Organic fertilizer detectives

By Peggy Miars, OMRI Executive Director/CEO

At OMRI we relish a good mystery, and we’re always working to sort out details behind a given product or formulation. What’s that you say? You can simply look at all of the ingredients to determine whether a fertilizer meets organic standards? Sadly, we find that nine times out of 10, this is not the case. Products are complicated! And the difference between compliant and noncompliant fertilizers can be difficult to discern.

Let’s look at fish-based fertilizer, for example. We all know that fish is a great source of important nutrients, especially nitrogen and phosphorous. And it’s great that organic gardeners can reuse what are essentially waste products created by fisheries and canneries. However, there are several important questions to ask before deciding whether a fish product is appropriate for use in your organic farm or field.

First of all, if we are looking at a fish meal product, are we sure that it just contains fish meal with no added ingredients? Some powdered fertilizers utilize a dust suppressant to mitigate dust hazards and prevent product loss. Others are pelletized for easier application and may have an added pelletizing agent. Additives like dust suppressants and pelletizing agents are not always listed on the label, and they may or may not be allowed under organic standards.

The issues become even more complex when the fish fertilizer is sold as a liquid product. Liquid fish fertilizers are very potent and they can be convenient to apply. However, these products usually must be stabilized with a small amount of acid, often in the form of phosphoric acid, to prevent spoilage. The organic standards allow this type of stabilization, but the added phosphoric acid is limited to just the amount needed for stabilization. If the phosphoric acid is added in an excessive amount, it will “spike” the naturally derived fertilizer with synthetic phosphorous, rendering the final product synthetic and prohibited in organic agriculture.

For these types of fertilizers, and for many other products for organic use, verification means looking carefully at ingredients, ingredient proportions, and manufacturing process to determine whether the product is appropriate for organics.

Unfortunately, liquid fertilizers that are high in nitrogen, including many fish fertilizers, have also been identified by the U.S. Department of Agriculture (USDA) National Organic Program (NOP) as having a high potential for fraud. In order to address this issue, the NOP Guidance 5012 issued in 2009 mandates additional inspections and verification steps for these “high-nitrogen” liquid fertilizers. Any products that advertise or contain over 3% nitrogen must undergo two inspections per year, including one unannounced inspection, in order to be allowed for use in organic production.

This policy came out of actual fraud cases that took place in California several years ago where two manufacturers of liquid fertilizers were found guilty of intentionally spiking their products with synthetic additives before selling them at a premium to organic farmers. In each case, the guilty party served jail time and was assessed financial penalties by the U.S. Attorney’s Office.

OMRI is one of only a few verification organizations that provide this type of “high-nitrogen” inspection, which is one reason why the OMRI Products List© contains so many liquid fertilizer products! If a farmer wants to use a liquid fertilizer that has not been inspected by OMRI, their certification agent must find a way to provide two very costly annual inspections to meet NOP requirements.

Finally, the same fish meal that we discussed earlier may also be used as a feed additive or supplement for organic livestock. When we look at the same product for this completely different use, we have still another set of questions. Since the product will be ingested, we must now be on the lookout for yet another set of ingredients in the form of synthetic preservatives. Many preservatives are prohibited, so here at OMRI we must check the ingredients against both the USDA organic standard and the Food and Drug Administration (FDA) regulations for livestock feed.

In order to piece together all of this information and make verified and reliable compliance decisions, OMRI collects and reviews purchase receipts for all product ingredients. This review ensures that ingredients are purchased from verified sources. And there are a number of ingredients which may be compliant or prohibited depending on the manufacturing process. In these cases, OMRI also collects information about the ingredient manufacturing process to verify that the process does not result in a prohibited synthetic material. It takes a whole world of detective work that could never come from simply looking at a label!

Peggy Miars came to OMRI in 2010 from California Certified Organic Farmers (CCOF), where she served for six years as the Executive Director/CEO. She holds a Bachelor of Business Administration degree from Western Michigan University and completed post-graduate courses in nonprofit management at Regis University in Colorado Springs. Peggy has worked in the organic industry for more than 17 years, previously in marketing and management positions with Earthbound Farm, Whole Foods Market, Granary Market, various nonprofit organizations, and her own marketing consulting business. She completed IOIA inspector training for crops in 2007.

Lead photo by Mike "Dakinewavamon" Kline.

3 Responses to “Organic fertilizer detectives”

  1. John Hood

    I have been a follower of the organic movement and Rodale,
    for over 40 years. I am always impressed by the foresight
    of this organization as it pertains to improving the safeguards
    around organics.

    One of our local papers reported that the economy should come before the green movement but I think if we encourage the green movement, with safeguards, the economy will follow
    and we all benefit.

    Thanks again and keep up the great work.
    The Gardening Guru

  2. Michael LaBelle

    Good article. I do have one question not directly related to the article but it does concern another organic input. What are your thoughts about CMS or concentrated molasses solubles? I am looking at using such a product as a base for a liquid organic fertilizer.

  3. Kyle


    I am wondering what preservatives can be used when making organic liquid fertilizer products. Any information would be greatly appreciated. Thank you,



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