Saturated ground and delayed harvest are shrinking the fall manure application window across the Midwest. While producers must balance storage capacity with soil health, Iowa State University professor and Extension specialist Dan Andersen urges patience: take advantage of suitable field conditions as they appear, but avoid panic-driven decisions.
When wet ground forces an earlier or narrower application window, practical agronomic steps can minimize soil compaction and runoff risks:
1. Target Hay and Pasture First.
If pit levels demand immediate relief before row crop ground is fit, prioritize older hay or pasture ground. As Andersen notes, it might not leave “a pretty or a great stand when you are done,” but the established sod offers superior traction and nutrient uptake.
2. Prioritize Well-Drained and Cover-Cropped Fields.
When moving into crop ground after soils cool, target high ground, well-drained acreage, or fields with living cover crops that actively capture nitrogen.
3. Maintain 300-Foot Buffers Around Water Features.
Identify sensitive landscape risks—including surface tile inlets, streams, waterways and concentrated flow channels. Melissa Wilson, associate professor and Extension specialist at the University of Minnesota, advises maintaining a 300-foot setback from all sensitive features. Selectively bypass wet pockets and fill them in later with commercial fertilizer or manure when ground dries out.
4. Lighten Loads and Optimize Tires.
To avoid deep ruts and severe subsoil compaction, Wilson recommends filling tankers and spreaders below full capacity. Andersen also advises adjusting field tire pressures, utilizing flotation tires, or switching to umbilical dragline systems where feasible to reduce equipment weight.
5. Work the Contours and Check Slopes.
In rolling terrain, tillage along contours creates furrows that intercept downslope nutrient movement. Wilson points out that in Minnesota, guidelines restrict application of solid manure on slopes exceeding 6%, and liquid manure on slopes greater than 2%.
6. Lower Liquid Application Rates.
Reduce liquid application rates to prevent surface ponding and runoff. If pits are nearing capacity, pump only enough to establish a safe cushion rather than attempting a full cleanout on marginal ground.
Manure Spill? Here’s What to Do
If an accidental discharge or storage breach occurs, immediate containment is essential:
- Notify State Officials: Call your state emergency response line immediately.
- Build Containment Berms: Construct temporary earthen dams to arrest surface movement.
- Plug Intakes: Block downstream culverts and surface tile intakes to keep manure out of subsurface drainage networks.
- Deploy Absorbents: Use straw, wood shavings, or hay to soak up pooled liquid.
Wilson also encourages producers and custom applicators to communicate early with neighbors regarding available, permitted storage capacity or drier, suitable fields before emergencies develop.
