five years. 

Note - following a review in 2016, we will set targets for renewable energy use and a date for 

making this standard a requirement. 

5.2.5 You may use carbon dioxide in your protected cropping structure only if it has been 

produced as a by-product of another process. You must not burn fuel solely to produce carbon 

dioxide. 

5.2.6 You should collect and use rainwater run-off from your protected cropping structures. 

Note – see sections 4.5 and 4.16 for additional standards on water management.

5.2.3 If you use fuel or electricity to heat your protected cropping structure, you must record 

the energy you use for heating in kWh per metre2 per week. You must also record the type and 

source of energy used. 

5.2.4 If you heat your protected cropping structure and use more than 100kWh per metre2 per 

year for heating, you should produce an energy plan outlining how you will progress towards 

renewable energy or combined heat and power over the next five years. 
89

Note - following a review in 2016, we will set targets for renewable energy use and a date for 

making this standard a requirement. 

5.2.5 You may use carbon dioxide in your protected cropping structure only if it has been 

produced as a by-product of another process. You must not burn fuel solely to produce carbon 

dioxide. 

5.2.6 You should collect and use rainwater run-off from your protected cropping structures. 

Note – see sections 4.5 and 4.16 for additional standards on water management.

5.3 Using seed and propagation material 5.3.1 Where appropriate you should use bare root 

transplants raised on your own organic unit.

5.3.2 Revised 2014 (applies from June 2014) When buying seed and plant material (including 

potato tubers, onion sets, strawberry runners, fruit tree root stock and bud material), you must, 

in order of preference: use organic seeds and plant material when a suitable variety is 

available. Use in-conversion seeds and plant material when a suitable variety is available. 

Obtain our permission to use non-organic seed and plant material. You must send us a 

completed seed derogation form before we can give you permission. You must apply for 

permission every season. Note - seed derogation forms are available from us on request. You 

can also submit them on-line, and find details of available organic varieties, at 

www.organicxseeds.co.uk. 

5.3.3 Revised 2014 (applies from February 2014) You may use non-organic treated seed or seed 

potatoes if: Defra advise so for plant health (phytosanitary) reasons. It must not be treated 

with anything that is not allowed under section 4.11 unless Defra prescribe chemical treatment 

for all varieties of a species in a defined geographical area. Defra approve its use for research, 

for small-scale field trials or for variety conservation purposes. 

5.3.4 Revised 2014 (applies from February 2014) Except for the purposes outlined in standard 

5.3.3, you must not use seed treated with anything that is not allowed under section 4.11. 

5.3.5 To produce organic seeds you must grow the mother plant to organic standards for at 

least one generation, or for perennial plants, two growing seasons. 

5.3.6 To produce organic propagating material you must grow the mother plant to organic 

standards for at least one generation or, in the case of perennial plants, two growing seasons. 

5.3.7 If you use transplants (bare root, blocks, modules) they must have been grown to organic 

standards by a registered organic producer. 
90

5.3.8 You must use organic propagating material (sets, root stock and bud material) when 

available. 

5.3.9 With our permission, you may use non-organic propagating material (not including 

transplants) when organic material is not available. 

5.3.10 In propagating substrates you may use: clay, including bentonite and zeolites, and 

vermiculite and perlite. These must not have been treated with materials we do not allow. 

Growing transplants 

5.3.11 To produce transplants for use in organic growing, you may only use substrates made 

from materials in section 4.7 and supplementary nutrients in section 4.8. 5.3.12 You may 

describe these transplants as, for example, ‘plants suitable for organic growing’ or ‘transplants 

suitable for organic production’. 

5.3.13 You must have all labels and marketing literature approved by us before you use them. 

5.3.14 You must not describe transplants as organic. Growing plants in pots and containers to 

sell as organic 

5.3.15 The only plants that you can grow in pots or other containers are ornamentals or herbs 

(including salad cress). You may sell them as organic only if: the substrate is made of at least 

51% (by fresh weight of the end product) of materials from organic farming origin no more 

than 49% of the substrate is made up of non-organic materials listed in standards 4.7.8 and 

4.7.9, which you must treat according to standard 4.7.19 the substrate provides more than 

50% of their nutrient needs, until the point of sale you make sure the substrate is biologically 

active (emphasis added), for example by including composted material you meet all other 

relevant standards the entire plant and the pot are sold together you do not use peat or 

slaughterhouse wastes, and you do not use soil from organic farms. 

5.3.16 You must not harvest parts of herbs or ornamentals that have been grown in pots and 

sell them as organic.
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Appendix E: Language for the EU rule on growing in the ground 

Council regulation 834/2007. This is the basis for all legislation in the EU for organic production

http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A32007R0834

Article 4

Overall principles

Organic production shall be based on the following principles:

(

a

)

the appropriate design and management of biological processes based on ecological 

systems using natural resources which are internal to the system by methods that:

(

i

)

use living organisms and mechanical production methods;

(

i

i

)

practice land-related crop cultivation and livestock production or practice aquaculture 

which complies with the principle of sustainable exploitation of fisheries;

(

b

)

the restriction of the use of external inputs. Where external inputs are required or the 

appropriate management practices and methods referred to in paragraph (a) do not exist, 

these shall be limited to:

(i) inputs from organic production;

(ii) natural or naturally-derived substances;

(iii) low solubility mineral fertilisers;

Article 5

Specific principles applicable to farming

In addition to the overall principles set out in Article 4, organic farming shall be based on the 

following specific principles:
92

(

a

)

the maintenance and enhancement of soil life and natural soil fertility, soil stability and 

soil biodiversity preventing and combating soil compaction and soil erosion, and the 

nourishing of plants primarily through the soil ecosystem;

1. In addition to the general farm production rules laid down in Article 11, the following rules 

shall apply to organic plant production:

a. organic plant production shall use tillage and cultivation practices that maintain or 

increase soil organic matter, enhance soil stability and soil biodiversity, and prevent soil 

compaction and soil erosion

b. the fertility and biological activity of the soil shall be maintained and increased by 

multiannual crop rotation including legumes and other green manure crops, and by the 

application of livestock manure or organic material, both preferably composted, from 

organic production;

c. the use of biodynamic preparations is allowed;

d. in addition, fertilisers and soil conditioners may only be used if they have been 

authorised for use in organic production under Article 16;

e. mineral nitrogen fertilisers shall not be used;
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Appendix F: Bioland Standards on Soils and Substrates and Growing of 

Seedlings, Transplants, Sprouts and Potted Herbs in Greenhouses (Bioland -

the leading association for organic farming in Germany)

http://www.bioland.de/fileadmin/dateien/HP_Dokumente/Richtlinien/Bioland_Standards_201

6-03-14.pdf

5 Horticulture and Permanent Crops

The general parts of these standards apply also to horticulture and permanent crops in as far as 

no exceptions are specified in the following. In farming without animals the supply of nitrogen 

must be effected as far as possible by leguminous growing in the operation itself. The amounts 

of nitrogen fertiliser which is additionally required and permissible may be purchased in the 

form of external, organic additional fertilisers.

5.1 Vegetable production

5.1.1 Fertilising

The total amount of fertiliser from the operation and organic supplemental fertiliser to be used 

in free range vegetable gardening may not exceed 110 kg of nitrogen per ha and year. In 

greenhouses, the quantity of the nitrogen fertilization shall be matched to the length of the 

growing period and the yield expectations. In free range vegetable gardening, at annual 

average for a total period of 12 weeks, 20 % of the arable area has to be cultivated with green 

manure during growing season, the assessment period for accounting the green manure areas 

is 2 years. In general, in vegetable gardening, art. 3.4.5 is of particular importance. In order to 

control the nitrogen dynamics in the soil it is urgently recommended that N-min-tests be 

carried out on a regular basis.

5.1.2 Soils and Substrates

Growing vegetables on stone wool, hydroponics, nutritional film technology, thin layer culture 

and similar systems are not permissible neither the production in bags and containers. 

Permissible is the growing of herbs in pots and similar products, whereas the container is sold 

together with the plant.

The production of chicory sprouts in water is possible.

The use of peat to enrich the soil with organic substance is not permitted. It is also forbidden to 

use styrol mull and other synthetic materials in soils and in substrates.

5.1.3 Steaming Soil and Substrates

Soil and substrates may be steamed. Flat steaming of the soil for the purpose of weed 

regulation is permissible. Depth steaming to de-pollute the soil may only be permissible, if the 

plant protection problem may not be solved by other measures, e.g. change of crop, and 

requires express approval by the BIOLAND association.
94

5.1.4 Crop production in Greenhouses (Glass and Plastics)

Heating greenhouses is – in general - limited to the reasonable extension of the growing period 

in autumn and to earlier starting in spring. In winter, the crops should merely be kept free of 

frost (approx. 5°C). The growing of seedlings and transplants, forced sprouting and potted herbs 

are excepted. When choosing the system of heating and the kind of fuel, the environmental 

compatibility should be taken into account. The buildings should be well insulated thermally.
95

Appendix G: 1980 USDA Report on Organic Agriculture

http://pubs.nal.usda.gov/sites/pubs.nal.usda.gov/files/Report%20and%20Recommendatio

ns%20on%20Organic%20Agriculture_0.pdf

"Organic farming is a production system which avoids or largely excludes the use of 

synthetically compounded fertilizers, pesticides, growth regulators, and livestock feed 

additives. To the maximum extent feasible, organic farming systems rely upon organic wastes, 

mechanical cultivation, mineral-bearing rocks, and aspects of biological pest control to maintain 

soil productivity and tilth, to supply plant nutrients, and to control insects, weeds, and other 

pests...

The concept of the soil as a living system which must be "fed" in a way that does not restrict the 

activities of beneficial organisms necessary for recycling nutrients and producing humus is 

central to this definition....

...(3) Motivations for shifting from chemical farming to organic farming include concern for 

protecting soil, human, and animal health from the potential hazards of pesticides; the desire 

for lower production inputs; concern for the environment and protection of soil resources." (p. 

xii)

2.4 ORGANIC AGRICULTURE: SOME BASIC TENETS (p. 8-9)

Despite the range of agricultural practices followed by organic farmers, most of them are 

guided by certain basic values and beliefs which may be called the "organic ethic." Some of the 

principal tenets of this ethic are summarized below. However, not all organic farmers would 

place equal weight on these tenets. 

Nature is Capital -- Energy-intensive modes of conventional agriculture place man on a collision 

course with nature. Present trends and practices signal difficult times ahead. More concern over 

finite nutrient resources is needed. Organic farming focuses on recycled nutrients. 

Soil is the Source of Life -- Soil quality and balance (that is, soil with proper levels of organic 

matter, bacterial and biological activity, trace elements, and other nutrients) are essential to the 

long-term future of agriculture. Human and animal health are directly related to the health of 

the soil. 

Feed the Soil, Not the Plant -- Healthy plants, animals, and humans result from balanced, 

biologically active soil. 

Diversify Production Systems -- Overspecialization (monoculture) is biologically and 

environmentally unstable. 
96

Independence -- Organic farming contributes to personal and community independence by 

reducing dependence on energy-intensive agricultural production and distribution systems. 

Antimaterialism -- Finite resources and Nature's limitations must be recognized. 

In summary, organic farmers seek to establish ecologically harmonious, resource-efficient, and 

nutritionally sound agricultural methods.

3.2 CROP PRODUCTION (p. 12)

3.2.1 Cropping Practices A legume-based rotation with green manure or cover crops was an 

integral part of the management system on most of the organic farms studied. Legume crops 

frequently comprised 30 to 50 percent of the cultivated acreage. However, in some cases 

legumes were not used; for example, on vegetable farms receiving heavy applications of 

manure and in low rainfall areas. Other crops in the rotation were generally similar to those 

grown on neighboring farms. However, in areas where farm size was smaller, organic farmers 

seemed more inclined than their neighbors to produce vegetable crops for fresh markets. 

The Rodale survey disclosed that about 50 percent of the farmers grew legume hay, mixed hay, 

or pasture in their rotations. A high percentage (50 percent) of these organic farmers were 

vegetable and/or small fruit producers that grew only limited amounts of small grains and 

cultivated field crops. As the farm size increased, the percentage of farmers growing meadow 

increased sharply (15 percent for farms of 9 acres or less, 71 percent for farms of 100 acres or 

more). The survey also showed that the percentage of farmers growing vegetables and small 

fruits decreased sharply with increasing farm size. These data emphasize the importance of 

legumes in rotation with small grains and cultivated field crops on organic farms. 

Organic farmers on non-irrigated land followed crop rotations similar to those used on farms 30 

to 40 years ago. A typical pattern was to follow a heavy green manure crop with a high 

nitrogen-demanding crop such as corn, sorghum, or wheat. For example, in a corn-soybean 

area such as the Midwest a rotation might be: oats - 3 years of alfalfa - corn (or wheat) -

soybeans - corn - soybeans. On more productive soils, there might be an additional corn or 

wheat and soybean crop after 3 years of alfalfa. Vegetable crops grown with or without 

legumes are rotated so that the same crops are not followed sequentially. Organic vegetable 

farmers alternate deep and shallow rooted crops, root crops, and above-ground crops 

throughout the growing season by careful crop selection and consideration of planting and 

maturity dates. Organic farmers using irrigation often did not follow rotations systematically 

but instead based their cropping patterns on short-term demand for produce, plant disease 

problems, and availability of land and water.

3.7 ORGANIC AGRICULTURE IN JAPAN (p. 19)

Some guiding principles and objectives of the organic agricultural movement in Japan include: 

1) To achieve self sufficiency; 

2) To recycle organic wastes back to the land (cited as being commensurate with Buddhism and 
97

its principles); 

3) To protect and maintain human health; and 

4) To achieve a mutually beneficial relationship between the farmer, the consumer, and the 

environment. The importance of a close and cooperative relationship between the farmer and 

consumer in the production and marketing of organically grown produce was emphasized.

4.3 ORGANIC FARMING AND ORGANIC WASTES (p. 35)

Organic farmers are well aware that the proper management of crop residues, green manures, 

and animal manures on their land is essential for protecting soils from wind and water erosion, 

and for preventing nutrient runoff. Certainly, they recognize that efficient and effective use of 

their residues and manures is essential for maintaining the productivity of their soils and for 

recycling plant nutrients. A 1978 USDA report, Improving Soils with Organic Wastes (1), is 

particularly relevant to the needs of organic farmers and some of the problems with which they 

must deal. 4.3.1 USDA Report, Improving Soils with Organic Wastes (1978) The Food and 

Agriculture Act of 1977 (P.L. 95-113) directed the U.S. Department of Agriculture to prepare a 

report to the Congress on "the practicability, desirability, and feasibility of collecting, 

transporting, and placing organic wastes on land to improve soil tilth and fertility." The urgency 

for this information stems from the increased cost of energy, fertilizers, and pesticides that 

confronts U.S. farmers, and the problems of soil deterioration and erosion associated with 

intensive farming systems. This report is now available upon request from the Office of the 

Secretary of Agriculture in Washington, D.C. 20250. It contains detailed information on the 

availability of seven major organic waste materials for use in improving soil tilth and fertility: (a) 

animal manures, (b) crop residues, (c) sewage sludge, (d) food processing wastes, (e) industrial 

organic wastes, (f) logging and wood manufacturing wastes, and (g) muni ci pat refuse. For each 

waste, information is reported on the quantity currently generated, current usage, potential 

value as fertilizers (based on major plant nutrients contained), cost of land application, 

competitive uses, and problems and constraints affecting their use. The report points out that 

this kind of information is absolutely essential for sound agricultural planning and successful 

implementation of organic recycling programs.
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Appendix H: Moratorium Letter

February 17, 2016

Mr. Tom Vilsack

Secretary of Agriculture

U.S. Department of Agriculture

1400 Independence Ave SW

Washington, DC 20250

 

CC: Elanor Starmer, Acting Administrator, USDA Agricultural Marketing Service

Miles McEvoy, Deputy Administrator, USDA National Organic Program

Tracy Favre, Chair, National Organic Standards Board

Re: Ending the Organic Certification of Hydroponics

Dear Secretary Vilsack,

This letter serves as a formal request for the U.S. Department of Agriculture (USDA) to institute 

an immediate moratorium on the organic certification of all new hydroponic and aquaponic 

operations, until the agency enacts a final rule. We believe that it is incumbent upon USDA to 

accept the NOSB’s 2010 recommendations to prohibit soilless hydroponic vegetable production 

as certified organic. The recommendation specifically states that hydroponic and aeroponic 

“cannot be certified as organic growing methods....” NOP’s written response to the NOSB’s 

recommendations acknowledges the completion of their work on greenhouse standards and that 

“the NOP will develop a proposed rule based on the NOSB final recommendations."[1]

The NOP’s decision to allow organic certification of hydroponic systems, in direct opposition to 

the 2010 NOSB recommendations, and without formal proposed standards, violates the 

program’s legal responsibility to follow the established due process in setting organic standards. 

Moreover, the harsh reality of the extreme variations that exist in how such operations are being 

certified (or not) is creating consumer confusion and undermining the integrity of the organic 

label that is relied upon by the organic sector for its market success.

Unlawful and Extreme Variations in Certification Requirements Weaken Organic Markets

Due to the lack of formal organic greenhouse standards, organic certification agencies have been 

acting independently and creating and recreating their own rules to address public concerns, 

particularly with respect to the organic soil requirement. While some certifiers allow crops to be 

grown in an undefined “biodegradable substrate,” others do not. Some certifying organizations 

such as Vermont Organic Farmers, OneCert, and New York NOFA do not permit any form of 
99

hydroponic certification. They require crops to be grown in the soil, in keeping with the 

European standards. Other organizations have certified hydroponic crops for many years. 

One of the central tenants of the Organic Foods Production Act of 1990 (OFPA) is to “assure 

consumers that organically produced products meet a consistent standard” (7 U.S.C. § 6501(2)).

This lack of a consistent standard with respect to hydroponic systems is exactly the type of 

problem that OFPA and the NOP were specifically designed to avoid.

Consumers Have a Right to Know How Their Organic Food is Grown

All produce sold under these disparate organic hydroponics certification standards use the same 

USDA seal without differentiation. Therefore, there is no way for customers to identify which 

food is grown hydroponically and which is not. Indeed, most consumers have no idea that 

hydroponic growing is permitted under existing USDA organic standards.

Public Notice and Comment on Hydroponics Regulations is Required by Law

The NOP hydroponics rule must be subjected to public notice, review, and comment and 

specifically address the January 23, 2010 formal National Organic Standards Board (NOSB) 

Recommendations on the “Production Standard for Terrestrial Plants in Containers and 

Enclosures (Greenhouses).” NOSB passed this recommendation by a majority vote -- twelve to 

one -- after six years of hard work and public hearings. The recommendation unequivocally 

states that hydroponic production should not be permitted in organic certification and that 

organic production of terrestrial plants must be soil-based.[2]

U.S. Organic Rules Must be Consistent with International Hydroponic Rules

Strong international support for the 2010 NOSB Recommendations already exists. The 

recommendations are consistent with the vast majority of world organic standards, including 

twenty-four countries in the European Union (EU). It is also worth noting that Canada prohibits 

hydroponically grown produce to be certified organic, a situation that has forced the U.S. to 

create a specific hydroponics exception in its trade agreement with Canada.

The 2013 position papers of both the International Federation of Organic Agriculture Movements 

European Union (IFOAM EU) and the Expert Group for Technical Advice on Organic 

Production (EGTOP) offer well-researched recommendations on organic hydroponics that are in 

accord with the organic standards of twenty-four EU countries. IFOAM EU has also produced a 

position paper calling for USDA to regulate organic hydroponics based on the NOSB’s 2010 

recommendations.

As an influential participant in global organic trade, it is incumbent upon the U.S. to join the 

international community in maintaining strong and consistent organic standards. 

“Soil is the Source of Life” and the Foundation of U.S. Organic Farming Systems
100

Soil fertility and soil management are prerequisites for organic certification of crop production. 

Hydroponics systems do not meet this mandate. Both the OFPA and the NOP final rule describe 

organic agricultural production as being much more than substituting approved inputs for nonapproved ones. 

The 2010 NOSB Recommendation strongly reinforces foundational principles and descriptions 

of “organic,” as practiced on U.S. organic farms. The 1980 USDA Report and Recommendation 

on Organic Farming,[3] clearly states:

● “Soil is the Source of Life—Soil quality and balance (that is, soil with proper 

levels of organic matter, bacterial and biological activity, trace elements, and other 

nutrients) are essential to the long-term future of agriculture. Human and animal health 

are directly related to the health of the soil.

● Feed the Soil, Not the Plant—Healthy plants, animals, and humans result from balanced, 

biologically active soil.”

Hydroponic operations on the market do not enhance the biological diversity of plant/soil system 

or meet other essential requirements inherent in organic soil and ecosystem-based agricultural 

systems.

OFPA also makes clear that managing soil health is central to organic agriculture systems, as 

evidenced by the inclusion of details about what is expected by organic farmers as they design 

their annual crop and animal production system plans. In the discussion of what constitutes an 

Organic Plan (6513) it states:

(b) Crop Production Farm Plan.

(1) Soil Fertility. An organic plan shall contain provisions designed to foster soil fertility, 

primarily through the management of the organic content of the soil through proper tillage, crop 

rotation, and manuring. 

The Rule also outlines a practice standard for soil fertility and crop management that is 

impossible to meet in a hydroponic system. In the Soil fertility and crop nutrient management 

practice standard (§ 205.203): 

(a) The producer must select and implement tillage and cultivation practices that maintain or 

improve the physical, chemical, and biological condition of soil and minimize soil erosion.

(b) The producer must manage crop nutrients and soil fertility through rotations, cover crops, and 

the application of plant and animal materials.
101

(c) The producer must manage plant and animal materials to maintain or improve soil organic 

matter content in a manner that does not contribute to contamination of crops, soil, or water by 

plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances.

Animal and plant materials include: 

(1) Raw animal manure, which must be composted unless it is: 

(i) Applied to land used for a crop not intended for human consumption; 

(ii) Incorporated into the soil not less than 120 days prior to the harvest of a product whose 

edible portion has direct contact with the soil surface or soil particles; or

(iii) Incorporated into the soil not less than 90 days prior to the harvest of a product whose edible 

portion does not have direct contact with the soil surface or soil particles;

No language exists in either OFPA or the rule which outlines requirements for soilless 

hydroponic systems. In contrast, clear language exists to justify the prohibition of hydroponics 

in organic given the fact that they cannot meet the minimum standards described above. This 

conflict with OFPA makes it impossible to allow the universal organic certification of 

hydroponic production.

NOP Allowance of Hydroponic Certification is Unjustified

NOP's rationale for allowing hydroponic certification is based on a single sentence taken from 

the 1995 NOSB Recommendation for Specialized Standards for Hydroponic Production in 

Soilless Media. It states: "Hydroponic production in soilless media to be labeled organically 

produced shall be allowed if all provisions of the OFPA have been met." This recommendation 

was not included in the final rule and so it has no legal basis for current organic certification.

No provision in OFPA or the NOP regulations justifies the certification of hydroponics. In fact, 

in its written response to the NOSB recommendation in 2005 the NOP implies that standards 

need to be developed before hydroponic operations can be certified. It states that:

NOP concurs with the NOSB and agrees to proceed with additional rulemaking for mushrooms, 

apiculture and honey, and greenhouse operations and their products, and not to propose hydroponic 

standards until the NOSB has submitted a final recommendation.

Hydroponics Task Force Must Uphold and Clarify NOSB Recommendations

A stated primary objective of the USDA/NOP-created Hydroponics Task Force is to clarify the 

NOSB’s 2010 Recommendation (80 Fed Reg. 12,422, Mar. 9, 2015). Yet, widespread concern 

exists regarding the actual purpose of this task force, which appears to be to rewrite rather than to 

clarify the recommendation. Justification for this concern is based upon the composition of this 
102

task force, the majority of which seem to have a vested interest in advancing organic certification 

of hydroponics rather than in clarifying the 2010 NOSB recommendations.

It is troubling that taskforce membership was initially limited to those with at least three years of 

experience in hydroponic or aquaponic production. This restriction was later amended to include 

those with experience in soil-based organic systems of production. Nonetheless, the initial 

Federal Register notice gave an accurate foreshadowing of the affiliation of those who would be 

chosen to join. Several highly qualified task force applicants known to support the exclusion of 

hydroponic from organic were not chosen. This unfortunate situation created an unfairly biased 

task force which, coupled with USDA’s allowance of hydroponics certification in the absence of 

clear and consistent regulations, has sparked increasing discontentment with the NOP by the 

wider organic community. Opaque decision-making runs counter to the practices that the 

organic sector expects from USDA and the NOP.

Conclusion

We must not take trust in organic for granted, either from the organic community as a whole, or 

from organic agriculture producers. It took decades to build trust in the organic label, and we 

must not squander it by ignoring due process. Yet, disturbing signs of eroding public trust in 

organic are evident. In 2015, the Consumers Union (CU) downgraded the rating of USDA’s 

Organic Seal from “highly meaningful” to “meaningful,” based upon extensive survey research 

of organic consumers. While we have heard from the NOP that it is not overly concerned about 

the study’s results, we view CU’s research (which did not specifically ask about hydroponics) as 

a first alarm. To us, it sends a powerful warning signal of the urgent need for course corrections 

to be taken by the USDA/NOP. Stopping the organic certification of hydroponic operations is a 

correction that is urgently and sorely needed. 

To allow the entire organic industry to suffer public mistrust due to unnecessary confusion 

regarding basic greenhouse standards is short-sighted public policy. We must not compromise 

the organic standards in an effort to increase sales and open new markets at the expense of the 

public confidence.

For the reasons outlined above, the undersigned urge USDA to uphold the integrity of the 

organic label for farmers, handlers, and consumers by instituting an immediate moratorium on 

the organic certification of all new hydroponic and aquaponic operations until the agency enacts 

a final rule. We believe that it is incumbent upon USDA to accept the NOSB’s 2010 

recommendations to prohibit soilless hydroponic vegetable production as certified organic and 

have the details of that recommendation flushed out and reflected in the final rule.

This is the only way to ensure that all products carrying the organic label and USDA organic seal 

have met rigorous organic standards, and that organic farmers are protected from harm arising 

from inconsistent certification practices.

Respectfully yours,
103

Dave Chapman, Long Wind Farm, Vermont

David Miskell, Miskell’s Premium Organics, Vermont

Anaïs Beddard, Lady Moon Farms, Pennsylvania, Georgia, and Florida

Dru Rivers, Full Belly Farm, California 

Eliot Coleman, Four Season Farm, Maine

Pete Johnson, Pete’s Greens, Vermont

Margit Kaltenekker Hall, Prairie Star Farm, Kansas

(On behalf of the diverse organic stakeholders who have signed the attached position statement 

calling for an immediate moratorium on new certified organic hydroponic operations)

US Organizations

National Organic Coalition

NOFA VT

NOFA NH

NOFA NY

NOFA NJ

NOFA CT

NOFA MA

NOFA RI

MOFGA (Maine Organic Farmers and Gardeners Association)

Center For Food Safety

Beyond Pesticides

Food and Water Watch

Northeastern Organic Dairy Producers Association

Organic Consumers Association

Organic Seed Growers and Trade Association
104

NOFA Interstate Council

Cornucopia Institute

Carbon Underground

Agrarian Elders

Forrest and Frances Lattner Foundation

Biodynamic Association

Demeter Association

Organic Crop Improvement Association

Deep Root Growers Cooperative

New England Farmers Union

Food Democracy Now!

Tuscagora Organic Growers Cooperative

International Organizations

Soil Association (Great Britain)

Organic Growers Alliance (Great Britain)

French National Organic Farmers Federation (France)

Bionext (Holland)

Biohuis (Holland)

Study Network of Organic Greenhouse Growers of the Dutch Federation of Agriculture and 

Horticulture (Holland)

Study Network of Organic Arable Farmers in Southwest Netherlands (Italy)

Nautilus Organic (Dutch Organic Growers Association-Holland)
105

BDEKO (Federation of Biodynamic and Organic Farmers-Holland)

AIAB (Associazione Italiana per l'Agricoltura Biologica- Italy)

AIAB Liguria (Italy)

BOLW (Bund Ökologische Lebensmittelwirtschaft e.V.)

CAPE (Cooperative pour l'Agriculture de Proximite Ecologique- Canada)

Amis de la Terre Estrie (Canada)

Former NOSB members

Michael Sligh - NOSB 1992 to 1996. Founding Chair.- Executive Director Rafi

Fred Kirschenmann- NOSB 1995 to 1999- Farmer. President Stone Barns Center For Food and 

Agriculture, Distinguished Fellow for Leopold Center For Sustainable Agriculture, Professor of 

Religion and Philosophy at ISU, Cofounder Farm Verified Organic, Inc.

Dr. Joan Gussow- NOSB 1996 to 2000 - Professor Emeritus Columbia University, Author.

Dave Carter - NOSB 2001 to 2005 - Executive Director National Bison Association, USDA 

Agricultural Trade Advisory Committee on Animals and Animal Products, Consultant with 

Crystal Springs Consulting Inc.

Jim Riddle - NOSB 2001 to 2005. Former Chair.- Farmer at Blue Fruit Farm, Inspector, Trainer, 

Policy Specialist, Co-author of OTA's American Organic Standards, Outreach Coordinator 

University of Minnesota Southwest Research and Outreach Center, Cofounder International 

Organic Inspectors Association, former University of Minnesota Extension Organic Outreach 

Coordinator, Ceres Trust.

Dr. Hubert Karreman - NOSB 2005 to 2009. - Former Chair of the Livestock Committee 

Organic veterinarian, member Biodynamic Educators Collaborative.

Jeff Moyer - NOSB 2005 to 2010. Former Chair. - Executive Director and former Farm Director 

Rodale Institute, Board Chair for the Seed Farm, Founding and current member of the 

Pennsylvania Certified Organic, past board member of the Organic Farming Research 

Foundation, Project member of the Noble Foundation's Soil Renaissance project.

Joe Smillie - NOSB 2006 to 2010- Former Vice President of Quality Assurance International. 

Former President and board member of the Organic Trade Association.

Kevin Englebert - NOSB 2006 to 2010 - Farmer at Englebert Farms.
106

Dr. Barry Flamm - NOSB 2008 to 2012. Former Chair - Farmer, Founder and Vice-Chair of the 

Montana Organic Association, Former Director of the USDA Office of Environmental Quality, 

Former Senior Staff Member for natural resources and agriculture at the President's Council For 

Environmental Quality, former teacher of environmental policy at the University of Montana, 

Former Chief Forester at the Wilderness Society.

Nick Maravell - NOSB 2011 to 2015 - Farmer at Nick's Organic Farm.

Jennifer Taylor - NOSB 2011 to 2015 - Associate Professor Florida A&M University.

Colehour Bondera - NOSB 2011 to 2015 - Farmer at Kanalani Ohana Farm.

Goldie Caughlan - NOSB 2001 to 2005 - Nutrition Education Manager at PCC Natural Markets, 

Board member Cornucopia Institute.

Jay Feldman - 2010 NOSB. Later Chair of crops subcommittee. - Executive Director Beyond 

Pesticides.

Farmers and Organic Advocates

Dr. Stuart Hill Retired professor of soil zoology, McGill University

Elizabeth Henderson Co-chair NOFA NY Policy Committee

Edward Maltby Farmer, Executive Director NOFPA

Terry Shistar Beyond Pesticides

Bob Scowcroft Cofounder and former Executive Director of the Organic Farming 

Research Foundation, First Executive Director of the California Certified Organic Farmers

Tom Beddard Farmer Lady Moon Farm

Bart Hall P. Ag. Farmer, former inspector

Bill Duesing Executive Director NOFA CT

Enid Wonnecott Executive Director VT NOFA

Jack Kitteridge Farmer Many Hands Organic Farm, Editor The Natural Farmer

Julie Rawson Farmer Many Hands Organic Farm, Editor The Natural Farmer
107

Mitch Blumenthal Farmer and Founder/President of Global Organic Specialty Source

Ronnie Cummins Co-founder and International Director of The Organic Consumers 

Association, Author

Lisa Bunin Former Organic Policy Director for Center For Food Safety

Jim Gerritsen Farmer Wood Prairie Family Farm, President of Organic Seed Growers And 

Trade Association, named an Organic Food Champion by the Utne Reader, Agrarian Elder

Megan Gerritsen Farmer Wood Prairie Family Farm, Agrarian Elder

Alan Schofield Farmer Growing With Nature, Chairman of the Horticultural Standards 

Committee for the Soil Association, Chairman of the Organic Growers Alliance

Steve Gilman Farmer, Policy Coordinator NOFA Interstate Council

Tom Newmark Farmer Finca Luna Nueva, Co-Founder and Chair Carbon Underground, 

Founder Sacred Seeds, Trustee American Botanical Council, Founder New Chapter

Patty Lovera Assistant Director Food & Water Watch, former Deputy Director at Public Citizen

Paul Hawken Environmentalist, Entrepreneur, journalist, and author. Founder of Natural 

Capital Institute. Former board member of Point Foundation, Center For Plant Conservation, 

Conservation International, Trust For Public Land, Friends of the Earth, and National Audubon 

Society.

Karl Hammer Farmer, Founder and President Vermont Compost Company

Will Allen Farmer Cedar Circle Farm

Liana Hoodes Former Executive Director NOC

Tom Page Farmer Page's Organics

Frank Morton Farmer Shoulder To Shoulder Farm, Agrarian Elder

Clara Coleman Four Season Farm Consulting

Zoe Bradbury Farmer Valley Flora Farm, Agrarian Younger

Amigo Bob Cantisano Consultant, Founder Ecological Farming Conference, Steward of 

Sustainable Agriculture, Agrarian Elder
108

Jack Algiere Farmer Four Season Farm at Stone Barns Center, Agrarian Younger

Dan Pullman Manager of Fresh Source Capital, Board of Food and Environment Reporting 

Network, Board of Yale Sustainable Food Project, Founding President of Sprout Lenders, Board 

of FarmPlate

Dr. Will Brinton President Woods End Laboratories

Will Raap Founder Intervale Foundation, Cofounder Gardeners Supply

Barbara Damrosch Farmer Four Season Farm, Journalist Washington Post, Author

Dr. William Liebhardt Emeritus UC Davis , Former Director UC Sustainable Agricultural 

Research and Education Program 1987-2001, Former chief scientist Rodale Institute 1981-1987, 

professor U of Delaware 1970 to 1981

Frederic Jobin-Lawler Farmer Abri Vegetal (Canada)

Thea Maria Carlson Co-director Biodynamic Association

Robert Karp Co-director Biodynamic Association, founder New Spirit Farmland Partnerships, 

Former Executive Director of Practical Farmers of Iowa, former board chair of Michael Fields 

Agricultural Institute.

Stephan Schneider Farmer, Board member Biodynamic Association, President Hawthorne 

Valley Farm

Daphne Amory Board member Biodynamic Association, Inspector for Demeter USA

Gregory Georgaklis Board member Biodynamic Association, Founder Farmers To You

Peter Littell Board member Biodynamic Association, President of Biodynamic Farmland 

Conservation Trust

Terry Brett Board member Biodynamic Association, Co-owner Kimberton Whole Foods

Jim Fullmer Co-Directer Demetor USA

Dr. Larry Phelan Professor of entomology at Ohio State University

Jean-Paul Courtens Farmer Roxbury Farm, former president of the Biodynamic Association, 

Teacher
109

Jim Crawford Farmer New Morning Farm, Agrarian Elder

Jake Guest Farmer Killdeer Farm, Agrarian Elder

Betsy Hitt Farmer Peregrine Farm, Agrarian Elder

Gloria Decater Farmer Live Power Community Farm, Agrarian Elder

Stephen Decater Farmer Live Power Community Farm, Agrarian Elder

Carly Delsignore Farmer Tide Mill Organic Farm, Agrarian Elder

Andrea Hazzard Farmer Hazzard Free Farm, Agrarian Elder

Zachary Wolfe Farmer Farm at Locusts on Hudson, Agrarian Elder

Tom Willey Farmer T&D Willey Farms, Agrarian Elder

Bavo van den Idsert Director, Bionext, The Netherlands

Lisa Stokke Cofounder Food Democracy Now!

Dave Murphy Cofounder Food Democracy Now!

[1] September 30, 2010,

[2] 80 Fed Reg. 12,422, Mar. 9, 2015

[3] US Department of Agriculture Study Team on Organic Farming. (1980) USDA Report and 

Recommendation on Organic Farming, section 2.4, “Organic Agriculture, Some Basic Tenets,”
110

Appendix I: USDA Regulations of the use of Chilean Nitrate in Organic 

Agriculture

http://www.ecfr.gov/cgi-bin/ECFR?page=browse

§205.602 Nonsynthetic substances prohibited for use in organic crop production.

The following nonsynthetic substances may not be used in organic crop production:

(g) Sodium nitrate—unless use is restricted to no more than 20% of the crop's total nitrogen requirement; 

use in spirulina production is unrestricted until October 21, 2005.
111

Appendix J: Letter from Michael Sligh

I am Michael Sligh, and was a founding member of the NOSB from 1992-1997and served as the 

founding chair and vice-chair to the second chair. I did publish, A Guide To The Development of 

US. Organic Standards, in 1997, that contains all of the Original NOSB recommendation to USDA 

for the development of the US Organic Regulations.

This record records that the Board did pass a three line recommendation on April, 25, 1995:

Hydroponic production in soilless media to be labeled organically produced shall be allowed, if 

all provisions of the OFPA have been met.

We had been required to make some recommendations on a wide range of specialized subjects 

prior to submitting our final recommendation to USDA for the development of US NOP 

regulations. The Hydroponic discussion was very short and consisted of only a few minutes of 

full board discussion during our April, 25, (1995) meeting. USDA’s own transcripts from the 

period of 1992 - 1995, also only records this same one reference from that April 25th meeting, 

but it does add that:

“*Kahn concluded his report by reading the hydroponics recommendation that would allow 

organic labeling for products from soilless media if all other National Program requirements are 

satisfied. Baker expressed his concerns about the philosophical problems associated with 

soilless production. Kahn noted that the recommendation only allows for the possibility of an 

organic hydroponics industry developing. Kahn recognized that hydroponics is a practice that is 

dependent on synthetic inputs and wants to open up dialogue with its proponents.”

* Gene Kahn was the chair of the Crops during that period and wanted a “place-holder” for 

future discussions.

On a personal note, my understanding of that statement, that “all provisions of OFPA have 

been met”, was the key to my voting for that very brief recommendation. As one that both 

worked on the OFPA and as the founding chair and a founding board member; I understood 

OFPA to be about organic farming, which meant that the goal,(as our NOSB definition of organic 

farming stated and was also adopted at that same April meeting in Orlando, states” ...based on 

management practices that restore, maintain and enhance ecological harmony....The primary 

goal of organic agriculture is to optimize the health and productivity of interdependent 

communities of soil life, plants, animals and people.”

Additionally, the OFPA refers to soil about ten times:

and specifically;
112

"(b) Crop production farm plan.

 (1) Soil fertility. An organic plan shall contain provisions designed to foster soil fertility, 

primarily through the management of the organic content of the soil through proper tillage, 

crop rotation, and manuring.

 (2) Manuring.

 (A) Inclusion in organic plan. An organic plan shall contain terms and conditions that 

regulate the application of manure to crops."

So, in conclusion, in my opinion OPFA includes the "following key provisions that must be met” 

- "would include a farm plan; that fosters soil fertility, includes crop rotations, is compatible 

with a system of sustainable agriculture, does not harm soil organisms and does not include any 

production practices that are inconsistent with this chapter.”

Hope this helps,

all the best,

Michael
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2. Hydroponic & Aquaponic Subcommittee Report

Preserving a philosophy while embracing a changing world

Colin Archipley

Angela Caporelli

Marianne Cufone

Charlie Shultz

Pierre Sleiman

Stacy Tollefson

Edgar Torres

Jessica Vaughan

Please note - this document was prepared under very tight time constraints. The Hydroponics and 

Aquaponics Subcommittee was tasked with both providing specific information about growing systems, 

supported by scientific research and case studies, as well as reviewing and answering other questions 

regarding coordination with organic production standards and the 2010 NOSB Recommendations. The full 

Task Force, now split into three subcommittees, was initially to be a full year project. It began in November 

2015 with preliminary discussions. The first and only in-person meeting was January 2016. The project 

deadline was shortened by five months to June 2016 and then a slight extension to mid-July 2016. As such, it 

was not possible to complete all the tasks of the Hydroponics and Aquaponics Subcommittee with the detail 

and specific information, supported by research, as initially intended, due to the lack of adequate time to 

address all matters.
2

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Table of Contents

Introduction.......................................................................................................................................... 4

Definitions............................................................................................................................................ 5

Brief Review of the Organic Food Productions Act (OFPA) and USDA Organic Regulations ............... 7

History.............................................................................................................................................. 7

Traditional (non-organic) Hydroponic Systems .................................................................................. 12

a) Water-based Systems................................................................................................................ 13

b) Aggregate culture....................................................................................................................... 13

Organic Hydroponics - Bioponics....................................................................................................... 15

a) Why bioponics is relevant to the NOSB/NOP............................................................................. 15

b) How is bioponics different from Hydroponics.............................................................................. 16

c) Containers and Container Systems............................................................................................ 17

d) Growing Media........................................................................................................................... 18

1. Solid (aggregate) growing media ............................................................................................ 18

2. Liquid growing media.............................................................................................................. 19

e) Biology....................................................................................................................................... 20

f) Nutrition ...................................................................................................................................... 22

Examples of Organic Inputs and Associated Nutrients................................................................ 23

Advantages of Bioponic Systems....................................................................................................... 24

a) Water Conservation ................................................................................................................... 24

b) Food Safety ............................................................................................................................... 24

c) Disease Suppression ................................................................................................................. 24

d) Nutrient Conservation & Retention............................................................................................. 25

e) Soil Conservation....................................................................................................................... 25

Aquaponics........................................................................................................................................ 26

a) Water-based production............................................................................................................. 26

b) Types of aquaponic systems...................................................................................................... 26

c) Fish waste and mineralization in aquaponic systems ................................................................. 26

d) Aquaponic System Factors ........................................................................................................ 27

e) Aquaponic System Designs ....................................................................................................... 28

f) Fish............................................................................................................................................. 28

g) Crop Production......................................................................................................................... 28
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h) Nutrients .................................................................................................................................... 28

i) Growing media............................................................................................................................ 28

Considerations and Analysis.............................................................................................................. 30

a) Bioponics and Organic Certification ........................................................................................... 30

b) Areas of alignment ..................................................................................................................... 31

Proposed Changes to USDA Standards ............................................................................................ 42

§205.2 Terms defined. ................................................................................................................. 42

§205.208 Bioponic Production Standard ........................................................................................ 42

Organic Systems Plan Considerations for Bioponics...................................................................... 43

Clarifications of 2010 NOSB Recommendations................................................................................ 45

Purpose and Context for this Analysis............................................................................................ 45

References ........................................................................................................................................ 53

Appendix ........................................................................................................................................... 55

Greenhouse technology to promote soil life ................................................................................... 55

pH that is not too low or too high.................................................................................................... 55

Stable Temperatures of Soil or Growing Media .............................................................................. 55

Soil life wants a Carbon source to feed on ..................................................................................... 56

Case study 1 - Bioponic Tomato Growing.......................................................................................... 57

Case study 2 - Decoupled Bioponic NFT ........................................................................................... 61

Case study 3 - Bio Digestion within a Water Culture System ............................................................. 62

Case study 4 - DWC Aquaponics....................................................................................................... 66

Fish................................................................................................................................................ 66

Plants............................................................................................................................................. 67

Shared Water Quality..................................................................................................................... 67

Effluent Management..................................................................................................................... 68

Case study 5 - Container production systems.................................................................................... 72
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Introduction

The words organic farming conjure not just a set of guidelines for agricultural practices, but also 

often are associated with a deep philosophy rooted in the concept of improving and maintaining our 

environment, promoting life beyond just the crop and staying true to preserving nature’s life processes. 

For as far back as history has recorded, societies worked with limited resources and flourished or failed 

based on their ability to innovate and adapt to changing environments, resources and conditions. 

Humans farmed in the basic sense of “organically” since the time we learned to sow a seed. However, 

it is not until recent decades that synthetic materials have become widely available for use in 

agriculture, and thus specific legal guidelines have emerged to identify and certify “Organic” growing

under U.S. Department of Agriculture guidelines.

Challenges in the farming industry such as drought, food safety, limited arable land, climate 

change and rapid population growth constantly evolve, and with it, the farming industry continually 

adapts as well. One part of a solution to these challenges is use of growing techniques such as 

hydroponics and aquaponics, as addressed in this report. 

It is important to note that extensive documentation shows that ancient civilizations practiced 

innovative growing techniques similar to hydroponics and aquaponics, including the Aztecs with 

Chinampa “floating gardens” and the Babylonians and their famed “hanging gardens of Babylon.” 

These historic techniques are still in practice and are continually expanding today to be an active part 

of U.S. agriculture.

In 2010, the NOP conducted a survey and reported that there were 8 certifiers who were 

certifying hydroponic operations as “organic”, and only 39 hydroponic growers. A second survey in 

2016, which asked about certification of hydroponic and aquaponic as well as other types of container 

operations reported an 88% increase in certifiers who certify hydroponic and aquaponic operations 

and an increase of over 33% in these operations.

In 2010, the National Organic Standards Board (NOSB) recommended that hydroponic systems

not be eligible for organic certification “... due to their exclusions of the soil-plant ecology intrinsic to 

organic farming systems...” (NOSB may 2009). 

It is this Subcommittee’s intent, via this report, to among other tasks, provide additional 

information, background and clarification about hydroponic and aquaponic growing systems that likely 

were not available to the NOSB at the time of their 2010 recommendation.

Specifically, the description of “hydroponic” systems in the NOSB’s 2010 recommendations 

addresses a traditional method of hydroponics that is sterile and inert. This Subcommittee agrees with 

the NOSB’s 2010 position that such systems should not be eligible for organic certification. However, 

there are other container growing systems that may resemble traditional hydroponic systems, but are 
5

5

fundamentally and completely different. Such systems require and contain rich, diverse and complete 

soil-plant ecology that symbiotically work with plants to biologically process animal, plant and mineral 

inputs. This subcommittee has termed such “organic hydroponic” practice as “bioponic” – this report 

will discuss in detail how bioponic growing practice works and its alignment with current organic 

regulations.

As will be discussed in detail below, it is critically important to consider hydroponic and 

aquaponic production systems as eligible for organic certification, because these practices conserve 

incredible amounts of water, dramatically reduce food safety risks and pose very low environmental 

impacts – while at the same time holding soil-plant biology and the use of the same animal/plant-based 

inputs, as soil-field farmers, at the core of their practice.

Definitions

Hydroponic production - The growing of plants in mineral nutrient solutions with or without an inert 

growing media to provide mechanical support

Bioponic production - A contained and controlled growing system in which plants in growing media 

derive nutrients from natural animal, plant and mineral substances that are released by the biological 

activity of microorganisms

Aquaponic production - A type of bioponic system in which wastes produced from the life cycle of 

fish or other aquatic animals supplies nutrients for plants grown in container systems. As plants 

absorb nutrients, the water is purified for reuse 

Aeroponics - A type of growing system in which plant roots are suspended in an enclosed space and 

at regular intervals are moistened with nutrient solution or microbial solution, which is then returned 

to the reservoir and re-used

Soil - The outermost layer of the earth comprised of minerals, water, air, organic matter, fungi and 

bacteria in which plants may grow roots

Growing media - Material which provides sufficient support for the plant root system and a diverse 

ecosystem of soil-borne microorganisms

Compost Tea - A water extract of compost produced to transfer microbial biomass, fine particulate 

organic matter, and soluble chemical components into an aqueous phase, intending to maintain or 

increase the living, beneficial microorganisms extracted from the compost. 

Nutrient solution - Growing solution used in traditional hydroponic production which is commonly 

composed of immediately plant-available soluble synthetic mineral salts in water
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6

Microbial solution - Growing solution used in bioponic production which is commonly composed of 

organic substances and a diverse ecosystem of beneficial microorganisms in water

Container - any vessel and associated equipment used to house growing media and the complete root 

structure of terrestrial plants and to prevent the roots from contacting the soil or surface underneath 

the vessel (per the 2010 NOSB Recommendations). Containers may range from pots to plastic grow 

bags, to mats, to PVC channels, to large troughs containing nutrient-rich water. 
7

7

Brief Review of the Organic Food Productions Act (OFPA) and USDA Organic 

Regulations

History

In 1990, Congress passed the Organic Foods Production Act (OFPA)10. This is the main federal law 

regulating organics in the United States. Congress delegated authority to the United States 

Department of Agriculture through the Secretary of Agriculture11 to make specific regulations to 

manage and implement organic production and set standards for which products are eligible for 

organic regulation through a regulatory, rule-making process. This law also created the National 

Organic Standards Board (NOSB)12, a federal advisory committee, which makes non-binding 

recommendations to the USDA for potential final approval and implementation through the official 

legal rule-making process. Public input and participation are required in the process as well, and 

USDA considers public comments in approving and enacting final rules. Notices related to USDA rules 

are published in the Federal Register and final rules are eventually codified in the Code of Federal 

Regulations.

The USDA’s first organic regulations were created as a Proposed Rule in 1997, a second Proposed Rule in 

March 2000 and the Final Rule was enacted in December 2000.

In the Second Proposed Rule in March 2000, the preamble discusses removing the term “organic agriculture” 

and replacing it with “organic production” to “provide a more encompassing term, which may come to include 

such diverse activities as hydroponics, green house production and harvesting of aquatic animals.”

The final legal definition in the new rules for organic production was “[a] production system that is 

managed in accordance with the Act and regulations in this part to respond to site-specific conditions 

by integrating cultural, biological, and mechanical practices that foster cycling of resources, promote 

ecological balance, and conserve biodiversity.”13 These rules went into effect in October 2002. This 

remains the current legal definition of organic production today.

This definition requires that organic methods include the use of biological practices that foster the 

cycling of resources, but does not mention or require “soil” for organic production.

In 2003, the NOSB prepared a guidance document for hydroponics and other “soil-less” growing 

systems, but did not present any final recommendations to USDA for approval. 

A 2008 NOSB meeting included a discussion regarding hydroponics. The Crops Subcommittee of the 

NOSB led a discussion on guidance statements relative to limiting hydroponic systems to naturally 

aquatic plant species, but it was never voted on by the full NOSB. 

In 2009, the Crops Subcommittee presented a discussion item at the spring meeting which noted: 

 

10 7 U.S.C. § 6501 et seq.

11 7 U.S.C. § 6503. 

12 7 U.S.C. § 6518 (governed by the Federal Advisory Committee Act (FACA), 5 U.S.C. App. 2).

13 7 C.F.R. § 205.2.
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“Hydroponics ...certainly cannot be classified as certified organic growing methods due to their 

exclusion of the soil-plant ecology intrinsic to organic farming systems ...” However, the NOP did not 

adopt this recommendation, but rather stated that further information and review was necessary due 

to the complexity and diversity of production systems, making it difficult to develop guidance with 

the limited information.

At the September 2009 NOSB meeting, the NOSB presented a recommendation for federal 

rulemaking – the addition of specific rules for Greenhouse Production Systems. The recommendation 

again stated a prohibition of hydroponic systems. After public comment was received, the Crops 

Subcommittee wrote a new recommendation, Production Standards for Terrestrial Plants in 

Containers and Enclosures.

14 The full NOSB approved the document, and made a formal 

recommendation for approval by the USDA, which was submitted to the NOP on April 29, 2010. The 

recommended regulations state, in part: “Growing media shall contain sufficient organic matter 

capable of supporting natural and diverse soil ecology. For this reason, hydroponic and aeroponic 

systems are prohibited.”15

Although the full NOSB developed a recommendation to prohibit hydroponics and aeroponics in 

2010, as discussed above, the NOP/USDA has not adopted nor implemented this recommendation 

and therefore it is not current law.

In 2015, the NOP appointed the Hydroponic and Aquaponic Task Force to prepare a report to the 

NOSB to provide additional information and industry expertise that may have not been available to 

the NOP/NOSB in the past.

Discussion

In May 2014, NOP published in its Organic Integrity Quarterly, a piece explaining organic hydroponics, 

including a statement regarding NOP’s position of current law and its corresponding policy with 

respect to hydroponics, and arguably, other non-traditional soil-based growing techniques. It stated, 

“[o]rganic hydroponic production is allowed as long as the producer can demonstrate compliance

with the USDA organic regulations.” This statement is not law, but offers the USDA/NOP 

interpretation of existing law regarding organic production, which is under the legal jurisdiction of the 

USDA. This serves as guidance to growers and certifiers who wish to certify hydroponic production 

systems as USDA Organic. In this statement, NOP/USDA notes that crop production can be considered 

organic even when terrestrial plants are grown in pure microbial solution, as may be the case with 

hydroponics and aquaponics.

Several provisions within existing regulations mention the word soil, but as reviewed below, do not 

explicitly prohibit soil-free production from organic certification. 

 

14 See Production Standards for Terrestrial Plants in Containers and Enclosures, available at 

https://www.ams.usda.gov/sites/default/files/media/NOP%20Final%20Rec%20Production%20Standards%20for%20Terres

trial%20Plants.pdf

15 Id.
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7 CFR §205.202 states: “Any field or farm parcel from which harvested crops are intended to be sold, 

labeled, or represented as organic,” must: (a) Have been managed in accordance with the provisions 

of §§ 205.203 through 205.206.” Those sections within these requirements (§§ 205.203 through 

205.206) that mention soil are discussed following:

Section 205.203 covers “soil fertility and crop nutrient management practice standards.” Later in this 

report, the Subcommittee explains that while what is considered traditional soil may not be used in 

bioponic systems, soil ecology fully exists in bioponic systems, and all of these provisions may be met. 

For the purposes of this section, we review the legal requirements of these provisions.

7 CFR § 205.203, it states: “(a) The producer must select and implement tillage and cultivation 

practices that maintain or improve the physical, chemical, and biological condition of soil and 

minimize soil erosion.” This provision does not expressly say soil must be used. Rather, it appears to 

suggest that if there is soil, then the producer must follow these particular practices. 

Even if this provision is interpreted in the most strict sense, “OR” creates two potentially mutually 

exclusive possibilities. An organic facility must either 1. maintain the physical, chemical, and biological 

condition of soil, OR 2. it must improve the physical, chemical, and biological condition of soil. 

There is no definition for “soil” in the OFPA nor in the USDA organic regulations. A definition of “soil” 

can be found in the USDA Agricultural Handbook:

The collection of natural bodies on the earth's surface, in places modified or even made 

by man of earthly materials, containing living matter and supporting or capable of 

supporting plants out-of-doors. Its upper limit is air or shallow water. At its margins it 

grades to deep water or to barren areas of rock or ice. Its lower limit to the not-soil 

beneath is perhaps the most difficult to define. Soil includes the horizons near the surface 

that differ from the underlying rock material as a result of interactions, through time, of 

climate, living organisms, parent materials, and relief. In the few places where it contains 

thin cemented horizons that are impermeable to roots, animals, or marks of other 

biologic activity. The lower limit of soil, therefore, is normally the lower limit of biologic 

activity, which generally coincides with the common rooting depth of native perennial 

plants.

For the purposes of this report, the Task Force defined soil as “the outermost layer of the earth 

comprised of minerals, water, air, organic matter, fungi and bacteria in which plants may grow roots.”

As hydroponic and aquaponic growing methods generally do not rely on the use of what traditionally 

is considered “soil” for providing nutrients to the plants being grown within the system, such systems 

will not deplete the physical, chemical, and biological condition of soil, and thus falls within the text 

of 7 CFR §205.203. When there is no depletion, there is the status quo, thus maintenance. By the 

same logic then, there would be no soil erosion at all, as also required by the same provision.

Section 205.203(b) states that “[t]he producer must manage crop nutrients and soil fertility through 

rotations, cover crops, and the application of plant and animal materials.” Again the discussion 
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hinges on the context of “soil”. This section could be interpreted to mean that if there is traditional 

soil in a growing system, producers must follow these requirements. Or it could be read that this 

hinges on “soil fertility”, which is not the same as soil. In bioponics, the soil ecology, and thus fertility 

in the system is maintained through various methods including changing crop variety over time and 

the application of plant and animal materials, as is similarly done in field crops.

Section 205.203(c) states “[t]he producer must manage plant and animal materials to maintain or 

improve soil organic matter content in a manner that does not contribute to contamination of crops, 

soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited 

substances.” In bioponics, the soil ecology is maintained within the contained system. Producers can 

manage plant and animal materials in a manner that does not contribute to contamination of crops, 

soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited 

substances in the system, just as field producers do. Again if this is read most strictly, that producers 

must maintain or improve organic matter in “soil”, then as stated above, bioponic growing methods 

generally do not rely on the use of what traditionally is considered “soil”, so such systems will not 

impact soil, thus will “maintain” it and fall within the requirements of the text of 7 CFR §205.203(c). 

Section 205.203(d) states “[a] producer may manage crop nutrients and soil fertility to maintain or 

improve soil organic matter content in a manner that does not contribute to contamination of crops, 

soil, or water by plant nutrients, pathogenic organisms, heavy metals, or residues of prohibited

substances by applying [various substances].” The word “may” indicates that this provision is 

optional, and therefore just like for field crops, may or may not be utilized in bioponic production, 

based on the producer’s preference.

Section 205.203(e) lists substances that producers may not use, and would apply to bioponic

production.

Section 205.205 concerns crop rotation practice standards and requires “[t]he producer must 

implement a crop rotation including but not limited sod, cover crops, green manure crops, and catch 

crops that provide the following functions that are applicable to the operation: (a) [m]aintain or 

improve soil and organic matter content.” The use of the words “including but not limited to” 

infinitely expands the options to achieve this requirement. Again the “maintain or improve” language 

appears here. Bioponic production maintains traditional soil as discussed above pertaining to 

§205.203(a) and the similar requirement to “maintain or improve soil.”

Finally, § 205.206 (a) states that “[t]he producer must use management practices to prevent crop 

pests, weeds, and diseases including but not limited to: (1) Crop rotation and soil and crop nutrient 

management practices, as provided for in §§ 205.203 and 205.205” As discussed above, the words 

“including but not limited to” provide for infinite methods to comply with this requirement. See the 

above discussion regarding the requirements of §§ 205.203 and 205.205.

Conclusion 

Under current law and clarification from NOP/USDA, hydroponic and aquaponic production methods 

are legally allowed for certification as USDA Organic as long as the producer can demonstrate 
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compliance with the USDA organic regulations. 
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Traditional (non-organic) Hydroponic Systems

Hydroponics is the growing of plants in a container with mineral nutrient solutions, with or without an 

inert growing media to provide mechanical support. Traditional hydroponic systems are inorganic 

systems that do not rely on biological organisms to make minerals available to the plants. Instead, the 

plants are fed nutrients in their basic ionic forms (ex. nitrate, potassium, iron) that can immediately be 

taken up through their roots. The growing media is considered inert because it has little to no cation

exchange capacity (a measure of the ability of nutrients to be adsorbed and later released to the plants) 

compared to typical soils and because of the lack of microbiology, the media itself is stable and does 

not readily decompose or contribute nutrition to the plants.

There is wide variety of hydroponic systems. The most common systems will be described below. 

However, despite the variety of system configurations, the systems typically only differ in their 

mechanical setup, but the underlying science is virtually identical. The following diagram illustrates 

some of the most common systems. (Note: the design of a system is not relevant for determination of 

whether it is hydroponic or bioponic, rather it is the function and microbial content of the system that 

is relevant, and in fact some of the typical designs below may be the same or similar for a bioponic 

system).

Hydroponic growing systems may be categorized by where the roots are located in the system:

1. Water-based systems - roots are directly in the liquid nutrient solution or somehow regularly 

moistened by it 

2. Aggregate culture - roots grow into an inert medium such as sand, perlite, vermiculite, peat 

moss, or coconut coir, and are irrigated with a complete nutrient solution

Systems may also be categorized by what happens to the nutrient solution:
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1. Open - the nutrient solution is distributed from a reservoir to the plants and is then “drained to 

waste” (i.e. not used again). 

2. Recirculating- the nutrient solution is distributed from a reservoir to the plants. After passing 

through the root zone, it is collected and reused. The recycled nutrient solution may or may 

not be sterilized (UV light, ozone etc.) to eliminate plant pathogens so they are not reintroduced to the plant roots.

There are many different types of hydroponic systems. However, the majority of small farms and 

commercial growers use the following water-based and aggregate systems. For the clarity of this 

report, container systems include hydroponic production, aquaponic plant production and greenhouse 

production. (Note: many of these same systems are used in bioponic production).

a) Water-based Systems 

1. Deep water culture(DWC)/raft - Plants are suspended through foam boards which float on the 

surface of the nutrient solution. Oxygen must be supplied to the roots using an air pump and air 

stones, or using a venturi system. This is a closed system where the nutrient solution remains within 

the same enclosed container throughout the growing cycle.

2. Nutrient Film Technique (NFT) - Plants are suspended through holes in the top of a long tube or 

channel that is slightly slanted. Nutrient solution is pumped to the higher end, constantly flowing 

as a thin film across the plant roots to the lower end where it is collected and then recirculated. 

3. Ebb and Flow (Flood and Drain) - Used for propagating seedlings and growing plants in pots. 

Seedlings and potted plants are placed in a drain table. Nutrient solution is periodically pumped 

into the drain table from a reservoir below, flooding the media for a short time before draining back 

into the tank below.

4. Aeroponics - Roots are suspended in an enclosed space and at regular intervals are moistened 

with nutrient solution, which returns to the reservoir and is re-used.

b) Aggregate culture 

Inert media is placed in some type of container where nutrient solution is fed to each plant through a 

top-drip system (main irrigation line with emitters and spaghetti tubing going to each plant head). 

Because the nutrient solution consists of dissolved minerals, these minerals can build up in the media, 

necessitating some excess watering (leaching) to flush salts. These systems typically require 10-30% 

excess watering, which is re-circulated, re-directed to outdoor cropping systems, or sent to waste to 

septic or sewer. Aggregate systems are used primarily for vining crop production (ex. tomato, 

cucumber, pepper) or other fruiting crops such as strawberries.

1. Slab - This is the traditional method for commercial hydroponic tomato growers. Plants are 

grown in 3ft long x 3 or 4-inch-thick polyethylene lay-flat bags (or slabs) filled with coconut coir 

or similar natural fibers. 

2. Upright bag or Dutch Bucket - Another common method for commercial growers is 3 or 5-gallon 

upright polyethylene bags, or 3-gallon square hard plastic buckets called Dutch buckets or Bato 

buckets. These systems typically use coconut coir sometimes mixed with perlite and 

vermiculite.
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3. Trough - A long above-ground container where a large amount of plants are sharing growing 

media. Troughs can be made of plastic, PVC, metal, wood, concrete or even on a plastic cover 

on top of a soil trench. Most troughs are closed off to the ground so roots and water cannot 

penetrate the soil surface, but drainage is collected to be recycled or re-used.

4. Tower - Plants are grown in hard plastic or Styrofoam pots containing a media mix that are 

stacked into a tower. Nutrient solution from a reservoir is pumped to the top of the tower 

where it drips or sprays onto the top pot, trickling through subsequent pots until it is collected 

into a reservoir at the bottom to be drained to waste or recirculated.

5. Pots - Round or square pots usually made of plastic are sometimes used to grow smaller or 

short cycle plants, such as starter seedlings or herbs. These are usually used with a drip 

irrigation system or ebb and flow table.

Traditional (non-organic) hydroponic systems place a great deal of importance on sterility. The goal is 

to keep biology out of these systems, namely soil-borne pathogens that are ubiquitous in soil-based 

growing systems. Plant fertilization is based on chemistry. Plant nutrition comes in the form of 

inorganic minerals that become available through solubilization with water. Because nutrients are not 

bound within organic molecules, these systems do not require the work of microorganisms to free up 

the nutrients for uptake by the plants.

The media in traditional hydroponic systems is typically inert. This means that the media itself does 

not readily degrade or contribute significant nutrition to the plant nor does it significantly interact 

chemically or biologically with the nutrient solution. Rockwool, historically the most popular media 

used in the hydroponic industry, fits this definition. However, it is important to note that the U.S. 

hydroponic industry has now moved to the use of alternate media, such as coconut coir instead of 

rockwool, as its base media for growing. Coconut coir (also called coco coir, cocopeat, fiber, husk, pith) 

is the outside fiber of the coconut which is a waste product of the coconut industry. While coconut coir 

is organic in nature and has a cation exchange capacity similar to typical mineral soils (sand, clay), it is 

considered inert when used in traditional hydroponic systems because the lack of biology in hydroponic 

systems keeps the material from decomposing readily. However, it is important to note that when 

significant organic matter and microbiology are added to coconut coir, it is capable of maintaining 

biology and decomposing the coconut husk into humus (Prabhu, S.R. and Thomas, G.V.; Suresh Kumar 

and Ganesh, 2012;). 
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Organic Hydroponics - Bioponics

a) Why Bioponics is Relevant to the NOSB/NOP

Organic hydroponics, or bioponics, as this Subcommittee has termed it, is fundamentally and entirely 

different from conventional (non-organic) hydroponics. Bioponics is a growing method that 

completely relies on a soil food web micro-biological ecosystem to provide nutrients to a crop. All 

inputs come from animal, plants and minerals and require biology to convert these raw inputs into 

plant-usable form. This is the opposite of conventional hydroponics, where synthetic/inert nutrients 

are fully provided to a crop without the need for any biology.

In the 2010 NOSB recommendation, the NOSB addresses the specific growing practice of 

conventional hydroponics. Rightfully, the NOSB determined that this production practice should not 

be eligible for organic certification “due to their exclusion of the soil-plant ecology intrinsic to organic 

farming systems...” (NOSB May 2009). However, due to the relatively new emergence of bioponics, 

this form of organic production system was not addressed in the 2010 NOSB recommendation. 

Specifically, because bioponics relies entirely on soil-plant ecology, it is technically the opposite 

concept of a sterile traditional hydroponic system. This section describes in detail how bioponic 

systems work.
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b) How is Bioponics different from Hydroponics

The simplest and most fundamental difference between hydroponics and bioponics is that bioponics 

uses plant-based, animal-based and mineral inputs that require a biological eco-system to make 

nutrients available to plants, whereas conventional hydroponics uses inert already soluble nutrients 

that require no biology for plants to use the nutrients.

In the past 10 to 15 years, advances in research and technology allowed growers to minimize the use 

of natural resources, decrease soil and water contamination, increase production, and maintain or 

improve fruit and vegetable quality while growing using organic substrates, organic nutrition, and 

natural microbial nutrient cycling. We define these systems as “bioponic”. The term “bioponic” is a 

recent concept that is used frequently in practice, but is not yet common in research literature. Just 

as hydroponics means “water-working”, bioponics mean “life-working”. More than one person has 

been credited with developing or “coining” the term. David Yarrow (1997) as one of the first to use 

the concept of bioponics to describe aquaponic growing. There is no record of patents or trademarks 

with the U.S Patent and Trademark Office regarding “bioponics.” In any case, bioponics combines the 

philosophies of organic farming with the efficiencies of hydroponics to create a new organic farming 

model that can address modern day resource conservation, food safety, food availability and social 

justice issues.

After gathering and reviewing information in the public domain and from those in the industry 

practicing bioponics, this Subcommittee has adopted a definition for bioponics:

Bioponics - A contained and controlled growing system in which plants in growing 

media derive nutrients from plant-based, animal-based and mineral natural substances 

which are released by the biological activity of microorganisms.

Bioponic systems use the same organic inputs, processes, and principles as field growers. Only NOPcompliant growing media and inputs are used in such systems. Organic matter (plant and animal 

material) is added to the system to provide nutrition for the soil microbiology to flourish and thus 

provide nutrients to the plants. NOP-compliant minerals may be added as needed. A natural soil 

ecology is cultivated in the system by adding microbes through compost, compost-tea, liquid nutrient 

products, or specific consortiums of microbes from commercially produced products, as do certified 

organic field growers. This microbial community must be carefully maintained in order for nutrients 

to become available to the plants to uptake. If the microbial community is not sufficient in numbers 

and diversity, the plants will suffer or not be able to grow.

Bioponic systems evolved from conventional hydroponic systems, but can also look more like a

traditional container growing system (for example, growing berries in a compost/potting soil mix). 

The most common form of bioponics is aquaponics, where the waste produced from farmed fish, or 

other aquatic animals, supplies nutrients for plants grown in container systems, which in turn purifies 

the water for reuse. An example of a bioponic tomato system is described in a case study appended 

to this report. The system consists of plants in containers of growing media, fertilizer, added 

microbiology, and earthworms which cycle nutrients to make them available to the plants. Just like in 
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field growing, periodic solid and liquid additions may be necessary to maintain crop growth and 

yields. However, with container systems, it is easier to maintain optimal conditions for microbial 

growth and nutrient cycling as well as being better able to control soil moisture and temperature, 

especially if used in a greenhouse environment. In addition, any excess drainage can be captured and 

recycled or reused so as not to contribute to surface or groundwater contamination or soil erosion.

Another type of bioponic system for growing lettuce and greens is described in a second appended 

case study. This system uses a Nutrient Film Technique (NFT) design, and uses carbon-based plant 

and animal materials and NOP-compliant minerals as the fertilizer which is mineralized by soil 

microbiology in the system.

Bioponics systems will be described in the following 4 components:

1) Container and container systems

2) Growing media

3) Biology

4) Nutrition

c) Containers and Container Systems

A container is any vessel and associated equipment used to house growing media and the complete 

root structure of terrestrial plants and to prevent the roots from contacting the soil or surface 

underneath the vessel (2010 NOSB Recommendations). Containers may range from pots to plastic 

grow bags, to floor mats, to PVC channels, to large troughs containing nutrient-rich water. 

A container system includes all components connected to the containers which enable the system to 

function in order to grow the plants. The container system may include things such as clarifiers, biofilters, mechanical filters, pumps, plant support structures, irrigation plumbing, drainage collection 

apparatus, etc. 

Just as with field growing systems, a container system may rely on a separate system (on-farm or offfarm) to create nutrient amendments to be added to the growing system. For example, compost tea 

created on the farm site may be produced in a brewer not hydraulically connected to the growing 

system, but the tea will be added to the system as needed. Similarly, a commercial company may 

biologically produce an NOP-compliant liquid fertilizer that will be purchased by the grower and 

applied to the crop as needed.
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d) Growing Media

In a conventional hydroponic system, growing media is sterile, whereas in a Bioponic system, growing 

media is designed to promote and sustain biology in order for the system to function. A simple 

definition of growing media is “a substance through which plant roots grow and extract water and 

nutrients” (Landis et al., 2014). Growing media often is primarily made up of solid particles 

(aggregate) such as soil or potting mix. However, growing media can also be water based. In waterbased media systems, seeds are typically started 

in a solid medium, and are then transplanted into 

the bioponic system where the roots are grown 

out of the solid medium and placed directly into 

contact with water that contains nutrients, 

oxygen and microbial ecosystem. In bioponic

systems, the media, whether aggregate or waterbased, must contain sufficient carbon, minerals, 

plant/animal-based nutrients, oxygen and a 

diverse and complete microbial ecology so that

biology can thrive and provide plants nutrition to 

thrive. Therefore, this committee will use the 

same definition of growing media as given by the 

2010 Committee “material which contains 

sufficient organic matter capable of supporting 

the plant root system and a natural and diverse soil 

ecology,” which may include water as a type of 

growing media. The sources of carbon, nutrition, and microbiology in each of these media will be 

discussed in the next sections. This section will further describe the different types of growing media. 

1. Solid (aggregate) growing media

In bioponic systems, seedlings are often started in solid media. A single type of media or a mix of 

media may be used for seedling production and to be added to containers to grow the plant to 

harvest. 

Examples of solid growing media used in bioponic systems include:

● Soil

● Potting Soil Mix

● Compost

● Vermicompost

● Coconut coir

● Peat moss

● Bark

● Saw dust

● Rice hulls

● Perlite

● Vermiculite

In a conventional hydroponic system, the growing media is inert and sterile. Whereas, in a bioponic

systems, biology and carbon sources are added to the media, which promotes the growth of 

microorganisms and decomposition of solid media with a release of its minerals and nutrients. 

For example, potting mixes, bark, sawdust, and coconut coir have a high resistance to decomposition 

(high C:N ratio), but when they are inoculated with beneficial organisms (bacteria, fungi, protozoa, 

Seedling ready to be transplanted into water-based 

bioponic system.
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nematodes, earthworms and microarthropods), degradation is accelerated. Also, naturally occurring 

microbes on each material are activated when given favorable conditions for reproduction and 

activity, thus releasing nutrients from the organic materials and starting mineralization. When 

growing media is inoculated and fed with microbial foods (such as molasses and kelp), a sufficient 

level of decomposition and a diminished C/N ratio can be reached, creating an environment where 

enough water and air capacity is maintained for roots to develop.

An example from a study in India using a fungi such as Pleurotus platypus inoculation on coconut coir 

resulted in 58.6% reduction in cellulose, and 78% reduction in lignin after 35 days of inoculation. The 

C:N ratio was reduced to 18:1 versus the uncomposted coir pith of 104:1. In addition, the study found 

that earthworms and bacteria enhance coir decomposition (S.R. Prabhu and George V. Thomas Indian 

Institute Agricultural Research, 2002). Another study showed when coconut coir was inoculated with 

the earthworm Eudrilus sp. at a rate of 1000/ton of organic material, protected from direct sunlight 

and maintained moisture level over 50%, a granular vermicompost can be obtained with a 16.7:1 C:N 

ration in two months, (K.V.Peters,2008). Earthworms and microarthropods also help keep air 

passages intact for optimal root health and to avoid soil compaction which fosters anaerobic 

conditions.

Therefore, solid growing media in bioponic systems is by design, not inert. Through the additions of 

carbon and soil-microorganisms, the solid growing media goes through the same decomposition 

processes as field soil. In fact, this decomposition can occur at a faster rate because the soil moisture 

and temperatures of the media can be more closely controlled for optimal microbial conditions. 

Methods of adding biology are addressed in subsequent sections.

In some cases, soil from the ground may be added, but the growing media is usually not 100% soil. 

Soil is not often used due to the risk of soil pathogens and non-ideal water holding and transmission 

properties. If soil is used in container systems, it is commonly disinfected first by solarizing or 

steaming methods. If the soil is sterilized, it will be necessary to add biology back into the soil. 

Compost or compost tea is often added or applied to establish an adequate number of organisms to 

inoculate the media. Also, it is necessary to assure organic matter is present in the soil for biology to 

establish (minimum 3% organic matter). If compost is added to the media, whether for nutrition or 

biology, it typically will not make up more than 50% of the media because it holds too much water 

(Grubinger, 2012). Because only a limited amount of compost can be added to the growing media, 

and because the nutrients in compost are slow to release, there are usually not enough nutrients to 

grow a crop for an entire season. Therefore, supplemental amendments of organic fertilizer may

need to be added throughout the growing season.
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2. Liquid growing media

By definition, water can be a growing media when it “contains sufficient organic matter capable of 

supporting the plant root system and a natural and diverse soil ecology”, which is the case in bioponic

liquid media growing systems. In these systems, organic plant and animal material and 

microorganisms are added to the water to create a liquid compost. In aquaponic systems, fish waste 

is decomposed by aerobic microorganisms that can be in the biofilter and throughout the growing 

system. In other liquid bioponic systems, such as NFT or deep water culture systems, compost teas or 

commercially produced liquid organic fertilizers (as described below under nutrition) are added to the 

water. Microbiology is present within these products naturally or from the biological processing 

which it goes through. This microbiology or added microbial inoculants are the catalyst for the

decomposition of the organic material within the growing system.

Source water in these systems primarily come from municipalities, well water, or through rain water 

collecting. Water should be tested to ensure it does not contain heavy metals or pollutants at levels 

detrimental to plant growth, and to ensure that human pathogens are at or better than drinking 

water standards.
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e) Biology

1. Soil-Food Web in Bioponics

There are 16 elements that are essential for plant growth: Carbon, oxygen, hydrogen, nitrogen, 

phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, boron, zinc, copper, 

molybdenum, and chloride (Hoagland, 1947), although nickel has now become thought of as a 17th 

(K-state). Whether nutrients are derived from inorganic or organic sources, plants need them to be in 

ionic form. An ion is a positively or negatively charged atom or group of atoms that can be taken up 

by plant roots. 

In soil, plant nutrients are bound up in organic molecules and rock material. Dead and decaying 

organic material decomposes through physical, chemical, and biological processes. As this material is 

broken down into smaller and smaller fractions, minerals may be dissolved into soil solution and soil 

microorganisms can use the organic matter as food sources, releasing plant nutrients into soil 

solution. These soil organisms make up the soil food web, or the community of organisms living all or 

part of their lives in the soil (Ingham). Bacteria, fungi, nematodes, protozoa, earthworms, 

arthropods, and living roots are dependent on each other to live and reproduce. Exudates from plant 

roots and decaying plant and animal material feed bacteria and fungi. Bacteria and fungi incorporate 

some of the nutrients into their bodies but release any excess nutrients they cannot incorporate into 

their own cells. Higher level organisms such as protozoa eat the bacteria and fungi, again releasing 

excess nutrients into the soil that will dissolve into water. Nematodes and larger organisms such as 

earthworms eat the protozoa. When any of these organisms die, they release the nutrients that were 

stored inside their cells. Some of the nutrients that are released will be available immediately to 

plants because they go into soil/water solution. This process of microbes decomposing and releasing 

plant nutrients from organic matter is called mineralization. In optimal environmental conditions and 

with enough food sources, plants and microbes are able to regulate the processes so that they each 

get what they need at the rates needed (Bot and Benites). The microbes decompose carbon sources 

to create soil organic matter which enhances soil structure and creates available nutrients for plant 

growth.

Soil is highly variable in the amount of organic matter and number and diversity of microorganisms it 

contains, decreasing over time and with multiple plantings. Most soil growers must amend their 

fields with manure, compost, compost teas, and organic fertilizers to increase carbon content, 

microbial activity, and nutrient availability.

The same is true of bioponic systems. Bioponic systems start out with growing media that may or 

may not have a sufficient amount and diversity of carbon and microbial population. Just like with 

soil, nutrients may be added in solid or liquid form. Solid soil amendments may include compost, 

manure, bone meal, alfalfa meal, magnesium sulfate, gypsum, potassium sulfate, kelp, bat guano, 

etc., all of which are NOP-compliant (see list in Table 1). Commercial liquid organic fertilizers which 

are NOP-compliant or homemade liquid organic fertilizers made from organic-compliant substances 

such as compost tea, may also be applied at varying frequencies depending on the nutrition added to 

the media, the same method as in organic soil-field farming. Solid amendments must be 

decomposed by soil microorganisms in the media for the plants to make use of them. The majority of 
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liquid organic fertilizers are composed of complex proteins and carbohydrates which contain plant 

nutrients that only become available upon the action of microbiology within the growing system.

2. Where Microbiology Comes from in a Bioponic System

As stated earlier, bioponic nutrition is supplied as complex organic compounds that need to be 

decomposed and mineralized so that nutrients can become available to the plants. This 

decomposition may occur in-line with the container system or outside the growing system in an onfarm or off-farm system. In the case of field growing, the organic matter is applied in the soil and 

decomposition must occur primarily locally at the root zone. In the case of container growing, 

biological decomposition and mineralization of organic matter can occur in controlled environments 

to enhance its efficiency. The decomposition of organic matter outside the growing system is by no 

means complete, as it would be too time-intensive and costly a process. However, some organic 

material (such as produce and plant material wastes) can be biologically processed or fermented to 

make them partially digested and easier for soil microbes to process completely within the growing 

system. For example, compost teas can be made in a separate brewer and then added to the system. 

These teas add biology and some nutrients, but organic matter in the teas still need to be further 

broken down within the growing system. This added biology is used to break down other solid 

nutrients that are added within the system. Commercially produced liquid fertilizers do not 

decompose organic matter completely to the ionic form of nutrients that the plants can take up. 

These products need to be further decomposed in the growing system by microbes in the system. 

The key point is that in a bioponic system, biology is required to break down organic material into 

plant available nutrients, either completely within the growing system or partially outside the 

growing system. In either case, biology is the engine that drives a bioponic system, just as in an 

organic soil/field growing system.

The data shown at the end of the appended case study of bioponic tomatoes illustrates the diversity 

and numbers of soil microbes that can be found in bioponic systems. The numbers of bacteria, fungi, 

protozoa, and nematodes are at least as much, if not higher than would be expected in good soil. 

These numbers and diversity indicate a high ability to cycle nitrogen.

3. Where Microbial Activity Takes Place in a Bioponic System

Water based growing media contains particulate organic matter (POM) and dissolved organic matter 

(DOM). Bacteria typically aggregate onto solid surfaces such as soil particles, particulate organic 

matter, or biofilters that are designed to have a high surface area. Biofilms are microorganisms 

attached to a surface and embedded in an extracellular gel-like matrix of polymeric substances. 

Dissolved organic matter absorbs and diffuses into the biofilm, the microbes release enzymes to 

decompose the organic matter, and then microbes can take up the released nutrients. Microbes can 

still aggregate or “floc” together without the aid of a solid surface. Microorganisms such as 

Pseudomonas sp. and Bacillus sp. excrete extracellular polymeric substances (EPS) that allow the 

microbes to aggregate together within the water column (Guibad (2010); Sheng; Subramanian, 2010). 

These aggregates and EPS material attracts and adheres POM and DOM to it. Therefore, microbes 

are actively cycling nutrients within the water-based growing media as well as on surface of the 

containers and in biofilters. 
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The biological processing of organic nutrition occurs throughout bioponic systems. In aggregate 

systems, the processes occur throughout the growing media and rhizosphere. In liquid systems, 

microbes in the nutrient-rich water are constantly decomposing suspended and dissolved organic 

materials within the water column. The microbes congregate at the root zone in the rhizosphere, in 

both solid and liquid growing media where they also assist in chelating metals to increase uptake of 

nutrients into the plant roots. It is very common for bioponic systems to have a component in the 

system which adds high amounts of surface area to provide biology a place to attach, such as 

biofilters, growing media, etc.

4. How can you demonstrate that a bioponic system has enough biology?

A commonly asked question is how to demonstrate that a bioponic system has enough 

microorganisms and/or if they are diverse enough to create a true soil-plant ecology intrinsic to 

organic farming. The answer is, in fact, very simple; it involves observing the system inputs and the 

final crop health. If the inputs used are in such a form that require microbial breakdown and the 

grower is able to achieve a healthy final crop, then it must be true that there is sufficient biology and 

biological diversity in the system, otherwise the nutrients would not have been fully microbially 

processed and the crop would show signs of deficiencies. As with any organic farming operation, the 

farmer is directly punished or rewarded with the quality of his/her crop based on the quality of the 

microbiological activity and organic content in their growing system.

f) Nutrition

In bioponic systems, nutrition comes in many forms. Nutrition may be added to the growing media 

itself or to the water in the system. Nutrient sources may be in solid or liquid form as long as they are 

NOP-compliant. Providing enough organic nitrogen and phosphorus to these growing systems is the 

greatest challenge. Nitrogen is typically provided by compost, bat guano, sugar beet molasses, 

and/or soy proteins. Nitrogen is also provided through some commercially available liquid organic 

fertilizers derived from fermented plant material (see table below). Phosphorus can be provided 

using rock phosphate, bat guano, and commercial NOP-compliant organic liquid fertilizers. The table 

below shows a variety of other organic inputs that provide different nutrients for plant growth. 

Because most of these materials are in rock form or are organic molecules containing the various 

nutrient elements, the same soil microbiological processes must occur in these growing systems as in 

soil-based growing systems. Without the action of microorganisms, nutritional ions would not be 

available for the plant to uptake.
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Examples of Organic Inputs and Associated Nutrients

Input Associated nutrients

Animal Based Compost N,P,K

Soy protein N

Fish Emulsion N,P,K

Kelp N,P,K

Seaweed N,P,K, Mg, S, Ca, Na, B, Fe, Mn, Cu, Zn

Molasses K, P, S, Ca, Mg

Gypsum Ca, S

Humic acid Biostimulant

Fulvic acid Biostimulant

Epsom salt Mg, S

Bone meal N,P

Fulvic acid Chelator

Alfalfa meal N,P,K

Potassium sulfate K,S

Potassium Chloride K, Cl

Fish Water N,P,K, S

Worm Tea N, Ca, Fe

Plant based compost N, P, K

Hydrolyzed animal protein N

Hydrolyzed plant protein Biostimulant, chelator

Composted poultry manure N,P,K

Bird/Bat Guano N,P,K

Insect frass N, dependent on host plants

Dairy manure N,P,K

Blood meal, N,P,K

Rock phosphate P

Volcanic rock dust P, K, Ca, Cu2+, Zn2+, Mn2+, Fe3+, Co2+, Ni2+, V4+

Cotton seed meal N,P,K

Limestone Ca, Mg

Calcium carbonate Ca

Oyster shell lime Ca

Langbeinite K, Mg, S

Fish meal N,P

Neem seed meal N,P,K

Worm castings N,P,K

Molasses Carbon

In bioponic systems, nutrients primarily come from plant and animal material that must be 

decomposed by biological processes either in the growing system or in a separate decoupled 

container. The extent to which these materials are decomposed before they are placed into a 

growing system will dictate how much biology is required by the growing system to make nutrients 

available to the plants.
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Advantages of Bioponic Systems

In general, the advantages to bioponic growing practices are centered on the concept of precision 

control of inputs, reducing waste, and controlling growing conditions in order to reduce 

environmental impact and conserve resources such as water and arable land. While there are many 

additional practical advantages such as improved ergonomic conditions for workers, this section 

focuses on the overarching advantages of bioponics.

a) Water Conservation

Water conservation is one of the greatest advantages to bioponic growing. A recirculating bioponic 

system can use up to 80% less water than field grown crops. This is achieved due to the design of a 

bioponic system where no water is lost to evaporation, runoff or leaching. The grower can virtually 

use only the exact amount of water needed by each individual plant to grow.

In a state such as California that has suffered from an almost a decade long severe drought, this is of 

extreme importance. California is the number one producer, by volume, of organic produce in the 

United States. This is a strong example for the reasoning behind evolving growing practices to adapt 

to changing environments and resource scarcity.

b) Food Safety

Increased food safety is another major advantage of bioponics. The greatest food safety risk is 

contamination of crops with human pathogens such as E. coli and Salmonella. These risks are 

generally high in crops such as leafy greens (lettuces) where the edible portion of the crop is in 

contact with the ground. Animal feces, including bird droppings, and downstream rain water runoff 

pose huge food safety risks for any farm. However, a bioponic system greatly mitigates such risks 

because crops are grown off the ground using a closed loop watering system. This virtually eliminates 

the runoff and ground animal intrusion risk and, coupled with a greenhouse, also mitigates the 

overhead risk of bird droppings. Furthermore, pathogen testing is very easy to test for by sampling 

water circulating in the system at any point will indicate if there is any human pathogen present in 

the entire operation.

c) Disease Suppression

Bioponic systems are effectively a container growing system where the grower has ultimate control 

over growing media, nutrient and biological inputs. There is a significant advantage to being able to 

guarantee that the growing media, nutrient and biology are free of disease prior to starting a crop. 

This is achieved by testing inputs prior to use.

Furthermore, if the grower maintains a balanced soil-food web ecology in the system, then no single 

organism can overpopulate and take over. A good example of this is how a properly designed 

compost tea can help suppress disease when it is applied to soil or bioponic container systems. 

Because a bioponic system is a containerized biological system, there is the ability to better control 

specific microbial populations by controlling inputs, system environment and inoculum.
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d) Nutrient Conservation & Retention

In a bioponic system, inputs can be precisely measured and added to the system with a high degree 

of certainty for the quantity of inputs required based on the system size and crop. Furthermore, 

bioponic systems are completely contained and therefore do not lose any inputs or resources to the 

environment thereby eliminating the chance of runoff contamination, leaching and soil erosion. 

e) Soil Conservation

Growers who implement a bioponic growing practice are not limited to setting up their operation on 

fertile soil. Because the system is completely containerized, it is able to be placed on any type of ground 

– for example areas where farming would otherwise not be possible such as rocky areas, paved areas, 

sand and urban sites such as rooftops. Therefore, by growing in areas that are otherwise not farmable, 

this is the ultimate level of soil conservation and an added tool for farmers to be able to keep up with 

increasing population, but limited arable land.
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Aquaponics

Over the past three decades, aquaponic systems have continued to increase in number and scale. 

Pioneer systems were developed in arid regions such as Australia and the Caribbean where fresh water 

was limited. Typically, the systems supply both plants and protein (fish), however many systems focus 

on the plant production and may never harvest the fish. Aquaponics depends on a biologically active 

water-based ecosystem, allowing for consistent nutrient availability without the use of synthetic 

fertilizers. Besides the input of fish food, very few other inputs are used in aquaponic food production 

systems. Research at the University of the Virgin Islands (UVI), St. Croix, produced a balanced 

integrated fish and plant system that has been a model for much of the small commercial aquaponic 

industry in the U.S. Currently, some aquaponic farms are being organically certified for their crops by 

various certification agencies. No organic rules for fish exist in the U.S. to date, so only plant crops are 

being certified as organic.

a) Water-based production

Most aquaponic systems recycle greater than 98% of their water daily. As the water is continuously 

recycled, a microbial-based ecosystem develops. Research in Alberta, Canada has shown that as 

aquaponic systems mature over time, a more diverse ecosystem develops and crop production 

increases (Savidov et al, 2007). The same researchers have shown that aquaponics can out-produce 

conventional hydroponic growers that are using synthetic fertilizers. The protagonist microbes are also 

believed to fend off diseases that would otherwise attack a sterile, non-biologically active system. For 

any aquaponic facility to succeed, a water source with good quality and quantity is required.

b) Types of aquaponic systems

Aquaponic systems may be categorized as balanced or de-coupled. A balanced system is a system 

where the fish provide the nutrients for the plants and the plants purify the water for the fish. A 

balance is achieved following recommended daily feed to plant area rates. If a balance is achieved, the 

water quality stays optimal for the fish and the nutrient quantity stays optimal for the plants. Many 

current systems are balanced systems. 

De-coupled systems are becoming more common. In these systems, there is separation in some 

manner between the fish and the plants. The use of fish waste that has been mineralized into dissolved 

nutrients for a separate plant culture system would be an example. De-coupled systems are used in 

temperate climates where the plant greenhouse is only used seasonally. The greenhouse can be 

isolated during the winter and shut down, while the fish system is designed to operate with other 

filtration methods. In these regions de-coupled systems also allow the integrated production of coldwater fish and tropical vegetables.

c) Fish waste and mineralization in aquaponic systems

Fish are cold-blooded animals and do not harbor pathogenic E. coli strains. All published food safety 

data has shown no risk, and more work is being done in this field (Chalmers 2004). The waste consists 

of dissolved nutrients and nutrients bound in the solids. Some systems discharge solids, while others 

digest or mineralize the solids in a side loop, then return the dissolved nutrients back to the system 

after a certain digest time. A digester, or bio-reactor, is heavily aerated allowing aerobic bacteria to 
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mineralize the fish solid waste. Systems utilizing this technique have become nearly-zero discharge 

systems. 

Nitrification and mineralization occurs whether in soil or water. The water processes typically occur in 

the soil matrix, but outside the soil matrix it is not well researched or published. In a sense, waterbased mineralization is aquatic composting. Nitrification in the water is well researched and published 

as it is the biological process that allows for Recirculating Aquaculture Systems (RAS) to convert toxic 

ammonia to less toxic nitrites to even less toxic nitrates. Typically, RAS fish farmers utilize a biofilter 

which supports nitrifying bacteria (Nitrobacter, Nitrosommonas, Nitrospiria esp) using a media that is 

designed for high surface area for the billions of bacteria that thrive in the ammonia and oxygen rich 

environment. 

Aquaponic systems provide surface area for nitrifying bacteria on the side walls of the containers used 

(tanks, troughs, etc.), in the root zone, in the filtration system and also on fine particles suspended in 

the water column. Some aquaponic systems incorporate a denitrification zone where solids are 

allowed to accumulate for a short period of time between cleanings. As water passes through this zone 

of no oxygen, denitrification occurs, stripping N from the system. This would be preferential when a 

grower wants to produce fruiting crops. The process of denitrification will produce alkalinity as a 

byproduct, raising pH or buffering acid produced via the nitrification process.

The mineralization process is being researched in areas of de-coupled aquaponics, or dual-loop 

aquaponics. When fish are fed, approximately 70% of N is excreted by the fish (most in the soluble 

form) and 70% of P (most bound in the solid waste). Growers are removing the non-available solids 

from the system and using a separate bioreactor to mineralize the solids creating dissolved nutrients 

over time. We refer to this as bioponics. Now the nutrients are dissolved and able to cross cell walls 

into the plant. Other researchers have identified a very diverse microbial community in bioponic

systems including plant growth promoters, and other beneficial enzymes the serve as facilitators for 

nutrient uptake as well as a probiotic to pathogen attack.

Referenced is a paper about this mineralization process as it pertains to the breakdown of fish effluents 

in water (Rakocy, et al 2007). Many other producers are using this idea now on much larger systems 

to extend use of the original fish food input.

d) Aquaponic System Factors

Aquaponic systems can be sited at any location, allowing arable land to be saved for soil crop 

production. Current certified organic aquaponic producers did not have to adhere to a transition period 

like is required by a soil producer. Breaking in an aquaponics system is referred to as a transition period, 

or an acclimation period. This allows the microbial population to develop and flourish.

Most certified aquaponic growers use conventional fish feeds. The feeds have been formulated to 

provide complete nutrition for the species being reared. To take pressure off wild fish stocks, 

alternatives to fish meal are being researched including insect and plant based proteins. One USDA 

Organic fish feed exists currently, but is not required as the fish are not certifiable. Like most livestock 

feed in the US, most conventional fish feed contains GMO corn and soybean.
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e) Aquaponic System Designs

Any hydroponic plant production method can be integrated into a fish-based system to remediate the 

nutrients released by the fish. 

Deep Water Culture (DWC) is the most commonly used method in the commercial setting. Nutrient 

Film Technique (NFT) is also used. Smaller systems, or systems that use a low fish stocking/feeding 

rate, often use the flood and drain (ebb/flow) method. Aeroponics is not commonly used since the 

microbial solution can lead to clogs in the misters. Vertical towers are sometimes used. Often, a hybrid 

system is designed using more than one of these techniques.

f) Fish

Many options exist for fish in an aquaponic system. Temperature requirements and tolerance to 

recirculating aquaculture conditions often dictate which fish to choose. Growers select fish and plants 

that have similar temperature requirements (i.e. Warm-water fish with warm-weather crops). 

Regulatory issues also dictate when fish may or may not be used legally. The most common fish being 

used across the US are Tilapia, Catfish, Bass, Sunfish, Koi, Sturgeon, Perch, Trout and Ornamentals. Fish 

health is maintained through Best Husbandry Practices, quality diet, selective breeding for disease 

resistance and maintaining optimum water quality.

g) Crop Production

Virtually every type of plant can be grown in some variation of an aquaponics system. Pest control is 

accomplished through IPM, biological controls, and as a last resort, an organic compliant spray. Some 

organic compliant pesticides are toxic to aquatic life and are not recommended for use in aquaponic 

systems. Some commonly used organic pesticides toxic to fish are: copper sulfate, Rotenone, and 

sulfur. 

h) Nutrients

Research from UVI, using rainwater and conventional fish feed, showed three elements lacking for 

optimal growth of lettuce. The nutrients Ca, K, and Fe may be required as a supplement in an aquaponic 

system, depending on source water quality. Many systems supplement only Fe. The form of Fe has 

been a bottleneck in organic certification for some. pH is often near neutral in an aquaponics system. 

At that pH, Fe particularly is not available. Aquaponic growers may supplement with a chelated iron, 

allowing the Fe to remain in solution. One product that is used is chelated with citric acid (Biomin Iron, 

OMRI) and is allowable, but does not promote a healthy system. The addition clouds the system water 

for 24 hours and lowers the pH. Operating systems at a lower pH can lead to more Fe availability, 

however the health of the fish should be considered when deciding on a system pH level. Iron chelated 

with DTPA is by far the most common form used by non-certified organic aquaponic growers. 

Producers may identify other deficiencies (perhaps Mg). Some producers will supplement 

micronutrient products. These could be organic compliant or not depending on the producer’s goals. 

i) Growing media

Many planting media options exist for aquaponic growers. Growers are looking for a certified organic 

plug that uses an organic polymer to hold it together, preventing wash out in the water based systems. 

Coconut media is preferred over peat for most growers. Many also use a coconut/vermiculite mix to 
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start seedlings. Ebb and Flow systems often use clay pellets, expanded shale, or lava rock. Worm

castings and compost are sometimes incorporated into the planting media.
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Considerations and Analysis 

a) Bioponics and Organic Certification

Bioponics and other types of container production which rely on biological activity are in a unique 

category of crop production systems that allow for increased conservation of land and water resources, 

a growing area of concern and attention given diminishing resources, rising populations and arable 

land. 

These production systems can conserve land resources as they don’t involve tillage, require less 

acreage to produce crops and minimize erosion when the systems are recirculating (closed loop). These 

types of systems can also exist in places where traditional soil-based production cannot, like rooftops, 

land unsuitable for field crops due to soil toxicity or type and areas with seasonably unsuitable climates.

Recirculating systems allow for increased water conservation, as water is added to the system only to 

replenish what’s evaporated and the nutrients and water in the system are constantly recirculated and 

reused by the plants rather than in single applications as in in-ground production.

With regard to bioponics and container production and current USDA regulations, this Subcommittee 

believes that most areas of the standards can be followed as currently written, including implementing 

and maintaining an Organic System Plan, maintaining and providing records at inspection and using all 

organic-compliant inputs. This question of alignment is limited to production practices surrounding 

crops grown in the ground versus those grown in containers and whether those systems align with 

regard to the ecological focus of organic production, OFPA and the USDA organic regulations. 

Citations below (Table 2) address those areas where this Subcommittee believes that bioponic systems 

align with the USDA organic regulations, particularly in terms of environmental/ecological aspects of 

the regulation, such as cycling of nutrients, promoting ecological balance and conserving biodiversity. 

Within these citations, we also address areas where we see that bioponics doesn’t align with the 

current regulations, because the described practices are soil-specific or as otherwise noted.
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b) Areas of alignment

NOP 205.2 Terms defined.

Natural resources of the operation. The physical, hydrological, and biological features of a 

production operation, including soil, water, wetlands, woodlands and wildlife.

When considering the natural resources of a bioponic farm, bioponics aligns with this requirement as 

soil is conserved due to lack of tillage and cultivation of plants. 

Nutrients are not removed from the soil when a bioponic farm is active above it. The bioponic system 

can be removed from the area and the land, if arable to begin with, can be returned to traditional 

agricultural production. For bioponic systems on non-arable land, as is often the case in urban farming, 

this is not applicable.

Water is actively conserved in bioponic farming, particularly in recirculating systems which add water 

in measured amounts to make up only for that which is lost to evaporation and plant uptake. Bioponic

systems are designed to maintain their microbial solution indefinitely, rather than be emptied and 

restarted, as in conventional hydroponics. 

Further accounting for conservation could include a requirement for the use of only recirculating 

systems or ecologically sound methods for managing water runoff from non-recirculating systems. One 

example of water run-off management could be irrigating in-ground crops, other container crops, 

landscaping, hedgerows or orchards with discharged microbial solution.

Organic Matter: The remains, residues, or waste products of any organism.

The organic matter in a bioponic system include compost inputs (teas, solid matrix), some types of 

growing media, some nutrient inputs and the active biology present in the system. While there isn’t a 

constant variable for amount, concentration or combination of compost (whether tea or solid matrix), 

growing media, nutrient inputs or active biology from system to system, all bioponic systems 

incorporate some of these elements. For example, growing media components such as coco fiber, 

nutrient inputs like molasses, and the remains, residue and waste of biological organisms are 

considered organic matter. 

Organic Production. A production system that is managed in accordance with the Act and regulations 

in this part to respond to site-specific conditions by integrating cultural, biological, and mechanical 

practices that foster cycling of resources, promote ecological balance, and conserve biodiversity.

The site-specific conditions of a bioponic farm can vary drastically from a warehouse to a greenhouse 

on a traditional farm to a kitchen in a restaurant, but all can comply with the regulation. 
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Bioponics interprets the cycling of resources as the system’s reliance on biological activity to function 

and, in some cases, the incorporation of plant material back into the production process. Nutrient 

cycling occurs as the microorganisms, bacteria, protozoa and fungi interact and proliferate in the 

microbial solution, mineralize nutrients for plant uptake and release nutrients held in their physical 

bodies into the solution as remains, residue and waste. In some cases, excess plant material from 

bioponic systems can be incorporated into compost and/or compost tea to be reintroduced to the 

system, though this is site-specific and differs from farm to farm. Additionally, microarthropods like 

earthworms are sometimes employed within substrate bioponic systems, which represents another 

integration of biological and mechanical practices, fostering of cycling of resources and promotion of 

ecological balance.

Bioponics relies on the careful balance of the biological ecosystem to produce healthy crops. The 

intention of a bioponic system is to establish active biology and maintain this ecosystem indefinitely 

for the benefit of the crop, diversity of ecology and conservation of resources and inputs. While specific 

levels may vary from farm to farm, bioponic systems require attention to oxygen levels, temperatures 

and food sources in order to keep the biological ecosystem in balance. 

§205.200 General.

“...Production practices implemented in accordance with this subpart must maintain or improve the 

natural resources of the operation including soil or water quality.” 

While formal scientific analysis has not been conducted on the effects of bioponic production on soil 

or water quality, based on field experience, soil quality is maintained at levels that existed prior to the 

bioponic operation as bioponic production doesn’t remove soil nutrients or till the soil for crop 

production. Experiential evidence demonstrates how crops planted in ground previously covered with 

weed cloth for bioponic production were equally productive compared to in-ground crops and did not 

exhibit increased disease pressure or nutrient deficiency once being uncovered and amended with 

standard pre-planting amounts of compost and then tilled.

Similarly, it is expected that water quality would also be maintained at existing levels, particularly in 

cases of recirculating bioponic systems where the microbial solution is contained within the system 

indefinitely or rarely or minimally discharged. In the cases of drain-to-waste bioponics, analysis would 

have to be conducted to determine what effects the discharged microbial solution may have on overall 

water quality in comparison to the effects of soil-based fertilization of in-ground agriculture.

As bioponic production can take place in locations without arable soil, a determination should be made 

to identify relevant resources to be evaluated for their maintenance or improvement resulting from 

production practices. Water quality would continue to be a relevant resource to evaluate. 
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§205.203 Soil fertility and crop nutrient management practice standard.

(a) The producer must select and implement tillage and cultivation practices that maintain or 

improve the physical, chemical, and biological condition of soil and minimize soil erosion.

Similar to §205.200, this subsection also can mean that the lack of tilling and extraction of nutrients 

from the soil and minimal microbial solution discharged from bioponic systems to demonstrate 

alignment with cultivation practices that maintain the physical, chemical and biological condition of 

soil and minimize soil erosion. Based on the same experiential evidence mentioned in response to 

§205.200 and the lack of formal scientific analysis to the contrary, likely the physical, chemical and 

biological condition of the soil would be unaffected by covering the soil to facilitate a bioponic system 

and that minimal soil erosion would occur. 

(b) The producer must manage crop nutrients and soil fertility through rotations, cover crops, and 

the application of plant and animal materials.

This can be applied to bioponic production, specifically to mean that management of crop nutrients 

and growing media fertility are maintained or improved without contributing to contamination of crops 

or growing media in the containers as well as the surrounding ground soil and groundwater. 

Crop nutrients and growing media fertility are maintained or improved through the maintenance and 

monitoring of the biological ecosystem’s environment to ensure optimal ranges are met to allow the 

proliferation of active biology throughout the crop and system. The active biology, or organic matter 

as it is interpreted by this subcommittee, would be maintained or improved as the system is established 

and brought into balance. 

As bioponic systems have not been shown to affect the soil fertility or crop nutrient management of 

surrounding in-ground agricultural production, it is expected that the requirement of rotations, cover 

crops and application of plant and animal materials to surrounding soil to manage or improve such soil 

organic matter would be satisfied by alternative practices applicable to the operation as detailed in the 

2010 Formal Recommendation by the National Organic Standards Board (NOSB) to the National 

Organic Program (NOP), “Production Standards for Terrestrial Plants in Containers and Enclosures”, 

part 205.205(a,b,c,d) as it is in the cases of organic transplant container production and other container 

systems. 

(c) The producer must manage plant and animal materials to maintain or improve soil organic matter 

content in a manner that does not contribute to contamination of crops, soil, or water by plant 

nutrients, pathogenic organisms, heavy metals, or residues of prohibited substances.

The management of bioponic systems to avoid contributing to the contamination of crops, soil or water 

by plant nutrients, pathogenic organisms, heavy metals or residues of prohibited substances is 
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achieved by maintaining a healthy biological ecosystem within the system and further by minimizing 

discharge into ground soil or groundwater, discharging in a compliant manner when it is necessary to 

discharge microbial solution, maintaining a regular water testing schedule to ensure no human 

pathogens are present in the microbial solution and the use of only organic-compliant inputs in organiccompliant ways. Some of these safeguards are enforced further in those operations that are also GAP 

(Good Agricultural Practices) certified. 

§205.205 Crop rotation practice standard.

The producer must implement a crop rotation including but not limited to sod, cover crops, green 

manure crops, and catch crops that provide the following functions that are applicable to the 

operation:

(a) Maintain or improve soil organic matter content;

(b) Provide for pest management in annual and perennial crops;

(c) Manage deficient or excess plant nutrients; and

(d) Provide erosion control. 

In a bioponic system, rotation is accomplished with the renewal of growing media at the time when it

is appropriate for the specific crop. Typically, this occurs at the end of the crop cycle and the growing 

media is not reused to prevent the buildup of pests and because, in some types of container 

production, the accumulation of roots in the growing media prevents its reasonable reuse. In some 

cases, the roots and remaining growing media are composted in accordance with the regulation and 

can be reincorporated into the production cycle to generate some fertility, but is not currently a 

common practice.

As bioponic systems do not impact the soil organic matter below the system as would an in-ground 

crop, it is expected that the requirement of rotations and cover crops to maintain or improve such 

surrounding soil organic matter would be inapplicable to bioponic production. 
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Table 2

NOP Section Aligns Does not align

NOP 205.2 Definitions

Natural resources of the operation: 

The physical, hydrological, and 

biological features of a production 

operation, including soil, water, 

wetlands, woodlands and wildlife.

The definition speaks to the 

"features of the production 

operation" meaning the 

applicable features. 

Woodlands and wildlife may 

not be applicable for 

enclosed systems, as it is not 

always applicable to inground field production.

Bioponic and container 

operations conserve the soil 

beneath their production by 

not tilling or extracting 

nutrients and minimally 

discharging water solution. 

Water is conserved in 

recirculating systems which 

enable greatly reduced 

overall water use.

Recommendations could 

include requirement that 

operations use recirculating 

systems or account for any 

water run-off in drain-towaste systems. 

Organic Production: A production 

system that is managed in 

accordance with this Act and 

regulations in this part to respond to 

site-specific conditions by integrating 

cultural, biological, and mechanical 

practices that foster cycling of 

resources, promote ecological 

balance, and conserve biodiversity

Cycling of Nutrients: 

Wikipedia defines Nutrient 

cycle as "the movement and 

exchange of organic and 

inorganic matter back into 

the production of living 

matter. The process is 

regulated by food web 

pathways that decompose 

matter into mineral 

nutrients."
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Within biologically active 

container systems like 

Bioponics, microorganisms 

decompose matter into 

mineral nutrients enabling 

them to be used by the 

plants. Container systems 

which contain a greater 

diversity of growing media 

volume and components may 

include significantly more 

decomposition within the 

growing season. Container 

based systems for annual 

crop production would likely 

not include decomposition of 

plant material back into the 

system

Promote ecological balance: 

Ecological balance as defined 

by the WWF "a state of 

dynamic equilibrium within a 

community of organisms in 

which genetic species and 

ecosystem diversity remain 

relatively stable, subject to 

gradual changes through 

natural succession" or "A 

stable balance in the 

numbers of each species in 

an ecosystem.”

Bioponics relies on the 

stability of the biological 

ecosystem for the health of 

their system and crops. 

It may not contribute to long 

term ecological stability, but 

rather stability within their 

production cycle.

Conserving biodiversity is 

described by the WWF as "... 

ensuring that natural 

landscapes, with their array 

of ecosystems, are 

maintained and that species, 

populations, genes, and the 

complex interactions 

between them, persist into 
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the future." This includes 

diversity at all trophic levels, 

birds, beetles, butterflies, soil 

microbes, earthworms, 

mammals and vegetation. 

Wild Farm Alliance adds that 

"It encompasses diversity 

found at all levels of 

organization, from genetic 

differences between 

individuals and populations 

to the types of natural 

communities found in a 

particular area."

While not all trophic levels 

will be found in every 

agricultural system, 

particularly controlled 

environments, bioponic

systems contain diverse 

ecology within their growing 

media and/or nutrient 

solution

Organic Matter: The remains, 

residues, or waste products of any 

organism

Bioponic systems which use 

solid matrix, liquid compost 

products or microbial 

products align with the 

definition of organic matter. 

The question of how much 

OM is present to distinguish 

bioponic systems should be 

clarified.

Production practices implemented in 

accordance with this subpart must 

maintain or improve the natural 

resources of the operation including 

soil or water quality. (§205.200)

Container and bioponic

systems align with this 

requirement. Particularly 

those with recirculating 

systems. Because soil on the 

site is not tilled, it could be 

considered to be maintained, 

although not improved. 
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The producer must manage plant 

and animal materials to maintain soil 

organic matter content in a manner 

that does not contribute to 

contamination of crops, soil or water 

by plant nutrients, pathogenic 

organisms, heavy metals, or residues 

of prohibited substances. 

(§205.201c)

If soil (as defined by the task 

force) is used as part of the 

growing media, bioponic and 

container systems would 

appear to maintain soil OM 

levels for perennial systems if 

additional media is added 

over time. For short season 

crops, additions of microbial 

rich nutrients would be 

maintaining the OM in the 

container. 

For systems that do not use 

soil in their growing media: 

recirculating systems would 

have to manage the 

discharging of microbial 

solution in a compliant 

manner when the system is 

purged and cleaned. For 

container systems where the 

water drains through the 

container to surface soil, we 

would have to consider if the 

concentration of nutrients is 

significantly different than 

that used in an in-ground 

system sufficient to warrant 

additional oversight 

measures.

Crop pest, weed, and disease management (§205.206) 

(a) The producer must use management practices to prevent crop pests, weeds, and diseases 

including but not limited to:

(1) Crop rotation and soil and crop

nutrient management practices, as 

provided for in §§205.203 and 

205.205;

Rotation is accomplished with 

the renewal of the growing 

media when appropriate. 

Cover crops are not 

appropriate when the 

rotation includes the removal 

of soil and growing media. 

Applying plant and animal 

materials is required to 

generate fertility. As in inground soil systems, the 

mineralization of the 

animal/plant/mineral 

materials requires a healthy 

balanced 

microflora/macroflora. 

This could be considered a 

soil-specific production 

requirement and an 

exemption for crop rotation 

could be granted for all types 

of container production.

(2) Sanitation measures to remove 

disease vectors, weed seeds, and 

habitat for pest organisms.

Managing the nutrient 

solution's healthy biological 

activity (climate, active 

bacteria levels, oxygen 
39

39

levels...) manages water 

pathogens and boosts plant 

immune system to resist 

disease.

Greenhouse ground is 

commonly tarped or covered 

to inhibit weeds and majority 

of pests are excluded by 

protected structure.

(3) Cultural practices that enhance 

crop health, including selection of 

plant species and varieties with 

regard to suitability to site-specific 

conditions and resistance to 

prevalent pests, weeds, and diseases.

Selection of varieties suitable 

to container and site and 

system-specific conditions for 

production satisfy this 

requirement.

(b) Pest problems may be controlled through mechanical or physical methods including but not 

limited to:

(1) Augmentation or introduction of 

predators or parasites of the pest 

species;

Use of biologicals is common 

practice in organic 

greenhouse container 

production.

Biological pest management 

in water systems is also used 

in container systems, as it is 

in in-ground systems.

(2) Development of habitat for 

natural enemies of pests;

Containerized banker and 

insectary crops can be used 

for pest management and 

habitat for biologicals. 

Similarly, microbial solution 

conditions that favor 

biologicals are used.

(3) Nonsynthetic controls such as 

lures, traps, and repellents.

Use of nonsynthetic lures, 

traps and repellents is 

common in organic 

greenhouse container 

production.

(c) Weed problems may be controlled through:
40

40

(1) Mulching with fully biodegradable 

materials;

Floors could be tarped with 

biodegradable materials.

(2) Mowing; N/A

(3) Livestock grazing; N/A

(4) Hand weeding and mechanical 

cultivation;

Greenhouse edges are 

commonly managed with hand 

weeding

(5) Flame, heat, or electrical means; 

or

Greenhouse weeds are 

sometimes managed with 

handheld torches

(6) Plastic or other synthetic mulches: 

Provided, that, they are removed 

from the field at the end of the 

growing or harvest season.

Greenhouse floors are 

commonly covered with plastic 

or other weed-blocking 

covering during time of 

cultivation.

(d) Disease problems may be controlled through:

(1) Management practices which 

suppress the spread of disease 

organisms.

Managing the nutrient 

solution's healthy biological 

activity with climate, active 

bacteria levels and oxygen 

levels satisfies this 

requirement.

(2) Application of nonsynthetic 

biological, botanical, or mineral 

inputs.

In bioponics, with the 

exception of aquaponics, 

horticultural oils and other 

non-synthetic and biological 

inputs can be used without 

harming biological activity in 

nutrient solution. In the case 

of aquaponics, inputs must 

also be determined to be safe 

for the fish in the system 

before use. 

To be avoided are any inputs 

or treatments that 

indiscriminately kill bacteria 

unless nutrient solution is 

inoculated after application to 
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41

maintain healthy bacteria 

levels.

(e) When the practices provided for 

in paragraphs (a) through (d) of this 

section are insufficient to prevent or 

control crop pests, weeds, and 

diseases, a biological or botanical 

substance or a substance included on 

the National List of synthetic 

substances allowed for use in organic 

crop production may be applied to 

prevent, suppress, or control pests, 

weeds, or diseases: Provided, That, 

the conditions for using the 

substance are documented in the 

organic system plan.

In bioponics, with the 

exception of aquaponics, 

horticultural oils and other 

non-synthetic and biological 

inputs can be used without 

harming biological activity in 

nutrient solution. In the case 

of aquaponics, inputs must 

also be determined to be safe 

for the fish in the system 

before use. 

To be avoided are any inputs 

or treatments that 

indiscriminately kill bacteria 

unless nutrient solution is 

inoculated after application to 

maintain healthy bacteria 

levels.

(f) The producer must not use lumber 

treated with arsenate or other 

prohibited materials for new 

installations or replacement purposes 

in contact with soil or livestock.

Adequate alternative materials 

exist to satisfy this 

requirement.
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Proposed Changes to USDA Standards

Relevant Sections of the USDA Organic Standards

§205.2 Terms defined.

Aquaponics – A type of bioponic system in which the waste produced from farmed fish, or other 

aquatic animals, supplies nutrients for plants grown in container systems, which in turn purifies the 

water for reuse

Bioponic production – contained and controlled growing system in which plants in growing media 

derive nutrients from natural animal, plant and mineral substances that are released by the biological 

activity of microorganisms

Container – Any vessel and associated equipment used to house growing media and/or the complete 

root structure of plants and to prevent the roots from contacting the soil or surface beneath the 

vessel, such as but not limited to, pots, troughs, plastic bags and liners, etc.

Growing media - Material which provides sufficient support for the plant root system and a diverse 

ecosystem of soil-borne microorganisms

Hydroponics - The growing of plants in mineral nutrient solutions with or without an inert growing 

media to provide mechanical support

Soil - The outermost layer of the earth comprised of minerals, water, air, organic matter,

fungi and bacteria in which plants may grow roots

§205.208 Bioponic Production Standard

Any container system from which harvested crops are intended to be sold, labeled, or represented as 

“organic”, must meet all applicable requirements except: §205.202(b), §205.203(a and b), §205.205. 

In lieu of §205.202, §205.203, §205.205, container systems must meet the following requirements:

(a) Growing media. 

1. Growing media may include soil that has been managed in accordance with §205.202 through 

§205.206 and other substances in accordance with 205.105, 205.601 and 205.602.

2. Growing media must be composted, recycled, or reused.

3. The containment system must prevent plant roots from contacting underlying soil.

(b) Growing media fertility and crop nutrient management.

1. The producer must manage crop nutrients within the system through the addition and/or 

maintenance of soil-dwelling micro- and macro-organisms and the application of plant, animal, and 

mineral materials in accordance with 205.105, 205.203(c, d and e), 205.601 and 205.602
43

43

2. Excess drainage of plant nutrient water must be captured and reused within the containment 

system or used on a crop outside the system.

(c) Crop rotation functions. The producer must implement a system to provide the following 

functions to the container system:

1. Maintain or improve organic matter content;

2. Provide for pest management in annual and perennial crops;

3. Manage deficient or excess plant nutrients.

Organic Systems Plan Considerations for Bioponics

For a bioponics system to be certified organic, a certifier needs to be able to:

"Evaluate an OSP and look for straightforward evidences that a bioponics producer is 

managing crop nutrients within the system through the addition and/or 

maintenance of soil-dwelling micro- and macro-organisms and the application of 

plant, animal, and mineral materials not listed as prohibited in §205.105.”

The following are some suggested ways that an OSP can demonstrate the above by providing

evidence of organic material microbial cycling:

1. Frequency and types of plant, animal, mineral material additions

2. Frequency and types of microbial and macro-organism additions (ex. Compost, commercial 

inoculants, worms) and reasons for use (ex. nutrient cycling, biocontrol)

3. Provide the insoluble and soluble nutrient breakdown of the plant and animal materials added to 

the system.

4. Provide lab analysis of the nutrient concentrations in growing media or microbial solution in the 

middle and end of a growing cycle, particularly looking at nitrogen conversion from ammonia to 

nitrite to nitrate. Nitrifying bacteria are necessary to convert nitrogen to nitrate.

5. Provide lab analysis of the plant tissue nutrient levels.

6. Records of dissolved oxygen over time and the need to add oxygen to the system (microbes use 

up oxygen as they decompose organic matter).

7. Records of biological oxygen demand (BOD). BOD would be high when organic matter is not yet 

degraded, lower after degradation.

8. Records of Oxidation Reduction Potential (ORP). ORP will be lower when organic materials are 

not yet mineralized, higher after mineralization.

9. Records of pH over time (biologically active media usually has natural pH fluctuations and mature 

aquaponic systems will have a decrease in pH over time due to nitrification).

10. Laboratory analysis of growing media using Formazan Test (measures respiration by 

microorganisms as they decompose organic matter. The higher the Formazan rating, the more 

biological activity in the soil).

11. Laboratory analysis of actual microbiology in growing media or microbial solution, throughout the 

system (ex. numbers of active bacteria, fungi, protozoa, nematodes)
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44

12. Laboratory analysis of C:N ratio of the growing media overtime (C:N decreases as microbes 

decompose carbon).

13. Microscope records of microbes in growing media or microbial solution.

14. If compost tea is used, microscopic analysis records of microbial activity.

15. If aquaponics, plant to fish ratio, feed inputs over time.
45

45

Clarifications of 2010 NOSB Recommendations

Purpose and Context for this Analysis

Over the past 20 years, the NOSB has addressed and provided recommendations and formal 

comments to the NOP regarding greenhouse, container and hydroponic growing methods including:

1. 1995 – NOSB states that hydroponic systems can be certified if they can comply with OFPA

2. October 2001 – NOSB Final Recommendation Greenhouse Production Systems

3. April 2008 – Crops Committee Discussions on Guidance Statements Relative to Soil-less 

Growing Systems

4. May 2009 – NOSB Crops Committee Soil-less Growing Systems Discussion

5. September 2009 – Crops Committee Recommendation Greenhouse Production Systems

6. April 2010 – Production Standards for Terrestrial Plants in Containers and Enclosures

Over this time, container, greenhouse and hydroponic growing practices have significantly increased 

and intensified as commercial growing methods. In a survey conducted by the NOP in 2010 and 

another in 2016, the results are the following:

2010 2016 % Change

Certifiers certifying 

hydroponic/aquaponic

8 17 112% increase

Certified 

hydroponic/aquaponic 

operations

39 52 33% increase

Certified Containerbased operationsn/a 69

* NOP 2010 & 2016 survey to certifiers

The increasing industry movement towards controlled growing systems has further created the need 

for USDA guidance on this matter. The challenges for developing standards that address container, 

greenhouse and hydroponic growing practices primarily stem from the limited amount of public 

information that has been available to the NOSB/NOP regarding these subjects, especially as it relates 

to hydroponics.

This report section has a primary objective of providing additional information and clarification 

regarding these specific methods and emerging technologies that was not previously available to the 

NOP/NOSB.
46

46

NOSB 2010 

Recommendation 

Summary

Introduction

Recommendation addresses 

rulemaking for container based 

media, hydroponics, 

aeroponics and protection 

against commingling.

Background

States that the NOSB provided 

a clarifying document on its 

soil-less growing position in 

May 2009, attached as an 

appendix to the 2010 

Recommendation; and, that 

although the 2010 

recommendation focuses on 

greenhouse production, it is

based on the same criteria and 

principles outlined in the 2009 

document. 

Task Force Analysis

Introduction 

No comments.

Background

The Appendix referred to as the May 2009 NOSB discussion 

has two (2) primary messages:

1. Hydroponic systems should not be certifiable “... due 

to their exclusion of the soil-plant ecology intrinsic 

to organic farming systems...” (NOSB May 2009)

2. Properly designed compost based growing media 

“...producing the beneficial symbiotic ecological 

relationships found in soil, such growing media 

should be rightfully considered soil.” (NOSB May 

2009)

Regarding point number 1 above – that hydroponic systems 

exclude soil-plant ecology. This is true for the first 

generation of hydroponic systems that first emerged, where 

inert, synthetic nutrients are used as the plant nutrition 

source. However, there are a variety of different 

hydroponic growing systems that do not use any synthetic 

nutrients at all, but rather use plant, animal and mineral 

inputs only that rely on soil-plant microbial action (such as 

nitrifying bacteria, protozoa and fungi found in soil) to 

convert such inputs into plant usable form. This is described 

in more detail in other areas of this report.

Regarding point number 2 above – the NOSB establishes 

the concept of equivalency between compost and soil 

because compost is capable of achieving the same functions 

as soil. By the same logic, a properly designed bioponic

system is capable of achieving the same functions as 

compost would beneficial biology, then a bioponic system 

should rightfully be eligible for organic certification.
47

47

NOSB 2010 

Recommendation 

Summary

Discussion

“Organic farming” refers to the 

practice of maintaining or 

improving carbon containing 

organic matter in soil through 

various methods – the organic 

matter itself is not what is 

necessarily important but 

rather the diverse microbial 

populations that it proliferates. 

The organic farmer “is not just 

a tiller of the soil, but a 

steward of the soil ecology” 

(NOSB 2010). Thus, 

hydroponic systems that 

eliminate such soil ecology, 

cannot be acceptable organic 

practices.

Task Force Analysis

Discussion

The discussion by the NOSB in the 2010 recommendation 

defines the following key principles:

1. It is not the physical soil that is necessarily 

important, but the biological ecosystems that it 

fosters.

2. “The organic farmer is not a tiller of soil, but a 

steward of soil ecology” (NOSB 2010).

3. Growing systems that eliminate soil ecology should 

not be certifiable.

The NOSB 2010 discussion provides emphasis that the core 

principal of organic farming is the concept of fostering soil 

biology to create symbiotic relationships with the plant. 

Physical soil itself is not necessary so long as the soil 

ecosystem can be fostered and achieved – this is clarified 

further by the statement that a properly designed compost 

based growing media (which is not soil) where typical soil 

dwelling organisms can thrive, should rightfully be 

considered soil – demonstrating the NOSB’s 2010 position 

that if proper soil functions can be achieved, the physical

soil itself is not necessary, such as the case with compostbased container systems.

Based on these principles of achieving equivalent soil 

functions, as does a properly designed compost container 

growing system, there also exist specific types of organic 

hydroponic growing systems that also achieve such 

equivalent soil functions by integrating plant, animal and 

mineral inputs with organic growing media and high levels 

of soil microbiology. It is important to differentiate that 

hydroponic systems can be fundamentally different from 

one to the next with respect to inputs and biology, as can 

any open field farm. For the purpose of this analysis, it is 

important to understand that the hydroponic systems that 

should be considered for organic alignment are only those 

that specifically achieve, promote and maintain a soilmicrobial ecosystem that soil or a compost-equivalent 

would achieve.
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48

NOSB 2010 

Recommendation 

Summary

Relevant Areas in the Rule

OFPA §6513(b) requires an organic 

plan designed to foster soil fertility. 

The resulting NOP regulations are:

● §205.203(a) – producer 

must implement tillage and 

cultivation practices that 

maintain or improve the 

physical, chemical and 

biological condition of the 

soil;

● §205.203(b) – producer 

must manage crop nutrients 

and soil fertility through 

rotations, cover crops and 

the application of plant and 

animal materials;

● §205.203(c) – producer 

must manage plant and 

animal materials to 

maintain or improve soil 

organic matter content in a 

manner that does not 

contribute to contamination

Reiteration that compost is a soilequivalent and should be rightfully 

considered soil because it achieves 

the same functions of fostering soil 

ecology. 

Task Force Analysis

Relevant Areas in the Rule

NOSB’s 2010 recommendation that compost be 

considered soil is acceptable because OFPA §6513(b)

requires an organic plan to foster soil fertility – but not 

necessarily contain soil, thus consistent with the 

concept that properly designed compost that achieves 

all soil functions should be considered soil.

NOP §205.203(a-c) describes required practices to help 

foster soil fertility which is directly applicable for open 

field operations. The NOSB has addressed the need for 

NOP to modify the rule to create additional guidance 

and exceptions where necessary for greenhouse and 

container growing systems in 2001, 2003, 2008, 2009 

and 2010, specifically with respect to §205.203 – tilling, 

crop rotations and cover crops. The specific 

modifications recommended by the NOSB is described 

in the next section.

Hydroponic growing systems are a type of container 

growing system that would require the same rules 

applicable to greenhouse container systems. 
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NOSB 2010 

Recommendation 

Summary

Terms Defined:

Greenhouse – permanent 

enclosed structure... used to 

grow crops... in organic 

production

Hydroponics – the production 

of normally terrestrial, vascular 

plants in nutrient rich solutions 

or in an inert, porous, solid 

matrix bathed in nutrient rich 

solutions

Aeroponics – a variation of 

hydroponics in which plant 

roots are suspended in air and 

misted with nutrient solution

Containers – any vessel and 

associated equipment used to 

house growing media and the 

complete root structure of 

terrestrial plants and to 

prevent the roots from 

contacting the soil or surface 

beneath the vessel, such as, 

but not limited to, pots, 

troughs, plastic bags, floor 

mats., etc.

Task Force Analysis

Terms Defined:

Greenhouse – no comment

Hydroponics – this NOSB’s 2010 definition captures the 

description for a conventional/non-organic hydroponic 

system. As explained in other areas of this report, there are 

organic hydroponic systems that are fundamentally 

different than the non-organic system described to the left.

A more appropriate definition for an organic hydroponic 

system could be: A container production system that 

derives the majority of nutrients from animal and plant 

based organic matter and relies on soil food web 

microbiology to make nutrients available to plants.

Aeroponics – this is a mechanical variation of a hydroponic 

container system where water, nutrition and biology is 

sprayed onto plant roots, as opposed to being in direct 

contact.

Containers – this definition is consistent with classifying 

hydroponic systems as a type of container system.

Recirculating System with additional 

growing media in separate container

Recirculating System
50

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NOSB 2010 

Recommendation 

Summary

Growing Media – Material 

which contains sufficient 

organic matter capable of 

supporting the plant root 

system and a natural and 

diverse soil ecology

Task Force Analysis

Growing Media – In a container system, materials are mixed 

together to achieve the equivalent properties of soil including 

materials that provide support, nutrition and biology. The base 

substrate can be/include coco-fiber, peat, perlite, water, 

compost, etc. Some systems use water exclusively as the 

growing media – with properly designed aeration, inputs and 

biology, water can be a very good host for soil microorganisms.

Similar to the concept of a properly designed compost achieving 

soil equivalency, a properly designed growing media can also 

achieve the same properties.

It is impossible to determine a universal volume of growing 

media that is necessary to support plant root systems. Rather, 

the inputs/contents of the growing media should be measured 

to determine adequacy rather than volume. A well-designed 

growing media versus a poorly designed growing media will 

vary tremendously in volume to achieve equivalent results; 

therefore, the makeup is more important than the volume.

In a recirculating container system where water and nutrition 

are shared by all plants in the system, the entire system must 

be considered as a single “container” as opposed to individual 

plant sites because all resources are shared and biology flows 

and distributes freely among the plant sites. In many systems, 

there are often large containers with organic material and 

significant amounts of biology where water continuously 

recirculates along with all plant sites adding additional 

biological holding capacity beyond the individual plant sites. 

Thus, the entire system must be considered as a single 

container. See illustration:
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NOSB 2010 Recommendation 

Summary

Recommendation - § 205.209

NOSB 2010 recommendation for additional 

rule(s) and exception(s):

§205.209(a)(1) – greenhouse container 

systems with growing media that does not 

contain soil is exempt from 205.202 (b) and 

(a)

§205.209.a.2 – container systems are exempt 

from crop rotation and cover cropping 

requirements in 205.203(b) and 205.205.

In lieu of crop rotation and cover cropping, 

soil regeneration and recycling practices shall 

be implemented to “demonstrate that the 

required functions/goals of crop rotation and 

cover cropping in 205.205(a,b,c,d) have been 

achieved through these alternate practices, 

as applicable to the operation” (NOSB 2010)

Task Force Analysis

Recommendation - § 205.209

In NOSB’s 205.209(a)(1) recommendation, it 

is explicitly recommended that container 

systems that do not contain soil are [should 

be] exempt from cover cropping and tillage 

requirements. This is specifically important 

to note that the 2010 NOSB 

recommendation, and virtually all other 

2001, 2003, 2005, 2009 recommendations, 

align with the principal that soil is not 

required if the functions can be achieved by 

other methods/organic materials.

This same reasoning is used throughout the 

rest of the recommendations provided by the 

2010 NOSB where the concept of achieving 

equivalency or “functions/goals” of required 

practices are acceptable alternate practices.

This is specifically important because as 

stated in NOP §205.2: “Organic production 

[is] a production system that... respond[s] to 

site-specific conditions by integrating 

cultural, biological, and mechanical practices 

that foster the cycling of resources, promote 

ecological balance and conserve bio 

diversity.” The key is that farming is, by 

nature, site-specific and the grower must be 

able to uniquely adapt to his/her

environmental constraints/resources.
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NOSB 2010 Recommendation

§205.209(b) – growing media ingredients 

shall be verified by certifying agent and shall 

not include prohibited materials. Growing 

media shall contain sufficient organic matter 

capable of supporting natural and diverse soil 

ecology. For this reason, hydroponic systems 

should be prohibited.

§205.209(c) – producers may use fullspectrum light sources.

Task Force Analysis

§205.209(b) – The 2010 NOSB 

recommendation makes an important 

distinction that the growing media “shall 

contain sufficient organic matter capable of 

supporting natural and diverse soil ecology.” 

The emphasis is on supporting the soil 

ecology, not the plant, which allows the 

grower the important flexibility to make 

soil/nutrient amendments, as needed, to the 

growing media based on environmental 

conditions and crop requirements – i.e. the 

ability to “feed the soil.”

The statement that hydroponic systems 

should be prohibited because they do not 

contain growing media that can support soil 

ecology, again, is true only for inorganic 

hydroponic systems that are based on 

sterile/inert synthetic solutions. On the other 

hand, organic hydroponic systems (a form of 

bioponics) contain substantial soil biology 

including large numbers of bacteria, fungi, 

protozoa and nematodes, found in soil – in 

many cases, organic hydroponic systems use 

the same organic potting soil mixes used in 

common organic pot containers.

§205.209(c) – this issue is not specific to 

hydroponic growing, but rather greenhouse 

growing in general. Supplemental lighting is 

an important tool for both ornamental and 

vegetables growers alike to extend day length 

during the winter and grow during times of 

the year that would otherwise be impossible. 
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Appendix

Greenhouse technology to promote soil life

Life in soil and growing media is a huge contributor to nutrient availability, good structure, plant, soil 

and growing media health. Biological farms can use technology or practices that help increase this 

biology, and ideal conditions are reached, for biology to thrive.

pH that is not too low or too high

In general, bacteria prefer slightly acidic environments, or low pH. Fungi prefer slightly more basic 

environments or higher pH. Earthworms do best at a neutral pH. If the pH is too far toward either 

extreme, none of the organisms that help the crops will do well.

In a greenhouse environment, pH control can be achieved very precisely since there is no influence 

from heavy rain that could leach elements like Ca and Mg and create acidic environments. The pH value 

of a soil is influenced by the kinds of parent materials from which the soil was formed. In a container 

the volume of media allows changes to pH to be made and levels kept in check with adjustments 

allowable if needed. (Clemson University, Cooperative Extension.)

Stable Temperatures of Soil or Growing Media

In order for roots and soil life to survive, the temperature has to stay relatively moderate, which is why 

it is recommended to keep soil covered with growing plants or residues of plants, and to avoid bare 

ground. Bare soil would be too cold in winter and too hot in the summer. Even on covered soil, the 

influence of winter to the top layer of the soil will cause biology to be dormant or not active enough 

and a slowdown of processes like mineralization and nutrient cycling would be expected.

In container growing, conditions of temperature of media and water can be controlled very accurately, 

using technology (heating and cooling systems) that keeps ideal conditions of temperatures inside the

greenhouse. Also water temperature can be regulated to better fit the conditions for biology to thrive.
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Soil life wants a Carbon source to feed on

Carbon is food for microorganisms. They need a blend of slow and fast released carbon sources, with 

the slow released carbon sources feeding fungi and the fast releasing materials feeding bacteria. 

Diversity of food is important in order to have diversity of organisms.

Some container growers are able to grow plants in growing media that is rich in organic matter of slowly 

released carbon, like peat, coco coir and bark. These materials are good fungal carbon sources and 

provide excellent pathogen-free growing media. These growing systems require continuous fast 

release carbon sources to feed the biology and the crops.

When growing in low organic matter content soils (<2%) biology would never reach full potential of 

activity and it could take several years to increase organic matter in soil by 1%.

Why does it take so long for organic matter levels to increase? An acre of soil six inches deep weighs 

about 1000 tons, so increasing the proportion of organic matter from two to three percent is actually 

a 10-ton change. However, you cannot simply add 10 tons of manure or residue and expect to measure 

a one percent increase in soil organic matter. Only ten to twenty percent of the original material 

becomes part of the soil organic matter. Much of the rest is converted over several years into carbon 

dioxide. (University of Minnesota extension).

Fine-textured soils can hold much more organic matter than sandy soils for two reasons. First, clay 

particles form electrochemical bonds that hold organic compounds. Second, decomposition occurs 

faster in well-aerated sandy soils. A sandy loam rarely holds more than 2% organic matter.

Low, poorly-drained areas have higher organic matter levels, because less oxygen is available in the soil 

for decomposition. Low spots also accumulate organic matter that erodes off hilltops and steep slopes. 

(University of Minnesota extension).
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Case study 1 - Bioponic Tomato Growing

The container system consists of multiple three-gallon plastic containers with four tomato heads in 

each. These containers are placed on a metal trough. There are holes in the containers to allow 

water to drain out and be collected and partially recycled. The growing media consists of a coarse 

mix of coconut husk which comes pre-washed to reduce salt content. This media must be mixed with 

fertilizer and soil microbes to establish sufficient soil ecology and nutrient cycling before seedlings are 

planted. This takes approximately one month. Biology is introduced to the media through compost 

tea or solid compost application. Between ten to fifteen earthworms are added to each container to 

enhance media structure, increase microbiology, and increase nutrition through processing of organic 

material into fertilizer. Nutrition is also added to enhance the growth of soil microbes and add 

nutrition for plants. Approximately 50% of the nutrition needs of the plant can be added at this 

point. During the month long incubation period, this media mix is exposed to optimal temperature 

and water content to allow the microbial population to increase and diversify as they decompose the 

solid fertilizers and coconut husk itself.
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After planting the seedlings in this growing media, it is necessary to add supplemental nutrition 

throughout the growing cycle (approximately one year). About once per week, solid and liquid 

nutrients are added to the growing media. Some fertilizer can be applied through the irrigation lines 

because they are soluble enough and will not clog the lines. The use of soluble nitrogen fertilizers is 

limited because of their high costs, for instance for plant-based amino acids. As long as the sodium 

nitrate rule continues to apply, it will be used as a lower cost nitrogen source. Soluble organiccompliant inorganic minerals are also added through the irrigation system, such as potassium and 

magnesium sulfate. Other liquids which can clog the irrigation lines are added as a drench, such as 

fish emulsion, certain fulvic acids, kelp, rock phosphate and gypsum in liquid form, and any products 

which are oil in nature or contain biology. Solid fertilizers will also be applied to the growing media to 

provide continuous slow-release of nutrition. Organic granulate products with higher concentrations 

of multiple elements are top- dressed on the growing media but are manually worked into the media 

so that the soil biology can access it readily. 

The biological analysis shown below is from a sample taken of growing media about halfway through 

a crop cycle. The number of bacteria, fungi, protozoa, and nematodes is above expected levels to be 

found in a typical organic soil. This means it has a high capacity to cycle nutrients, equivalent to over 

300 lbs. nitrogen per acre. This level of nutrient cycling is achieved even with a small container size 

of three gallons.
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The irrigation cycles are dependent on many environmental variables, including amount of solar 

radiation, humidity, and continual measurements of soil moisture within the containers. During 

radiation peak hours, plants are irrigated three times per hour. Every time they are irrigated, it 

includes the soluble nutrients in the line. The collected drain water is filtered through 5-micron silica 

media filters to reduce solids suspended in the water which could potentially clog the system. The 

water is then ozonated to eliminate any pathogens that might be present. After a short time, ozone 

(O3) converts to oxygen (O2). This increases the dissolved oxygen level in the irrigation water to 13 –

15ppm which keeps the irrigation lines cleaner and promotes biology in the root zone.

While ozone oxidizes any organic matter in the water, including beneficial microbiology, data from 

this system shows very high concentrations of soil microbes in the growing media and relatively lower 

microbial levels leaving the system through drainage. As long as plant and microbial foods are being 

added to the containers, the microbes stay in the container doing their work. Therefore, the “sterile” 

water being re-circulated into the system is not killing the critical microbial workers of the system. 

Continued monitoring of the microbiology in the growing media is necessary in case replenishment is 

needed. For example, on a cloudy weather week, the plants would not be as photosynthetically 

active and have little energy left over to produce exudates for root microorganisms. On colder days, 

the root zone is colder, decreasing reproductive rates of the microbes. 

After a year-long growing season, the same container of growing media can be reused to grow a 

cucumber crop. After growing cucumbers, the growing media is then incorporated into the soil at the 

site and used for cover crop or summer crops like squash, eggplant, and cucumbers. A fraction of the 

earthworms will be harvested and transferred to new containers for the next container crop.

This system has been designed and adjusted for a decade based on the advice of biological and plant 

nutrition experts. It has consumed much time and money to be able to achieve this commercially 

viable organic system of tomato production. 
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Case study 2 - Decoupled Bioponic NFT 

The system consists of 900 NFT channels, divided into three systems of 300 channels each, with 20 flat 

channels dedicated to nursery production in each system. These channels are placed on a raised platform and 

connected to the underground portion of the system with spaghetti tubes at the head of each channel and a 

return channel at the foot of the channels. 

The water solution recirculates constantly and receives supplemental 

water to account for evaporation via an autofill valve connected to the 

system’s return tank and onsite well. The system’s plumbing includes 

multiple oxygen sources and gravity fed tanks designed to introduce 

oxygen throughout the system. Filters are installed throughout the 

system to prevent clogging from loose debris.

The growing media consists of coco fiber, perlite, and two species of 

trichoderma. Basil seedlings are produced in standard plastic nursery 

trays and grown in the nursery channels within the recirculating system 

until the seedlings are root bound. At that point, they are transplanted 

into the NFT channels, allowed to grow to maturity and then either 

harvested as living plants or cut as loose bunches. Roots and growing 

media are then incorporated into the site’s soil for production of other 

organic vegetable and herb crops.

The balanced water solution consists of a microbial inoculated molasses-based fertilizer, bacillus species, 

nematode species and well water. When starting the system for the first time, the system’s return tank is filled 
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with water and the microbial inoculated fertilizer. At addition, the microbial population in the fertilizer is 

dormant. As the water, fertilizer and microbiology circulates through the oxygenated system, the biology is 

activated, resulting in a stable pH and mineralization of the fertilizer’s nutrients. This process can take 

anywhere from one day to one week depending on the plant load and age. 

Once the system is balanced, plants are grown and harvested constantly and the system runs continuously 

with additions of the same microbial inoculated molasses-based fertilizer added automatically to maintain a 

preset EC level, bacterial food source and active biology. Nematode species and bacillus species are added to 

the system via the nursery channels and growing channels, respectively, for disease suppression and overall 

plant health. 

Dissolved oxygen, water temperature, EC, pH and water solution levels are monitored and recorded twice 

daily. Active biology is observed under a 400x microscope when disease symptoms are present, before and 

after inoculation with nematode or bacillus species and at random intervals for observation.

This system has been designed and adjusted for two years to minimize water, fertility, media, seed and labor 

inputs and to maximize the health and yield of various types of organic basil production. 

Case study 3 - Bio Digestion within a Water Culture System

This process begins with brewing a compost tea with additional protein inputs for approx. 36 hours, 

or until samples under microscope shows a diverse level of microbial activity. We are specifically 

looking for bacteria, protozoa, and hyphae. Aeration is constant and temperature is maintained at or 

around 75 deg. Observing bacteria and Protozoa help identify if nitrification is or will be occurring. 

When the desired biology is observed, the tea is then added to the greenhouse reservoir of 

recirculating irrigation water feeding an NFT system. This typically occurs twice per week, but the 

environment, systems, and crop dictate actuals. 
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The crop is produced in a 4,200 sq. ft. greenhouse with a 1,500 gal reservoir for the recirculating 

water and produces over 60,000 plants per year with each plant weighing about 1/3-1/2 lbs. (without 

roots attached). The plants are seeded using a common organic potting mix consisting of peat, 

perlite, and compost, in a flood and drain system, using the same fertility, at lower rates, and 

methodology. 

After 3-5 weeks, when the roots begin to bind in the tray and they are easy to remove from the tray, 

they are planted in the NFT system where they will be grown to maturity over approximately three 

weeks. The growing environments temperature is regulated, as well as the temperature and oxygen 
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content of the irrigation water of the recirculating system to ensure the metabolism of the system is 

hyperactive to digest the organic matter and synthesize nutrients. 

The metabolism of the system is monitored by measuring pH, EC, and observing plant development 

of both the leaf tissue and root structure. There is typically organic matter built up in the roots and 

slight discoloration, but the plants have primarily white roots with green and well developed leaf 

tissue and favorable growth rates.

Monitoring has shown that, after compost tea was added, the pH decreases several hours later, as 

insoluble nitrogen converts to ammoniacal nitrogen. Then the pH stabilizes for a period of time, but, 

as the pH begins to rise, this is considered as a sign that the available nitrogen has been depleted and 

it is time to add more tea to the system. This occurs typically twice per week, but the system and its 

ability to metabolize dictate actuals. It can take several weeks to get the nitrogen content built up to 

adequate levels.

A vital component of the system is the biological digester. A digester, in this case, is essentially a 

media filter, but using a volcanic stone as a media. The more surface area of the media, the more 

biological activity, which is why the volcanic rock is chosen to be the media of the digester. As the 

inoculated water (from compost tea) passes through the digester, the organisms colonize the volcanic 

rock, creating a "microbial field" containing the same organisms found in healthy organic soils 

including bacteria, protozoa, mycorrhizae, nematodes, earthworms, etc. As organic matter in the 

water passes through the digester, the organisms consume the organic matter causing nitrification 

and other biological processes to occur. The organisms also inoculate the plants roots zones, creating 

an even larger microbial field in the NFT system and increasing the metabolism of the system as a 

whole. Samples are taken from both the digester and the plant root zones to observe and ensure 

biological activity. 
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The plant roots provide stimulants to the organisms to encourage their activity. This system can show 

that there is as much or more biological activity in bioponic systems than in many healthy soil or 

compost samples observed. However, each system, environment, soils and compost, used to 

compare are different. 

By providing an ideal environment for both the plants and the organisms, the organisms live in 

harmony with the plants and do work on their behalf. Controlled environments and recirculating 

irrigation systems like the NFT provide the grower with certain levels and capability of control, but 

also put more responsibility on the grower to create a habitable and productive environment not 

having any buffers.

Why: Reasons why this system is used include but are not limited to:

● Water - Recirculating systems have shown to use much less water than conventional 

production systems since the water is contained, some say up to 90% water savings, although 

there are many variables between various production systems. In San Diego, for example, the 

cost of water is now above $2,100/acre foot, more than double the cost than just 10 years 

ago. The reality of it is that the access to available free water will only become more limited, 

which will continue to encourage and upward pressure on water pricing. Also, irrigation water 

has caused massive environmental damages, whether it be the brine that fill the Salton Sea 

which is a designated agricultural sump or the degradation of the Great Coral Reef, and 

although organics may mitigate that exposure, it doesn't guarantee exclusion of salt runoff to 

groundwater.
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● Yields - Because a containerized system provides a unique level of environmental control that 

allows for an ideal environment for plants and biology to thrive, an increase in yields can be 

achieved. The system described here produces 17 turns per year with losses of less than 5%.

● Land Use - This system, and other containerized systems, allow growers to put into production 

small plots of land that may not have been the right scale to provide the needed returns, land 

that is contaminated and land that urbanized.

Case study 4 - DWC Aquaponics

Three replicated, balanced Deep Water Culture (DWC) Aquaponic systems have been in continuous 

operation for 6 years producing tilapia fish and primarily lettuce, herbs and other leafy green crops. 

During this time only city water, fish feed and supplemental iron have been added. The water 

solution is fully recycled through one water pump running 24 hours/7 days per week. Top-off city 

water is added weekly, with the systems using approximately 0.5% system volume per day (due to 

transpiration and evaporation). Each system holds approximately 18,000 US gallons of water. The 

components of each system include 2 fish rearing tanks, 4 tanks used for solids removal and 

mineralization of fish effluents, and two deep water hydroponic troughs (8’x75’x1’), one water pump 

and one air blower. Air stones deliver air to the fish tanks as well as the hydroponic troughs. Simple 

hoop house structures are used to protect the plants from the elements. Poly material is used in the 

winter, replaced with shade cloth during the extreme summer heat. 

Fish

Young 1g tilapia fish fry are purchased and reared in protective recirculating aquaculture systems 

until they reach 50g, in about 4 months. At that time fish are released into the Aquaponic system 

tanks. 1250 fish are stocked into each 3000 gallon fish tank. After another 6 months, the tilapia are 

ready for harvest (approximately 900g). When a fish tank is harvested completely, the next cohort of 

50g fish is stocked into the tank. Feed is complete nutrition for tilapia from Cargill Feed. 

Snails are a persistent problem along surfaces of the container system. They multiply rapidly and 

graze fixed film bacteria, including beneficial nitrifying bacteria. To combat this pest, the farm uses 

the biological control fish, the “shellcracker” (aka, pumpkinseed, red-ear sunfish, Lepomis sp.). The 
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sunfish are stocked at 10 fish per hydroponic trough and have completely eliminated the snails and 

their reproduction.

Fish Health is ensured through optimal water quality conditions for tilapia and good husbandry 

practices. Genetics and diet also contribute greatly to fish well-being. Tilapia survival is greater than 

99%.

Plants

Seedlings are started in a mix of coconut coir/vermiculite outside of the main aquaponic systems 

using approved organic seedling production methods. After 2-3 weeks, seedlings are transplanted 

into the DWC aquaponic systems. The seedlings are placed into of nest of long-fiber coconut coir in 

3” net pots on a food-grade plastic floating raft. With a three week grow out period, 1800 plants are 

harvested, transplanted and seeded weekly. Plants including flowers, cucumber and herbs may be 

harvested multiple times before replanting.

Common plant pests are caterpillars and aphids. Besides a well-developed IPM plan, biological 

controls may be used occasionally and organically approved sprays when required are used. Other 

diseases like mildews, molds, viruses, etc... are controlled using organic methods. Root rot (Pythium

spps.) is common in water based systems and is exacerbated when temperatures rise above 27C. 

During these hot months, crops are rotated to resistant plants such as cucumber, basil, and other 

herbs and vegetables. During the mild winters the farm produces primarily kale, bok choi, lettuce and 

herbs.

The produce is primarily sold via wholesale to a local grocery chain. Food is also regularly donated to 

the local food bank in the community. Most plants are sold as living plants, others like kale and beet 

greens are sold as cut leaves. 

Shared Water Quality

Water quality parameters are optimized for fish health, including high oxygen, low ammonia and 

nitrite nitrogen, and low total suspended solids (TSS). Plants are then selected that produce well 

under these conditions. Most plants produced have shown iron deficiencies from lack of inclusion in 

fish feed. Options for iron supplementation are currently being trialed on the farm and Fe levels are 

maintained at 2ppm. Included at the end of this case study is a water nutritional analysis from two 

current systems (Sample A and B). An analysis of source water (city water) is also included (Sample 

S). Farm staff monitors water quality 3x weekly for pH, Temp, EC, Ammonia, and Nitrite. 
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Effluent Management

The systems grow fish at a rate of approximately 0.5lbs/gallon of fish tank at final biomass. Feed is 

given at a rate of 35g/m2 of plant area/day. Consistent nutrient input balanced with consistent 

nutrient uptake, by staggering fish and plant production, creates a system that provides optimum 

water quality for the fish and plants. 

Large solids are collected at the bottom of a cylindro-conical clarifier tank and discharged from the 

system. Approximately 3 US gallons are discharged from each system daily. This effluent is 

incorporated into the soil around the farm, either directly or applied to an active compost pile. Three 

additional solids removal tanks follow, allowing for the microbial mineralization of fine suspended 

solids into usable plant nutrients. Each tank has fine filter screens on the outlets that trap the fine 

solids preventing them from entering the deep water hydroponic troughs. 
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Case study 5 - Container production systems

As a growing sector of agriculture, container production has increased and diversified considerably within the 

past 5 years. Responding to increased variability of climatic conditions, including droughts in western states 

with limited access to quality water as well as increased land prices, innovation in this sector has led to, and 

continues to increase adoption of these production practices. As innovation increases, it is important that 

regulatory processes take into consideration not only production practices in place today, but also 

development over the coming years. As resource restrictions and production systems evolve, operations and 

certifiers are looking to the 2010 recommendation and future clarification to understand what systems are 

allowed under USDA organic regulations.

Perennial crops grown in containers

This section provides a case study of 2 certified organic container perennial berries and is presented as a reallife example of container systems currently within our organic agricultural universe. These systems highlight 

specific regulatory challenges for certifiers as well as specific production benefits realized by the growers. The 

information in this section was provided by Ian Justus, Driscoll Strawberry Associates Sr. Manager Controlled 

Environment Production. This is presented in order in order to further the dialogue about container 

production, and is not intended as an endorsement of this system or its alignment with OFPA or the USDA 

organic regulations.

The photos below show two certified organic perennial container systems for blueberries and raspberries in 

California. The systems are a rapidly growing sector of organic agriculture in the West and range in terms of 

their specific production practices including: Crop, growing media, container size and fertility program. These 

systems have been developed over the past 3-4 years and have not yet reached the end of lifecycle for these 

crops which is expected to be 8-10 years. This is an active time for research and system refinement. 
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Blueberries do particularly well within this type of system due to the low pH of the peat based growing media 

and consistent delivery of water and nutrients. Tunnels are not enclosed, and the metal hoops will be covered 

with plastic to create warmer temperatures and diffuse light. Weed cloth covers the soil. This system could be 

in place for 8-10 years.
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This photo shows Raspberry production in containers. No weed cloth has been used at this site, however this 

system uses similar practices to the blueberries such as high tunnels covered with plastic and other specific 

production methods.

Container size ranges from 10-40 liter pots. The size of the container is based on the eventual size of the root 

mass of the plant, lifespan of the crop and the volume of growing media needed. 

Growing media consists mainly of peat, coconut coir and perlite. Some growers may also include compost, 

wood chips or solid fertilizer such as guano. The analogous non-organic system uses pure coconut coir 

because the increased surface area and organic matter content provided with the peat is not needed due to 

the highly available nutrients used in the non-organic system. Blended media is more common in the organic 

systems because it provides better buffering for moisture and fertility retention (increased CEC) and higher 

organic matter, and therefore surface area for needed to support biological activity. 

Fertility is derived predominantly from liquid fish and with some operations using hydrolyzed (and other) soy 

products (less common due to high cost) fed through the irrigation lines. Some growers also use compost or 

other solid-state fertilizers as part of the growing media, but this is not typical. 

Biological Activity is mostly the result of microbial populations in the air which colonize growing media under 

the right moisture and temperature levels. Microbial products may or may not be added to encourage of 

speed up establishment of these populations but research with these systems has shown that is isn’t necessary 

in order to establish microbial populations. Additionally, the organic systems outperform comparable nonorganic systems which these growers attribute to the benefits the organic systems see from the established 

microbial populations. 
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Production benefits found with container perennial crop production

Producers report specific production benefits using container production which is increasing interest and 

conversion to these systems. In addition to the 3 benefits discussed below, producers report higher yields, 

extended growing season and improved conditions for workers due to the cleaner conditions, higher plant 

height and consistent production.

A. Precision

The key benefit these growers find when using container production for these perennial systems is precision. 

These systems are extremely water and fertility efficient. Plants are watered several times a day with very 

precise amounts and little to no run-off. Liquid fertility is also delivered in very precise amounts down to ppm 

of fertility needed by the plant. In terms of both water and fertility, plants are given “exactly what they need 

exactly when they need it.” This has allowed plants to thrive and produce fruit more quickly when coupled 

with specific varietal selection.

B. Reduced resource use

Even with planting densities much higher than in-ground systems, producers see a 40-70% reduction in water 

use (depending on the crop), and reduction in fertilizers compared with the same crops grown in ground. This 

is an important consideration for agricultural areas reliant on summer irrigation, as is common throughout the 

West. Importantly, due to the low level, consistent watering, these systems require vigilant and constant 

monitoring. If water is not delivered correctly for one day, the entire crop could be lost.

C. Utilizing non-ideal growing locations

Container systems have opened up production areas which, due to soil or water quality issues, may not be 

suitable for in-ground growing. This could lead to increased agricultural production in urban areas, on 

rooftops, as well as on contaminated or other marginal ground if the sites can meet requirements outlined in 

the USDA organic regulations.

Conclusion

In a time of increasing climatic instability and variability, systems that are resource efficient will become 

increasingly important in order to maintain a consistent food supply. However, the fact that growers find 

benefits using these methods is not sufficient justification for their allowance in USDA organic regulations. The 

challenge still remains in determining if these methods align with OFPA and current USDA organic regulations, 

and can/should the USDA organic regulations be updated to specify requirements for crops produced in 

containers to ensure adherence to fundamental organic agricultural methodology.
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3. Alternative Labeling Subcommittee Report

Amy Lamendella

Colin Archipley

Dave Chapman

Eric Sideman

Jessica Vaughan

Marianne Cufone

Pierre Sleiman

Sam Welsch

Stacy Tollefson

Theresa Lam
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Alternative Production Methods and the Benefits and Challenges of Alternate 

Labeling Strategies 

In addition to the original objectives laid out for the Hydroponic and Aquaponic Task Force, the 

task force was also asked to explore alternative labeling concepts that could be applied to 

hydroponic, aquaponic and/or other container based production methods. To carry out this 

task, the task force created the Alternative Labeling Subcommittee. The tasks of the 

subcommittee was two-fold:

1. Consider labeling options for hydroponic and container production systems both within 

the existing USDA organic standards and outside them based on a request by the NOSB 

Crops Committee. 

2. Additionally, this report attempts to assess benefits and challenges of alternate labeling 

categories for container based/soil-less/hydroponic production systems within the 

current NOP organic standards. 

There is not consensus among members of the committee regarding these alternatives. Rather, 

the alternatives are being presented to represent the range of ideas shared by members of the 

committee.

A limitation of the suggestions below is that currently there are neither clear, agreed upon 

definitions for these systems nor finalized standards on which to base a distinction. Adoption 

of any alternate strategy, requires a clear production standards as a starting point to develop 

clear labeling standards. Since there are already significant differences among certifiers 

regarding the certification of hydroponic systems, some members of the task force feel that it is 

premature to suggest any alternative labeling. 

The goal of developing an alternate labeling category (for the benefit of writing and reading this 

report, we use Alternate Label as a placeholder name for any specific alternate labeling 

strategy) is to create transparency within the organic marketplace; enabling producers to 

distinguish their crops/products and consumers to make informed choices. This report 

discusses mainly alternate labeling strategies within the USDA organic regulations, however, it 

is the opinion of some members of this subcommittee that requirements in OFPA and the USDA 

organic regulations would not allow a container/soil-less/hydroponic label to be included under 

the organic label and would therefore necessitate separate standards development. Therefore, 

an alternate label outside of USDA organic regulations is also listed, however details of a 

separate standard are not discussed within this report. 

Goals of an alternate label within or outside of USDA organic regulations:

1. Provide a transparent label to consumers.
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2. Enable clear communication regarding what is the distinguishing characteristic of this 

set of production systems.

Challenges of alternate labeling within the USDA organic regulations:

1. Determining authority within OFPA to include container/soil-less/hydroponic production 

within USDA organic regulations. 

2. Dependent on clear standards to distinguish and define the productions systems 

included/excluded in the label.

3. The label distinction will, by design, group a variety of production practices together 

into the same category. This is a challenge due to the wide variety of production 

practices in use, including future industry innovation, and would require agreement as 

to the core difference between in-ground/soil-based systems and container/soilless/hydroponic systems.

4. The use of an alternate seal (a seal’s use being optional under § 205.303) and the 

associated phrase (phrase being required under § 205.303) for single vs multi ingredient 

products would require significant changes to the USDA organic regulations and create 

additional complexity during the certification process. Changes to § 205.303 Packaged 

products labeled “100% organic” or “organic” would be needed to define use of the 

additional modifier to organic.

5. If transparency is the goal, an Alternate Label would need to be used on all products and 

through all labeling scenarios. This would necessitate a % cut-off of Alternate Label 

ingredients to be able/required to use an Alternate Label label

a) For example, an USDA organic tomato sauce using Alternate Label tomatoes. Would 

the sauce need to be identified as Alternate Label Tomato Sauce”? What if only 2 % 

of the tomatoes used the Alternate Label? Could a product use a portion of regular 

Organic and Alternate Label tomatoes in the same sauce? What if the sauce was 

from 100% Alternate Label crops?

6. Challenges for multi-ingredient products:

a) Would the producer have to use the seal? (not required under current NOP organic 

standards)

b) If the phrase-only is required as it is under §205.303 (b) 1 (ingredients) &2 (COB 

statement) does it only need to be on ingredient panel or will it also be required on 

front label?

c) Would a product be required to use the Alternate Label only if a defined % of the 

product is Alternate Label (herbs are very commonly grown in containers and are 

often only a small % of a recipe)
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d) What is the cut-off? 5%? 25% 75% of a recipe?

e) Anywhere the word Organic is used, will it need to be modified? If no, then the 

transparency being sought will be lost.

f) What about Made with Organic claims?

7. Given the added complexity for multi-ingredient products, an alternate label may only 

be realistic if used only for fresh produce or single ingredient products and therefore 

would not create consistent transparency.

8. Creates what is in effect a “2nd-class” product category which is unlikely to be seen as a 

value added label and may not be beneficial to the Organic label overall.

9. Could open the door to request for additional alternate labeling strategies for other 

production systems in the future.

10. Not in line with international organic standards, such as Canadian, who have specific 

production standards for container production within their current organic label.

Discussion on alternate labeling within USDA organic regulations:

The ability or willingness for consumers to understand what is behind the Organic label is 

always a challenge. Consumer understanding of the production standards behind the label vary 

widely. Alternate labeling will require adding layers to an already confusing labeling 

environment. Creating additional labeling categories based on specific production systems 

would require easy-to-understand definitions and requirements as well as continued education 

efforts by the NOP and ACAs. 

An alternate label within the USDA organic regulations may be more feasible for single 

ingredient crops/products in the produce aisle, however when considering the impact on multiingredient products, it is the opinion of this subcommittee that developing alternate labeling 

categories within the USDA organic regulations will lead to considerable challenges during the 

certification process and even greater confusion for consumers. 

Additionally, creating an alternate label may take the pressure off of developing and ensuring 

high integrity production requirements. It may be more motivating to develop stricter 

requirements and ensure production practices are held to a high standard when using the same 

label for all production systems.

 

Alternatives to Organic Certification:

Given the challenges to creating a label for hydroponic crops within the USDA organic 

regulations, it may be more feasible to create a separate standard for those who want to 

distinguish container/soil-less or “Bioponic” production from standard hydroponic systems. 

Two possible paths for creating a separate standard include: a) establishing a separate labeling 
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program--similar to but separate from the NOP; b) creating a Process Verified Program (PVP). 

Creating a new labeling program may require an act of Congress and would take significant time 

and resources. Alternatively, creating a PVP would be much easier, as the USDA’s Agricultural 

Marketing Service (AMS) already offers this service to the industry. The USDA’s PVP is a 

verification service that offers industry groups a unique way to market their products to 

customers using clearly defined, implemented, and transparent processes. PVP applicants work 

with USDA to establish clear standards for production and, once the program is approved, the 

USDA provides independent verification by a qualified AMS auditor.

Aquaponic:

Some aquaponic growers have stated that they can market their crops successfully without 

using the organic label. An aquaponic system will appeal to some consumers because it is a 

closed system based on efficient use of fish waste for growing crops.

Alternate labeling suggestions within the USDA organic regulations:

When considering alternate label options below, in addition to production standard updates 

needed to define these systems, sections of the regulation that would need to be updated 

include § 205.300 - § 205.311. Specifically:

a. § 205.301 Product Composition, to distinguish soil grown and container grown 

ingredients.

b. § 205.303 to define usage of alternate labeling phrases

c. § 205.310(b) –would container grown need to be identified on ingredient panel as 

such.

d. § 205.312 to specifically outline design and use requirements of a new seal.

Additionally, it may be necessary to amend OFPA to provide authority for alternate labeling 

options under USDA organic regulations.

A. LABEL : USDA Organic - Container Grown

1. Systems include any system under USDA organic regulations where terrestrial plants are 

grown to maturity in an enclosed container. Would include rooftop gardens, perennial 

container systems, herbs in pots, annual greenhouse container systems. Would not

include transplants, mushrooms, aquatic plants and sprouts for reasons discussed in the 

2010 Subcommittee report.

a. Could include hydroponic or aquaponic systems once determination is made by the 

NOP regarding their inclusion/exclusion in the USDA organic regulations.

2. Definitions required in order to apply this label change include those needed to define 

and implement certification for container and hydroponic production systems as 

discussed in 2010 hydroponic/aquaponic taskforce including – soil, container, growing 

media, hydroponic, container production.
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B. LABEL: USDA Organic - Soil-Less

1. Systems include any allowed system where terrestrial plants are grown to maturity in an 

enclosed container or otherwise not planted in the ground. Would include rooftop 

gardens, perennial container systems, herbs in pots, annual greenhouse container 

systems. 

a) Could include hydroponic systems once determination is made by the NOP regarding 

their inclusion/exclusion in the USDA organic regulations.

b) Would include systems that use some percent soil within their growing media.

2. Definitions needed include those required to define and implement certification for 

container and hydroponic production systems as discussed previously– soil, container, 

growing media, hydroponic and soil-less production.

C. LABEL - USDA Organic - Hydroponic

1. Systems include those determined to be hydroponic under (possible future) USDA organic 

regulations. 

2. Definitions needed include those used to define and implement certification for container 

and hydroponic production. Most importantly, Hydroponic, and including soil, container, 

growing media etc

D. LABEL - USDA Organic - Bioponic

1. Systems included:

a. Systems defined as Bioponic under (future) USDA organic regulations

2. Definitions needed include those required to define and implement certification for 

container and hydroponic production. Most importantly, Bioponic, and including

hydroponic, soil, container, growing media etc