Manure is often an undervalued and underutilized resource in the state of Nebraska. It has many soil health benefits. When manure is managed properly and applied at appropriate rates, soil benefits include better drought tolerance and greater resilience to heavy rainfall events, when compared to soil without. Manure has been shown to lift soil organic matter, increasing the amount of water that soil can hold for later plant use.
Manured soils also have greater soil aggregate stability, increasing water infiltration during heavy rains and decreasing erosion caused by runoff. Additionally, manured soils have enhanced microbial activity, which increases nutrient cycling in the soil. Overall, manure has been shown to increase soil infiltration rates by 40% and water holding capacity by 15%, when compared to non-manured soil. Crop yields are also generally higher for manured fields.
Mulch, which is typically comprised of crop residue or wood chips, also increases resilience of soils to drought and heavy rainfall for many of the same reasons as manure. In addition, mulch decreases evaporation of water from the soil surface and suppresses weed pressure. Overall, mulch has been shown to increase water infiltration by 50% and water-holding capacity by 35%, when compared to non-mulched soil.
"Weather-ready Farms: Successfully Managing Extremes" was the 2016 theme of the exhibits for the University of Nebraska-Lincoln Institute of Agriculture and Natural Resources at Husker Harvest Days, Sept. 13-15 near Grand Island. Typically, thousands of agricultural producers and supporters attend this annual event to view in-field equipment demonstrations. However, the HHD educational booth during this event also provides IANR faculty and educators an opportunity to speak with the public about ag-related topics. Visitors generally come from diverse backgrounds and occupations, such as teachers, students, producers, policymakers and business owners. The 2016 Nebraska Extension/IANR Husker Harvest Days booth highlighted 12 indoor and outdoor exhibits, allowing engagement with visitors on a wide variety of topics related to the "weather ready" theme.
The "Building Weather-ready Soils With Manure and Mulch" exhibit featured actively growing corn to demonstrate the effects of manure and mulch on soil, water and crops. Three small corn plots were established in May to demonstrate the impacts of three different soil treatments. Beef feedlot manure was surfaced applied on two plots, providing about 50 pounds of plant-available nitrogen per acre. The two manured plots received an additional 150 pounds of nitrogen per acre via urea, and the third plot received all 200 pounds of nitrogen per acre via urea. On one of the manured plots, wood chips were surfaced-applied over the top of the manure at a rate of about 13 tons per acre. This display further demonstrated how manure and mulch can increase resilience to drought and heavy rainfall events through a desktop rainfall simulator. Overall, the demonstration confirmed that manure and mulch increased infiltration, water-holding capacity and soil aggregation.
Ongoing research by the Schmidt Lab for Livestock and Environmental Research continues to assess the impacts on soil quality and crop productivity of multiple combinations of manure and mulch application to cropland and grazing land. This research is partially funded by the Nebraska Forest Service and is a collaborative effort among UNL, NFS, the Middle Niobrara Natural Resource District and farmer cooperators in the MNNRD.
Schott is an Extension graduate research assistant at the University of Nebraska-Lincoln's Biological Systems Engineering Department. This report comes from UNL BeefWatch.