As another winter of heavy snowfall gives way to warming temperatures, rapid melting and potential for flooding pose challenges for manure management among the more than 25,000 livestock farms in Minnesota. Farmers who spread solid manure during winter must ensure that it doesn’t run off with rapid snowmelt flowing to ditches, streams, and other waters.
This may be even more important in some areas this year because of frozen snow conditions. In January and February, the snow was saturated by rain, and then froze. This can prevent surface-applied manure from soaking in to the soil, and being more susceptible to runoff. Manure-contaminated runoff not only threatens water quality, it reduces the value of manure as a crop nutrient.
Minnesota rules require a 300-foot setback from surface waters and open tile intakes for all manure spread onto frozen or snow-covered soil. However, this spring the Minnesota Pollution Control Agency encourages farmers to refrain from surface application until the snow and ice layers are melted. In January and February the snow was saturated by rain, and then froze. This prevents surface-applied manure from soaking in to the soil, and more susceptible to runoff.
"We have already had several cases where manure was applied in accordance with the rule, but has negatively impacted surface and groundwater a significant distance away,” says Wayne Cords, MPCA feedlot program supervisor.
Steps to prevent manure runoff
If manure land application can’t wait, to reduce the impact of manure applied to the surface of wet or frozen soil,
- Avoid steeper slopes by choosing the flattest field or flattest parts of fields with less than 6% slope for solid manure, 2% for liquid manure.
- Choose fields that contain the most crop residue; greater than 30% crop residue. Tillage along contours creates furrows to help capture any potential runoff.
- Do not apply non-incorporated manure within 300 feet of surface waters. If possible apply manure at even greater setback distances.
- Avoid flood or floodway zones.
- Avoid applying to fields where the furrows are full of ice and snow.
- Keep application rate low enough to avoid runoff or ponding during application.
For more information
For more information, see the MPCA fact sheet:
Managing Manure and Land Application During Adverse Weather Conditions
You can contact your county or MPCA feedlot staff, or call the MPCA at 800-657-3864.
Visit the MPCA Feedlots webpage.