2014, Volume 11, Paper 2

Expected benefits on and off farm from including lucerne (Medicago sativa) in crop rotations on the Broken Plains of north-eastern Victoria

Lindsay Trapnell – Department of Agricultural Economics, Extension and Rural Development, University of Pretoria 0002, Republic of South Africa.

Bill Malcolm – Department of Agriculture and Food Systems, Melbourne School of Land and Environment, Parkville, 3010, Australia.

Email: Lindsay.Trapnell@up.ac.za

Abstract

Deep drainage to groundwater in the Broken Plains area has been predicted to bring the watertable to within two metres of the surface over the next 66 years. However, with reduced rainfall as a result of climate change, this may not happen for 113 years. The rising watertable will lead to waterlogging and dryland salinity. A solution is to introduce deep-rooted perennial species such as lucerne. Lucerne extracts more water than annual crops and pasture. Results of this analysis show that private investment decisions to change to cropping with lucerne as the legume component in the crop sequence, instead of subterranean clover, increases expected profitability and cumulative net cash flow of crop sequences. Still, farmers in this area generally believe that lucerne is riskier than annual legume pastures which constitutes a barrier to its widespread adoption. From the public perspective, keeping watertables below two metres prevents damage to infrastructure, roads, wetlands and bio-diversity. Policy instruments may be required to overcome farmers’ resistance to growing lucerne, especially for them to do so on the 50 per cent of the arable area of the Broken Plains that would need to be growing lucerne to prevent watertables rising to the surface. The amount of grants per hectare of lucerne that would be required to achieve 50 per cent of the land growing lucerne are calculated.

Keywords: Farming systems, dryland salinity, risk analysis

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