Manure and the Environment

Many of the manure management and environmental resources and publications are written for large livestock operations. Yet, most of the farming operations in the US are small. In Nebraska, for example, nearly 70% of all beef operations are less than 300 head and 90% are less than 1,000 head.

Large animal feeding operations (AFO's) must follow regulations to protect water quality and preserve the environment. Smaller operations can help the environment as well. Livestock Producer Environmental Assistance Project (LPEAP) works with small farms to implement appropriate technologies and best management practices designed to protect water resources and our environment.

Wind direction and speed affect dust and odor risk. A first step in assessing and minimizing potential dust and odor nuisance risk of a livestock operation is identifying the most likely downwind directions. This article will share wind frequency data for 44 Nebraska locations to consider siting options for reducing these nuisances.

Manure increases formation of larger and more stable soil aggregates. Several benefits result for fields fertilized by manure compared to commercial fertilizer including reduced runoff and soil erosion and increased water infiltration leading to greater drought tolerance.

This article reviews the value that results from changes to soil’s physical characteristics. Charles Wortmann and Dan Walters, faculty with the University of Nebraska-Lincoln monitored soil erosion, runoff, and phosphorus (P) loss from replicated field plots over three cropping seasons immediately after manure application and four subsequent years when no manure was applied. Significant erosion and runoff benefits were observed for sites receiving animal manures.

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.

Soil health management refers to the preservation and improvement in soil physical, chemical, and biological properties to maximize the productive capacity of soil. Cover crops and reduced tillage are promoted for improving soil health; however, soil amendments such as application of livestock manure and municipal biosolids have received less attention as a soil health improvement practice. A literature review, funded by the North Central Region Water Network and the Soil Health Institute, was conducted to summarize and discuss results of studies reporting chemical, physical, and biological soil properties from application of livestock manure, animal by-products (i.e. compost), and municipal biosolids and to identify further research needs.

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.

Abandoned manure storages present a risk to the environment by accidental overflow or leakage due to lack of management. It is in the best interest of the environment and the property owner, who is liable for any environmental damage resulting from any discharge, whether leakage or overflow, to properly close any unused manure storage structure.

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.