Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/23/2020
Publication Date: N/A
Interpretive Summary: Manure is an important source of nutrients and organic matter for dairy farm fields, however it can pose water quality risks and contribute to greenhouse gas emission. Managing manure to optimize nutrient use efficiency while minimizing losses to air and water is an increasingly important issue for many dairy farms. While conventional tillage incorporation of manure reduces ammonia loss and runoff nutrient loss compared to unincorporated manure, these methods (i.e., chisel plowing, disking, moldboard plowing) cause high soil disturbance and increase erosion potential compared to reduced or no-tillage. Vertical tillage (VT) implements are designed with the goal of reducing soil disturbance compared to more conventional forms of tillage. In this study, incorporating liquid dairy manure via chisel plowing and VT were compared to broadcast application (surface applied/no incorporation) and a no manure control in a corn silage-winter rye cover crop system in the spring before planting corn. Differences in runoff water quality, GHG emission, and corn yield were assessed over the 2018-2019 growing seasons. Results indicated that VT significantly reduced runoff nutrient losses and had numerically lower GHG emissions compared to the other application methods. Additional research is needed over multiple years and sites to better evaluate longer-term impacts on yield, soil quality, and runoff water quality risk.
Technical Abstract: Runoff water quality and greenhouse gas (GHG) emissions are two challenging nutrient management issues in dairy production. During 2018-2019, field runoff water quality and GHG fluxes were measured in a corn silage field after: i) no manure, ii) surface application, iii) chisel plow incorporation, and iv) vertical tillage incorporation (VT). Results indicate that VT reduced both GHG fluxes (nitrous oxide and methane) and runoff nutrient losses (nitrogen and phosphorus) compared to other methods.