Dean T. Thomas1, Eric J. Zurcher2, Gonzalo Mata1, Neville I. Herrmann2, Dave A. Henry3
1CSIRO Agriculture and Food, Centre for Environment and Life Sciences, Floreat, WA 6014, firstname.lastname@example.org,
2CSIRO Agriculture and Food, Black Mountain Laboratories, Canberra, ACT 2601, 3CSIRO Agriculture and Food, Food Innovation Centre, Werribee, Vic. 3030
We present the first gridded modelling of grazing systems across southern Australia to estimate the carrying capacity of land for ruminant livestock production in relation to climate, soil and pasture species characteristics. A static Merino sheep trading enterprise was simulated using GrassGro™ software across a 5 km continental grid. A batch processing wrapper was developed to select inputs by geolocation and transfer these data to the simulation engine. The key output was a continental map of the optimised stocking rate per winter-grazed pasture hectare, as determined through maximising gross margin ($/ha), constrained by a supplementary feeding limit (< 20% of total energy intake) and a ground cover threshold (>50% cover for more than 90% of the time). We use the study to highlight some likely sources of error in existing methods, and how our method can help to compare livestock carrying capacity across a wider geographic region.