Economic evaluation of establishing pasture legumes in the Brigalow Belt

Abstract

The Brigalow Belt is important because it carries approximately 40% of Queensland’s beef cattle herd, but pasture rundown and seasonal variability constrain grazing productivity and profitability. Integrating pasture legumes can improve cattle performance and enterprise profitability, yet adoption remains relatively low. This study evaluated the economics of establishing legumes in a 500 ha production paddock across contrasting land types and establishment methods to identify commercially viable options for beef producers.
Twenty-nine scenarios were modelled across high-, moderate- and low-productivity arable land and non-arable land, comparing leucaena, herbaceous legumes such as desmanthus or stylos, and medics. Establishment methods included low-cost whole-paddock sowing, high-cost whole-paddock cultivation and strip planting. The analysis accounted for establishment risk, fallow periods, phosphorus (P) fertiliser requirements and long-term changes in pasture and cattle production. Investment performance was assessed over 30 years using discounted cashflow analysis at a 5% discount rate.
The modelling indicated that legume development could substantially increase cattle production and gross margins relative to buffel grass-only systems. Leucaena generated the largest profitability gains on high- and moderate-productivity land, increasing annual profitability by $62,400 to $103,400 and generating rates of return of 25% to 31%, although establishment costs and peak cashflow deficits were comparatively high. herbaceous legumes provided profitable options across a broader range of land types, while strip planting generally strengthened investment performance through higher returns, shorter payback periods and lower upfront capital requirements. Medics also generated favourable returns, particularly when established in strips.
Overall, strip planting was the most attractive establishment method across most scenarios. The results highlight that there is no single optimal legume development strategy across the Brigalow Belt. Rather, matching legume species and establishment method to land capability, establishment risk and available capital can substantially improve the profitability and resilience of beef enterprises. (Generated by Copilot from document summary).