Editor's note: A special thanks to Dr. Monica Ozores-Hampton at the Southwest Florida Research and Education Center for coordinating The Immokalee Report, of which the article below is part.

Organic compost must meet strict definitionsAs the market for organic food and fiber increases in the United States, there is a greater need to improve soil quality in organic production systems. Improving soil quality can be an opportunity for compost facilities around the country, especially those close to agriculture and urban areas.  

Organic certification of food and fiber and products to be used in organic production in the United States is regulated under the U.S. Department of Agriculture’s National Organic Program (NOP) rule 7 CFR Part 205. (http://www.ams.usda.gov/AMSv1.0/nop).  

The NOP defines organic compost as “the product of a managed process through which microorganisms break down plant and animal materials into more available forms suitable for application to the soil.”

Composting converts waste material into a valuable resource that can build soil fertility by improving soil physical, chemical and biological properties. Under the NOP, the use of sewage sludge or biosolids is prohibited in the production of organic compost.


Organic compost production criteria

The NOP has only two criteria for organic compost production.

1. The initial carbon:nitrogen or C:N ratio of the blended feedstocks should be between 25:1 and 40:1.

2. The temperature must remain between 131degrees Fahrenheit and 170 degrees F for three days in an in-vessel or static aerated pile or 15 days in windrows, which must be turned at least five times during this period.

Products, such as compost to be used for organic production of food and fiber, can be found in the OMRI (Organic Materials Review Institute) listing. As a marketing tool, organic composters can be listed in the compost section in the Organic Products List (OPL), which represents OMRI’s recommendations regarding the acceptability of brand name products for organic production, processing, and handling.

Products included in the OPL have been reviewed against standards developed by OMRI for assessing compliance with the NOP. Only those products that have passed this review are included in the OPL and can display the OMRI Listed seal on labels and in advertisement and promotions.  

Since participation in the OMRI program is voluntary, the OPL is not a comprehensive listing of products suitable for organic production, processing and handling. In addition, the product’s absence from the OPL does not imply its failure to comply with the NOP rule. 

Dr. Monica Ozores-Hampton is an assistant professor specializing in vegetable production based at the Southwest Florida Research and Education Center in Immokalee. She may be reached at ozores@ufl.edu.