Combining Restricted Grazing and Nitrification Inhibitors to Reduce Nitrogen Leaching on New Zealand Dairy Farms.

Intensification of pastoral dairy systems often means more nitrogen (N) leaching. A number of mitigation strategies have been proposed to reduce or reverse this trend. The main strategies focus on reducing the urinary N load onto pastures or reducing the rate of nitrification once the urine has been deposited.

Assessing the production and economic benefits from preventing cows grazing on wet soils in New Zealand.

Background: Intensive grazing by cattle on wet pasture can have a negative effect on soil physical quality and future pasture production. On a North Otago dairy farm in New Zealand, experimental plots were monitored for four years to assess whether preventing cow grazing of wet pastures during the milking season would improve soil structure and pasture production compared with unrestricted access to pastures. The DairyNZ Whole Farm Model was used to scale up results to a farm system level and ascertain the cost benefit of deferred grazing management.

Screening for diets that reduce urinary nitrogen excretion and methane emissions while maintaining or increasing production by dairy cows.

Farmers face complex decisions at the time to feed animals, trying to achieve production goals while contemplating social and environmental constraints. Our purpose was to facilitate such decision making for pastoral dairy farmers, aiming to reduce urinary N (UN) and methane emissions (CH4), while maintaining or increasing milk production (MP). There is a number of feeds the farmers can choose from and combine.

Cost-effective mitigation of greenhouse gas emissions from different dairy systems in the Waikato region of New Zealand.

The New Zealand dairy industry produces approximately 17% of this country's total greenhouse gas emissions (GHG-e) and it is also this nation's largest export industry. The industry needs to reduce GHG-e under proposed policy directives and for ongoing market security. Given these pressures, there is the need to identify cost-effective management strategies to reduce on-farm GHG-e.