By Scout Nelson
As crops come off the field, it is also time to think ahead to next year’s planting season. For operations with livestock, this includes decisions on manure use. A manure management plan provides a framework to use manure wisely while reducing fertilizer costs and protecting soil health.
A plan begins with knowing two key things about manure: how much is available and what nutrients it contains. For new operations, estimates from the American Society of Agricultural and Biosystems Engineers or the Midwest Plan Service can help. For existing operations, three to five years of manure records give the best reflection of conditions. Regular sampling and lab testing are essential to keep information accurate.
Crops and fields also play an important role. Field maps should include sensitive features such as streams, ditches, or wetlands, along with setbacks where manure cannot be applied. Crop rotations for the past two years and the next year should be listed, along with nitrogen credits from past manure applications.
Soil testing is another critical step. Fields with lower phosphorus and potassium levels can better use manure nutrients than fields already testing high. Regular tests every three to five years—or more often if manure is applied frequently—help guide decisions.
When applying manure, producers may choose nitrogen-based or phosphorus-based rates. Nitrogen-based rates meet crop nitrogen needs but can result in higher phosphorus buildup, while phosphorus-based rates help avoid nutrient overloads but may require supplemental nitrogen from fertilizers.
Other considerations include transportation distance, field conditions, weather, odor, and community relations. Flexibility is important, since conditions can change quickly. Keeping accurate records ensures better planning for future years.
Manure also adds organic matter and micronutrients that commercial fertilizers often lack. Having more fields than manure allows for wider distribution of these benefits, while limited land may require arranging for transfer to neighboring farms.
As a resource, the Minnesota Pollution Control Agency provides guidelines on land application of manure. The University of Minnesota manure team is also preparing an online course to offer further training and insights.
Photo Credit:gettyimages-eugenesergeev
Categories: Minnesota, Crops