Sustainability of Stylosanthes based pasture systems in Northern Australia - Managing Soil Acidity

Summary

Accelerated soil acidification due to agricultural practices is recognised as a national soil degradation issue and brings into question the long-term sustainability of current production systems. Evidence of accelerated acidification under Stylosanthes dominant pasture systems was the catalyst behind this project. The main outcomes from this project include; recommendations on the management of Stylosanthes-based pasture systems that reduce the risk of Stylosanthes dominance; the development of a soil acidity risk map for the Dalrymple Shire and a simple field based tool kit to assess the predisposition of soils to acidification that will assist in the decision making process with respect to the establishment of improved legume pastures; quantification of the potential role of a diverse range of species in mediating acid input to these ecosystem based on their ash alkalinity; a clear understanding of the processes that contribute to the pattern of soil acidification under Stylosanthes-based pasture systems, these being nitrate leaching and excess cation uptake from deep in the profile; and finally several scientific publications that have either been or are in the process of being published in peer reviewed journals will contributed to our knowledge of acidity in semi-arid tropical environments.