Offered Papers Theme C: Delivering the Benefits from Grassland
Description
Dairy farming systems have a low efficiency of converting nitrogen (N) into milk protein, due to the many transfers which occur in the production process. Losses of N from the system can be detrimental to the environment and represent wasted inputs. At SAC, in a systems research project, management changes achieved increases in nitrogen efficiency (milk N output/ N inputs) (NE) from 23 to 34% in a grass-clover based system (GC), and 13 to 21% in a purchased fertiliser based system (GN) (Leach & Roberts, 2002). Nitrogen surplus (NS = N inputs - N output in sold produce) was reduced from 184 to 90 kg N/ha in GC and from 369 to 258 kg N/ha in GN. This work was then incorporated into a participatory research project, to obtain data on N balances in commercial dairy systems and investigate the effects of suggesting management changes to improve NE.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Assessment and Improvement of the Efficiency of Nitrogen Use on Commercial Dairy Farms
Dairy farming systems have a low efficiency of converting nitrogen (N) into milk protein, due to the many transfers which occur in the production process. Losses of N from the system can be detrimental to the environment and represent wasted inputs. At SAC, in a systems research project, management changes achieved increases in nitrogen efficiency (milk N output/ N inputs) (NE) from 23 to 34% in a grass-clover based system (GC), and 13 to 21% in a purchased fertiliser based system (GN) (Leach & Roberts, 2002). Nitrogen surplus (NS = N inputs - N output in sold produce) was reduced from 184 to 90 kg N/ha in GC and from 369 to 258 kg N/ha in GN. This work was then incorporated into a participatory research project, to obtain data on N balances in commercial dairy systems and investigate the effects of suggesting management changes to improve NE.
