Formal Recommendation 

From: The National Organic Standards Board (NOSB)

To: The National Organic Program (NOP)

Date: April 28, 2022

Subject: Highly Soluble Nitrogen

NOSB Chair: Nate Powell-Palm

The NOSB hereby recommends to the NOP the following:

Rulemaking Action: X

Statement of the Recommendation: 

As discussed at the Spring meeting, the Board intends that this practice standard limit nitrogen fertilizers 

with a C:N ratio of 3:1 or less, including those individual components of a blended fertilizer formulation. 

The Board recommends these fertilizers be limited unless use is restricted to a cumulative total use of 20% 

of crop needs. This practice standard would apply to all organic producers but would not cover materials 

traditionally used on organic farms such as compost teas, fish emulsions, or protein hydrolysates. 

The Board suggests that the final listing should ensure that it applies equally to all producers of food crops, 

similar to the materials placed at §205.602 or §205.105. The National Organic Program (NOP) can define 

the details of where this practice standard appears on the National List.

Rationale Supporting Recommendation: 

The historical interpretation of OFPA supports restricting highly soluble fertilizers. In the preamble to the 

publication of the National Organic Program final rule, the NOP agreed with the NOSB recommendations to 

put limits on materials of high solubility. For example, sodium nitrate was limited to 20% of crop needs, 

and subsequent boards recommended the prohibition of sodium nitrate. Calcium chloride use was also 

strictly limited. One commenter voiced this approach by noting that if there are nutrient problems on a 

particular soil, solving them with a single, highly soluble material should not be allowed. Those nutrient 

problems should be addressed using a systems approach, not just the use of a single product. Past NOSB 

actions note that in contrast to the reductionism of chemical-intensive agriculture, the origins of organic 

agriculture are in holistic and ecological thinking.

The intent of this recommendation is to implement a practice standard for all organic producers regarding

the use of Highly Soluble Nitrogen Fertilizers with a carbon to nitrogen ratio of 3:1 or less, including those 

individual components of a blended fertilizer formulation, which are restricted to a cumulative total use of 

20% of crop needs. 

Public comments indicated broad support from stakeholders. Some commenters noted that publishing a 

list of materials that would be considered lower than the 3:1 carbon to nitrogen ratio would be helpful so 

re-assessment of materials wouldn’t have to take place every year. The NOSB has also proposed that 

certifiers or material review organizations could develop a list of unrestricted, allowed materials so that 

they would not need to be continually reanalyzed. A small percentage of stakeholders that opposed the 

practice standard, primarily a few manufacturers of HSN fertilizers, had concerns that this would restrict 

the organic industry from the law of return. Supporters of the motion included, but weren’t exclusively 

from, the National Organic Coalition (NOC), Organic Farmers Association (OFA), Grimmway Farms, 

Cornucopia, Beyond Pesticides, Maine Organic Farmers and Gardeners Association (MOFGA), Ohio 
Ecological Food and Farm Association (OEFFA), and Northeast Organic Farming Association - Vermont 

(NOFA VT). 

The need for a practice standard exists as a commenter stated that highly soluble sources of nitrogen 

fertilizers cannot be addressed in a vacuum and looked at one material at a time. A broader approach 

needs to be taken to avoid the potential of “stacking” the usage. As discussed at the spring meeting, the 

current proposal is designed to prevent the widespread use of new, non-synthetic HSN fertilizers while also 

allowing for the potential of restricted use of these materials in critical situations. Restriction of these 

materials is based on OFPA criteria that soil management practices maintain or improve soil organic matter. 

That producers must select and implement practices that maintain or improve the soil's physical, chemical, 

and biological condition. Many commenters noted that the use of HSN fertilizers runs counter to the 

organic principles outlined in the regulations by directly applying plant nutrients rather than applying 

nutrients that improve the biological condition of the soil. Another commenter mentions that if these new, 

non-synthetic fertilizers are currently allowed without restriction, growers could use large amounts of these 

materials and directly feed plants nitrogen without the typical biological soil transformations. Thus, the 

main principles of OFPA can now largely be ignored or sidestepped. While growers still have to document 

soil building practices in their organic systems plan, the evaluation of whether those practices are sufficient 

to meet OFPA criteria is left to interpretation by certifiers and can often be nebulous and difficult to 

enforce.

Some commenters suggested that the overall C: N ratio of the final product be used, rather than looking at 

individual components of a blend. While this would simplify the evaluation, it would sidestep the intention 

of the motion. For example, a high carbon source could be mixed with an HSN fertilizer composed entirely 

of nitrate to bring the blend above the required 3:1 ratio. There isn’t a known test, including isotope 

testing, that can be performed on a blend to identify HSN components; therefore, it is necessary to 

deconstruct it into its components for evaluation.

Some commenters mentioned that solubility should be considered versus looking at the C: N ratio; 

however, finding a percentage above which a limit is triggered is challenging and becomes difficult to test 

for if you begin to look at ratios that examine total nitrogen to soluble inorganic nitrogen and soluble 

organic nitrogen. For example, compost tea could contain less than 1% total nitrogen, but nearly all that 

nitrogen could be soluble. To allow for the use of teas, the percent soluble to total N would have to be very 

high. There is no reason to restrict commonly used products, but the percentage of soluble N to total N 

ratio would have to be high to allow their unrestricted use. 

Another point made in public comments was that the manufacture of these products helps recycle 

ammonia that might otherwise be lost to the atmosphere or might not be readily available due to 

transportation or other availability. While capturing or recycling ammonia present in manures may be of 

interest, OFPA does not require organic farms to be the market for the extracts produced. OFPA does not 

include language that recycling or capturing materials is a reason for their use. 

NOSB Vote: 

Motion to add at § 205.105: nitrogen fertilizers with a C: N ratio of 3:1 or less, including those individual 

components of a blended fertilizer formulation, are limited unless use is restricted to a cumulative total use 

of 20% of crop needs.

Motion by: Amy Bruch

Seconded by: Brian Caldwell

Yes: 15 No: 0 Abstain: 0 Absent: 0 Recuse: 0 

Motion Passed
National Organic Standards Board

Crops Subcommittee Proposal

Highly Soluble Nitrogen Fertilizers

January 18, 2022

Note: References are made to the 2020 Technical Report (TR) throughout this document. It is intended 

that the citation of the TR inherently includes the citations of the references contained within the TR. 

When the TR is quoted, the citations noted in the text of the TR have been removed for clarity – for a 

complete list of references, please refer to the TR.

References to ammonia or ammonium are specifically intended to include both unless stated explicitly

that it is only one or the other.

Use

Highly soluble nitrogen sources such as sodium nitrate, guano, and the recently reviewed ammonia 

extracts are used as nitrogen sources to produce a wide range of annual and perennial crops. Of these 

materials, sodium nitrate and guano have historically been used for organic agriculture. Sodium nitrate 

is on the prohibited section of the National List but is annotated to allow use to no more than 20% of 

crop needs. Other organic materials such as protein hydrolysates, feather meals, blood meals, and 

liquid fish fertilizers also provide rapid nitrogen availability to crops. A primary difference in these 

materials is that they are mostly protein or amino acid-based compared to materials containing 

primarily ammonia or nitrates. Thus, these biologically derived products require soil conversion from 

amino acids or proteins to ammonia and nitrates before they are plant available.

More recently, non-synthetic processes to produce highly soluble fertilizers have been developed. The 

recent NOSB vote to prohibit ammonia extracts is an example of when a new material, meeting the 

organic definition of naturally derived, enters the organic marketplace without a review process as to 

whether the material complies with OFPA criteria. Future processes will likely be developed for new, 

highly soluble nitrogen fertilizers. Therefore, it is critical that restrictions on the use of these materials 

occur before they can be reviewed and become widely used. If, after review, the NOSB determines that 

the use of a particular material falls within organic production standards, that material could be 

exempted from any restriction on the National List and allowed for use.

Nitrogen is often a major limitation to crop yields and is biologically vital as a macronutrient. It 

contributes to plant growth by forming amino acids, serves as the building block for proteins, and 

improves photosynthetic efficiency (2020 TR). However, as was determined with ammonia extracts, the 

use of highly soluble nitrogen fertilizers may not be compatible with organic production. In the past, the 

NOSB and those responsible for developing the USDA organic guidelines have restricted or prohibited 

materials of high solubility. These materials include calcium chloride, potassium chloride, sodium 

nitrate, and, more recently, ammonia extracts. In the preamble to the publication of the NOP Final Rule 

on December 21, 2000, NOP discusses how it decided to agree with the NOSB recommendation and to 

put specific regulation of substances of high solubility into the annotations for each of these materials 

where they appear on the National List of Allowed and Prohibited Substances. NOP goes on to say, 

"Based on the recommendation of the NOSB, the final rule would prohibit the use of these materials 

[substances of high solubility], unless the NOSB developed recommendations on conditions for their use 

and the Secretary added them to the National List." At the time, the discussion was about mined 
substances of high solubility because there were not concentrated, highly soluble plant nutrient 

materials other than mined sources available at that time. However, the same rationale would apply to 

newly developed nitrogen fertilizers of high solubility.

Manufacture

While the Haber-Bosch process is the primary method for making nitrogen fertilizers, it is not relevant to 

organic processing and use. More recently, several methods have been developed to produce ammonia 

products non-synthetically (2020 TR). Given recent developments in novel technologies, it seems likely 

that other non-synthetic nitrogen fertilizers could be developed similarly to ammonia extracts. Other 

historically used organic materials such as sodium nitrate and guano are mined from naturally occurring 

deposits. Protein and amino acid-based materials such as hydrolysates, fish emulsions, feather meal,

and blood meal are produced from by-products of other manufacturing processes. They are allowed for 

use in organic production. 

International

While highly soluble nitrogen products are not addressed as a group, sodium nitrate is not allowed in 

Canadian production, and crops grown with sodium nitrate may not be exported to Canada. While it is 

unknown, comments received at the Spring and Fall 2021 NOSB meetings voiced concerns that the use 

of ammonia extracts or other new highly soluble nitrogen materials in the United States might also be 

rejected by other countries for exported products.

Summary of Review

The reviews of non-protein/amino acid highly soluble nitrogen materials have resulted in a wide variety 

of public comments and perspectives. These comments were often focused on reviews of sodium 

nitrate and ammonia extracts. These perspectives ranged from issues with soil health and 

environmental concerns and the use of multiple sources of highly soluble nitrogen fertilizers (HSN 

fertilizers). Comments were submitted that argued for both pros and cons on each issue.

In general, the comments from long-time organic organizations and growers tended to favor limiting 

HSN fertilizers based on the organic principles of enhancing soil biological processes rather than 

applying a nutrient that is immediately available to the plant. They also noted the low carbon to 

nitrogen ratios and the high solubility of these materials could cause environmental issues.

Proponents cite the need for immediately available nitrogen sources as a bridge for when unusual 

events cause nitrogen deficits to crops, and soil processes have not had a chance to recharge the 

available nitrogen. They also note that using these materials can help prevent nitrogen loss since they 

could allow better targeting of nitrogen applications to specific crop needs.

As noted previously, several materials are already in the organic marketplace. These materials have 

been approved by OMRI and other material review organizations, although with the caveat that nonsynthetic, liquid fertilizers that have a nitrogen analysis greater than 3 percent must comply with 

additional recordkeeping and inspection requirements following NOP Guidance on the Approval of 

Liquid Fertilizers for Use in Organic Production (NOP 5012). Non-synthetic fertilizers that test above 3 

percent ammoniacal nitrogen are considered at higher risk for violating the soil fertility and crop 

nutrient management practice standards at 205.203. OMRI attaches a note that “this product contains 

highly soluble nitrogen and must be applied in a manner that does not contribute to the contamination 

of crops, soil or water. Its use must be part of an organic system plan that maintains or improves the 

natural resources of the operation, including soil and water quality, and comply with crop nutrient and 
soil fertility requirements.” The NOSB determined at the Fall 2021 meeting that ammonia extracts did 

not meet the criteria for use in an organic system plan and subsequently voted to prohibit ammonia 

extracts in organic production.

Furthermore, the Board and other stakeholders expressed concerns that new, non-synthetic HSN 

fertilizers that fall outside the definitions of ammonia extracts could be developed in the future. Those 

materials would have no limit to their use unless a petition to restrict or prohibit them was submitted to 

the NOSB and the NOSB voted to restrict their use.. The use of new non-synthetic fertilizers might have 

similar issues to ammonia extracts with regard to compatibility with organic systems. Thus, the NOSB 

proposes that limitations be put on any HSN fertilizer until the NOSB can review it, and if so desired, a

developer of a new HSN fertilizer could petition the NOSB to remove the restriction. Manufacturers 

would also know of potential limitations before investing in novel production methods for these 

fertilizers.

Soil Health

The Organic Foods Production Act (OFPA) through regulations at § 205.203(a) requires that a producer 

must select and implement tillage and cultivation practices that maintain or improve the physical, 

chemical, and biological condition of the soil and minimize soil erosion. At §§ 205.203(c) and (d), OFPA 

states that the producer must manage plant and animal materials or crop nutrients and soil fertility to 

maintain or improve soil organic matter content. 

At the Fall 2020, and Spring and Fall 2021 NOSB meetings, many commenters noted that the use of HSN 

fertilizers runs counter to the organic principles outlined in the regulations by directly applying plant 

nutrients rather than applying nutrients that improve the biological condition of the soil. Inherently, the 

annotation added to high nitrogen (N) ammonia/ammonium-containing-products notes that “this 

product contains highly soluble nitrogen and must be applied in a manner that does not contribute to 

the contamination of crops, soil or water. Its use must be part of an organic system plan that maintains 

or improves the natural resources of the operation, including soil and water quality, and comply with 

crop nutrient and soil fertility requirements.” This annotation would not be added unless there was a 

risk that the materials do not contribute to the stated OFPA criteria. For example, several commenters 

testifying in favor of ammonia extracts at the 2020 and 2021 NOSB meetings reinforced this by stating 

that these ammonia extracts should not be used alone – they must be used with other soil building 

practices to comply with OFPA. 

An example of a comment that refers to basic tenets of organic agriculture and prior OFPA and NOSB 

actions was submitted at the Spring 2020 meeting:

In contrast to the reductionism of “conventional” chemical-intensive agriculture, the origins of 

organic agriculture are in holistic and ecological thinking. Historically, perhaps the most 

important principle of organic production is the “Law of Return,” which, together with the 

foundational philosophy “Feed the soil, not the plant,” and the promotion of biodiversity, 

provide the ecological basis for organic production. Together these three principles describe a 

production system that mimics natural systems—the Law of Return. In an organic system, 

residues are returned to the soil by tillage, composting, or mulching. While most organic 

growers depend on some off-site inputs, most of the fertility in a soil-based system comes from 

practices that recycle organic matter produced on-site. The cycling of organic matter and onsite production of nutrients—as from nitrogen-fixing bacteria and microorganisms that make 

nutrients in native mineral soil fractions available to plants—is essential to organic production.

The Law of Return is not about feeding plants but about conserving the biodiversity of the soilplant-animal ecological community. The Law of Return says that we must return to the soil 
what we take from the soil. Non-crop organic matter is returned directly or through composting 

plant materials or manures. To the extent that the cash crop removes nutrients, they must be 

replaced by cover crops, crop rotation, animal manures, or additions of off-site materials when 

necessary. Feed the soil, not the plant.

The dictum to “Feed the soil, not the plant” reminds us that the soil is a living superorganism 

that supports plant life as part of an ecological community. We do not feed soil organisms in 

isolation to process nutrients for crop plants; we feed the soil to support a healthy soil ecology, 

which is the basis of terrestrial life.

Biodiversity. Finally, biological diversity is important to the health of natural ecosystems and 

agro-ecosystems. Biodiversity promotes balance, which protects farms from damaging insects 

and disease outbreaks. It supports the health of the soil through the progression of the seasons 

and stresses associated with weather and farming. It supports our health by offering a diversity 

of foods. Ultimately, holistically healthy, genuinely organic farms produce healthy plants that 

require far fewer applications of insecticides and fungicides (even if approved for organic 

production).

The principle of feeding the soil rather than the crop. OFPA §6513(b) requires that organic 

operations establish a plan designed to “foster soil fertility, primarily through the management 

of the organic content of the soil through proper tillage, crop rotation, and manuring.” 

Substances of high solubility, i.e., those materials that provide nutrients directly to the plant 

because they are quickly taken up into the plant from the soil solution, are counter to 

foundational organic principles, so they have always been restricted. Such materials are listed 

in §205.602—non-synthetic substances prohibited for use in Organic Crop Production or the 

“prohibited naturals” section of the National List: 

1) Calcium chloride is limited to treating a physiological disorder;

2) Potassium chloride must be used in a manner that minimizes chloride accumulation in the soil

 and;

3) Sodium nitrate is restricted to no more than 20% of the crop's total nitrogen requirement. 

The organic regulations limit substances of high solubility. In the preamble to the publication of 

the NOP Final Rule on December 21, 2000, NOP discusses how it decided to agree with the 

NOSB recommendation and to put specific regulation of substances of high solubility into the

annotations for each of these materials where they appear on the National List of Allowed and 

Prohibited Substances. NOP goes on to say, "Based on the recommendation of the NOSB, the 

final rule would prohibit the use of these materials [substances of high solubility], unless the 

NOSB developed recommendations on conditions for their use and the Secretary added them to 

the National List." At the time, the discussion was about mined substances of high solubility 

because there were no concentrated, highly soluble plant nutrient materials other than mined 

sources available at that time. New materials of high solubility should be prohibited or 

restricted.

The current motion to restrict the use of highly soluble nitrogen fertilizers follows this recommendation 

to prohibit or limit the uses of highly soluble materials unless the NOSB develops recommendations and 

conditions for their use. The motion would prevent the widespread use of new, non-synthetic fertilizers 

while also allowing for the potential of restricted use of these materials in critical situations. Some of 

those situations were outlined in the ammonia extract proposal. These include times when abnormal 
weather events cause temporary nitrogen deficiencies or limited situations where the release rate of 

appropriately applied organic inputs does not meet crop needs. 

Studies show that long-term organic fertilizer inputs enrich carbon-related soil functions. Manure 

additions can strongly influence the formation, storage, and cycling of soil organic carbon and nitrogen 

and soil microecology (Sharif, Thompson, et al., 2021; Ozlu, Sandhu, et al., 2019). Living organisms' total 

amounts (weights) vary in different cropping systems. In general, soil organisms are more abundant and 

diverse in systems with complex rotations that return more diverse crop residues and use other organic 

materials such as cover crops, animal manures, and composts. When crops are rotated regularly, fewer

parasites, diseases, weeds, and insect problems occur than when the same crop is grown year after year 

(Magdoff and Van Es, 2021). These biotic links can also positively influence the ability of plants to resist 

insect pests. Plants grown in a balanced nutrient system are less likely to be attacked by pests than

plants with readily available nitrogen added (Phelan, Mason, et al., 1995). 

The NOSB received comments that HSN fertilizers may increase the mineralization rate in soils and thus 

be beneficial. This could be true in a short time frame, but this accelerated mineralization rate could 

come at the cost of long-term soil carbon resources. Wang, Juliang, et al., 2018, found that long-term

application of N-fertilizers causes an abundance of bacterial groups responsible for the denitrification

process, which causes the turnover of nitrogen to increase and results in more significant nitrogen loss 

over time. Essentially, adding more nitrogen fertilizer results in long-term nitrogen loss while altering 

other soil components, like decreasing soil pH and C: N ratio. When soil carbon and nitrogen are 

reduced in response to the application of chemical fertilizers, the beneficial enzymatic activity of the soil 

also decreases (Ozlu, Sandhu, et al., 2019). Another study concluded:

Annual nitrate leaching was 4.4–5.6 times higher in conventional plots than in organic plots, 

with the integrated plots in between. This study demonstrates that organic and integrated 

fertilization practices support more active and efficient denitrifier communities, shift the 

balance of N2 emissions and nitrate losses, and reduce environmentally damaging nitrate losses.

Although this study specifically examines a perennial orchard system, the ecological and 

biogeochemical processes we evaluated are present in all agro-ecosystems. The reductions in 

nitrate loss in this study could also be achievable in other studies cropping systems (Kramer, 

Reganold, et al., 2006).

Organic systems include cover cropping and interplanting and varied crops and the addition of manures 

and composts. This mix of fertility sources is used to mitigate issues of nutrient excesses. 

Incorporating crop residues and compost [emphasis added] provides a potential long-term 

alternative to ammonia extract and other nitrogen fertilizers. Nitrogen content in compost is 

slowly released through mineralization processes in the soil, primarily facilitated by its 

metabolism by microorganisms in the soil. Unlike ammonia extract, the use of compost also 

contributes to soil organic matter and available carbon, phosphorous, and micronutrients, as 

well as soil microorganism populations and activities. The incorporation of compost into the 

agro-ecosystem has been reported to improve soil characteristics, specifically water holding 

capacity and cation exchange capacity (CEC). Increased soil CEC allows it to more effectively 

retain cations, including ammonium ions and metal cations required as micronutrients (e.g., iron 

[Fe], copper [Cu], zinc [Zn]) (2020 TR)

Public comments and scientific research publications demonstrate that much more research regarding 

the use of these materials and the soil health, plant health, and biological interactions need to be 
conducted. There is conflicting information from conventional soils and very little research conducted 

on organic soils. For example, a study on tomatoes in California (Bowles, Hollander, et al., 2015) found 

that the complex plant and microbial processes that affect nitrogen cycling are affected by the ecology 

of each farm and between fields within a farm. Most research-oriented toward nitrogen cycling occurs

at research stations with fixed factors and limited soil variations; there has been little research about 

how nitrogen cycling happens on working organic farms. The study detailed how organic tomato farms 

can achieve high yields even though tests showed relatively low nitrogen availability. They attributed 

this to the possibility that the nitrogen cycling was tightly coupled with tomato plant needs. While tests 

showed low nitrogen with respect to conventional standards, the sustained release curve of the 

nitrogen in those plots met plant needs. They concluded that new indicators of N availability are 

needed that consider active C and N processes in organic systems. This is another indicator that our lack 

of understanding of nutrient processes and needs in organic systems makes conclusions about the need 

for fast-acting nitrogen applications problematic.

These factors make reaching a conclusion difficult. In the absence of consistent research showing 

overwhelming benefits from the high applications of HSN fertilizers, and with the requirement to fulfill 

OFPA criteria, the use of these compounds raises questions regarding soil health and the maintenance 

or improvement of soil organic matter. There are effective organic systems that pay close attention to 

nitrogen needs using multiple approaches to fertility that include the basics of crop rotations and 

applications of manures and composts. By paying attention, these systems do not result in large buildups of phosphorous or excessive loss of nitrogen to the environment. There are arguments for the 

limited use of allowed HSN fertilizers in emergency situations or when soil availability of nitrogen is 

limited. However, there are strong arguments that the use of these materials should be limited. The

ecosystem managed to maintain or increase soil organic matter does not include reliance on a highly 

soluble fertilizer. 

While organic regulations require an organic soil fertility plan to maintain or improve soil organic matter 

(205.203), the interpretation of this requirement can be complicated for certifiers to enforce. Does 

growing the same crop for several years, followed by a different crop, and then back to the first crop 

conform to this requirement? What level of highly soluble, low carbon to nitrogen ratio materials can 

be used before they are too much and do not comply with OFPA. Given the wide range of organic soil 

fertility options available, it can be challenging to have a notice of non-compliance from a certifier be 

enforceable. A prohibition with an annotation allowing restricted use of HSN fertilizers would give 

certifiers an additional tool to interpret growing practices that comply or do not comply with OFPA.

The restriction of the use of sodium nitrate to 20% of crop needs from the beginning of the National 

Organic Program limits the potential for overuse of that form of highly soluble nitrogen fertilizers. The 

prior vote of the NOSB to completely prohibit ammonia extracts illustrates the concern the organic 

community has for using these highly soluble nitrogen fertilizers. One comment received at the Spring 

2020 meeting demonstrates the slippery slope of using these types of fertilizers, including ammonia 

extracts:

Fertilizing through drip irrigation systems allows for precise placement and timing of the

fertilizer for optimum crop production. Drip irrigation has become a major method of irrigating 

crops, especially in California. The growth in drip irrigation is driven by drought, over-draft of 

aquifers, and the need for more precise fertilization... The type of crops irrigated with drip 

irrigation include all kinds of vegetables, tree fruit, strawberries, cane berries, and tomatoes.

Many of these crops, such as tree fruit and berries, are only irrigated using drip irrigation 

systems. These crops often have very long cropping cycles making it impossible to apply 
nutrients by a method other than through the drip irrigation system. Any fertilizing material 

added to drip irrigation water must have little to no solids, with most of the nutrients in a 

soluble form. Two major liquid nitrogen products are made with liquid fish (fish solubles, fish

protein, fish emulsion, hydrolyzed fish) and corn steep liquor. These ingredients contain high 

levels of insoluble material, which cause costly plugging of drip irrigation lines.

This illustrates a system that utilizes a large amount of highly soluble fertilizer for the fertility program. 

At what point does the use of highly soluble nitrogen fertilizers cross the line to being the primary

source of nitrogen, with other soil organic building practices being a minor part of the fertility program?

Sodium nitrate is approved for organic use with a limitation of use to 20% of crop nitrogen needs. 

Sodium nitrate is a non-synthetic alternative to bioavailable nitrogen for plants. Unlike other naturally 

derived substances that must undergo mineralization to be plant available, sodium nitrate acts more like 

conventional fertilizers. The 2020 TR cites several sources that demonstrate the benefits of materials 

that need to undergo mineralization as opposed to those that are immediately available and states:

Many substances derived from natural products are allowed as organic fertilizers, including fish 

meal, liquid fish residues, feather meal, bird or bat guano, alfalfa meal, soybean meal, bone meal, 

kelp, seaweed, blood meal, and meat meal. Like crop residues and compost, organic fertilizers 

require additional mineralization processes and provide a slow release of nitrogen, which is 

primarily present in complex molecules. Like crop residues and compost, organic fertilizers also 

contribute to increased soil organic matter, CEC capacity, and other nutrients and micronutrients. 

Unlike nitrogen fertilizers used in conventional agriculture, organic fertilizers have been reported to 

have minimal negative to long-term positive effects. 

There is the potential to use multiple sources of low C: N ratio high bioavailability fertilizers to replace 

basic soil fertility methods such as crop rotation, intercropping, and appropriate manure and compost 

use. Traditional organic materials, with the exceptions of sodium nitrate and guano, have a C: N ratio 

above 3:1:

Material C: N ratio range

Sodium nitrate 0.02: 1

Sea bird guano 1.2 - 3.3: 1 

Blood meal 3.1 - 3.8: 1

Fish powder 3.4 - 4.0: 1

Feather meal 3.5 - 3.8:1

Bone meal 3.6: 1

Liquid food-based fertilizer 4.6-5.2: 1

Liquid fish emulsion 5.2: 1

Cottonseed 5.5: 1

Poultry litters 8-12: 1

Composts 10.7 - 99.3:1

Soil 10-12

Clover and alfalfa (early) 13

Alfalfa meal 15.9: 1

Dairy manure (low bedding) 17

Alfalfa hay 20

Green rye 36

Corn stover 60
Wheat, oat, or rye straw 80

Oak leaves 90

Fresh sawdust 400

Newspaper 600

Sources: Cassity-Duffey, Cabrera, et al., 2020; Hartz and Johnstone, 2006; Lazicki, Geisseler, et al., 2020; 

Magdoff and Van Es, 2021.

Ammonia extracts have C: N ratios below 3:1 as compared to other liquid products:

Type of product Ammonia-N 

(%)

Total N (%) Ammonia-N/Total 

N (%)

C: N

manure tea 0.003 - 0.42 0.09 - 0.71 3.3 - 59.2 17:1

restricted ammonia product 4.2 – 7.47 5.78 – 8.23 51.0 – 99.6 2:1

liquid fish fertilizer 0.4 - 0.95 3.96 – 5.25 7.6 – 20.7 3.35

anaerobic digestate 0.048 - 0.68 0.28 – 2.21 2.2 – 43.2 1.25 - 5.48

Source: OMRI

 

Any amendment applied over 40:1 can cause temporary plant nitrogen deficits since nitrogen must be 

taken from surrounding soil to break down these materials. Conversely, amendments with lower C: N 

ratios can contribute available nitrogen to the system (Magdoff and Van Es, 2021).

As written by one public commenter (Spring, 2021):

The prohibition of synthetic nitrogen fertilizers manufactured through the Haber-Bosch process 

is a longstanding and fundamental prohibition in organic agriculture. The proliferation of these 

fossil-fuel-based synthetic fertilizers in conventional agriculture was a primary motivator of the 

modern organic agricultural movement. The principles of organic (as described in the 2001 

NOSB Recommendation) seek to achieve agricultural and environmental goals through the “use 

of cultural, biological, and mechanical methods, as opposed to using synthetic materials to fulfill 

specific functions within the system.” Therefore, substances that mimic synthetic nitrogen 

fertilizers' chemistry and functionality can be considered equally incompatible with traditional 

organic principles.

Another commenter stated:

Highly soluble sources of nitrogen cannot be addressed in a vacuum, and we cannot look at one 

material at a time. We must take a broader approach to limiting highly soluble sources of 

nitrogen as a whole. To evaluate and list each individually, even with a restriction, is a slippery 

slope and raises the concern of “stacking.” [Question #4 of the Spring 2020 Discussion 

document] asks: “Should the use of natural ammonia extract be limited to a certain percent of 

nitrogen use in crops (similar to the Chilean nitrate restriction)?” With this approach, producers 

could potentially “stack” highly soluble sources of nitrogen, using 20% of the crop’s needs from 

Chilean nitrate, 20% of the crop’s needs from another source, and 20% of the crop’s needs from 

yet another source.

Products that are immediately plant bioavailable mimic conventional nitrogen sources. Products that 

require additional mineralization, such as protein sources, require soil biotic transformation to be 
bioavailable to plants. While not perfect, organic products with greater than a 3:1 C: N ratio fit into the 

category of materials that require soil biotic transformation. Non-synthetic products below a 3:1 ratio 

tend to be those that are immediately plant available.

Public comments received during the Fall 2021 NOSB meeting raised several concerns regarding the 

motion to restrict nitrogen fertilizers with a C: N ratio of 3:1 or less, including those individual 

components of a blended fertilizer formulation, to a cumulative total use of 20% of crop needs.

As always, stakeholder insights are a welcome part of NOSB decision-making. A number of certifiers 

submitted comments at the Fall 2021 meeting supporting the motion as written. However, others had 

concerns and asked for further vetting of the motion. The following address specific comments raised 

by stakeholders.

Clarifying which nitrogen materials might be covered – the proposal initially read “Nitrogen products.” 

Since this could cover any material with nitrogen incorporated in it, the phrasing has been changed to 

read “Nitrogen fertilizers.” This specifies materials used to fertilize crops rather than any nitrogen 

compound and follows the definition of fertilizers listed in the organic regulations.

Clarification as to how fertilizer blends are evaluated – Some commenters suggested that the final 

product’s overall C: N ratio is used rather than looking at individual components of a blend. While this 

would simplify the evaluation, it would sidestep the intention of the motion. For example, a high carbon 

source could be mixed with an HSN composed entirely of nitrate to bring the blend above the required 

3:1 ratio. However, that blend would still be mainly composed of a nitrogen fertilizer that is 

immediately plant available. Carbon would be added to the soil, but the nitrogen component would 

bypass important nitrogen cycling soil processes described previously. While some fertilizers include 

some nitrate or ammonia (such as liquid fish), the preponderance of nitrogen is not ammonia or nitrate 

(see chart previously cited). Likewise, to support soil biological processes, a blended fertilizer should 

contain components that include soil biological processes for nitrogen release. 

To determine the amount of nitrogen in a blend that would be included in the restriction, the 

percentage of the nitrogen in a multi-component product (blend) that is below the 3:1 ratio can be 

calculated. 

In order to know what percent of the nitrogen in a blend counts toward the 3:1 restriction, a 

manufacturer could either provide the percent of the nitrogen in the blend that is restricted on the label 

(without disclosing what that material is) or a Material Review Organization could list that on the 

product certificate. As a last resort, if neither of those listings is available, the grower could call the 

manufacturer for that information. This would be similar to the soluble and insoluble nitrogen subanalysis that is already present on fertilizer labels, i.e., 3% N from ingredients below 3:1 C: N. If a grower 

uses multiple fertility sources, they will total all the N application from restricted materials and make 

sure the total is less than 20% of the crop needs. 

If manufacturers won’t disclose the information, one certifier notes:

When people say manufacturers won’t disclose, with pesticide materials it is the same way. If 

you won’t tell us, we won’t approve it. Besides, saying 20% of a blend is below 3:1 doesn’t say 

anything about what the actual materials are that make up that 20%. Things can still be 

confidential. I think many of these materials will go through an MRO anyhow and they can just 

list the C: N ratio on their listing, or at least whether it is above or below 3:1. And, it may push 
people to use less of these highly soluble materials since it will be very transparent as to what 

they use.

The process to identify the total nitrogen in a blend that is restricted is as follows:

1. What is the source of the material?

2. Does the HSN Fertilizer contain multiple components (blend)?

a. NOTE: Make sure to determine the source of all the material(s) within a product

3. What is the C:N ratio of the components(s)?

4. Does any of the components(s) of the fertilizer fall below the 3:1 C: N ratio

a. If no, then the fertilizer (and its respective components) has no restrictions

b. If yes, then component(s) of the fertilizer needs to be analyzed, and a nitrogen 

calculation needs to be conducted to quantify pounds of N from a restricted source. 

5. Obtain the %nitrogen of the product and the %nitrogen that is restricted from the material(s) 

that fertilizer product is composed of from the manufacturer, MRO, product certificate, or 

product label

6. Based on the overall Nitrogen composition – determine how many pounds of N would be 

restricted from the known concentration of HSN that is restricted due to falling below the 3:1 

ratio in relation to the entire product

7. Identify what 20% of crop needs are and ensure that restricted material(s) fall below that level.

An example:

- If a product containing multiple components (a blend) contains a material that would be 

restricted (below a 3:1 ratio) and that material provides 50% of the nitrogen in the overall 

product, then 50% of the amount of nitrogen in the fertilizer would fall under the HSN fertilizer 

restriction.

- If the blended product was an 8-0-0 and a producer applied 100 lbs., then 8 lbs. of actual N 

would be applied to the crop. 

- Since 50% of the nitrogen in the blended product falls under the restriction, therefore in this 

example, 4 lbs. of the actual N being applied would count towards the overall limit of 20% of 

crop needs. 

- If the total crop need is 80 lbs. of nitrogen, then up to 16 lbs. of that N could come from a 

restricted material(s) (20%*80lbs = 16lbs).

- If the blend is the only fertilizer applied, then up to 400 lbs. of the blend could be used. 
Additional Examples: 

Determination of total crop nitrogen needs – this approach is consistent with the sodium nitrate listing. 

The limitation of use to 20% of total crop needs parallels the sodium nitrate wording. It prevents 

conflicting interpretations of how this listing and the sodium nitrate listing would apply to each other. 

Certifiers also evaluated the 20% of total crop needs for sodium nitrate for twelve years before that 

listing became technically incorrect. While several certifiers have stated that they had difficulty with 

those calculations, they were still enforced. Guidelines could be developed with crop needs that all 

certifiers could use. If a producer argued that the figure was too low, they could present soil analyses, 

production data, or other means to support their higher crop needs.

Crop nitrogen needs are widely available from university extension publications on a state and regional 

basis. For example, the University of Georgia College of Agricultural Sciences has a publication available 

on the internet showing N crop needs: http://aesl.ces.uga.edu/publications/soil/cropsheets.pdf It 

shows canola as needing 135-175 lbs. of nitrogen per year. Thus, up to 27- 35 lbs. (actual N) of fertilizer 

below a 3:1 C: N ratio could be applied per year. 
The Supplemental Technical Report on sodium nitrate (2011) includes an example chart with nitrogen 

requirements for select organic crops in the Midwestern United States: 

Table 1: Per Acre Applications of Nitrogen Required for Select Crops Grown on Organic Farms in the 

Midwestern United States

Crop 

Amount of N 

Required 

lbs./acre) 

Maximum NOP 

Allowed 20% of 

Requirement 

(lbs./acre) 

Projected 

Amount of 

Chilean Nitrate 

16-0-01 

(lbs./acre) 

Winter wheat 80-100 16-20 100-130 

Spring wheat 

Oats, barley, spelt 

Corn 

80-100 

60-80 

120-150 

16-20 

12-16 

24-30 

100-130 

75-100 

150-180 

Sweet corn 80-100 16-20 100-130 

Pasture-grass 

Soybean 

Alfalfa-low OM 

100-120 

8-15 

8-10 

20-24 

1.5-3 

1.5-2 

120-150 

10-20 

10-12 

soil 

Cotton 50-75 10-15 60-100 

Peanuts 80-120 16-20 100-130 

Potatoes 180-200 36-40 225-250 

Cole Crops 

Green Beans 

150-175 

60-80 

24-35 

12-16 

150-200 

75-100 

Cucurbit 100-150 20-30 120-180 

Onions, Leeks, 100-150 20-30 120-180 

Garlic 

Tomatoes 100-150 20-30 120-180 

Carrots 100-150 16-20 120-180 

Finally, a common source of crop nitrogen needs is those listed in soil analyses. Recommendations from 

labs doing those soil tests are a readily available reference source of accepted crop needs. 

Traditional organic fertilizers that might be affected by the 3:1 ratio – Stakeholders raised concerns 

that several organic fertilizers traditionally used by producers might fall just below the 3:1 ratio. As 

noted in the table previously listed, feather, bone, and blood meals are above the 3:1 ratio but are very 

close. Certifiers or material review organizations could develop a list of unrestricted, allowed materials, 

such as these, that could be referenced so that they would not need to be continually reanalyzed. 

Several commenters suggested developing a closed list of materials that would fall below the 3:1 ratio 

and specifically state they could not be used. However, one concern is that new, not identified 

materials will be introduced. The purpose of this motion is to limit the use of new, novel nitrogen 

sources. Specifically stating what materials would be limited by this proposal would not limit new, 

currently unidentified products. If, for example, manufacturers develop products that are not covered 

under the specifics of the ammonia extract prohibition, this motion would limit the use of those 

products falling outside those definitions. A manufacturer could submit a petition for unrestricted use if 

they wanted their product to be exempt from this restriction. While creating a closed list of products 
below a 3:1 ratio would defeat the purpose of this motion, making a list of what known materials 

(feather meal, bone meals) are recognized as being above the 3:1 ratio might be useful.

Clarification of why the C: N ratio is used rather than total fertilizer N or percentage of 

ammonia/nitrate to total N – existing fertilizers commonly used in organic production have widely 

varying amounts of ammonia/nitrate to total N ratios. Given this range, it is difficult to determine 

where a material would be acceptable in terms of ammonia/nitrate to total N ratio. The motion could 

read that, materials with greater than 50% of ammonia/nitrate compared to total N would be restricted. 

But then there would be an incentive to make a material that included only 49% of these HSN fertilizers. 

In addition, fertilizers that contain proteins require soil mineralization to become plant available. These 

materials inherently contain carbon to form proteins. Using a C: N ratio addresses the need to have 

carbon-based materials applied to soil to promote the soil biology and transformation processes rather 

than only applying plant-available nitrogen fertilizers composed of nitrate or ammonia. 

Clarification on listing – Several commenters raised the question of whether § 205.203(f) is the correct 

place to put this motion. Ultimately, where this motion would be listed would be determined by the 

NOP. This motion intends that this limitation of HSN fertilizers apply to all crop producers, regardless of 

production system. This is similar to how synthetic materials added to the National List are allowed for 

all crop producers. Thus, the motion could be placed at § 205.602, similar to the prohibition on sodium 

nitrate or the suggested listing of ammonia extracts. Materials with a C: N ratio below 3:1 would be 

prohibited, but with an annotation allowing up to 20% of crop needs, similar to sodium nitrate. The 

listing could also be placed in the practice standards at § 205.105 or § 205.203(e) – “the producer must 

not use.” This would be like the practice standard of prohibiting the use of sewage sludge or materials 

that contain synthetic substances not included on the National List. The final placing of the listing by the 

NOP should ensure that it applies equally to all producers of food crops like the materials placed at § 

205.602 or § 205.105. Other motions approved by the NOSB and passed through rulemaking have had 

similar intent in uniform applicability.

Category 1: Classification

1. For CROP use: Is the substance X Non-synthetic or Synthetic?

Is the substance formulated or manufactured by a process that chemically changes a substance

extracted from naturally occurring plant, animal, or mineral sources? [OFPA §6502(21)] If so,

describe, using NOP 5033-1 as a guide.

Highly soluble nitrogen fertilizers can be manufactured using non-synthetic processes, as

demonstrated by the development of ammonia extracts. The development of ammonia extract

could not be anticipated at the time of the National Organic Program's adoption. Similarly, it is likely 

that there will be the development of additional, non-synthetic HSN fertilizers through novel

manufacturing processes.

1. Reference to appropriate OFPA category:

Is the substance used in production, and does it contain an active synthetic ingredient in the following 

categories: [§6517(c)(1)(B)(i)]; copper and sulfur compounds; toxins derived from bacteria; pheromones, 

soaps, horticultural oils, fish emulsions, treated seed, vitamins, and minerals; livestock parasiticides and 

medicines and production aids including netting, tree wraps and seals, insect traps, sticky barriers, row 

covers, and equipment cleansers; or (ii) is used in production and contains synthetic inert ingredients 
that are not classified by the Administrator of the Environmental Protection Agency as inerts of 

toxicological concern?

Highly soluble nitrogen fertilizers do not include any of the above materials.

Category 2: Adverse Impacts

1. What is the potential for the substance to have detrimental chemical interactions with other

materials used in organic farming systems? [§6518(m)(1)]

To the extent that the application of highly soluble nitrogen fertilizers can affect soil pH and/or

other microbial processes, other nutrients may or may not be released based on the soil pH effects. 

2. What is the toxicity and mode of action of the substance and its breakdown products or

contaminants and their persistence and areas of concentration in the environment? [§6518(m)(2)]

Highly soluble nitrogen materials may have short lifetimes in the environment, typically ranging from

hours to days based on environmental conditions. The short environmental lifetimes are due to the 

bioavailability of nitrogen in these compounds, which are readily incorporated into amino acids and 

other biologically important molecules. 

Furthermore, the TR states that the high-water solubility of ammonia, ammonium, and nitrate ions 

makes them conducive to leaching into water ecosystems. While aquatic microorganisms can 

metabolize these compounds, if they are overabundant, eutrophication can occur, and ammonia and 

ammonium can be toxic to aquatic life. Algal blooms can be caused by the influx of high concentrations 

of nitrogen nutrients. Algal blooms can reduce oxygen concentrations and result in hypoxic and anoxic 

environments. 

3. Describe the probability of environmental contamination during manufacture, use, misuse, or

disposal of such substance? [§6518(m)(3)]

The production of highly soluble nitrogen materials could result in the release of nitrogen into the 

environment. This is expected due to the inability of processes to capture 100% of the nitrogen content 

of feedstocks. The efficiency of capture depends on the processes used (2020 TR).

The release of these compounds into the atmosphere can contribute to the degradation of air quality 

and visibility due to the formation of aerosols. Additionally, the primary issue of environmental 

contamination is the over-application of nitrogen products and their subsequent leaching into nonagricultural environments. Dramatic losses of 20-80% have been noted. (2020 TR).

Finally, the disposal/use of the feedstock material that may be used to produce these compounds will 

depend on the processes. Depending on the use of that feedstock, there are potential environmental 

issues with that remaining material. Comments have focused on issues with phosphorous increases and 

issues when using manures/composts. This same problem could be an issue when a feedstock is 

disposed of after removing nitrogen. 

4. Discuss the effect of the substance on human health. [§6517(c)(1)(A)(i); §6517(c)(2)(A)(i);

§6518(m)(4)].
The 2020 TR refers to several human health effects from highly soluble nitrogen materials such as 

ammonia. Ammonium is a positive ion, and its impact on human health depends on the remaining 

negative portions of the ionic compound. Ammonium ions play a critical role in the Krebs cycle.

Ammonia is classified as a respiratory irritant – long-term exposure to gaseous ammonia can result in 

bronchial or pulmonary inflammation. Repeated exposure can lead to pulmonary fibrosis. Direct 

inhalation or ingestion can cause esophageal burns.

5. Discuss any effects the substance may have on biological and chemical interactions in the agro

ecosystem, including the physiological effects of the substance on soil organisms (including the salt 

index and solubility of the soil), crops, and livestock. [§6518(m)(5)] 

The 2020 TR states: Highly soluble nitrogen compounds can readily migrate from the applied soil system 

into the atmosphere and marine environments. When these materials remain in their applied soils, they

can also induce changes to the local environment. For example, the acidity of ammonium ions is 

recognized as a cause of soil acidification, reducing the soil pH. These pH changes result in changes to 

the solubility and bioavailability of other nutrients, affecting crops and soil organisms. Changes in soil 

pH may also negatively impact the viability of soil organisms, including earthworms and various 

microbial populations. High soil concentrations of inorganic nitrogen sources have been shown to slow 

the natural nitrogen fixation processes of plants. This shift in natural nitrogen production reduces the 

natural efficiency of the soil, making it more reliant on continued nitrogen inputs. 

6. Are there any adverse impacts on biodiversity? (§205.200)

The use of HSN fertilizers can alter nitrogen uptake rates and alter plant nutrient production. Studies by 

Phelan, Mason, et al., 1995, demonstrate that these altered plant nutrient production cycles can lead to 

increased susceptibility to pests.

Other studies show that long-term organic fertilizer inputs enrich carbon-related soil functions. Manure 

additions can strongly influence the formation, storage, and cycling of soil organic carbon and nitrogen 

and soil microecology (Sharaf, Thompson, et al., 2021; Ozlu, Sandhu, et al., 2019). Living organisms' 

total amounts (weights) vary in different cropping systems. In general, soil organisms are more 

abundant and diverse in systems with complex rotations that return more diverse crop residues and use 

other organic materials such as cover crops, animal manures, and composts. When crops are rotated 

regularly, fewer parasite, disease, weed, and insect problems occur than when the same crop is grown 

year after year. (Magdoff and Van Es, 2021)

Several public comments noted that the use of HSN fertilizers could increase the rate of mineralization 

in soils and thus be beneficial. In a short timeframe, this could be true, but this accelerated rate of 

mineralization could come at the cost of long-term soil carbon resources. Wang, Juliang, et al., 2018, 

found that long-term application of N-fertilizers causes an abundance of bacterial groups responsible for 

the denitrification process, which causes the turnover of nitrogen to increase and results in more 

significant nitrogen loss over time. Essentially, adding more nitrogen fertilizer results in long-term 

nitrogen loss while altering other soil components, like decreasing soil pH and C: N ratio. When soil 

carbon and nitrogen are reduced in response to the application of chemical fertilizers, the beneficial 

enzymatic activity of the soil also decreases (Ozlu, Sandhu, et al., 2019). Another study concluded:

Annual nitrate leaching was 4.4–5.6 times higher in conventional plots than in organic plots, 

with the integrated plots in between. This study demonstrates that organic and integrated 
fertilization practices support more active and efficient denitrifier communities, shift the 

balance of N2 emissions and nitrate losses, and reduce environmentally damaging nitrate losses.

Although this study specifically examines a perennial orchard system, the ecological and 

biogeochemical processes we evaluated are present in all agro-ecosystems, and the reductions 

in nitrate loss in this study could also be achievable in other cropping systems (Kramer, 

Reganold, et al., 2006).

The TR states that incorporating crop residues and compost provides a potential long-term alternative 

to HSN fertilizers. Nitrogen content in compost is slowly released through mineralization processes in 

the soil, primarily facilitated by its metabolism by microorganisms in the soil. Unlike ammonia extract, 

the use of compost also contributes to soil organic matter and available carbon, phosphorous, and 

micronutrients, as well as soil microorganism populations and activities.

Category 3: Alternatives/Compatibility

1. Are there alternatives to using the substance? Evaluate alternative practices as well as nonsynthetic and synthetic available materials. [§6518(m)(6)]

The following statements are taken from the 2020 TR.

There are many natural soil amendments that can deliver nitrogen for crops. Manure is a source of 

nitrogen compounds, including ammonia, ammonium ions, and urea, which are biological waste 

compounds. However, manure has a relatively low level of biologically available nitrogen compared to 

HSN fertilizers. The biologically available forms of nitrogen in manures may also lead to similar issues 

with nutrient leaching as ammonia extract, potentially polluting surrounding water systems and leading 

to atmospheric ammonia emissions. Manure from both organic and conventional livestock is permitted 

for use in the production of organic crops. However, the availability of manure may be limited 

regionally due to the continued segregation of crop and animal agricultural production.

In addition to manure, crop residues and compost may be added as a source of bioavailable nitrogen.

This includes the direct integration and composting of manure and other organic agricultural wastes.

These feedstocks' high protein and amino acid content allow for their conversion to ammonia and 

ammonium compounds through anaerobic digestion and metabolism by soil microorganisms. When 

composts do not include manures, they are generally low in nitrogen-containing compounds (2020 TR).

Incorporating crop residues and compost provides a potential long-term alternative to ammonia extract 

and other nitrogen fertilizers. Nitrogen content in compost is slowly released through mineralization 

processes in the soil, primarily facilitated by its metabolism by microorganisms in the soil. Unlike 

ammonia extract, the use of compost also contributes to soil organic matter and available carbon, 

phosphorous, and micronutrients, as well as soil microorganism populations and activities. The 

incorporation of compost into the agro-ecosystem has been reported to improve soil characteristics, 

specifically water holding capacity and cation exchange capacity (CEC). Increased soil CEC allows it to 

retain cations more effectively, including ammonium ions and metal cations required as micronutrients 

(e.g., iron [Fe], copper [Cu], zinc [Zn]) (2020 TR).

Many other substances derived from natural products are allowed as organic fertilizers. These include 

fish meal, liquid fish residues, feather meal, bird or bat guano, alfalfa meal, bone meal, kelp, seaweed,

and meat meal. These materials may be more readily available to crops due to their lower C: N ratio, 

but all require mineralization to be plant bioavailable. The mineralization is required due to the nitrogen 
available in these materials being present as more complex molecules and proteins. These materials 

provide a slower N release than ammonia extracts. They also contribute to increased soil organic 

matter, CEC capacity, and other nutrients and micronutrients. Unlike conventional fertilizers, organic 

fertilizers have been reported to have minimal negative to long-term positive effects on soil health 

(2020 TR).

Crop rotation and intercropping are traditional methods to ensure soil health. They can be especially 

effective if legumes are included in the rotations. Legumes can fix nitrogen from the atmosphere by 

converting atmospheric dinitrogen into bioavailable nitrogen. Legumes and other nitrogen-fixing plants 

produce higher quantities of bioavailable nitrogen when there are low soil concentrations of ammonia 

and ammonium. Intercropping offers the potential of direct input of bioavailable nitrogen from 

legumes to other crops by growing them alongside each other. Intercropping has been shown to 

increase crop yields, and these yields have been shown to be less dependent on nutrient inputs 

compared to monocropping systems. Cover cropping also promotes increased organic matter, 

increased CEC properties, and prevents soil erosion. However, cover crops use can be limited by 

regional climates and require adequate soil temperatures to grow between agricultural seasons (2020 

TR). 

2. In balancing the responses to the criteria above, is the substance compatible with a system of

sustainable agriculture?

To evaluate compatibility, the Subcommittee review includes answers to the following 12 questions as 

noted in the NOSB Policy and Procedures Manual.

• Does the substance promote plant and animal health by enhancing the soil’s physical,

chemical, or biological properties? 

During the discussion and public comment period regarding ammonia extracts at the 2020 and 2021

NOSB meetings, commenters indicated that ammonia extracts must be used with other soil-building 

practices to comply with OFPA criteria. These comments would suggest that the use of ammonium 

extracts alone does not enhance the soil’s biological properties. For example:

The Petition ignores that the use of any fertilizer, including presently approved ammonia 

extracts, can only be applied under a holistic certified organic system plan.

This is a complex issue, and commenters provided a range of responses that either indicated that these 

extracts would harm soil biological properties or that they would enhance these properties. 

Diverse soil fertility practices can increase soil biological activity, as noted by one comment:

The impact of soil carbon on soil biological response was more closely related to the inputs of 

carbon due to crop rotations than fertilizer practice (Geisseler, 2014). These complexities have 

been explored by Hijbeeks et al. (2017) when they compared soil and crop responses to organic 

and inorganic fertilizers on a range of crops from long-term experiments across Europe. Their 

results showed no significant effect of the organic inputs on crop yield with the effects from 

organic additions dependent upon the clay content, climate, and the soil organic matter at the 

beginning of the experiment, as shown from their results (Fig. 4). These findings are consistent 

with those from Lori et al. (2017) in their meta-analysis of 56 experiments across the world.

They found organic systems exhibited 32-84% greater microbial biomass carbon, microbial 
biomass nitrogen, total phospholipid fatty acids, dehydrogenase, urease, and protease activities 

than conventional systems. When they used subgroup analyses, they found that crop rotation, 

inclusion of legumes in the rotation, along with the organic inputs were all significant factors 

affecting the soil microbial size and activity.

There were few comments comparing the environmental effects of any type of HSN Fertilizer to an 

organic system using manures, composts, crop rotations, cover crops, and interplanting. Several 

commenters wrote that this is an area where research is limited, and effects may largely be unknown.

Given that the comments and citations supporting these materials only be used in conjunction with 

other carbon contributing soil practices and that some research indicates their negative effects on soil 

biology, a conservative approach to this answer is that the use of HSN fertilizers does not positively 

contribute to plant health over the long term.

• Does use of the substance encourage and enhance preventative techniques, including cultural 

and biological methods for the management of crop, livestock, and/or handling operations? 

Commenters have argued that the limited use of HSN fertilizers in situations where nitrogen might be 

limited due to unusual weather events or cold soils could “prime” the soil system to increase biological 

activity or bridge short-term nitrogen deficits. But these situations do not meet the criteria of the 

wording “encourage and enhance preventative techniques” since they would be a response in an

unusual situation when other techniques have failed. Others have noted that if soils are wet or cold 

during planting time, this points to the inefficiency of the mycorrhizal fungi or the root system itself. 

Nitrogen is not generally needed in large amounts early on, and it is actually phosphorus that is needed. 

If mycorrhizal fungi are not active due to weather, they cannot process the needed phosphorus to assist 

early plant germination. There can be a phosphorus deficit in the plants when cold/wet soils occur, even 

in excess phosphorus soils. From the viewpoint of conventional farmers, a true starter fertilizer is 10-34-

0, indicating more phosphorus is needed early on to charge the soil for the plant “pop-up” than nitrogen 

itself. This same issue goes for organic soil.

Additionally, HSN fertilizers inherently contain a very low C: N ratio. In the past, the NOSB had 

prohibited materials sourced from agricultural waste when the carbon value of the original source 

material was not retained in the final product. The prohibition of ash from manure burning is an 

example where the carbon from the manures is removed by burning, and the value of the materials for 

restoring soil organic matter is destroyed. These precedents may lead to the conclusion that all HSN’s 

that are separated from their carbon source should be prohibited, similar to the vote by the NOSB to 

prohibit ammonia extracts. However, at this time, this motion mimics the annotation for sodium 

nitrate, allowing very limited use of an HSN.

• Is the substance made from renewable resources? If the source of the product is nonrenewable, are the materials used to produce the substance recyclable? Is the substance 

produced from recycled materials? Does use of the substance increase the efficiency of 

resources used by organic farms, complement the use of natural biological controls, or reduce 

the total amount of materials released into the environment? 

Arguments are made both ways as to whether applications of HSN fertilizers and their ready availability 

to plants reduce their leaching potential (since only the amounts needed can be applied) or whether 

they bypass soil systems that tie up and release soil nitrogen dynamically (those systems only have a 

small proportion of nitrogen available to leach). The timing of nitrogen application can be controlled 
with HSN fertilizers, and they can be applied in quantities that the crop needs at that point. This could 

lead to a better match of nitrogen added to the nitrogen required by the crop. However, there is also 

evidence that dynamic soil systems that release and then reabsorb nitrogen can supply crop needs while 

minimizing free nitrogen (Bowles, Hollander, et al., 2015). The free nitrogen would be limited and, thus,

leaching potential reduced. 

One researcher (Phelan, Mason, et al., 1995) has conducted studies showing that plants are more 

resistant to insect damage when organic fertilizers are used instead of readily available mineral 

materials. Thus, the use of HSN fertilizers can disrupt biological controls since they are readily available. 

• Does use of the substance have a positive influence on the health, natural behavior, and 

welfare of livestock? 

N/A

• Does the substance satisfy expectations of organic consumers regarding the authenticity and 

integrity of organic products? 

While the answer to this question is not referenced in the TR or other research reports, one public

commenter noted that:

Objections to the compatibility of these substances with organic principles are serious enough 

to potentially lead to fragmentation of the organic market. Some companies have indicated 

they may be prepared to establish private standards that exclude products produced with this 

input from their supply chain. This indicates that the substance could fail to align with the 2004 

NOSB Recommendation, which asks NOSB to consider whether the substance would “satisfy 

expectations of organic consumers regarding the authenticity and integrity of organic products.”

• Does the substance allow for an increase in the long-term viability of organic farm operations? 

This is a complex question. Some commenters argue that the potential for yield increases, precision 

application of nitrogen, and reduction of environmental contamination from excess nitrogen or 

phosphorous from composts and manures will increase the long-term viability of organic farms.

Others argue that using HSN fertilizers will degrade soil biological systems and interfere with biological 

processes important to plant and soil health. Using these materials may increase short-term yield but

not promote long-term soil carbon building. Thus, long-term resiliency and viability may be hurt by 

using these materials. 

Using OFPA and deploying a total systems approach is necessary. Precision technology independent of 

nitrogen sources should be adopted by organic farmers interested in increasing their yields and applying 

the right nutrients in the right places. Excess nitrogen or phosphorus applications need to be regulated 

through soil samples, removal rates, etc., and should not be an issue if the total systems approach is 

applied. Also, if there are nutrient management problems on a particular soil, avoiding solving them and 

bypassing them with a material that mimics conventional materials should not be permitted in an 

organic system. At a minimum, HSN fertilizers should be listed as a restriction on the OMRI certificate. 

They cannot be applied if work has not been done to remediate excess phosphorus or calcium build-up 

in soils due to over applications in prior years.
• Is there evidence that the substance is mined, manufactured, or produced through reliance on 

child labor or violations of applicable national labor regulations? 

There is no evidence that these materials violate labor regulations.

• If the substance is already on the National List, is the proposed use of the substance 

consistent with other listed uses of the substance? 

N/A

• Is the use of the substance consistent with other substances historically allowed or disallowed 

in organic production and handling? 

This is a proposal to limit the use of non-synthetic nitrogen materials. Other materials currently used in 

organic production (liquid fish, soy protein hydrolysate, blood meal, sodium nitrate) are similar in use. 

Still, all outside of sodium nitrate is protein-based, requiring some mineralization before impact to 

plants. Of these, only sodium nitrate has significant nitrogen in an immediately plant usable form. 

Sodium nitrate is annotated on the National List to a limit of not more than 20% of crop needs. When

this restriction was applied, sodium nitrate was one of the very few highly soluble nitrogen materials 

available, and it was naturally mined and not manufactured. However, it should be noted that a 

previous NOSB voted to prohibit the use of sodium nitrate due to concerns of salt build-up and similar 

concerns regarding soil biology effects. This motion mirrored restrictions on sodium nitrate when it was 

one of the few non-synthetic forms of highly soluble nitrogen.

In general, natural substances allowed in organic production are made up of complex chemical 

structures, including lignans, proteins, carbon, nitrogen, and other minerals and materials. As noted 

above, different behavior in the soil of HSN fertilizers may be beneficial or detrimental. These 

differences may be exhibited by the differing C: N ratio between these materials and other organic 

inputs. Except for sodium nitrate, most other traditional non-synthetic organic fertilizers have ratios of 

at least 3:1 and often greater. The low C: N ratio of HSN fertilizers would be expected to cause different 

soil effects than those materials with higher carbon amounts.

Proponents of HSN fertilizers argue that they are similar to other substances allowed and are only more 

immediately available. When used in moderate quantities, they enhance soil biology and can cause soil 

and plant ecosystems to be more productive.

Opponents argue that HSN fertilizers bypass and short circuit soil biological processes and do not 

enhance long-term carbon build-up in the soil. Their low C: N ratio is contrary to the original intent of 

the organic regulations in that soil fertility methods should promote long-term soil health and 

ecosystem stability. 

• Would approval of the substance be consistent with international organic regulations and 

guidelines, including Codex? 

The use of sodium nitrate for products exported to Canada is prohibited. Inconsistencies between 

international certifiers reduce export market potential and create additional confusion with countries 

with substantially different standards that the United States receives imports from.
• Is there adequate information about the substance to make a reasonable determination on 

the substance's compliance with each of the other applicable criteria? If adequate 

information has not been provided, does an abundance of caution warrant rejection of the 

substance? 

Given the conflicting information regarding the use of HSN fertilizers, it seems prudent to limit the usage

of extracts. As with the debate regarding ammonia extracts, adequate research demonstrating that 

these high-nitrogen, carbon-limited materials comply with OFPA criteria for maintaining and increasing

soil organic matter is very limited. As noted above, arguments can be made that these materials have a 

positive or negative effect. Given that there is no clear answer and adverse effects on soil health have 

been documented, an abundance of caution warrants a limitation on using HSN fertilizers. Since future 

innovations in the non-synthetic production of HSN fertilizers are possible, a limit on the cumulative use 

of HSN fertilizers in organic agriculture is prudent. If future research conclusively demonstrates that 

these materials comply with the OFPA criteria to maintain and build soil organic matter, a petition could 

be submitted to remove the limitation.

Furthermore, an abundance of caution warrants a close look at the use of low (below 3:1) C: N ratio 

materials, such as ammonia extracts, for organic fertility. The NOSB has set precedents to the limitation 

of these types of materials. Sodium nitrate is limited to 20% of crop needs. Other highly soluble, nonnitrogen materials are also limited by annotation. It was noted in public comments that:

An abundance of caution warrants a close look at the use of low (below 3:1) C: N ratio materials. The 

NOP and NOSB have previously discussed the need to limit materials of high solubility. Furthermore, 

the recent vote by the NOSB to prohibit ammonia extracts is another example of the concern over 

the use of these types of low C: N ratio materials. 

In the preamble to the publication of the NOP Final Rule on December 21, 2000, NOP discusses how 

it decided to agree with the NOSB recommendation and to put specific regulation of substances of 

high solubility into the annotations for each of these materials where they appear on the National 

List of Allowed and Prohibited Substances. NOP goes on to say, "Based on the recommendation of 

the NOSB, the final rule would prohibit use of these materials [substances of high solubility], unless 

the NOSB developed recommendations on conditions for their use and the Secretary added them to 

the National List." At the time, the discussion was about mined substances of high solubility because 

there were no concentrated, highly soluble plant nutrient materials other than mined sources 

available at that time.

This long-time concern for using highly soluble plant nutrients and the “an abundance of caution” 

criteria is important for this proposal. Concerning this motion, several options are open to the NOSB. 

The first is to reject the motion altogether and allow the unlimited use of non-synthetic HSN fertilizers

(except for the 20% limitation on sodium nitrate). The second is to annotate the use of each of these 

materials to some maximum percent of crop needs, like sodium nitrate. The third is to limit the 

cumulative total use of these materials to some maximum percent of crop needs.

If an annotation to limit the use of a single material were to be put in place, the potential exists for 

sodium nitrate, and another allowed HSN to both be used up to each of their maximum allowed rates. 

This stacked rate would allow for higher applications than either alone. The combined use would put 

the burden on certifiers to identify whether the total use of these highly soluble products violated the 

OFPA criteria to maintain or build soil organic matter. It is likely that different certifiers would have 

different interpretations and that notices of non-compliance would be challenging to enforce.
Additionally, the effectiveness of a prohibition or limitation is dependent on an exact definition of 

materials already prohibited or limited. If new products are developed that fall outside those

definitions, a future petition would have to be submitted to determine if they should or should not be 

allowed. This could create additional workloads and a perpetual cycle of review for each new product 

produced. It would seem prudent to set an additional limitation for materials that might fall outside the 

current definitions and other highly soluble nitrogen materials. 

A limitation restricting the total use of highly soluble nitrogen fertilizers would prevent the “stacking” of 

multiple highly soluble fertilizer types. With the proposed motion, to restrict nitrogen fertilizers with a 

C: N ratio of 3:1 or less, including those individual components of a blended fertilizer formulation, to a 

cumulative total use of 20% of crop needs, The NOSB should not have to continually be concerned about 

the introduction of novel non-synthetic nitrogen materials before a petition is submitted to restrict 

them. Manufacturers of these new HSN fertilizers would know that there is a limitation on an HSN

fertilizer before resources are invested in the process. A manufacturer could also submit a petition to 

remove any restriction applied to their product.

A public commenter noted:

Sodium nitrate was prohibited in part for this same rationale. As stated by NOSB in a past review to 

justify its recommendation to prohibit, the “use and dependence on sodium nitrate also can tend for

producers to put off the need for strong soil-building practices, consistent with §205.203 since it 

behaves similarly to conventional synthetic nitrogen fertilizers.” This is evidence that the substance

could fail to align with the 2004 NOSB Recommendation which asks NOSB to consider whether “use 

of the substance is consistent with other substances historically allowed or disallowed in organic 

production and handling.” Highly soluble sources of nitrogen cannot be addressed in a vacuum, and 

we cannot look at one material at a time. We must take a broader approach to limiting highly 

soluble sources of nitrogen as a whole. If each material must be evaluated and listed individually, 

the evaluation process could be endless. Additionally, there would be the possibility of stacking HSN 

fertilizers, thus bypassing any restrictions on individual HSN fertilizers.

• Does use of the substance have a positive impact on biodiversity? 

There are arguments that HSN fertilizers enhance soil biological processes, while others say that these 

materials either do not impact or decrease biodiversity. A proponent of the use of ammonia extracts 

cited Jerry Hatfield in that:

Bio-based fertilizers have been shown to increase the characteristics related to soil

health, e.g., organic matter, soil aggregates, enhanced biological activity, increased

nutrient cycling because they stimulate biological activity through a balanced

carbon: nitrogen (C: N) ratio

Contrarily, regarding ammonia extracts, the 2020 TR states:

While bioavailable nitrogen is also important for the function of microorganisms, high 

concentrations of ammonia and ammonium compounds result in changes to the native soil 

communities. These changes vary based on the initial soil communities and may result in either 

an increase or decrease in total population. However, while there are cases of population 

growth in some communities, the application of nitrogen fertilizers is associated with decreases 

in the diversity of these microbial communities.
Given the conflicting information regarding biodiversity impacts, it would be difficult to state 

unequivocally that the use of HSN fertilizers positively impacts biodiversity. While there is a chance that 

these materials increase diversity, there is also a very likely chance that they decrease biodiversity. As 

noted during the debate that eventually led to an NOSB vote to prohibit ammonia extracts, there are 

situations where the very limited use of highly soluble nitrogen fertilizer may be warranted. The current 

use of sodium nitrate or guano meets these situations. However, a limitation on the use of these 

materials and the use of any future HSN fertilizers prevents the potential stacking or overuse of these 

materials. In addition to the prohibition on ammonia extracts, this motion will limit the use of any new 

novel highly soluble nitrogen materials until their compliance with OFPA criteria can be evaluated 

through the petition process. 

References

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Subcommittee Vote:

National List Motion

Motion to add at § 205.105: nitrogen fertilizers with a C: N ratio of 3:1 or less, including those individual 

components of a blended fertilizer formulation, are limited unless use is restricted to a cumulative total 

use of 20% of crop needs.

Motion by: Amy Bruch

Seconded by: Brian Caldwell

Yes: 7 No: 1 Abstain: 0 Absent: 0 Recuse: 0