Manure-based composts must be produced according to NOP regulations in order to be considered compost. Composts composed entirely of plant-based materials are considered mulch and are generally not subject to restrictions on their use or production.
The NOP requires that compost containing manure be produced following one of these methods:
If the compost does not meet these requirements, it is considered “raw manure.” Raw manure must be incorporated into the soil no less than 120 days prior to the harvest of a product whose edible portion touches the soil (such as lettuce) or incorporated into the soil no less than 90 days prior to the harvest of a product whose edible portion does not touch the soil (such as corn). Application timing and compost production methods will be verified to these restrictions during annual inspections.