Using compost

In general, compost is only required to meet specific requirements if it has animal materials and is applied to crops destined for human consumption. A pre-harvest interval is not required for manure/compost applied to crops not for human consumption, as this requirement was put in place to prevent human microbial contamination.

What are the restrictions for using plant-based compost without manure or animal materials?

Compost made from plant byproducts — such as prunings, leaves, or hay — can be used on any crops without additional restrictions as long as feedstocks are non-synthetic. No pre-harvest interval is required. Please make sure to add the compost to your materials list if acquiring from off-site.

What are the restrictions for making and using compost with manure or other animal materials?

Compost containing animal materials such as manure or carcasses can either:

1. Be treated as raw manure, meaning it must be applied at least 90/120 days before harvest as described above, or
2. Be composted according to the NOP requirements as defined below

If you would like to apply compost containing animal materials to your crops closer to the harvest date than 90/120 days, it must be composted according to the following NOP requirements:

• Compost temperature must be kept for at least 3 days above 131 degrees Farenheight
• Clear, auditable records must be available of your composting process including feedstocks (ingredients) as well as, and logs measuring temperature and time

In either scenario please make sure you add the compost/manure to your approved materials list.

Are there any restrictions for using off-farm sourced compost with animal materials?

The product must come with a statement of feedstocks (ingredients), times, and temperatures and pile turnings to show it meets all the above requirements.

If you do not have documentation of times and temperatures, you may apply the compost as you would manure (at least 90/120 days before the harvest date if the crop is for human consumption).

For all non-OMRI or non-WSDA approved materials, request approval from your client service team. Never use an unapproved compost until after you’ve received approval from OTCO for the material review.