Fall 2004
Integrating manure application and tillage management
by Mark Licht and Mahdi Al-Kaisi, Department of Agronomy
As fall approaches and harvest begins, it is a good time think about manure application and tillage management. Manure is a vital nutrient source, but the application of manure can cause environmental problems, if not applied properly. One of those environmental problems is soil erosion. Manure application equipment typically used by producers and custom applicators in Iowa reduces surface residue to levels that no longer protect the soil from erosion, regardless of the tillage program being followed. Therefore, producers need to review their conservation plans and evaluate how manure application fits into that plan.
Manure application
into cornstalk residue
Manure application is generally not considered a tillage operation even though it acts as one by incorporating surface residue. When planning manure application, conservation plans should be used to determine the amount of residue cover that is needed. To determine how much residue will be left or predict soil erosion after manure application, tillage operation, or tillage program there are several models available to consider. Go to http://extension.agron.iastate.edu/soilmgmt to further explore suitable manure application, tillage management, and residue management best management practices.
Adoption of best management practices throughout an operation include taking into account both manure application and tillage management. Best management practices that integrate manure application into a tillage management system will leave residue on the soil surface for effective soil erosion control. In addition to improving residue management, soil quality will be improved resulting in less nutrient leaching and runoff.
ISU staff measuring
residue after manure application at a field day event
