The 90-120-Day Rule for Organic Crop Manure Amendment

Organic cultivation comes with a lot of rules. All crop inputs need to be certified organic or have approval according to US Organic Standards. To claim that your product is organic, it also needs to be certified as such by an FDA-registered accrediting body. Among the many rules for organic farming, the 90-120-Day Rule for Manure is very important and is an excellent guideline to follow even if you are not an organic producer. This rule ensures that manure is used correctly to avoid contaminating crops with microbes that can make people very sick.

The 90-120-Day Rule for Organic Crop Manure Amendment is a USDA regulation that states raw (un-composted) animal manure must be used according to these rules:

• Raw manure must be incorporated into the soil a minimum of 120 days prior to harvest when edible portions of crop contact the soil.
  • Leafy greens, melons, squash, peas, etc.
• Alternatively, if the edible portion of the crop does not contact the soil, raw manure may be applied 90 days prior to harvest.
  • Corn, tree fruits, etc.
• If any edible portion of the crop that may be splashed with raw manure amended soil from irrigation, precipitation, or manure application the 120-day rule is to be applied.
• These rules apply only to food crops and not to fiber crops, cover crops, or crops for livestock feed.
• These rules assume raw manure will be incorporated into the soil using mechanical tillage.