Daniel Andersen is an assistant professor in Iowa State University’s department of Agricultural and Biosystems Engineering. In October he started a blog called The Manure Scoop where he provides timely information about manure management, treatment and land application. Though he writes of nutrient issues relevant to Iowa, the information that he shares is of importance to all manure handlers, regardless where they call home.
His Jan. 7 Manure Scoop discusses manure management plans, as “a tool for animal farmers that describes how they plan to place and use their manure nutrients for crop production.”
Manure management plans make producers identify the amount of manure they expect their farm to produce, estimate the nutrient concentration in the manure, determine the number of acres that are required for land application, and then detail the amount of manure that will be applied to each available acre, Andersen says. In Iowa these plans are based both on the nitrogen needs of the crop as well as the phosphorus index for each field.
He adds that in Iowa, nitrogen-based manure rates shall account for legume production in the year prior to growing corn or other grass. He then goes on to compare manure management plans set to achieve a specific yield goal versus achieving the maximum return to nitrogen. This approach uses economic return to N application found in research trials as the basis for the suggested N rate.