Why do we care about manure? Manure is an organic fertilizer that contains essential plant nutrients. However, it can be a variable product, making it a challenge to match plant nutrient needs to the amount of nutrients in the manure. Like commercial fertilizers, we also need to be aware of the risk of losing nitrogen (N) and phosphorus (P) and affecting water quality.

What are manure nutrient “book values”? These nutrient averages are used for developing manure management plans, designing manure storages, creating best management practices for manure land application, and agricultural modeling. They show a range of nutrient values that can be expected from typical manure storages and encourage farmers to test their manure often. However, current book values are several decades old and may not reflect current production practices. Different animal diets, genetics, housing, and manure storage and handling practices can impact these manure nutrient values.

We are working with the Minnesota Supercomputing Institute to develop a manure nutrient database called ManureDB to create more accurate manure nutrient book values. In preparation for this project, we partnered with three Midwest U.S. laboratories to share data from approximately the last ten years. We compared those manure sample results to the estimated manure nutrient book values in Manure Characteristics published in 2004 by Midwest Plan Service (MWPS). We wanted to see if there were any nutrient trends and identify ways to make ManureDB useful and user-friendly.