Apply manure carefully during winter

During the past several years, manure nutrient recycling has come under scrutiny, particularly when applied on frozen or snow-covered ground. Farmers should take additional precautions when applying manure under less-than-ideal field conditions. This especially is true during the winter.
Protecting water quality should be a primary objective when applying nutrients. Sudden changes in weather that are typical of late fall/early winter and late winter/early spring increase the potential of manure to move off-sight.
Sudden weather changes might lead to manure runoff from farm fields that can pollute nearby creeks, streams and waterways. This impacts the environment and the public’s image of agriculture and reduces the available nutrients for the next crop.
Get help. Ultimately, any manure entering our water resources is violation of Ohio’s agricultural pollution abatement laws. Best Management Practices identified by the USDA Natural Resources Conservation Service Practice Standard 633 Waste Utilization can help avoid these situations.
By using the guidelines in this Practice Standard, manure nutrients can be recycled efficiently and the risk of pollution significantly reduced. However, producers should keep in mind that manure applied in the winter has a higher risk of running off the land than will manure that has been incorporated under ideal conditions.
Application of manure to frozen or snow-covered ground is not recommended and should be done only when deemed necessary because of extreme situations. Such situations typically arise from a lack of storage capacity or inflexibility in spreading schedule because of limited storage.
Some producers also take advantage of the availability of labor and equipment and the reduction of compaction on frozen soils to apply manure.
Rule of thumb. A rule of thumb for those with manure storage is to check your manure storage structures before fall harvest. If a producer does not have enough capacity to hold manure for the next six months, then hauling manure should become a priority.
For operations that have a frequent hauling schedule (daily to monthly) or less than six months of storage, manure either must be applied or stockpiled during the winter months.
Identify fields with the lowest risk of manure runoff and planting a cover crop early enough in the summer to achieve at least 90 percent cover by the end of the growing season. Local extension or soil and water conservation district offices can provide assistance.
For fields with slopes greater than 6 percent, manure should be applied in alternating strips 60 to 200 feet wide generally on the contour, or in the case of contour strips on alternating strips at rates identified above. Application rates, cover and set-back requirements also apply.
Take steps. Farmers can take additional steps to minimize the need for winter application of manure. For some, increasing storage capacity might help, and cost-share assistance might be available through the local natural resources and conservation offices or soil and water conservation district offices. Technical assistance also is available to help implement the best management practices for recycling manure nutrients.
Others might need to modify crop rotations to better manage manure application windows.
A manure management plan with manure storage should not plan for routine winter application. Winter manure application should be used only because of extenuating circumstances, and only apply enough manure to address storage limitations until non-frozen soils are available.
For those without long-term storage, winter application or stockpiling manure might be necessary. However, prior planning to identify those fields to receive manure is necessary and adequate cover is achieved before winter.
Ohio law. Although some states have prohibited manure application on frozen or snow-covered ground, it still is permitted under careful management in Ohio.
However, producers are at risk of losing this sometimes-necessary option if pollution problems resulting from wintertime application of manure continue.
For more information on winter manure application, contact your local soil and water conservation district office, natural resources and conservation office, extension office or USDA Natural Resources Conservation Service, Practice Standard 633.
(Jon Rausch is an extension associate in ag engineering at Ohio State University; Tami Combs is an extension coordinator for environmental management.)