Manure application on frozen ground poses risks to water
January 13, 2009 by Iowa Department of Natural Resources
January 12, 2009, Des Moines, IA – Livestock producers who lack
adequate manure storage may face a dilemma – how to apply manure after
the ground has frozen without risking adverse effects on nearby streams.
January 12, 2009, Des Moines, IA – Livestock producers who lack adequate manure storage may face a dilemma – how to apply manure after the ground has frozen without risking adverse effects on nearby streams.
“Applying manure on frozen or snow-covered ground is risky business,” said Dan Olson, an environmental specialist in the Iowa Department of Natural Resources Atlantic field office , “because the manure thaws on top of the ground and runs off before the ground thaws and it can soak in.
“Producers need to know that they may be setting themselves up for a problem, and carefully evaluate the risk that the manure could reach a stream or underground tile inlet before they apply,” he added.
Olson said if storage is full, the best choice is to transfer the manure to another storage structure. But, if they must land apply, they may be able to reduce the risks by choosing flat ground a long distance from a stream or tile inlet. Another good choice may be to remove just enough manure to keep the manure storage from overflowing before spring, without emptying the entire storage structure.
The risks go up as snow depth increases and the time between application and the spring thaw decreases. So, if winter application is unavoidable, it’s best to apply manure to bare ground early in the winter.
Following the Iowa DNR’s rules and recommendations for applying on frozen or snow-covered ground may help reduce the risks, but producers need to realize that they are responsible if manure reaches surface or groundwater and causes a water quality violation.
Olson added when surface applying manure, producers must stay at least 200 feet away from environmentally sensitive areas such as wells, streams and sinkholes, and at least 800 feet from high quality water resources, such as the Iowa great lakes.
The Iowa Manure Management Action Group also has information available on winter application at www.agronext.iastate.edu/immag/pubsimms.html or directly at www.agronext.iastate.edu/immag/pubs/imms/vol3.pdf.
The Iowa DNR recommended revisions to state rules for manure application on snow-covered or frozen ground at the Jan. 13 Environmental Protection Commission meeting. The recommendations are available at www.iowadnr.gov/epc/09jan13a.html.