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Soil Amendments

Soil Amendments

Soil amendments are any chemical, biological, or physical materials intentionally added to the soil to improve and support plant growth and development

Biological soil amendments, 
especially those that include untreated (raw) manure, pose significant microbial risks

Human waste is prohibited for use on produce crops, unless it meets the EPA regulation for biosolids (40 CFR part 503)

Untreated Soil Amendments
FDA is currently pursuing further research to support application intervals for raw manure
Raw manure must not be directly applied to the harvestable portion of the crop

Biological Soil Amendments

  • Raw Manure: The FDA is conducting a risk assessment and extensive research on the number of days needed between the applications of raw manure as a soil amendment and harvesting to minimize the risk of contamination. (A soil amendment is a material, including manure, that is intentionally added to the soil to improve its chemical or physical condition for growing plants or to improve its capacity to hold water.)
    • At this time, the FDA does not object to farmers complying with the USDA’s National Organic Program standards, which call for a 120-day interval between the application of raw manure for crops in contact with the soil and 90 days for crops not in contact with the soil. The agency considers adherence to these standards a prudent step toward minimizing the likelihood of contamination while its risk assessment and research is ongoing.
    • The final rule requires that untreated biological soil amendments of animal origin, such as raw manure, must be applied in a manner that does not contact covered produce during application and minimizes the potential for contact with covered produce after application.
  • Stabilized Compost: Microbial standards that set limits on detectable amounts of bacteria (including Listeria monocytogenes, Salmonella spp., fecal coliforms, and E. coli 0157:H7) have been established for processes used to treat biological soil amendments, including manure. The rule includes two examples of scientifically valid composting methods that meet those standards. Stabilized compost prepared using either of these methods must be applied in a manner that minimizes the potential for contact with produce during and after application.

Fact Sheet: Biological Soil Amendments of Animal Origin
https://www.fda.gov/downloads/Food/GuidanceRegulation/FSMA/UCM614282.pdf

Raw Manure under the FSMA Final Rule on Produce Safety
https://www.fda.gov/Food/GuidanceRegulation/FSMA/ucm482426.htm

Soil Amendments
https://gaps.cornell.edu/educational-materials/decision-trees/soil-amendments/

Soil Amendments