Rick S. Llewellyn1, Marta Monjardino1, Michael Moodie2, Mark Trotter3, Zac Economou2
1 CSIRO, Locked Bag 2, Glen Osmond, SA, 5064, Email email@example.com
2 Mallee Sustainable Farming/Moodie Agronomy PO Box 10189 MILDURA, VIC, 3502
3 Central Queensland University, Rockhampton, QLD, 4701
Mixed farming systems remain common but trends in management for cropping efficiency include increasingly large paddock sizes. This makes achieving high grazing efficiency and maintaining optimal levels of crop residue on areas vulnerable to soil erosion a major management challenge. Particularly in environments with substantial within-paddock soil variation there is potential for temporary sub-paddock fencing to greatly improve both cropping and livestock productivity. In this paper we report on the potential for virtual fencing technology that would allow spatial within-paddock grazing. We begin with a survey of Australian grain growers that indicates the extent of growers perceiving potential benefits from virtual fencing across major mixed farming regions. Using GPS monitoring of sheep grazing behaviour in a paddock at Nandaly, Victoria, the poor grazing inefficiency and potential erosion risk on large paddocks was demonstrated. For example, when grazing a vetch paddock, sheep were found to spend approximately 75% of time on 50% of the paddock and 25% of the available grazing area was unutilised. Whole-farm bio-economic modelling analysis was then used to evaluate the potential profitability of sub-paddock grazing technology in a low-rainfall region where farmers report high levels of soil variability and the potential for soil-specific management. Results show that introducing spatial grazing in a typical Mallee crop-livestock system has the potential to increase the profitability of livestock in the system, and increase farm profit by 15% (excluding the cost of the technology), largely by avoiding the need to remove livestock from an entire paddock when just one soil or zone incurs excessive groundcover loss and subsequent erosion risk.