Most arrangements between crop and livestock farmers for manure are pretty loose, says Mike Beard, who farms near Frankfort, Ind. However, farmer-to-farmer contracts are becoming more common says Bob Battel, a Michigan State University Extension field crops educator.

Items he recommends writing into a manure contract include:

A resource for helping you write a manure contract is available online from the University of Minnesota Extension Service

How Much Manure Do You Need?

Our Oct. 2009 article "Cut input costs with manure" (p. 22) offers ideas on how to reduce your fertilizer bill. Robert Koehler, a retired University of Minnesota Extension Educator from the Southwest Research and Outreach Center near Lamberton, Minn., gives us an example of how manure could replace $122 per acre in commercial fertilizer nutrients and application costs.

Assume you have access to hog finishing unit manure that tests 45 lbs. N, 28 lbs. P₂O₅, and 29 lbs. K₂O per 1,000 gallons. The example uses values of 37 cents/lb. for N, 73 cents/lb. for P₂O₅, and 58 cents/lb. for K₂O, plus $15.50 to apply the nutrients in a commercial form.

Based on application with sweeps, Koehler uses an availability of 80% for N and P₂O₅, and 90% for K₂O.

In this example the crop rotation and soil test calls for 140 lbs. N, 45 lbs. P₂O₅, and 40 lbs. K₂O per acre to meet crop needs for corn following soybeans. Koehler's spreadsheet calculates a need to apply 3,889 gallons. Rounded off to 4,000 gallons per acre, the rate would provide 144 lbs. N, 90 lbs. P₂O₅, and 104 lbs. K₂O per acre.