Farm-Scale Assessment of GHG Mitigation Strategies in Dairy Livestock-Cropping-Systems.

As a part of the Government of Canada's Agricultural Greenhouse Gases Program (AGGP), the University of Guelph recently received $2.8-million to study GHG mitigation strategies in dairy-cropping systems over 4 years.  Several projects are underway to examine feeding strategies, manure management, and cropping systems management.  New BMPs will be developed to improve the bottom-line of farm operations and reduce the dairy industry's impact on the environment.  This poster presents some preliminary results of these projects after the first year of study.

The overall effects of management changes on nitrous oxide (N₂O) and ammonia (NH₃) emissions from different cropping systems are being determined at the plot-scale and from 4-hectare fields.  Plot-level experiments at the Elora Research Station, Elora, ON are comparing the effects of liquid diary manure application methods (surface application vs. incorporation following surface application vs. band injection) and timing (fall vs. spring) and manure source (raw manure vs. digested manure) on GHG emissions from corn.  Plot-level experiments at Campus d'Alfred Research Station, Alfred, ON are examining GHG emissions from two soils (sand vs. clay) receiving raw and digested manure.  At both sites GHG fluxes are measured year-round using non-flow-through non-steady-state chambers.

Continuous N₂O emissions are being measured from four 4-hectare fields at the Elora Research Station using a flux-gradient micrometeorological approach.  Liquid dairy manure is being applied to corn and hay fields (annual vs. perennial) in the fall or spring to assess differences in GHG emissions.  Novel isotopic tools are also being employed to investigate changes in the nitrogen cycle and the source of N₂O emissions.