Potential returns and risk of growing aluminium-tolerant lucerne in a grazing system with acidic soils located in the high rainfall zone

The benefits, costs and risk from introducing aluminium-tolerant lucerne (alfalfa) into a sheep grazing enterprise, consisting of a perennial ryegrass-based pasture, located in the high rainfall zone of Victoria, Australia, were estimated using a discounted cash flow analysis. Two ‘what if’ scenarios were compared for a modelled representative case study farm; 1) where aluminium toxicity occurred in the top-soil, and 2) where aluminium toxicity occurred in the sub-soil. Discrete seasonal pasture growth scenarios were examined, and price variability was captured using Monte Carlo simulation. Growing aluminium-tolerant lucerne on 10% of the farm area was consistently more profitable than continuing to graze the perennial ryegrass pasture, returning an extra $7-28/ha/year of profit for the 9 year analysis period. However, if the use of conventional lucerne with liming was a viable option for incorporating lucerne into the grazing system, the advantage of the aluminium tolerance ( ‘Al Tol’) technology was minimal. The results of this analysis suggest that aluminium-tolerant lucerne could be a profitable option for livestock graziers in the high rainfall zone, and is likely to be more beneficial when aluminium toxicity occurs in the sub-soil compared to the top-soil.