Because of a growing concern about manure irrigation, the University of Wisconsin Extension assembled a workgroup to research the concerns. The workgroup included scientists, public health specialists, state agency experts, farmers, conservationists and others. Over the course of two years, the group gathered and studied the science of manure irrigation, which culminated in a report that contains findings, responses and recommendations. This article will review a few of their findings related to bacterial transport as well as highlight some of the reasons why a farmer might opt to apply manure via irrigation rather than other ways.

When designed properly, runoff holding ponds, lagoons, and other earthen manure storage structures are sized to contain manure, process wastewater, and storm water that drain into or fall on them throughout their designed storage period. Excess precipitation, particularly chronic wet weather, can lead to concerns about storages overflowing even when they have been managed correctly.

Winter cereal rye planted as a cover crop has been shown effective in capturing nitrate before it leaches from the root zone. We conducted on-farm trials in central and southern Minnesota to determine if a rye cover crop would capture significant root-zone nitrate in the fall and spring but release it in time to maintain yield in the subsequent corn crop.

Manure is often viewed by many as an environmental liability. However, if manure is applied at rates equal to or less than the nitrogen (N) requirement of a crop, can manure produce environmental benefits over commercial fertilizer? This was the focus of an Asian research group which summarized the results of 141 published studies from Asia, Europe, and the U.S. comparing manure substitution for fertilizer. This article summarizes the “Take Home Messages” from this research paper.

Land application of organic materials for soil management in Nebraska is important. The availability of applied organic N and the fertilizer N substitution values of applied organic materials is not well predicted. The uncertainty of applied organic N availability leads to over-application of fertilizer N resulting in low efficiency of applied N use. Research has been done to validate or adapt canopy sensor guided in-season N application practices for fields with manure or other organic material applied, and to improve the prediction of the fertilizer N substitution values for organic materials.