Pasture legumes for high-quality dry-season cattle forage on red basalt soils in north Queensland

Abstract

Beef cattle production in the seasonally dry zone of north Queensland is based on uncleared native grasslands. Rainfall-related cycles in native grass growth and maturation results in low levels of dietary protein and metabolisable energy during the dry season (May-October in most years), which limits animal growth and business productivity (Rolfe et al. 2016). Sown legumes (notably Stylosanthes spp.) can improve the seasonal supply and quality of feed on infertile soils used for extensive grazing (Anon 1994) and is the best option to improve business resilience and profitability (Bowen et al. 2019). The Department of Agriculture and Fisheries is testing 'production paddocks' using pasture legumes grown in strips (as one option) and supplementing soil available phosphorous (P) and/or sulphur (S) to improve dry-season diets. Initially a range of pasture legumes were grown in replicated (3) small plots on 14 land-types to identify legume (and grass) lines for subsequent research. The results presented here represent red basalt soils near Mt. Surprise in north Queensland, characterised by high available soil P and low S. This land-type can produce 2900 kg DM/ha native grass in good condition (Ash et al. 2016), but is often degraded and invaded by low biomass grasses (e.g. Bothriochloa pertusa).