By Mauricio Espinoza, Ohio State University
Saturated field conditions last fall and early this winter have made it difficult for livestock producers in Ohio and the Midwest to apply manure. As a result, most farmers are beginning to run out of manure storage room right now.
With colder weather in the forecast, applying excess manure on frozen ground is likely to be the only way producers will be able to get rid of it, according to Ohio State University Extension experts. But, they cautioned, producers need to be diligent about following proper application methods to minimize impact on water quality and maximize absorption in the soil for optimal fertility.
"Now is not the time to shirk on proper application methods," Amanda Meddles, OSU Extension program coordinator for environmental management, wrote in the university's Crop Observation and Recommendation Network (C.O.R.N.) newsletter. "Constant changes in weather are typical of winters in Ohio and neighboring states, which increases the potential for manure to move with surface run-off. Run-off can lead to polluting water resources, including streams, waterways and wells. This not only impacts water quality, but the nutrients are lost and not available for the next year's crop."
Meddles, along with OSU Extension educators Glen Arnold and Jon Rausch, reminded producers that winter manure application should be done only as a last resort -- because the potential for run-off increases substantially when manure is spread in the winter months. And, they insisted, only enough manure should be applied to frozen or snow-covered ground to address storage limitations.
In some states, manure application on frozen or snow-covered ground is prohibited, so producers are advised to check their local regulations.
In Ohio, the following are criteria that must be met in order for producers to begin spreading manure on frozen or snow-covered fields:
- Application rates are limited to 10 wet tons per acre for solid manure with more than 50 percent moisture, and five wet tons for manure with less than 50 percent moisture. For liquid manure, the application rate is limited to 5,000 gallons per acre.
- Applications are to be made on land with at least 90 percent surface residue cover, including good-quality hay or pasture field, all corn grain residue remaining after harvest, all wheat residue cover remaining after harvest, or a well-established cover crop.
- Manure must not be applied on more than 20 contiguous acres; each 20-acre block should be separated by a break of at least 200 feet.
- Farmers should use fields that are farthest from streams, ditches, waterways, surface inlets and other water sources, and which are the least likely to have manure move in a concentrated flow toward and into water resources.
- The application setback distance must be increased to a minimum of 200 feet from environmentally sensitive areas and areas of concentrated flow, such as grassed waterways, surfaced drainage ditches, streams, surface inlets and water bodies.
- For Ohio Department of Agriculture-permitted facilities and certified livestock managers (CLMs), setbacks should be 300 feet from wells and residences.
- Manure applied on frozen or snow-covered ground should not exceed the nitrogen need of the next growing crop; the crop removal rate for P2O5 for the next crop (not to exceed 250 pounds per acre); or the crop K2O needs (not to exceed 500 pounds per acre).
- 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 the rates identified above.
More information on winter manure application can be obtained through local Soil and Water Conservation District, Natural Resources Conservation Service, and OSU Extension offices. Additional resources regarding manure management are available at http://oema.osu.edu.