Impacts of Low Disturbance Liquid Dairy Manure Incorporation on Alfalfa Yield and Fluxes of Ammonia, Nitrous Oxide, and Methane

Surface applied liquid dairy manure application (i.e., broadcasting) after alfalfa (Medicago sativa L.) harvest is a common practice. Low disturbance incorporation (LDMI) may offer multiple benefits including lower ammonia (NH3), greenhouse gas (GHG) and hydrologic nutrient losses compared to broadcast. However, few studies have simultaneously quantified LDMI impacts on yield, NH3 fluxes. We measured NH3, nitrous oxide (N2O), methane (CH4) fluxes for treatments plots broadcast over three seasons (2014 2016) in central Wisconsin, USA. There were minor differences yield nitrogen (N) uptake across years. Shallow disk injection aerator/band reduced loss by 95 52% of broadcast, respectively, however both substantially increased N2O (6 4.5 kg ha−1 year−1 versus 3.6 respectively). The magnitude timing related precipitation events. Average CH4 similar among methods with soil moisture application. Results highlight the importance quantitatively evaluating agri-environmental tradeoffs farms.