What Is Manure Really Worth?

This presentation is designed to provide an overview of factors impacting the value of manure, specifically focusing on changes in soil physical and biological characteristics resulting from manure application, and will include a brief discussion of existing tools developed to assist farmers in making manure management decisions. Livestock manure has always been recognized as a beneficial input to cropland. However, U.S. agriculture has transitioned through multiple generations of crop farmers that have not commonly utilized manure. The availability of inorganic fertilizers and separation of crop production from livestock production have both contributed to this trend. In certain areas of intensive livestock production, over-application of nutrients can occur when sufficient land is not available to livestock system operators to accommodate manure production. While some livestock production system operators are challenged with managing excess nutrients, application of inorganic fertilizers to nearby cropland represents a net increase of nutrients to the region, contributing to an imbalance and over-application of nutrients as a whole. Excess nutrient application increases the risk for nutrient discharges that negatively impact water quality. Facilitating greater recycling of locally available nutrient resources, like manure, prior to importation of commercial fertilizer is viewed as a key component of the overall strategy to reduce non-point source nutrient discharges from agricultural cropping systems. As such, demonstrating the value of manure to crop farmers is essential and cannot be limited to quantifying nutrient contributions from the manure. For crop farmers, managing fertility expenses and improving soil health are key to ensuring productive, profitable and sustainable cropping systems. However, many other factors influence the value and cost of manure management as a fertilizer in cropping systems. Soil nutrient levels, crops benefitting from manure supplied nutrients, manure nutrient ratios, season of manure application, manner in which the manure is land applied, the value of commercial fertilizers and other factors work interactively to establish the value of manure to any individual crop farmer. Assigning a value to the benefits provided by manure beyond crop nutrient inputs requires greater understanding of what changes take place in soil when manure is introduced and how these soil properties can impact agronomic productivity.