Site Drop-in: UW-Madison’s work focuses on novel manure solids
January 25, 2025
Eight research institutions across the country are participating in the Dairy Soil & Water Regeneration (DSWR) project. Adam von Haden, a scientist at the University of Wisconsin-Madison, provided an update on what’s happening there.
Research focus: Our work on DSWR consists of three experiments at the Arlington Agricultural Research Station in south-central Wisconsin. While the experiments vary in their specific goals, understanding the agronomic and environmental impacts of novel manure solids (flocculated and evaporative solids) in dairy forage production systems is a unifying theme.
The first experiment uses large plots (0.13 acres) to understand how novel manure solids and soil health management systems, namely cover crops and strip tillage, affect corn silage yield, soil health and greenhouse gas (GHG) emissions. This experiment was started in 2021 and will conclude after six growing seasons.
The second experiment uses field-scale units (2.7 acres) to determine whether landscape position and soil wetness alter the effects that novel manure solids and soil health management systems (cover crops and strip tillage) have on corn silage yield, soil health and GHG emissions. This experiment began in 2022 and will be completed after five growing seasons.
The final experiment, which began in 2023 and is nearly complete, aims to quantify the first- and second-year nitrogen credits that can be provided by a single application of novel manure solids.
Overall, this work will provide critical data that can be directly used by dairy farmers, land management planners and policymakers to improve agronomic and environmental outcomes of forage production in the Upper Midwest.
What’s happening now: During the winter, our primary tasks are to organize and summarize our data from the previous year and to create plans for the busy field season ahead. The manure nitrogen credit experiment is winding down, and the data are now being summarized and prepared for publication. Our field planning includes creating nutrient management plans in SnapPlus, which takes into account our previous management history, soil type and soil nutrient test results and our future yield goals. In addition to the winter indoor work, we continue to take occasional GHG measurements in the field, which can be a very chilling experience!
Preliminary findings: Several soil health metrics have shown improvement under soil health management systems, but so far, no differences have been found between liquid dairy manure, a commonly used manuring practice, and novel manure solids. Corn silage yield was reduced slightly with soil health management for the first few growing seasons, but most recently, yield was similar between commonly used field practices and soil health management systems. In the first year following application, the novel manure solids provided nitrogen credits similar to traditional manure compost.
Key challenge: Maintaining three intensive field research experiments simultaneously has been challenging, particularly in the spring and fall when planting and harvesting occur. However, our team has managed to come together through these stressful times to get the job done!
Key success: Our preliminary research findings have sparked interest from both the nutrient management and environmental quality communities, who want to know more about the long-term outcomes of novel manure solids. It is fulfilling to know that our work will continue to provide key information that could help make dairy farming more economically viable and ecologically balanced.