Get reliable rangeland science

The vast open rangelands of Australia's Mitchell Grass Downs Bioregion as depicted in Figure 1 are a significant producer of livestock and the region is dominated by the Astrebla grass species. Multipurpose shrub and tree legumes could play a n important role in providing many ecosystem services such as drought fodder, shade, shelter, N fixation, carbon sequestration, biodiversity, habitat, and they may also potentially contain novel compounds that could have useful phenolic and or antioxidant, anti-methanogenic properties which could benefit animal production and the environment. As part of CRC P 58599 project "Legumes for the north" the seeds of a range of native and exotic shrub and tree legumes were sourced from across North Queensland, grown as tube stock and then transplanted at five sites across the region to evaluate the ir adaptability to the region. The mix of species included fast and slow growing, long lived and short-lived perennials including species of Acacia, Adenanthera, Albizia, Bauhinia Cajanus, Gliricidia, Peltophorum, Pongama, Sesbania, and Vachellia. Most of thes e species were planted at each site on vertosol soils in semi-arid locations with mean annual rainfall from 400mm to 580mm, and irregularly watered by artisan bore water until well established. After three years of growth, initial observation of the establishment phase and persistence indicates that several species across the sites show agronomic promise including but not limited : Albizia lebbeck, Gliricidia sepium, Peltophorum pterocarpum. Several species failed to persist or have had poor growth at least at some sites including Cajanus cajun, Sesbania sesban and Adenanthera pavonina. It is envisaged that the successful species could be planted as mixed species plantings on the open treeless grasslands radiating out along fence lines from existing bores/ farm dams with simple trickle irrigation likely to be essential for at least the establishment phase. Once established the shrubs and trees would provide many of the ecosystem services outlined above.