Organic Farming Methods Spotlight: Manure


Manure is used by both conventional and organic agriculture systems to fertilize and enrich soils. The use of raw manure is not regulated on conventional farms, while it is regulated by the USDA National Organic Program (NOP) on certified organic farms.

A common myth associated with raw manure use in both organic and conventional farming, is that it makes crops more susceptible to the bacteria Escherichia coli, commonly known as E. coli.
According to the Organic Trade Association (OTA), there is no reputable scientific evidence that proves this, referencing the following statement from the The Centers for Disease Control and Prevention (CDC):

"The CDC… has not conducted any study that compares or quantitates the specific risk for infection with Escherichia coli O157:H7 and eating either conventionally grown or organic/natural foods."

Consumers can be sure that products bearing the USDA organic seal have been certified by third-party independent certifiers and adhere to the rules and regulations set forth by the Organic Food Production Act of 1990 (OFPA) and the NOP rule of December 2000. In addition, organic farmers are required to follow the same stringent guidelines set forth by local, state and federal health standards as conventional farmers. All certified organic farmers must also document their farming methods.

According to the NOP rule of December 2000, certified organic farmers must compost raw animal manure if it is applied to crop land intended for human consumption. If the edible part of the crop does not come into contact with the soil, manure must be applied at least 90 days prior to harvest. If the edible part of the crop does comes in contact with the soil, it must be applied to the land at least 120 days prior to harvest. Additionally, the OFPA recommends a longer period if soil or other conditions are called for. The (OTA) sites these as the most strident regulations in the United States for the use of manure.

For more information:

USDA National Organic Program

Organic Food Production Act of 1990

Organic Trade Association