A METHOD FOR EXPLORING THE POTENTIAL OF AGRONOMIC PRACTICES TO MANAGE THE GREENHOUSE GAS BALANCE IN SUGARCANE PRIMARY PRODUCTION

A methodology is presented which enables different sugarcane primary production management scenarios to be evaluated on the basis of their potential to reduce greenhouse gas emissions. The methodology utilises the Agricultural Production Systems Simulator (APSIM), a spreadsheet based greenhouse gas calculator (GreenCalc) and analysis of private and social costs and benefits, to consider practical and effective on-farm abatement strategies. The approach is based on current understanding, but allows for future advances in knowledge to be incorporated into the methodology as it becomes available. As an example, we present analysis of the simulated impacts of a range of agronomic practices on crop yield, annual net greenhouse gas emissions, and the relative net financial margin and carbon dioxide equivalent (CO2-e) sink values for a hypothetical sugarcane farm in the Herbert River Region. The simulation results indicate that burning is the greatest source of greenhouse gas emissions during primary production and that the optimum production per unit of greenhouse gas emissions can be achieved at the paddock scale by introducing GCTB and a legume fallow into the cropping system. An economic analysis of the potential differences between private benefits, i.e. revenue from cane production, and public benefits, i.e. carbon sequestration, associated with each scenario indicates that the greatest financial benefits can be accrued to both sectors when GCTB and fallow periods are incorporated into the cropping system.