Formal Recommendation 

From: National Organic Standards Board (NOSB)

To: The National Organic Program (NOP)

Date: November 2, 2017

Subject: Aeroponics

NOSB Chair: Tom Chapman

The NOSB hereby recommends to the NOP the following: 

Rulemaking Action: X

Statement of the Recommendation:

The NOSB Recommends that aeroponic production be prohibited from organic certification.

Rationale Supporting Recommendation:

The NOSB recommends prohibiting aeroponic production systems from organic certification 

because they do not meet the requirements of OFPA or the Organic Rule. 

While many in the organic community supported various types of hydroponic production where 

terrestrial plants had their roots either in water or an inert substrate, and the plants are reliant 

on continuous application of fertility inputs for their nutrients, there was little to no support for 

aeroponic systems where terrestrial plants are suspended in the air and misted with nutrient 

rich water.

NOSB Vote: 

Motion to prohibit aeroponic production systems from organic certification.

Motion by: Emily Oakley 

Seconded by: Harriet Behar

Yes: 14 No: 0 Abstain: 1 Absent: 0 Recuse: 0

 

Outcome: Motion passed
Formal Recommendation 

From: National Organic Standards Board (NOSB)

To: the National Organic Program (NOP)

Date: November 2, 2017

Subject: Aquaponics 

NOSB Chair: Tom Chapman

The NOSB hereby recommends to the NOP the following: 

Rulemaking Action: None

Statement of the Recommendation: 

None. The motion to prohibit aquaponics failed, and no recommendation was made.

NOSB Vote: 

Motion to prohibit aquaponic production systems from organic certification. 

Motion by: Harriet Behar

Seconded by: Jesse Buie

Yes: 7 No: 8 Abstain: 0 Absent: 0 Recuse: 0

Outcome: Motion failed
Formal Recommendation 

From: National Organic Standards Board (NOSB)

To: the National Organic Program (NOP)

Date: November 2, 2017

Subject: Container Growing

NOSB Chair: Tom Chapman

The NOSB hereby recommends to the NOP the following: 

Rulemaking Action: None

Statement of the Recommendation: 

None. The motion to limit organic certification of crops grown in containers to containers/crop 

systems that meet the requirements as outlined below, failed. 

NOSB Vote: 

Motion that for container production to be certified organic, a limit of 20% of the plants’ 

nitrogen requirement can be supplied by liquid feeding, and a limit of 50% of the plants’ 

nitrogen requirement can be added to the container after the crop has been planted. For 

perennials, the nitrogen feeding limit is calculated on an annual basis. Transplants, 

ornamentals, herbs, sprouts, fodder, and aquatic plants are exempted from these 

requirements.

 

Motion by: Francis Thicke

Seconded by: Steve Ela

Yes: 7 No: 8 Abstain: 0 Absent: 0 Recuse: 0

 

Outcome: Motion failed
Formal Recommendation 

From: National Organic Standards Board (NOSB)

To: the National Organic Program (NOP)

Date: November 2, 2017

Subject: Hydroponic production systems 

NOSB Chair: Tom Chapman

The NOSB hereby recommends to the NOP the following: 

Rulemaking Action: None

Statement of the Recommendation: 

None. The motion to prohibit the organic certification of crops grown by hydroponic 

production, as defined below, failed. 

NOSB Vote: 

Motion: That any container production system that does not meet the standard of a limit of 

20% of the plants’ nitrogen requirement being supplied by liquid feeding, and a limit of 50% of 

the plants’ nitrogen requirement being added to the container after the crop has been planted 

is defined as hydroponic and should not be allowed to be certified organic. For perennials, the 

nitrogen feeding limit is calculated on an annual basis. Transplants, ornamentals, herbs, 

sprouts, fodder, and aquatic plants are exempted from these requirements.

Motion by: Jesse Buie

Seconded by: Dave Mortensen

Yes: 7 No: 8 Abstain: 0 Absent: 0 Recuse: 0

 

Outcome: Motion Failed
 National Organic Standards Board

Crops Subcommittee Proposal

Hydroponics and Container-Growing Recommendations

August 29, 2017

Introduction

Over the past year the Crops Subcommittee has prepared—and received many public comments on—two

discussion documents and a proposal covering the range of growing systems in which nutrient delivery to 

plants is water based, including aeroponics, hydroponics, aquaponics, and plants grown in containers. We 

have learned that the public is divided on these issues, as are members of the NOSB. Some think that 

organic certification should require plants be grown in soil that is connected to the earth’s surface. Others 

think that organic certification should allow the growing of plants in pure nutrient solution, without the 

presence of any soil or compost. Others favor positions somewhere in between.

Accredited organic certification agencies have been permitted to certify hydroponic operations as organic 

by the National Organic Program (NOP), with some agencies certifying hydroponic operations and some 

choosing not to. The lack of consistency among certifying agencies and lack of standards for water-based 

nutrient-delivery growing systems has led to the need for the National Organic Standards Board to review 

this issue in a holistic way and recommend a path forward to the National Organic Program. 

The purpose of this proposal is to delineate the range of growing systems, from soil to soilless, and make 

recommendations on a middle ground within that range, which we hope the NOSB and the organic 

community can support. To do that, we first summarize pertinent past discussions and legal considerations.

Background

The 1995 NOSB recommendation Standards for Greenhouses contains the statement: 

Hydroponic production in soilless media to be labeled organically produced shall be allowed if all 

provisions of the OFPA have been met.

This was before there was an NOP rule so the NOSB only had OFPA to guide them. Also, that statement 

indicated that an analysis had not been made of whether or not hydroponics met the provisions of OFPA.

The brief dialogue at the 1995 meeting indicates that while some board members were supportive of 

hydroponics, others had concerns about soilless production:

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. Crossley moved and Weakley seconded 

a motion to accept lines 101-105 as a Board Final Recommendation. Friedman first offered a 

friendly amendment that was accepted to strike "other applicable" from the document. Vote: 

Unanimous aye.1

A revised proposed rule for the National Organic Program was published in March 2000 revising the initial 

 1 NOSB Meeting Minutes - April 24-28, 1995. Orlando, Florida.
proposed rule published in December 1997. In the supplemental information, the following was stated:

(13) We have amended the term, “system of organic farming and handling,” to “system of organic 

production and handling” and retained the original definition in this proposal. The original 

definition was crafted to be consistent with the requirements of the Act. We have changed 

“farming” to “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 

purpose of the original definition was to describe practices and substances consistent with systems 

of organic farming and organic handling as required by the Act and to provide an explicit reference 

point for determining which practices and substances are most consistent with these systems. 

Several commenters suggested that the definition include the concepts, “agroecosystem health,” 

“ecological harmony,” and “biological diversity.” Commenters also suggested including definitions 

for “organic agriculture,” “organic farming,” and “transition to organic.” This definition is intended 

to clarify regulatory provisions in this proposal and is not intended as a broad philosophical 

statement. The terms “organic agriculture,” “organic farming,” and “transition to organic,” are not 

used in this proposal and, therefore, are not defined2

The final rule for the National Organic Program was published in December 2000 (65 FR 80547). In the 

supplemental information, the following was stated:

The proposed rule treated mined substances of high solubility as a single category of soil 

amendment and allowed their use where warranted by soil and crop tissue testing. Many 

commenters objected to the general allowance for this category of substances and were 

particularly disappointed that the NOSB annotations on two such materials, sodium (Chilean) 

nitrate and potassium chloride, were not included. Commenters cited the potential detrimental 

effects of these highly soluble and saline substances on soil quality and stated that several 

international organic certification programs severely prescribe or prohibit their use. One certifying 

agent recommended that natural substances of high solubility and salinity be handled comparably 

to similar synthetic materials such as liquid fish products and humic acids that appear on the 

National List, complete with their original NOSB annotations. 

At its June 2000 meeting, the NOSB recommended that the NOP delete general references to 

mined substances of high solubility from the final rule, and incorporate the NOSB's specific 

annotations for materials of this nature. We have adopted this recommendation by retaining a 

place for mined substances of high solubility in the soil 

fertility and crop nutrient management practice standard but restricting their use to the conditions 

established for the material as specified on the National List of prohibited natural substances. 

Under this approach, mined substances of high solubility are prohibited unless used in accordance 

with the annotation recommended by the NOSB 

and added by the Secretary to the National List.3

At the Spring 2002 Meeting the NOSB Crops Subcommittee brought forward a new proposal on 

hydroponics stating: 

Hydroponic production in soilless media shall be allowed if all other provisions of the Organic Food 

Production Act and NOP final rule have been met. However, the Crop Committee recommends that 

the principles of organic production as presented by the NOSB Board be met by any certified 

 2 Federal Register Volume 65 Number 49. Page 13521. Docket Number: TMD-00-02-PR2, RIN 0581-AA40. 

National Organic Program Proposed Rule. Agricultural Marketing Service, USDA. March 13, 2000

3 Federal Register Volume 65 Number 246. Page 80565. Docket Number: TMD-00-02-FR, RIN 0581-AA40. 

National Organic Program Final Rule. Agricultural Marketing Service, USDA. December 21, 2000
organic hydroponic system. 

We recognize it will be a challenge for many hydroponic operations to meet some of the principles, 

that is, promoting biological cycles, recycling materials, minimizing use of non-reusable resources, 

et cetera. And we recommend that hydroponic operations that do not meet such principles be 

denied organic certification.

Discussion went on to note that this proposal followed recommendations made on greenhouse 

management, which allowed for waivers of certain NOP requirements. It was further noted that the intent 

of the proposal was to allow hydroponics if they meet all parts of OFPA/NOP other than soil requirements. 

Board members debated this motion and some questioned if exempting operations from soil was 

consistent with organic principles. Input was sought from the program if hydroponics were allowed under 

the NOP as currently written:

MR. BANDELE: Rick, maybe it would be helpful to get a clarification on, is hydroponics already 

covered?

MR. MATHEWS [NOP Program Manager]: The policy statement that is on the Web with regard to 

the scope of the National Organic Standards includes hydroponics.2

After input from the program, the board decided to table the matter stating: 

Hydroponic -- based on a discussion yesterday, the crops committee will reconsider that it was 

pointed out by Rick that hydroponics is already covered as far as the existing rule is concerned. So 

what the crops committee will do is try to provide some -- a guidance document... to the 

hydroponic situation at a later date.4

At the October 2002 meeting there was some discussion of hydroponics being on the Crops agenda but no 

additional information.5

 At the May 2003 NOSB meeting a draft discussion document about hydroponic 

and soilless production techniques and questions was circulated and at the meeting the following 

statement was recorded in the minutes: 

Draft guidance document regarding certification of hydroponics and other soil-less production 

systems. The draft will be forwarded to the strategic planning committee and NOP for feedback and 

to determine if further work on the document is a priority.6

The topic of hydroponics was next discussed at the October 2004 meeting. In the context of a draft NOP 

scope document, the policy sub-committee stated the following: 

[In regards to the scope document] ...the sixth area, which was mushrooms, apiculture and honey, 

greenhouse operations and greenhouse products, hydroponic agriculture; these are areas that the 

NOSB has had -- has addressed. These products from the April directive, the products may be 

certified to the existing NOP regulations which will be amended in future rulemaking to cover any 

unique production and handling requirements. NOSB has provided recommendations and the NOP 

is saying they'll publish at the earliest possible date through notice and comment rulemaking any 

additional standards needed for these commodities. So the Policy Development Committee 

recommends that the NOSB agree with the NOP for a position that mushrooms, apiculture and 

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

and carry the USDA Organic logo. We point out that the NOSB adopted the support of an April 25, 

1995 greenhouse recommendation, a section entitled "Specialized Standards for Hydroponic 

Production in Soil-less Media" and that their recommendations stated, "Hydroponic production and 

 4 NOSB Meeting Transcripts – May 6-8, 2002. Austin, Texas 5 NOSB Meeting Minutes – October 19-20 2002. Washington DC

6 NOSB Meeting Minutes – May 13-14 2003. Austin, Texas
soil-less media to be labeled organically produced shall be allowed if all provisions of OFPA have 

been met." And though the issue has been discussed, the NOSB has not yet submitted a 

recommendation on hydroponic standards since a Final Rule was released, so we request that the 

Crops Committee place the item on its work plan and that rulemaking standards should not 

proceed until the NOSB has submitted a final recommendation.

Furthermore, during an exchange between Barbara Robinson (Agricultural Marketing Service Deputy 

Administrator) and a board member, the following was said:

MR. BANDELE: I just have a kind of related question in terms of the -- just a point of clarification. 

Like something like hydroponics, which is -- can be covered by the rule but in which no guidance 

has yet been given, than at this point a USDA accredited certifier could certify an operation that’s 

organic. Is that right? 

MS. ROBINSON: Yes. Yes. We believe that hydroponics are covered under the standards. They fall 

under the crop standards. But we recognize that, you know, there may be additional details that 

need to be added to the standards.7

Hydroponics was not discussed again until the August 2005 meeting and only to say there was no update8

. 

At the November 2005 meeting hydroponics was discussed again with frustration being expressed over this 

being a work agenda item for multiple years with no progress. It was noted that hydroponic operations 

were being currently certified organic and the next steps would be to survey certifiers on how they were 

meeting the regulations.9

 At the April 2006 NOSB meeting the following update was given: 

Hydroponics is still on the list. Gather information and fact-finding on how and if hydroponics 

should have or could have standards, organic standards.

At the October 2006 meeting the NOSB discussed potential issues with hydroponics and OFPA around 

soilless production and aquatic plants. A survey of certifiers was proposed by the Crops Subcommittee.10 In 

March 2007 the NOSB approved recommendations for aquaculture standards that included aquatic plants. 

As part of this recommendation the following definition was proposed:

Aquatic plant. Any plant grown in an aquaculture facility, including microscopic or macroscopic 

algae, and excluding vascular aquatic plants such as watercress, rice, water hyacinth, and 

hydroponically produced vascular plant crops.”

Additionally, the following was proposed regarding aquaculture effluent: 

(2) Metabolic products of aquaculture species are not considered animal manure under §205.2 

Terms Defined, Manure, and § 205.239 (c) Livestock Living Conditions.

(3) Metabolic products of one species are recognized as organic resources for one or more other 

species in an aquaculture production system. The Organic System Plan of facilities producing 

aquatic animals must consider measures to recycle or biologically process metabolic products. 

Where feasible, the Organic System plan must include the polyculture of two or more different 

species grown in the same body of water, and the integration of additional species as water moves 

through the aquaculture facility or into adjoining discharge areas.

(4) The feasibility of using water discharges and filtered metabolic products as nutrients for vascular 

plants in agricultural crops and constructed wetlands must be considered in Organic System Plans. 

 7 NOSB Meeting Transcripts – October 12-14, 2004. Washington DC

8 NOSB Meeting Transcripts – August 15-17 2005. Washington DC

9 NOSB Meeting Transcripts – November 16-17 2005. Washington DC

10 NOSB Meeting Transcripts – October 17-19 2006. Arlington, Virginia. 
The quantities of such discharges and filtered products applied shall not exceed the requirements 

of targeted plants in the receiving area, and shall not be discharged into unplanned areas. Vascular 

agriculture crops using nutrients from certified organic aquaculture operations may be certified 

organic if in compliance with other regulations in this Subpart.11

At the May 2009 board meeting the Crop Subcommittee brought forward a discussion document on 

hydroponic production systems. This document generated substantial public comment and board debate 

about the compatibility of hydroponics with organic principles.12At the November 2009 NOSB meeting, 

Barbara Robinson (Deputy Administrator Transportation and Marketing Programs USDA) talking in the 

context of Canadian Equivalence stated the following: 

I told Canada that although we do not specifically prohibit hydroponic production, that it was my 

understanding that we don't approve hydroponic what I referred to as crops in a bucket in this 

country.13

In 2009 a document titled Soil-less Growing Systems Discussion Item contains the following statement:

In previous Crops Committee discussion documents, the question has been asked: ‘Should 

container culture based growing media (typically utilized in greenhouse systems) that are 

predominately 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, insects, 

arachnids, protozoa, fungi, bacteria, and actinomycetes 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.

In 2010, the NOSB issued a recommendation entitled Production Standards for Terrestrial Plants in 

Containers and Enclosures (Greenhouses). The recommendation contained the following statements:

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, cannot be considered as examples of acceptable 

organic farming practices. Hydroponics...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, 

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.

In the May 2014 Organic Integrity Quarterly the following was stated about hydroponic operations:

Organic hydroponics is a method of growing plants using mineral nutrient solutions, in water, 

without soil. Terrestrial plants may be grown with their roots in the mineral nutrient solution only 

or in an inert medium, such as perlite, gravel, biochar, or coconut husk...Organic hydroponic 

production is allowed as long as the producer can demonstrate compliance with the USDA organic 

regulations...Accredited certifying agents are certifying organic hydroponic operations based on the 

 11 NOSB Recommendation on Aquaculture Standards – March 29, 2007 12 NOSB Meeting Transcripts - May 4-6, 2009. Washington DC

13 NOSB Meeting Transcripts - November 3-5, 2009. Washington DC
current organic regulations and the operation’s Organic System Plan. In the future, the NOP may 

provide additional guidance regarding organic hydroponic production and how the regulations 

apply to such methods...The NOSB’s 2010 recommendation included a provision for not allowing 

organic hydroponic production. The NOP continues to work on evaluating and implementing a 

backlog of older NOSB recommendations including the greenhouse recommendation.14

In 2015, the NOP established a Hydroponic and Aquaponic Task Force to further explore this issue and

summarize their findings in order to provide additional information to guide the NOSB’s deliberations on 

whether hydroponic and aquaponic production should be allowed under the current organic regulations,

and if not, how the regulations could or should be changed. At the April 2015 NOSB meeting Miles McEvoy, 

Deputy Administrator of the NOP, stated the following about the 2010 recommendation:

...in order for us to do something to not allow organic hydroponics, we would have to do a rule 

change, which is, as you know, quite challenging... So, in order to move this topic forward, we did 

not have enough information from the NOSB 2010 recommendation to do a proposed rulemaking 

to prohibit organic hydroponics. We need more information to be successful.15

The NOP Task Force report was completed in July 201616. The Task Force was divided in their discussions 

and recommendations, so much so that the Task Force report was divided into two separate subcommittee 

reports, one named the “2010 NOSB Recommendation Subcommittee,” which proposed that organic 

certification require that plants get all or most of their nutrition from soil or compost, and one named the 

“Hydroponic and Aquaponic Subcommittee,” which favored allowing water-based nutrient delivery systems 

in organic certification. A third subcommittee of the Task Force explored options for labeling of hydroponic 

and container-based systems.

In consideration of the information presented in the Task Force report and from past NOSB 

recommendations, the Crops Subcommittee prepared a proposal for consideration by the full NOSB at the 

Fall 2016 NOSB meeting. The proposal included the following motion: 

Motion to allow bioponic17 (including hydroponic, aeroponic, or aquaponic) as consistent with 

organic production under the provisions and recommendations to be developed by the NOSB in 

2017.

The motion was worded “to allow bioponic” in order to require a 2/3 majority of the Board to overturn the 

previous NOSB recommendation (in 2010) that soilless production is not consistent with organic 

production. The Crops Subcommittee vote on the motion failed by a vote of two in favor and five opposed

to allowing “bioponic.“

At the Fall 2016 NOSB meeting, questions were raised about the wording of the motion. Particularly, it was 

noted that if the vote were to result in a failed motion, there would be no recommendation going forward 

from the NOSB to the NOP, making the vote meaningless. Therefore, the NOSB did not vote on the proposal 

 14 Organic Integrity Quarterly, May 2014, page 13 “Organic Hydroponics”

15 NOSB Meeting Transcripts – April 27-30, 2015. San Diego, California

16 Hydroponic and Aquaponic Task Force Report, July 2016

17 While “bioponics” was used in the Fall 2016 NOSB proposal, that term is not used in this proposal. 

Operations popularly referred to as “bioponic” fit within the definitions of hydroponics, aeroponics, 

aquaponics, and container growing used in this proposal.
but instead voted to send it back to the Crops Subcommittee for further work. However, the NOSB did pass 

the following resolution at the Fall 2016 meeting: 

The NOSB respects the efforts of the former NOSB that led to their 2010 recommendation on 

terrestrial plants in greenhouses. The NOSB recognizes that the foundation of organic agriculture is 

based upon a systems approach to producing food in the natural environment, which respects the 

complex dynamic interaction between soil, water, air, sunlight, plants and animals needed to 

produce a thriving agro-ecosystem.

At the heart of the organic philosophy is the belief that our responsibilities of good stewardship go 

beyond production of healthy foods and include protection of natural resources, biodiversity and 

the ecosystem services upon which we all depend. We encourage future NOSB to consider this 

wider perspective as the board undertakes the challenges of assessing and defining innovations in 

agriculture that may be compatible in a system of organic production.

In the case of the hydroponic/bioponic/aquaponic issue, it is the consensus18 of the current 

members of the NOSB to prohibit hydroponic systems that have an entirely water based substrate. 

Although that was the original intent of the proposal before us today, the current proposal as 

structured does not achieve this objective. 

While the NOSB does not believe that the liquid substrate systems should be sold under the USDA 

organic label, these growers deserve the chance to promote their very commendable qualities and 

objectives in their own right.

For the Spring 2017 meeting, the Crops Subcommittee prepared a discussion document titled 

“Aeroponics/Hydroponics/Aquaponics,” which solicited additional public input on these types of growing 

systems as well as container-based growing systems.

Relevant areas in the Rule

Organic Foods Production Act of 1990 (OFPA)

§6504. National standards for organic production 

To be sold or labeled as an organically produced agricultural product under this chapter, an agricultural 

product shall—

(1) have been produced and handled without the use of synthetic chemicals, except as otherwise 

provided in this chapter; 

(2) except as otherwise provided in this chapter and excluding livestock, not be produced on land to 

which any prohibited substances, including synthetic chemicals, have been applied during the 3 

years immediately preceding the harvest of the agricultural products; and 

 18 Because two members of the NOSB did not support this resolution, the resolution was amended to 

substitute the word “majority” for “consensus.” However, it wasn’t recognized until later that that word 

change confused the sentence syntax. It should also be noted that the two NOSB members who did not 

support the resolution went on record as being opposed because they did not think the resolution was 

strong enough, but they too were opposed to “hydroponic systems that have an entirely water-based 

substrate.”
(3) be produced and handled in compliance with an organic plan agreed to by the producer and 

handler of such product and the certifying agent. 

§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.

USDA Organic Regulations

§205.2 Terms defined. 

Crop rotation. The practice of alternating the annual crops grown on a specific field in a planned pattern or 

sequence in successive crop years so that crops of the same species or family are not grown repeatedly 

without interruption on the same field. Perennial cropping systems employ means such as alley cropping, 

intercropping, and hedgerows to introduce biological diversity in lieu of crop rotation.

Field. An area of land identified as a discrete unit within a production operation.

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.

§ 205.200 General.

The producer or handler of a production or handling operation intending to sell, label, or 

represent agricultural products as “100 percent organic,” “organic,” or “made with organic

(specified ingredients or food group(s))” must comply with the applicable provisions of this subpart. 

Production practices implemented in accordance with this subpart must maintain or improve the natural 

resources of the operation, including soil and water quality. 

§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; 

Discussion

This discussion section provides background information in support of the voting motions that follow. 

Arguments in favor of allowing hydroponic systems to be certified organic are in a minority view at the end 

of this document.

The role of the NOSB centers on making recommendations that underpin the integrity of the USDA organic 

label. Consumers entrust the NOSB with the important role of critically assessing what constitutes organic 

production and processing. The NOSB understands that many production systems and brand labeling exist 

outside of the organic label; however, our role is as gatekeepers of the organic label. As such, it is our 

responsibility to recommend production practices that uphold the integrity of the USDA organic seal, that 

are built on the primacy of soil stewardship, that are managed to emulate ecological processes of 

productive ecosystems, that support and enhance biodiversity, and that minimize to the extent possible the 

downside effects of farming while at the same time producing safe, nutritious, and tasty foods.

 

The organic designation, with its roots in the teachings of Sir Albert Howard, is based on soil. This fact is 

evident throughout the Organic Foods Production Act (OFPA). Section 6513 of the Organic Plan under the 

Crop Production section begins with Soil Fertility, detailing the critical role that managing organic matter 

plays in the plan, then finishes (section (G)) stating “an organic plan shall not include any production or 

handling practices that are inconsistent with this chapter”. There are a number of other reasons not to 

include hydroponic agriculture within the organic designation.

Field-grown plants are physiologically different from hydroponically grown plants for a number of reasons. 

Hydroponic, greenhouse plants are not stressed the way field-grown plants are. Secondary plant 

metabolites, for example, frequently increase in concentration in stressed plants.19 Secondary plant 

metabolites have also been found to be higher in organic crops than conventional, in soil-based systems.20

 19 Ramakrishna, A. and Ravishandar, G.A., 2011. Influence of abiotic stress factors on secondary metabolites 

in plants. Plant Signal Behav. 2011 Nov 1; 6(11): 1720–173.

20 Benbrook, C.M., 2005. Elevating antioxidant levels in food through organic farming and food processing. 

An Organic Center State of Science Review. https://www.organiccenter.org/reportfiles/Antioxidant_SSR.pdf
Field-grown plants will also be symbiotic with sets of microbial communities that are distinct from those 

found in hydroponically grown plants, and there are many consequences of this. The endophytic fungi living 

in stems and leaves will also be very different in hydroponic container-grown and field-grown plants. These 

fungi influence a number of physiological variables including secondary metabolism, with consequences for 

flavor and nutrition.

In addition to bypassing naturally occurring, co-evolved relationships between plant roots and the many 

functional trait types of rhizospheric organisms, nutrient bathing is an unbuffered system. For example, 

nutrient solutions contain high concentrations of nitrate, which plants can accumulate beyond their 

requirement, storing excess nitrate in leaf (and root) vacuoles. This is particularly problematic for some 

species like spinach and chard. Nitrate is toxic in food, has been linked to stomach cancer, and can kill 

livestock. Meta-analyses have shown that organically produced produce has lower nitrate levels than 

conventionally grown produce, an example of a clearly documented health benefit of organic production. 

Nitrogen regimes in organic systems are slow release, making them more synchronized with plant demand, 

which is better for the environment (less leaching and volatilization) as well as better for consumers. The 

problem with solution culture in this context is that N and P regimes are orders of magnitude more 

concentrated than those found in soil solution which is naturally highly buffered (meaning only a fraction of 

the nutrients that exist in the soil are available at any one time). Nutrient solutions are unbuffered, so high 

N and P concentrations are needed, which could result in unnatural and (in the case of N) problematic 

mineral nutrient accumulation. High P regimes will also reduce phytoavailability of Fe and Zn, two nutrients 

deficient in many human diets.

An added concern about the difference between a buffered soil--where nutrients are built up over a long 

period of time with the bulk of the mineral nutrition coming from manure, crop rotation, cover cropping, 

compost, and nutrient capture from rainwater--is that for a number of hydroponic systems, the principle 

source of fertility comes from highly soluble sources such as hydrolyzed soybean meal. Today, 

approximately 95% of the soybeans grown in the U.S. are genetically modified, using molecular methods 

prohibited by the NOP. The engineered trait used in GM soybean has brought about a dramatic rise in 

herbicide use on the backs of the so-called transgene facilitated herbicide treadmill (Mortensen et al. 

2012).21 Hydroponic growers who use hydrolyzed soybean meal have indicated that they source it from 

Europe, to avoid GMO soybean meal. Are the environmental costs of importing this nutrient factored into 

the claimed environmental benefits of hydroponic production?

In a 2015 paper purporting to be “the first quantitative comparison of conventional and hydroponic 

produce production” (Barbosa et al. 2015),22 the authors compared the yield, water use efficiency, and 

energy use efficiency of the two production systems. The paper contained some misleading assumptions 

about the yield of the two systems. Specifically, the paper concludes that lettuce yield would be 11 times 

higher in the hydroponic production system. Only at the end of the paper is it clarified that the analysis is 

built on the assumption that lettuce is grown year round in the hydroponic system while “warm season 

crops” would be grown in the field, and the analysis only compared lettuce production and not those 

additional warm season crops. In effect, the paper far understates the yield of the “conventional, soil 

grown” crops. However, the energy required to produce the crops compared across the hydroponic and soil 

grown systems is revealing. The paper concludes that the pumps, heating and cooling, filtration, lighting 

 21 Mortensen, D.A., Egan, J.F., Maxwell, B.D., Ryan, M.R., and R.G. Smith, 2012. Navigating a critical juncture 

for sustainable weed management. Bioscience Volume 62:1. pp75-84. 22 Barbosa, G.L., Gadelha, F.D., Kublik, N., Proctor, A. Reichelm, L. Weissinger, E. Wohlleb, G.M. and R.U. 

Halden, 2015. Comparison of land, water, and energy requirements of lettuce grown using hydroponic vs. 

conventional agricultural methods. Int. J. Environ. Res. Public Health 2015, 12(6), 6879-6891
etc. would result in an approximately 100-fold increase in energy use per unit of lettuce produced. By the 

author’s own admission, energy analyses of this kind are surprisingly rare. 

In a study of indoor Cannabis production, Mills (2012)23 found that energy consumption for this practice in 

the United States is 1% of national electricity use, or $6 billion each year. One average kilogram of final 

product was associated with 4600 kg of carbon dioxide emissions to the atmosphere, or that of 3 million 

average U.S. cars when aggregated across all national production. The paper goes on to state, “the 

unchecked growth of electricity demand in this sector confounds energy forecasts and obscures savings 

from energy efficiency programs and policies”. 

In addition to these systems being energy inefficient, they lack resiliency. During a recent visit to an 

aquaponics facility in the northeastern U.S., one NOSB member observed staff replanting lettuce and other 

greens and awaiting a shipment of new fish. An ice storm had moved through the region and knocked 

power out for nine hours. During that time, the daytime heat load, coupled with the lack of nutrient 

delivery and oxygenation of the roots of the plants and fish tanks, resulted in most of the lettuce dying and 

all of the fish dying. In terms of systems resilience, this aquaponics system with its high dependence on 

electricity, predisposed the system to be very brittle. A system built on a high degree of external energy use 

is not in keeping with the spirit of the organic label.

Hydroponic proponents argue that as many bacteria and fungi are found in hydroponics as are found in soilbased systems. However, they are not able to cite data to indicate that hydroponic systems have the 

ecological complexity of soil-based systems. How soils are managed does affect microbial diversity. In a 

comparison of organic and conventional soil-based systems, it was found that the “Organically managed 

system increased taxonomic and phylogenetic richness, diversity and heterogeneity of the soil microbiota 

when compared with conventional farming system.”24

It is not surprising that hydroponic systems would have high numbers of decomposing microorganisms 

when labile feedstocks like hydrolyzed soybean or fish meal are fed into the system. Populations of 

microorganisms will multiply quickly when given such an easily degraded food source. However, those 

should not be considered equivalent to the diverse populations of microorganisms present in a soil-based 

rhizosphere. 

Natural soils are generally 95% or more mineral matter by weight. Soil mineral particles (clay, silt, and sand) 

are intimately intertwined and complexed with soil organic matter. This mineral/organic matter soil system 

provides habitat and food sources for a great diversity of soil microorganisms and creates pore spaces in 

soils for storing water and for air exchange with the atmosphere. The clay/humus complexes also serve a 

primary function of holding soil nutrients in reserve for plant uptake. 

The maintenance and regeneration of this complex, living soil system is a biological process that requires 

continual recycling of organic materials within the soil system. Crop rotations and cover crops are also 

important to create and maintain healthy soils, which contribute to healthy plants. It is this complex soil 

system that pioneer organic farmers learned to work with and optimize, in contrast to the prevalent 

industrial, input-based model of agriculture, which they rejected. Early organic certification standards 

reflected this system and 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 

 23 E. Mills, 2012. The carbon footprint of indoor cannabis production. Energy Policy 46 (2012) 58–67. 24 Lupatini, M., Korthals, G.W., de Hollander, M., Janssens, T.K.S., and Kuramae, E.E., 2016. Soil microbiome 

is more heterogeneous in organic than conventional farming system. Front Microbiol. 2016; 7: 2064.
rock powders (Task Force report p. 14). For these reasons, many organic producers reject hydroponic

systems that are input-based rather than soil-based.

Loss of arable land and the need to feed a growing world population are cited by pro-hydroponic 

advocates. However, organic agriculture, with its focus on soil building and protection or enhancement of 

natural resources, offers the opportunity to continually improve soil productivity and the natural resource

base while producing crops, as well as to transform land which has been degraded by poor farming 

practices or is of low productive capability into sustainable farming systems. Moreover, productivity per se

is not a measure of the legitimacy of organic agriculture. Maintenance and improvement of the natural 

resources of the operation are also mandated under the organic regulation. On soil-based organic farms, 

the production of food and fiber is accomplished in concert with improving habitat for wildlife of all types 

including pollinators, mammals, amphibians, and soil microbes. Increased soil organic matter, cover crops, 

rotations, contour strips, reduced tillage, and other activities continually improve soil structure and lessen 

erosion, which negatively affects water and soil quality. This integration of working lands with ecosystem 

stewardship is a foundational principle of organic agriculture.

Hydroponic production is highly dependent on continuous use of fertilizer inputs to the production system, 

rather than relying on a productive soil and natural recycling of nutrients through decaying organic matter

to regenerate the fertility needs of the crop. The “input substitution” approach used in hydroponics has 

long been considered incompatible with a system of organic agriculture. Some of the major fertility inputs 

used in hydroponic production are transported long distances to the hydroponic production site, negating 

the purported environmental benefits of hydroponic production.

Specific language from OFPA and the Organic Rule that justify disqualifying soilless production from organic 

certification includes the following:

• §6513 Organic Plan: “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...An organic plan shall not include any production or handling practices that 

are inconsistent with this chapter.”

• § 205.200 General: “Production practices implemented in accordance with this subpart must 

maintain or improve the natural resources of the operation, including soil and water quality.”

• § 205.203 Soil fertility and crop nutrient management practice standard:

o (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.”

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

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

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

organic matter content...”

Aeroponic, hydroponic, and aquaponic production systems can be productive cropping systems, which can 

be appropriate and well adapted to specific situations. However, that does not mean those systems are 

compatible with the principles of organic production or should quality them for organic certification. 

Public Comments from Previous Proposal and Discussion Documents

Numerous comments were received from the public in response to the Hydroponics Task Force report and 

the NOSB Crops Subcommittee proposal and two discussion documents on hydroponics and container 

growing over the past year. 
Those in favor of allowing hydroponics to carry the organic label in the marketplace discussed the efficient 

use of water and nutrients as important considerations. They also stated that there were fewer disease and 

pest problems in their controlled-environment production systems, leading to lower use of organically 

approved pesticides. Soil and water were considered by them to be equally acceptable as a medium to 

deliver nutrients to plant roots. Food safety, worker health, providing food to urban food deserts, or aiding 

inexperienced or small-scale growers were also cited as benefits of hydroponics. Hydroponic growers were 

also concerned that if hydroponics were no longer allowed, current hydroponic growers would lose their 

organic market.

Those against allowing hydroponics to carry the organic label in the marketplace discussed the foundational 

principles of organic as originating with care and improvement of the soil and the overall ecosystem. 

Longer-term improvements such as the use of nitrogen-fixing crops, cover crops for improved organic 

matter, and an overall regenerative system that protects water and wildlife as well as supporting 

biodiversity, were also noted in numerous comments. The OFPA and organic regulations were cited, 

illustrating where soil- and ecosystem-based production systems are in the basic description of certified 

organic production. Many agreed hydroponics can be an innovative system of production, but did not agree 

that it met the letter or spirit of the organic law or regulations. Organic growers using soil in greenhouses 

contended that it is the greenhouse environment, not hydroponics, that allows for lower pesticide use, 

improved food safety, worker health, and providing food to urban food deserts.

Rationale for Proposed Recommendations on Aeroponics, Hydroponics, Aquaponics, and Container 

Growing

At the first meeting of the Hydroponic/Aquaponic Task Force in January 2016, the NOP presented 

information about potential gaps and inconsistencies in the past NOSB recommendations, both for 

hydroponics and for greenhouse growing systems in general. The NOP presentation included the following 

statement, "Further analysis and clarification is necessary because regardless of what position the NOSB 

ultimately takes on the issue of hydroponics and aquaponics, the NOP will likely need to undertake 

rulemaking. Rulemaking requires a comprehensive recommendation from the NOSB that addresses grey 

areas left by past recommendations." 

The grey areas and gaps include the following (paraphrased from original):

• A clear explanation of the basis for each recommendation made.

• Acknowledging the continuum of production methods from field/soil to hydroponic and the role of 

compost or other biological growing media. Recommendations on each type of production and 

reasons for allowing or prohibiting.

• Guidelines are needed on exactly how different production types comply with provisions in 

regulations for soil fertility, rotation, and cover cropping.

• Definitions of vague terms including container, hydroponics, soil-less media, "compost-based", and 

soil ecology.

• How are OFPA and the NOP rule able to be consistent on other soilless production such as 

mushrooms, sprouts, aquatic plants and greenhouse in-ground systems?

• What is the justification for requiring soil (as opposed to cycling of resources, promoting ecological 

balance, and conserving biodiversity) but making an exception for cover crops, crop rotation, etc. 

when soil is not explicitly required in the regulations, but crop rotation is a MUST? 

• Aquaponic systems are not specifically addressed in previous NOSB recommendations. 
The lengthy report from the Task Force contains much more background information; too extensive to 

cover here. Selected portions are referenced throughout this proposal.

For clarity, terms used in this proposal, as well as some of the most common definitions taken from the 

NOSB 2010 Recommendation and the Task Force Report are appended in a glossary, amended for this 

discussion. 

1. Consistency with mushrooms, aquatic plants, seedlings, and other "soilless" culture.

The 2010 Subcommittee of the Task Force report points out the following, 

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.

They continue by pointing out that sprouts and wild harvest aquatic plants are addressed in the current 

organic regulations, and the Preamble to the final rule specifically states that additional standards would be 

needed for mushrooms and greenhouses.

The Crops Subcommittee concurs with this analysis. Sprouting seeds is similar to a processing step for an 

organic product. Therefore the ingredient (seeds) must be certified organic. There are no inputs to the 

seeds to make them grow besides water, an exempt handling ingredient. The essential elements otherwise 

needed for plants to complete their lifecycle are not added because all the nutrition they need to the point 

of harvest is provided by the seed.

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

(Greenhouses) includes the statement “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.”

Wild Aquatic plants are covered under the wild crop section of the rules, and the preamble specifically 

points out that the term "site" was used to replace "from land" in the proposed rule. This clarifies that wild 

aquatic plant certification was intended. However, there is now a large amount of aquatic plant farming 

occurring that would not be considered wild, and this is not covered in the current rules.

Seedlings, or transplants, are also specifically mentioned in the organic rules and must be certified 

organically grown but are considered acceptable if raised in soil-less media. These are future crops that will 

spend most of their time growing in soil, and the time to produce the transplant is short compared to the 

time spent in the ground.

Mushrooms are fungi, not plants, and that justifies that they don't have a direct link to soil. They are more 

similar to yeasts and microorganisms that may be grown on substrate that does not depend on minerals 

from soil. The parameters of their production may eventually need additional rulemaking, but so far many 

mushrooms are able to be certified organic under the existing rules.
2. Land Considerations and Natural Resources

Regardless of where the container production is occurring, the land underneath the containers and the 

surrounding environment must be considered. The land underneath an outdoor operation must comply 

with the same provisions of the rule regarding land history and transition as other land. It must also be 

maintained or improved with respect to avoiding contamination. Land that has a building on top of it with 

an impermeable floor must comply with whatever practices are adopted for greenhouse or enclosure 

production.

The 2010 Subcommittee of the Task Force asked the NOSB to consider limiting the use of land where crops 

could be grown in the soil from being converted to container production. It also suggested limiting the 

conversion of non-organic container plants to organic by re-potting them in organic growing media.

Natural resource conservation includes the resources of soil, water, and wildlife. This must be addressed in 

an Organic System plan for a container growing system. This includes maintaining the condition of land 

underneath the container production, fate of any water or nutrient run-off from container production, and 

any positive actions taken to encourage biodiversity, such as installing hedgerows, planting insectary plants 

amongst the containerized crop plants, and other similar techniques.

3. Rotation

The 2010 NOSB recommendation noted that the intent of the rotation and cover cropping clauses in the 

rule could be met by similar practices with the same functions or goals as the crop rotation that are 

applicable to the operation. Such techniques might include mulching, replacing growing media (thus 

replenishing the soil system), planting hedgerows, adding microbial inoculants to stimulate existing 

populations, and recycling and composting used growing media. It was noted by the 2010 Recommendation 

Subcommittee of the Task Force that the crop rotation requirement is already not enforced by some 

certifiers on greenhouse crops grown in soil and on perennial crops with limited water.

Similarly, Canadian standards 7.5.12 states: 

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 greenhouse soil or container soil, provided it is re-used outside 

the greenhouse for another crop.

4. Containers & Growing Media

The 2010 NOSB recommendation on Terrestrial Plants in Containers does partially address production in 

containers. It specifies that the substrate in the container be based on compost and reiterates the previous 

NOSB opinion that compost was equivalent to soil.

The weakness of the 2010 recommendation was that it didn't quantify "compost-based", nor did it specify 

upper or lower limits for the volume of soil or compost in a container to achieve a level of biological activity 

comparable to that found in soil. There was also no consideration of whether non-synthetic, carbon-based 

materials such as coir or peat moss could serve the same functions as soil in a container.

The statement from OFPA that fertility come "primarily through the management of the organic content of 

the soil" has been interpreted to mean that soluble fertilizers should not be the primary source of nutrients 

but only a supplement to an overall program focused on crop rotations, cover crops, and amending with 

compost or manure. This is reflected consistently throughout NOSB recommendations from the past, from 
limitations on sodium nitrate or potassium chloride, to many rejected petitions centered on adding soluble 

forms of nutrients to the National List. 

In order to specify an appropriate size of container or characteristics of the growing media that are 

appropriate for organic production, there needs to be a comparison of the characteristics of container 

system versus the soil system. The 2010 Recommendation Subcommittee of the Task Force uses bulk 

density as point of comparison to assess important distinctions between the two systems. Mineral soils 

have a bulk density of about 1.3 grams per cubic centimeter, while non-organic peat or coir-based media 

are only 0.13 gm/cubic cm, one tenth as much. With compost or other high organic matter media, the bulk 

density increases and so will the nutrient-supplying capacity.

A raised bed that has a liner between it and the ground is considered a container, regardless of the depth of 

the growing media. However, containers as referred to in this discussion are limited to those containing a 

solid substrate only25.

By making the containers large enough, the nutrients in the organic matter fraction will be able to supply 

the majority of the nutrition for the plant. What is large enough, and how can it be explained in a way that 

is appropriate for different plants? The 2010 Recommendation Subcommittee of the Task Force cites the 

work of Dr. Martine Dorais of Laval University and the Agassiz Research and Development Centre. At a 

volume of 100 to 180 liters of soil per m2

, 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. 

Both Canada and Sweden permit container growing while requiring minimum soil volumes based on 

growing area (although proposed new EU rules would prohibit container growing in the future). Canada 

requires a minimum soil volume of 70 liters26 per m2 of growing area. For staked crops like tomatoes and 

peppers, they require at least 10% compost at the start of production, and containers must be at least 30 

cm (12 inches) high. They state, 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.

The Canadian standards do not specify an amount of compost or soil for other crops such as lettuce or 

blueberries. They do not account for breakdown and settling of soil volume. It is unclear how certifiers can 

measure the soil volume, and the term "growing area" is not well defined.

In Sweden, at least 30 liters of soil per m2 are required for annual crops with long seasons and 0.2 liters per 

pot for other plants, such as herbs, lettuce, and strawberries. However, as mentioned above, proposed new 

EU rules would prohibit container growing in Sweden.

The 2010 Recommendation Subcommittee of the Task Force report states, "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." It is possible to have a compost- or soil-

 25 Container troughs in which water is recirculated are considered hydroponic. Similarly, container systems 

with troughs under the pots that collect, filter, and recirculate the water after adding additional liquid 

nutrients are considered hydroponic unless they meet the container standard in the Container Production 

Systems motion below. 26 For reference a 5-gallon pot holds 25 liters and a 10-gallon pot holds 40 liters.
based growing media with adequate aeration and water holding capacity that can provide enough fertility 

for production of annual plant crops or a season in the growth of perennial plants. 

The 2010 Recommendation Subcommittee of the Task Force proposed that organic growing media must 

have a minimum of 20% compost.

5. Nutrition

The 2010 Recommendation Subcommittee of the Task Force Report states, "The key distinction between 

organic fertility management and conventional fertility management is that under organic management the 

source of the bulk of the crop nutrients are from the biological activity of decomposing complex organic 

molecules (compost, manures, seed meals, etc.) and the mineral fractions." Soil is important due to the 

interactions of the physical, chemical, and biological properties together.

While hydroponic systems can be efficient in nutrient recycling and water conservation, they do not have 

the complex interactions found in an organic soil-based system. The backbone of organic production is the 

complex interactions between soils, plants, animals (from tiny insects to large herbivores and carnivores),

and humans.

It would seem logical to assess the continuum between grown in the ground and fully liquid-based systems 

by determining where the plant nutrition is coming from. If the nutrients are primarily coming from soil or 

compost and solid amendments, then they would be considered equivalent to in-ground production

whereas a container production system that relies primarily on liquid fertilizers would not be within the 

requirement for soil-based systems.

The NOSB recognizes that some soils contain very little inherent fertility and crops are being grown and 

certified organic which rely in large part on liquid fertilizers. While that is an area that the NOSB and NOP 

should examine to see if higher standards should be set to improve the inherent fertility of those soils over 

time, that is outside the scope of this attempt to set standards for crops grown in containers. Container 

producers have more flexibility to create a minimum level of fertility in the container substrate mix before 

beginning production, compared to producers growing in the ground. 

The 2010 Recommendation Subcommittee of the NOP Hydroponics Task Force proposed to “Limit organic 

certification to what is grown in the ground, with the exceptions of transplants, ornamental, and herbs.” 

That subcommittee further proposed that if organic certification were to include crops grown in containers, 

there should be 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. 

“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” (Task Force Report p. 54). That applies to crops grown in the ground. Other 

standards for greenhouses limit liquid nutrients to 25% of the total nutrients supplied. A recent revision to 

the Canadian standards27 also proposes limits on liquid fertilizers by stating that for small soil volumes, 70% 

of the nitrogen and phosphorus must be supplied by solid organic soil amendments that require an active 

soil ecosystem.

The suggestion of the 2010 Recommendation Subcommittee of the Task Force that liquid nutrients be 

limited to 20% of the total nutrients supplied is consistent with the current annotation for the use of the 

 27 2016 amended draft of Canada Organic Standards, pp 44-45: General Principles and Management 

Standards
highly soluble Chilean nitrate, which is listed at 205.602: “Sodium nitrate (is prohibited)—unless use is 

restricted to no more than 20% of the crop’s total nitrogen requirement.”

The policy on Chilean nitrate sets a precedent for the use of highly soluble inputs. How that policy came 

about is worth exploring here because it illustrates how the principles of organic agriculture influenced that 

policy. 

As mentioned above, in the Preamble to the Final Rule of the NOP of December 21, 2000, the Proposed 

Organic Rule of 1997 had allowed the use of mined substances of high solubility (e.g., Chilean nitrate). The 

Preamble to the Final Rule goes on to say “Many commenters objected to the general allowance for this 

category of substances.” Therefore, the Final Rule included the June 2000 recommendation of the NOSB, 

which is the annotation at §205.602 that sodium nitrate be “restricted to no more than 20% of the crop’s 

total nitrogen requirement.”

In April 2000, the NOSB recommended complete prohibition of sodium nitrate. The NOP has yet to fulfill 

that recommendation but issued a policy memo in September 201128 that states:

Organic producers must meet the requirements of 7 CFR 205.200 which states that production 

practices must maintain or improve the natural resources of the operation, including soil and water 

quality. Under 7 CFR 205.203(b), producers must manage crop nutrients and soil fertility through 

rotations, cover crops, and the application of plant and animal nutrients. Organic producers who 

use sodium nitrate need to ensure that the use of sodium nitrate is aligned with the requirements 

of 7 CFR 205.203(b). 

The principle of limiting soluble Chilean nitrate to 20% of a crop’s nitrogen requirement in order to remain 

aligned with the soil fertility requirements of the organic standards is consistent with a principle of limiting 

soluble fertility sources to 20% of a crop’s needs in container production systems. 

A requirement that would limit liquid feeding of crops is complicated by the number of essential elements 

needed by crops, and that some micronutrients may need higher percentages of supplemental feeding than 

macronutrients like nitrogen. Nitrogen is generally the most dynamic crop nutrient in the soil/substrate, 

and managing nitrogen in accord with organic principles will likely ensure that all nutrients are managed 

well. Also, limiting the requirement to just one indicator element (nitrogen) makes monitoring for 

compliance much easier. 

Chilean nitrate is generally about 16-0-0 (16% nitrogen). Hydrolyzed soybean meal (which is commonly 

used as a nitrogen source in hydroponic container systems) is also sold as 16-0-0 (16% nitrogen), and like 

Chilean nitrate, is completely water-soluble. Limiting use of soluble nitrogen feeding to 20% of crops’ needs 

will help ensure that container growing is aligned with the requirements of 7 CFR 205.203(b), as outlined in 

the quote from the NOP above.

Hydroponics proponents claim that the mineralization of nutrients into forms that plants can take up can be

performed by microbial digestion in a hydroponics system with carbon-based substrate, and that the 

microbial population and dynamics are equivalent to a "diverse soil ecology". The Crops Subcommittee 

questions those statements because simple, labile nutrient sources are used in container systems, and no 

definitive data has been provided to back up the claim that microbial dynamics are equivalent to a diverse 

soil ecology. Saying that "soil biology" can happen without soil is not substantiated by definition or data.

 28 https://www.ams.usda.gov/sites/default/files/media/NOP-Notice-12-1-SodiumNitrate.pdf
6. Other issues

The Task Force report included discussion about other issues related to indoor production. In a separate 

discussion document to be presented at the Fall 2017 meeting in Jacksonville, the Crops Subcommittee 

discusses three of those issues: use of artificial light; use of synthetic mulches; and disposal of crops, 

substrates, and containers at the end of the crops’ production cycle. The Crops Subcommittee seeks input 

from the organic community on those issues.

Some have expressed concern that if hydroponic and aquaponic production are prohibited from organic 

certification, it would be a hardship for those hydroponic and aquaponic operations currently certified. 

Certainly, some currently certified operations would lose certification, but the numbers would be quite 

small relative to the total number of operations certified through the NOP. 

At the April 2016 meeting of the NOSB, Deputy Administrator Miles McEvoy, presented the results29 of a 

2016 survey to certifying agents regarding the certification of hydroponic, aquaponic, and container-based 

systems. Of the 80 accredited certifying agents worldwide at the time of the survey, 17 certified 

hydroponic and aquaponic operations. Stated as a percentage, 21% of certified agents are certifying these 

operations. Similarly, of the approximately 31,000 certified organic operations, 30 (or less than 0.1% of all 

certified organic operations) were certified organic hydroponic. There were 22 certified organic aquaponic 

operations, or 0.07% of all certified organic operations. Finally, there were 69 certified organic containerbased operations, or 0.2% of all certified organic operations. As is clear from these figures, certified organic 

hydroponic, aquaponic, and container-based systems constitute an extreme minority of all certified organic 

operations, or less than 0.4% when combined.

Regarding the location within the organic standards where aeroponics, aquaponics, and hydroponics could 

be addressed, if any of the motions below to remove organic certification from a specific method of 

production are passed by the NOSB, the National Organic Program could add those prohibitions to 205.105, 

as well as adding the definitions of the various methods to 205.2 Terms Defined.

An example would be:

205.105 To be sold or labeled as “100% organic”, “organic”, or “made with organic (specified ingredients 

or food groups)”, the product must be produced and handled without the use of:

(h) aeroponics

(i) aquaponics

(j) hydroponics

Crops Subcommittee Proposed Recommendations:

Aeroponics

Discussion: Aeroponics systems do not require soil or a root-zone medium. The roots are intentionally 

suspended in midair, in part to expose them to more atmospheric oxygen to aid plant growth. The roots are 

regularly sprayed with water that contains water-soluble nutrients. 

The Crops Subcommittee is opposed to allowing aeroponic production systems to be certified organic 

because they do not meet the requirements of OFPA or the Organic Rule.

Subcommittee vote:

Motion to prohibit aeroponic production systems from organic certification.

Motion by: Emily Oakley 

 29 https://www.ams.usda.gov/sites/default/files/media/McEvoy%20NOSB%20April%202016.pdf
Seconded by: Harriet Behar

Yes: 8 No: 0 Abstain: 1 Absent: 0 Recuse: 0

Aquaponics

Discussion: Aquaponic production is a form of hydroponics in which plants get some or all of their nutrients 

delivered in liquid form from fish waste. Aquaponics is defined here as “A recirculating hydroponic system 

in which plants are grown in nutrients originating from aquatic animal waste water, which may include the 

use of bacteria to improve availability of these nutrients to the plants. The plants improve the water quality 

by using the nutrients, and the water is then recirculated back to the aquatic animals.”

The NOP has strict standards for handling animal manure in terrestrial organic production, but no such 

standards exist to ensure the safety of plant foods produced in the fecal waste of aquatic vertebrates. Also, 

the NOP has not yet issued standards for organic aquaculture production, upon which aquaponic plant 

production would be dependent.

The Crops Subcommittee is opposed to allowing aquaponic production systems to be certified organic at 

this time. If aquaculture standards are issued in the future, and concerns about food safety are resolved, 

aquaponics could be reconsidered.

Subcommittee vote:

Motion to prohibit aquaponic production systems from organic certification.

Motion by: Harriet Behar

Seconded by: Jesse Buie

Yes: 7 No: 2 Abstain: 0 Absent: 0 Recuse: 0

Hydroponics and Container Growing

Discussion: The word “hydroponics” comes from two Greek words: hydro, meaning water; and ponos, 

meaning labor. In popular use of the term, hydroponics means growing plants by providing the plants’ 

nutrition in liquid form. The Merriam-Webster Dictionary definition of hydroponics is “the growing of plants 

in nutrient solutions with or without an inert medium (such as soil) to provide mechanical support.”

Proponents of allowing hydroponic production to qualify as certified organic have created confusion in the 

hydroponics discussion by attempting to redefine some forms of hydroponic production as “container 

growing.” That creates confusion because, in fact, all hydroponic production is done in containers, and as 

noted above, hydroponics has traditionally been defined by the use of nutrient solutions to feed plants, not 

by the particular type of rooting medium used.

In particular, hydroponic producers who want to be certified organic claim that if plants are grown in 

certain rooting media, the growing system is no longer hydroponic, even if all, or virtually all, of the plants’ 

nutrition is provided as a liquid feed. That belies both common usage and dictionary definitions of 

“hydroponics.”

A common rooting medium that is used in hydroponic container production is coconut coir. One of the 

advantages of coir as a growing medium is that coir is resistant to microbial decomposition, so it will 

maintain its structure and water-holding capacity in the container longer than some other rooting 

materials. Hydroponic advocates argue that coir is not inert. However, the NOP, in the May 2014 Organic 

Integrity Quarterly (cited above), included “coconut husk” in a list of examples of an “inert medium.”
In a research paper investigating decomposition rates of coir, Prabhu and Thomas30 point out “Coir pith 

with high C:N ratio (about 100:1), lignin and polyphenol contents is highly resistant to easy 

decomposition...Lignin prevents the easy decomposition and mineralization of coir pith...making it a 

recalcitrant biopolymer.”

Coir is a good rooting medium for hydroponic production because it has high air- and water-holding 

capacity and because it is recalcitrant. Coir pith also has a cation exchange capacity of 20-30 meq/100g 

(Ravindranath)31. However, “As a nutrient source, coir pith has not much value” (Prabhu and Thomas). The 

nitrogen content of coir pith ranges from 0.26% (Ravindranath) to 0.57% (Bethke)32. Given the C:N ratio of 

100:1 for coir pith, the small amount of nitrogen in coir will not serve as a nitrogen source for growing 

plants, which means that in a hydroponic system using coir as the rooting medium, all of the plants’ 

nitrogen needs will have to be supplied by liquid feeding.

It is interesting to note that the Merriam-Webster definition of hydroponics noted above parenthetically 

equates soil to an inert medium in a system in which plants’ nutrient needs are being fulfilled through liquid 

feeding. Of course, we know that in a soil-based cropping system--in which the plants’ nutrient needs are 

being supplied by the soil--the soil is not inert, but dynamically supplies and cycles nutrients. However, any 

rooting medium—including soil—will not serve as an adequate or long-term source of fertility to grow 

plants unless it is managed to do so.

The majority of the Crops Subcommittee believes that providing most of a plant’s nutritional needs through 

liquid feeding in a container should be defined as hydroponics, regardless of the rooting medium used. The 

Crops Subcommittee further supports the suggestion of the 2010 Recommendation Subcommittee of the 

NOP Hydroponics Task Force, which stated that there should be 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.” In order to make monitoring simpler, and because nitrogen can serve as an indicator nutrient to 

demonstrate the nutrient-supplying power of a soil/compost system, the Crops Subcommittee proposes 

that this fertility requirement of container systems apply to nitrogen only.

The majority of the Crops Subcommittee believes that this standard is sufficient to ensure that crops grown 

in containers are not merely being fed hydroponically but have an active soil biology and ecology that can 

supply nutrients to the crops. This is in keeping with the 2010 NOSB recommendation, which states: 

"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, cannot be considered as examples of acceptable 

organic farming practices. Hydroponics...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.”

Universities and crop consultants who advise hydroponic growers can provide tables of the nitrogen 

requirement (or nitrogen removal) of crops, which can be used to calculate the 20% and 50% limits on 

liquid feeding of nitrogen. For example, Knotts Handbook for Vegetable Growers indicates that a 30-ton 

 30 Prabhu, S.R. and G.V. Thomas, 2002. Biological conversion of coir pith into a value-added organic 

resource and its application in Agri-Horticulture: Current status, prospects and perspective.

31 Ravindranath, Chief editor, Coir Pith Wealth from Waste, a Reference. 2016. Coir Board, Ministry of 

MS&ME, Govt. of India.

32 Bethke, C.L., 2008. Nutritional properties of agrocoir. Horticultural Soils and Nutrition Consulting 77 

Granite Road Williamston, Michigan 48895. 
tomato yield will require 180 lb/acre of nitrogen.33 The crop consulting firm Yara estimates (online)34 that 

the nitrogen requirement (removal) of tomatoes is 5 to 5.3 lbs of nitrogen per ton of yield. A grower would 

need to use a nitrogen requirement value appropriate for the region, growing conditions, and expected 

yield of the operation. Similar calculations are already commonly used to determine the 20% limit for

Chilean nitrate allowed in organic crop production.

Subcommittee vote, container production: 

Motion that for container production to be certified organic, a limit of 20% of the plants’ nitrogen 

requirement can be supplied by liquid feeding, and a limit of 50% of the plants’ nitrogen requirement can 

be added to the container after the crop has been planted. For perennials, the nitrogen feeding limit is 

calculated on an annual basis. Transplants, ornamentals, herbs, sprouts, fodder, and aquatic plants are 

exempted from these requirements.

Motion by: Francis Thicke

Seconded by: Steve Ela

Yes: 6 No: 3 Abstain: 0 Absent: 0 Recuse: 0

Subcommittee vote, hydroponics:

Motion that any container production system that does not meet the standard of a limit of 20% of the 

plants’ nitrogen requirement being supplied by liquid feeding, and a limit of 50% of the plants’ nitrogen 

requirement being added to the container after the crop has been planted is defined as hydroponic and 

should not be allowed to be certified organic. For perennials, the nitrogen feeding limit is calculated on an 

annual basis. Transplants, ornamentals, herbs, sprouts, fodder, and aquatic plants are exempted from these 

requirements.

Motion by: Jesse Buie

Seconded by: Dave Mortensen

Yes: 6 No: 3 Abstain: 0 Absent: 0 Recuse: 0

 

********************************

Glossary of terms 

Aeroponics: A variation of hydroponic plant production in which plant roots are suspended in air and 

misted with nutrient solution.

Aquaponics: A recirculating hydroponic plant production system in which plants are grown in nutrients 

originating from aquatic animal waste water, which may include the use of bacteria to improve availability 

of these nutrients to the plants. The plants improve the water quality by using the nutrients, and the water 

is then recirculated back to the aquatic animals.

Recalcitrant: Resistant to microbial attack.

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 beneath the 

 33 Maynard, D.N. and G.J. Hochmuth. Knotts Handbook for Vegetable Growers, 5th ed., 2007. John Wiley 

and Sons Inc., Hoboken, New Jersey.

34 http://www.yara.us/agriculture/crops/tomato/key-facts/nutritional-summary/
vessel, such as, but not limited to, pots, troughs, plastic bags, floor mats, etc. 

Greenhouse: Permanent enclosed structure that allows for an actively controlled environment used to 

grow crops, annual seedlings or planting stock. 

Growing media: Material which provides sufficient support for the plant root system and enables the plant 

to extract water and nutrients. Used interchangeably with the term "substrate". 

Hydroponics (for the purposes of this proposal): Any container production system that does not meet the 

standard of a limit of 20% of the plants’ nitrogen requirement being supplied by liquid feeding, and a limit 

of 50% of the plants’ nitrogen requirement being added to the container after the crop has been planted.

Nutrient solution: Growing solution used in traditional hydroponic production that is commonly composed 

of immediately plant-available soluble mineral salts in water 

Soil: The unconsolidated mineral or organic material on the immediate surface of the earth that serves as a 

natural medium for the growth of land plants. (ii) The unconsolidated mineral or organic matter on the 

surface of the earth that has been subjected to and shows effects of genetic and environmental factors of: 

climate (including water and temperature effects), and macro- and microorganisms, conditioned by relief, 

acting on parent material over a period of time. A product-soil differs from the material from which it is 

derived in many physical, chemical, biological, and morphological properties and characteristics (Soil 

Science Society of America Glossary).

Minority View:

Summary of Pro-Hydroponic Arguments

As is pointed out in the Aquaponics/Hydroponics Subcommittee of the Task Force report and in public 

comments received over the past year, hydroponics has a long history in agriculture from societies that 

worked with limited resources in changing conditions. Hydroponics is an innovative system that results in 

efficient water and nutrient use. This efficient use of water allows for conservation of vital water resources 

which have been scarce recently due to climate change and recent droughts. Due to its controlled 

environment, hydroponic operations—like other greenhouse operations—have been able to lessen the use 

of pesticides, and operators have been able to develop systems that rely on organically approved inputs for 

crop nutrition and health.

Hydroponics can be an appropriate way to address challenges in farming as a whole, such as drought, food 

safety, limited access to arable land and production of food in urban areas or on un-arable land. 

Hydroponics operations are quite diverse and can be stand-alone operations or part of a larger in-ground 

farming operation. Critics contend that hydroponics are reliant on off-site nutrients and while the site 

specific conditions will dictate the level and type of nutrient cycling that occurs, proponents would argue 

the same is true for most organic in-ground farmers as well, including reliance on off farm manure. 

Practitioners have developed systems that are integrated, use only materials on the National List, and 

incorporate microbial action to provide plant health and nutrition. The introduction of fish to create an 

aquaponic system can address production of a protein source and integrate in situ fertilizer production with 

an integrated system.
Hydroponic proponents argue that as much bacteria and fungi are found in hydroponics as is found in soilbased systems. They cite studies that look at the microbiology in hydroponics systems and find about 

10,000,000 bacteria per milliliter of nutrient solution35 36. Soil microbiology varies quite a bit, but compost 

consistently comes in at 100,000 to 1,000,000,000 colony forming units - or cfu- a measure of the viable 

bacterial and fungal cells - per milliliter of dry compost37 38 39. These systems are also rich in fungi-- a study 

that looked at both fungi and bacteria in hydroponic systems found 1,000,000 cfu/ml bacteria and 10 to 

1000 fungi cfu/ml in the system40. They supply research that shows suppression of plant disease by root 

flora and other microflora in hydroponics. A review of these studies in 2011 found suppressive flora in 

rockwool, NFT, peat, and other hydroponic methods41 42 43 44 45 46 47 48 49 50 51. It should be noted that 

 35 Berkelmann, B., W. Wohanka, and G. A. Wolf. 1994. Characterization of the bacterial flora in circulating 

nutrient solutions of a hydroponic system in rockwool. Acta Hortic. 361:372–381. 

36 Waechter-Kristensen, B., S. Caspersen, S. Adalsteinsson, P. Sundin, and P. Jensén. 1999. Organic 

compounds and micro-organisms in closed, hydroponic culture: Occurrence and effects on plant growth 

and mineral nutrition. Acta Hortic. 481:197–204.

37 Bess, V. 2008. Evaluating Microbiology Of Compost 83–85.

38 Chandna, P., L. Nain, S. Singh, and R. C. Kuhad. 2013. Assessment of bacterial diversity during composting 

of agricultural byproducts. BMC Microbiol. 13:99.

39 Hassen, A., K. Belguith, N. Jedidi, A. Cherif, M. Cherif, and A. Boudabous. 2001. Microbial characterization 

during composting of municipal solid waste. Bioresour. Technol. 80:217–225.

40 Berkelmann, B., W. Wohanka, and G. A. Wolf. 1994. Characterization of the bacterial flora in circulating 

nutrient solutions of a hydroponic system in rockwool. Acta Hortic. 361:372–381. 41 . Clematis, F., A. Minuto, M. L. Gullino, and A. Garibaldi. 2009. Suppressiveness to Fusarium oxysporum f. 

sp. radicis lycopersici in re-used perlite and perlite-peat substrates in soilless tomatoes. Biol. Control. 

Elsevier Inc. 48:108–114. 42 Folman, L. B., J. Postma, and J. a. Veen. 2001. Ecophysiological characterization of rhizosphere bacterial 

communities at different root locations and plant developmental stages of cucumber grown on rockwool. 

Microb. Ecol. 42:586–597.

43 Minuto, A., F. Clematis, M. L. Gullino, and A. Garibaldi. Induced suppressiveness toFusarium oxysporum 

f.sp.radicis lycopersici in rockwool substrate used in closed soilless systems. Phytoparasitica 35:77–85. 44 Muslim, A., H. Horinouchi, and M. Hyakumachi. 2003. Control of fusarium crown and root rot of tomato 

with hypovirulent binucleate Rhizodonia in soil and rock wool systems. Plant Dis. 87:739–747. 45 Postma, J., M. J. Willemsen-de Klein, and J. D. van Elsas. 2000. Effect of the Indigenous Microflora on the 

Development of Root and Crown Rot Caused by Pythium aphanidermatum in Cucumber Grown on 

Rockwool. Phytopathology 90:125–33. 

46 Postma, J. 2004. Suppressiveness of root pathogens in closed cultivation systems. Acta Hortic. 644:503–

510. 

47 Postma, J., B. P. J. Geraats, R. Pastoor, and J. D. van Elsas. 2005. Characterization of the Microbial 

Community Involved in the Suppression of Pythium aphanidermatum in Cucumber Grown on Rockwool. 

Phytopathology 95:808–818.

48 Tu, J. C. ., A. P. . Papadopoulos, X. Hao, and J. Zheng. 1999. The relationship of Pythium root rot and 

rhizosphere microorganisms in a closed circulating and an open system in rockwool culture of tomato. Acta 

Hortic. 481:577–583. 

49 Vallance, J., F. Déniel, G. Floch, L. Guérin-Dubrana, D. Blancard, and P. Rey. 2011. Pathogenic and 

beneficial microorganisms in soilless cultures. Agron. Sustain. Dev. 31:191–203.

50 . van Os, E. A., and J. Postma. 2000. Prevention of root diseases in closed soilless growing systems by 

microbial optimisation and slow sand filtration. Acta Hortic. 532:97–102. 51 Zhang, W., and J. C. Tu. 2000. Effect of ultraviolet disinfection of hydroponic solutions on Pythium root 

rot and non-target bacteria. Eur. J. Plant Pathol. 106:415–421
compared to soil, there have been many less studies on suppressive flora in hydroponics. The fact that of 

these few studies, so many have found strong evidence of suppressive flora in hydroponics is important.

While there has been ambiguity over the years on the position of the NOSB related to organic hydroponic 

production, the NOP has noted in 2002, 2004, 2009, 2014 and 2016 that organic hydroponic production is 

allowed as long as the producer can demonstrate compliance with the USDA organic regulations However, 

an NOP publication (the Organic Integrity Quarterly of May 2014) did state that there may be additional 

guidance issued in the future for these methods. The allowance of hydroponic certification without organic 

hydroponic production standards has led to inconsistent approval by certifiers.

The hydroponic proponents of the Task Force contended that advantages of hydroponic systems included 

water conservation, food safety, disease suppression, nutrient conservation and retention, and soil 

conservation (because of not using any soil and use of land unsuitable for cultivation). They argued that 

these production systems abide by the definition of 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. Additionally, proponents contend they comply with 

applicable areas of the rule, including writing and implementing an Organic System Plan, keeping records, 

preserving and cycling natural resources, and using compliant inputs. Precedence for exemptions for nonapplicable areas of the standards has already been set by NOSB recommendations on greenhouse 

production, mushroom production, aquaculture production and others.

Organic production systems

The justifications for how hydroponic systems comply with §205.203 (soil fertility and crop nutrients) and 

§205.205 (crop rotation) have been given as follows (see rule wording above):

• §205.203 (a) – Depends on the site specific conditions but generally, if the system interacts with soil 

these requirements apply as they would to in-ground farms. If production is soil-less then the nonuse of soil maintains the site’s soil. Operations are still responsible for not degrading soil. 

• §205.203 (b), (c) and 205.205 – In lieu of crop rotation and cover cropping, soil regeneration and 

recycling practices are implemented and documented 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. Specifically, by maintaining or 

improving organic matter content, providing for pest management in crops, managing deficient or 

excess plant nutrients, and by providing erosion control. Exemptions for crop rotation and cover 

cropping have been recommended by the NOSB in the past for specific types of operations like 

greenhouses. 

Minority Discussion

This minority view is a byproduct of numerous hours of debate, research, and contemplation about the 

diversity of the organic community. The industry is comprised of a variety of producers, processors, 

certifiers, retailers and consumers that all have evolved to define what compliant organic production 

systems look like under current NOP regulation. During many rounds of public comment, the NOSB has 

listened to the community and their opinions on the applicability and legality of hydroponic, aeroponic and 

aquaponic systems under the organic label. As with all complex issues, there are various viewpoints 

 
regarding the meaning and interpretation of the organic regulation. The minority position celebrates this 

diversity and respects all shareholders’ interpretations. 

There are some who believe that proper soil management following principles outlined in the standards are 

foundational to what organic certification should mean. Many founding farmers of the organic movement 

shared this perspective as they pioneered new methods of agricultural production as an alternative to 

conventional production. We agree that soil is historically linked with organic production and should be as 

well in its future – we are pro soil. However, we do not view this as a mutually exclusive decision – being 

pro soil does not mean there is not a home for other production methods that “respond to site-specific 

conditions by integrating cultural, biological, and mechanical practices that foster cycling of resources, 

promote ecological balance, and conserve biodiversity.”

Members of the organic community were drawn to organic foods and production for various reasons, 

including but not limited to: Environmental impacts of agriculture, resource conservation, avoidance of 

highly toxic synthetic pesticides and fertilizers, believed health benefits, local agriculture, etc. Some of 

these aspects were included in the law and regulations, while others were left out. Most members of the 

organic community are motivated by these concerns and more, each to varying degrees. Each of these 

concerns have tradeoffs which need to be balanced. Determining where this balance lies has unfortunately 

confounded the NOSB since its inception in 1995. 

The 1995 NOSB recommendation Standards for Greenhouses contains the statement, “Hydroponic 

production in soilless media to be labeled organically produced shall be allowed if all provisions of the OFPA 

have been met.” That statement indicated that an analysis had not been made of whether hydroponics met 

the provisions of OFPA. The brief dialogue at the meeting made it clear that while some board members 

were supportive of hydroponics, others had concerns about soilless production. 

In March 2000, a revised proposed rule for the National Organic Program was published, revising the initial 

proposed rule published in December 1997. In the supplemental information, the following was stated:

We have amended the term, “system of organic farming and handling,” to “system of organic 

production and handling” and retained the original definition in this proposal. The original 

definition was crafted to be consistent with the requirements of the Act. We have changed 

“farming” to “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 

purpose of the original definition was to describe practices and substances consistent with systems 

of organic farming and organic handling as required by the Act and to provide an explicit reference 

point for determining which practices and substances are most consistent with these systems.52

In an 1807 communication from Thomas Jefferson to William H. Cabbell as to statutory interpretation, 

Thomas Jefferson stated, 

"In the construction of a law, even in judiciary cases of meum et tuum, where the opposite parties 

have a right and counter right in the very words of the law, the Judge considers the intention of the 

lawgiver as his true guide, and gives to all the parts and expressions of the law, that meaning which 

will effect, instead of defeating, its intention. But in laws merely executive, where no private right 

stands in the way, and the public object is in the interest of all, a much freer scope of construction, in 

favor of the intention of the law, ought to be taken, and ingenuity ever should be exercised in devising 

constructions which may save to the public the benefit of the law. Its intention is the important thing: 

 52 Federal Register Volume 65 Number 49. Page 13521. Docket Number: TMD-00-02-PR2, RIN 0581-AA40. 

National Organic Program Proposed Rule. Agricultural Marketing Service, USDA. March 13, 2000
the means of attaining it quite subordinate." –Thomas Jefferson to William H. Cabbell, 1807.

The minority view does find some common ground with the majority proposal; however, we find it strays 

too far from the original intent of the previous NOSB recommendations. It is not consistent with previous 

Board decisions, nor its intent when crafting its recommendations. It would be difficult for the NOP to 

implement without additional justification. 

The minority view holds that the 2010 NOSB recommendation entitled Production Standards for Terrestrial 

Plants in Containers and Enclosures (Greenhouses) was generally complete in regards to addressing 

compliant characteristics of organic systems under the NOP regulation. However, as was discussed 

previously in the introduction and background section, the NOP returned to the NOSB following the 2016 

Task Force report, asking for additional clarity regarding the 2010 NOSB hydroponics recommendation 

because the NOP felt the 2010 recommendation left too many aspects of compliant organic production 

systems open for interpretation. As such, the minority position below is an edited and redlined version of 

the 2010 NOSB recommendation intended to provide further clarity requested by the NOP. 

The minority view notes that the 2010 recommendation allowed compost to be utilized in place of soil 

because it deemed it equivalent to soil. The foundation of this equivalency was stated as follows:

The 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.

As such, the minority view extends that if production systems, utilizing organically approved production 

techniques on majority carbon based substrate, can foster the proliferation of proper soil biology within 

their accompanying ecologies as evidenced by the presence of typical soil dwelling organisms, such as 

earthworms, protozoa, fungi, bacteria, actinomycetes then they should be eligible for organic certification. 

Therefore, we propose working on a production standard that requires verification of the presence of four 

trophic levels. We understand this concept is new and has not been reviewed or commented on by the 

organic community or industry. We welcome feedback from the community and industry on this concept, 

definition and feasibility. 

The minority view is based upon the beliefs that organic production should enforce responsible 

stewardship practices, address sustainability and conservation of resources (e.g. land, water, on-farm 

inputs, energy, biodiversity), and allow for novel developments in organic food production systems that 

assist in providing greater access of organic food to consumers. 

The minority is not supportive of taking either proposal (major or minority) through to a vote at the Fall 

2017 NOSB meeting. Given the division of the community reflected in the division of the board, all 

stakeholders need to come to terms that a greater compromise will be necessary to make progress on this 

issue. The minority view finds merit in a discussion on hydroponic/soilless production standards and 

mandatory additional labeling with the organic label/claim. This concept has not been fully explored. 

The minority view believes these proposed revisions to the 2010 recommendation require further 

refinement and as noted earlier we request additional feedback from the public on these proposed 

revisions. 
Proposal – based on 2010 NOSB Recommendation

§ 205.2 Terms Defined

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.

Hydroponics- The production of normally terrestrial, vascular plants in nutrient rich solutions or in an inert, 

porous, solid matrix bathed in nutrient rich solutions. Sprouts and fodder are considered a processed 

material and are not considered hydroponic.

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.

Growing media- Material which contains sufficient organic matter capable of supporting the plant root 

system and a natural and diverse soil ecology.

Container Production- The production of normally terrestrial, vascular plants in containers. Can be certified 

organic if production requirements of section of 205.209 are met.

Trophic levels: The hierarchical levels of organisms within an ecosystem; each level consisting of organisms 

that share the same function and food source in the food chain of a defined ecosystem.

§ 205.105 Allowed and prohibited substances, methods, and ingredients in organic production and 

handling. To be sold or labeled as “100 percent organic,” “organic,” or “made with organic (specified 

ingredients or food group(s)),” the product must be produced and handled without the use of:

(h) Aeroponics and Hydroponics.

§ 205.209 Terrestrial Plants in Containers and Enclosures (Greenhouses)

(a) Container and enclosure (such as a 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 container or enclosure operation greenhouse with crops grown in 

containers using a growing media that does not include soil from the production site is exempt from 

requirements of 205.202(b), 205.203(a).

(2) The producer operating with crops grown in containers shall comply with the applicable section of 

205.203(a) based on site specific conditions.

(3) 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 Accredited 

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. Specifically:

(i) Maintain or improve soil organic matter content (a)- Examples include, but are not limited to, 

recycling and re-use of growing media, addition of compost and other compostable materials, 

earthworm replenishment, microbial re-inoculation, etc.

(ii) Provide for pest management in crops (b)- Examples include, but are not limited to: Soil borne 

damping-off control through various low temperature heating methods; Soil inoculation using 

disease suppressant bacteria and fungi.
(iii) Manage deficient or excess plant nutrients (c)- Examples include, but are not limited to: Recycle 

excess plant nutrients contained in drain water from media containers, avoiding so called drain-towaste systems. Recycled nutrients must be re-used in the greenhouse, or alternatively, on a 

growing crop outside the facility.

(iv) Provide erosion control (d)- Examples include, but are not limited to: Though erosion is not 

generally applicable to greenhouse production, recycling of drain water prevents off-site

movement of nutrients, a common consequence of typical field erosion.

(4) The Container Organic System Plan must address how meets the requirements to conserve 

biodiversity and maintain or improve natural resources of the site-specific operations. The Organic 

System Plan should include the entire production site (containers and non-containers as applicable) as 

well as the surrounding environment.

(b) Growing media requirements:

(1) ingredients Inputs shall be verified by Accredited Certifying Agent and shall not include as 

ingredients any prohibited materials.

(2) Growing media shall be comprised of ingredients that allow for recycling and re-use as growing 

media within the operation, or alternatively, as a crop input outside the greenhouse.

(3) Growing media shall not be disposed of as waste, but should be recycled or reused whenever 

possible.

(4) Growing media shall contain sufficient organic matter capable of supporting natural and diverse soil 

ecology as evidenced by supporting four trophic levels. For this reason, hydroponic and aeroponic 

systems are prohibited.Growing media used to produce crop transplants should also be capable of 

supporting a natural and diverse soil ecology.

(5) Growing media shall be a minimum of 50% carbon based material.

(c) Producers may use full-spectrum light sources.

(d) Plants and soil shall not be in direct contact with, or indirect contact with condensates from, wood 

treated with prohibited materials that are used for greenhouse structures or frames of raised beds.

(e) Producers must recycle or reuse containers at end of life.

(f) To comply with the provisions of 205.201(a)(5) to prevent commingling and contamination, organic 

and non-organic crops can be grown within the same structure only if the following conditions are met:

(1) An impermeable wall shall separate organic and non-organic production sites if prohibited materials 

are applied to the non-organic crop to ensure that cross contamination does not occur.

(2) The ventilation systems must ensure that prohibited materials cannot drift, or be otherwise 

conveyed to the organic

(3) Separate watering systems must be established if prohibited fertilizers and/or pesticides are 

injected within the watering system.

(4) Producers must ensure that no contamination occurs to the organic crop through cross-pollination 

with crops produced through genetic engineering

(5) Soil mixing machines and other equipment used for non-organic crop production must be 

thoroughly cleaned prior to use in organic production.

(6) Adequate physical facilities, as determined by the certifying agent, shall separate organic and nonorganic crops and production materials in storage, production or holding areas.

(7) Organic and non-organic crops and production areas must be conspicuously labeled.