Modelling mixed farming enterprises using ausfarm

Abstract

Australian agriculture faces challenges to improve the efficiency and profitability in the face of changing weather, regulatory and economic conditions. As farmers adapt to changing conditions and attempt to reduce risk, it is necessary to assess the mix and composition of their farm enterprises (e.g. cropping and livestock). Whole farm models are a useful tool that can be used in this decision making process. The AusFarm software package has been designed to model biophysical systems and allow modelling of mixed crop and livestock farming systems. Cropping rotations, pasture mix, variability of soil types and integration of stock into these systems can be modelled successfully with AusFarm. Once a base simulation model has been constructed and tested, it is possible to modify management activities, cropping and stock parameters to examine how the production and natural resource management indicators are affected. AusFarm has been used in a recent national, Commonwealth funded project to assess risks associated with strategic changes to farming enterprises in the southern wheat-sheep zone (Western Australia, South Australia, Victoria). A feature of this project has been the development of a decision support tool called Farm4Prophet. It is designed to examine questions such as; what would be the effect of decreasing the area used for cropping, or increasing the area sown to pasture, and increasing the size of the sheep flock? During development of this system several different mixed farming systems were modelled, and a range of scenarios were tested. To model these systems it was necessary to describe crop rotations, animal flock structures and management activities using AusFarm Management scripts. On-farm data were used to validate the baseline simulation designs. This paper will describe the methodology used to model these farming systems and present the results.