Abandoned pasture legumes offer potential economic and environmental benefits in semiarid clay soil rangelands

In the 1980’s CSIRO and QDPI established a number of pasture legume evaluation trials throughout clay soil regions in Queensland’s semiarid tropical rangelands. These sites have long since been abandoned and incorporated into regularly grazed paddocks. Grass quality is often poor in semiarid rangelands; any surviving legumes from these trials would potentially enhance pasture quality, and thus livestock production in a region where suitable sown legume species are virtually unknown. Legumes also have the\ud potential of enteric methane abatement, reducing greenhouse gas emissions from ruminant livestock. Graziers are however unlikely to use legumes solely for the environmental benefits of CH4 mitigation unless there are positive economic impacts on livestock production. Re-examination of a number of abandoned legume trial sites in rangelands on clay soils show that accessions of Desmanthus are often the only survivors. Desmanthus genotypes offer exciting new prospects and choices for graziers, with\ud associated potential economic and environmental benefits. This paper focuses on the results of surveys at\ud “Hillgrove Station” Charters Towers where Desmanthus was found to be persisting some 25 years after the original trial was sown