Manure Management on Organic Farms
National Organic Program Standards for Manure
Use of livestock manure imported from conventional farming operations is allowed by National Organic Program (NOP) standards. There are, however, application restrictions. Manure may only be used in conjunction with other soil-building practices and be stored in a way that prevents contamination of surface or ground water. Many certifiers specify that manure application must not exceed “agronomic application rates,” which means the amount applied must be less than or equal to the requirements of the crop. Manure cannot be applied when the ground is frozen, snow-covered, or saturated.
National Organic Standards Final Rule
The National Organic Standards Final Rule (USDA National Organic Program states (§205.203(c)(1)) that “Raw animal manure must either be composted, applied to land used for a crop not intended for human consumption, or incorporated into the soil at least 90 days before harvesting an edible product that does not come into contact with the soil or soil particles (e.g., sweet corn) and at least 120 days before harvesting an edible product (especially important for nitrate accumulators, such as spinach) that does come into contact with the soil or soil particles."
Vegetable Production
Manure is used less in vegetable production systems than in more traditional grain production systems or rotations given the above limitations for un-composted manure by vegetable growers. In addition to these practical limitations, fresh produce marketers have voiced reservations about having manure in any way associated with their production operations, thus avoiding consumer concern or hesitation at the point of purchase.
Contaminants
Although raw manure is an excellent resource for organic production it may contain contaminants such as residual hormones, antibiotics, pesticides, disease organisms, and other undesirable substances. Organic substances are not the only contaminants found in manures. Heavy metals can be a problem too, especially where industrial-scale production systems are used (e.g., poultry plants).
NOP Recordkeeping Requirements
Accurate records of manure and compost application and production must be kept by all farmers using these soil amendments. Farmers must accurately record the application date of any untreated or composted soil amendment of animal origin.
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