Submitted to: Forage Focus
Publication Type: Trade Journal
Publication Acceptance Date: 12/9/2020
Publication Date: 12/15/2020
Citation: Young, E.O. 2020. Low disturbance manure incorporation benefits. Forage Focus. December 2020 issue. pg. 20-21.
Technical Abstract: Manure management is an important economic and environmental consideration on dairy farms. Medium to large dairy facilities frequently manage large volumes of liquid manure (<15% solids) that can provide a substantial fraction of annual nitrogen (N) and phosphorus (P) needs for hay and grain/silage crops if properly managed. Incorporating manure via tillage increases ammonia N retention but also affects erosion and is unsuitable for perennial forages. Low disturbance manure incorporation equipment (LDMI) is designed to facilitate interaction between soil and manure with less soil disturbance than traditional tillage-based incorporation. Multi-year research conducted at the USDA-ARS unit in Marshfield, Wisconsin compared agronomic and environmental impacts of LDMI for hay and corn silage crops. Liquid manure was applied using shallow disk injection, banded application with/without aeration, strip-till injection (corn only) and broadcast (unincorporated), along with no manure controls. Alfalfa-grass plots received manure after each cutting whereas manure was applied to corn plots in the fall after silage harvest. In the hay crop trial, shallow disk injection retained significantly more manure N and dissolved P in simulated runoff experiments compared to other methods and did not appear to negatively affect forage stand integrity. Strip-till injection (shallow disk ) also conserved more N when used in the corn silage system, producing corn yields similar to spring applied urea-N-only treatments (applied at 134 and 200 kg total N/ha/yr). Overall, results suggest that LDMI methods offer the potential to increase manure N and P use efficiency for liquid manure applied to corn and hay crops with lower erosion and nutrient loss potential compared to broadcast applications.