Solids from digested dairy manure and replacing translocated topsoil similarly improved short-term crop yields but differentially affected properties of eroded soil

Authors: Schneider, Sharon; Sutradhar, Apurba; SCHUMACHER, THOMAS - Retired Non ARS Employee; LOBB, DAVID - University Of Manitoba

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2026
Publication Date: 4/7/2026
Citation: Schneider, S.K., Sutradhar, A.K., Schumacher, T.E., Lobb, D.A. 2026. Solids from digested dairy manure and replacing translocated topsoil similarly improved short-term crop yields but differentially affected properties of eroded soil. Agronomy Journal. 18(2). https://doi.org/10.1002/agj2.70363.
DOI: https://doi.org/10.1002/agj2.70363

Interpretive Summary: Processing manure using anaerobic digesters produces energy, and digested manure can be used as a soil amendment. In our previous work, we found that replacing topsoil can restore crop productivity to severely eroded soils by improving soil properties. In these studies, we continued and expanded that work to measure the effects of adding digested dairy manure to (a) eroded soil and (b) eroded soil that had been restored 6 years prior by replacing topsoil. In this five-year study, during which weather conditions were near normal, corn and soybean yields were increased an average of 14-22% by adding soil only or manure only, and by 23-28% where both soil and manure were added. There were strong relationships between soil properties and crop response. These results showed that digested dairy manure solids can improve crop yields, but more research is needed to more fully evaluate the best way to remediate soils of different characteristics in different environments. Farmers, land managers, conservation professionals, and scientists can use this information to help design approaches to improve crop production on eroded land.

Technical Abstract: The use of anaerobic digesters is increasing in the U.S. to produce energy, and digested manure can be used as a soil amendment. These studies were a continuation of experiments that evaluated the effects of replacing translocated topsoil (soil-landscape rehabilitation). Crop response and soil properties were evaluated in highly-eroded land with (a) no amendment; (b) 15-20 cm of soil added once in fall 2005; (c) 40 Mg ha-1 of manure solids added once in fall 2011; and (d) both soil (2005) and manure solids (2011) added. Crop and soil parameters were monitored for five years, during which weather conditions were near normal. Corn (Zea mays L.) yields were increased an average of 14-15% by adding soil and/or manure, and by 23% in the combined treatment. Soybean (Glycine max L.) yields increased an average of 18, 22, and 28% in the soil, manure, and combined treatments, respectively. Manure solids had no impact on soil C concentrations, whereas soil addition increased surface soil organic C concentrations by 2× and decreased inorganic C by about 45%. Soil nutrients in the combined treatment were approximately the sum of the increases due to the individual treatments. Changes in P were mostly due to manure solids, and changes in N and K due to soil addition. There were strong relationships between soil properties and crop response. These results showed that soil amendment with digested dairy manure solids has the potential to improve crop yields, producing under favorable growing conditions a yield response similar to that achieved by replacing topsoil 6 years earlier.