Abstract

An optimisation model of a dairy farm was built to estimate the cost of mitigation of greenhouse gas emissions (GHG-e). First, the Farmax and Overseer models were used to describe production, profitability, and emissions to the environment of a medium-input dairy farm system for the Waikato-Bay of Plenty region of New Zealand. This process allowed generation of a valid and consistent set of input data for a detailed nonlinear programming model able to optimise resource use. The optimisation model was then used to investigate how producers may best respond to the introduction of a 10% restriction on GHG-e, with and without the use of strategic changes to their farm system to mitigate GHG-e. Profit decreased by 8% when the restriction was introduced without the availability of strategic mitigation options. The variables that changed most to achieve the reduction were nitrogen fertiliser input, which was reduced by 58%, and stocking rate which was reduced by 7%. In contrast, profit increased by 5% when strategic mitigation options were used under GHG-e restrictions. Using high genetic merit cows was enough to achieve this increase in profit under the emissions constraint.

AA, Adler, aj GJ Doole Romera, and PC Beukes

Proceedings of the New Zealand Society of Animal Production, Volume 72, Christchurch, 181-185, 2012