That means farmers must be attentive to the weather forecast when spreading manure. Manure should not be spread when the forecast is calling for rain or during a warming trend when snow is expected to melt.
Farmers also should avoid spreading manure on ice-packed ground. When the snowfall is interspersed with periods of rain and freezing, the ground may become saturated and frozen to the point where manure can’t effectively soak into the soil.
All in all, winter is a particularly risky time to be applying manure, and farmers are advised to wait for favorable conditions if they have the storage space. If soil is wet or frozen and a manure application just can’t wait, take special steps to reduce the risk:
- Select the flattest fields: 2% slope for liquid manure, 6% slope for solid
- Exceed minimum setback distances along streams and other boundaries whenever possible
- Till along the end of the field and contours to create furrows to help capture runoff
- Apply manure on fields with the most crop residue
- Avoid applying to fields where furrows are full of ice and snow
- Keep application rate low to avoid runoff or ponding during application
- When possible, work manure into the soil immediately after application
Finally, know who to call if a runoff event does occur. Know your state’s spill hotline and call on their emergency resources when you need help.