Incorporating companion legumes
MLA’s Feedbase Investment Plan funded a project exploring how to increase feedbase production and quality of subtropical grass-based pastures. As a result, producers in northern inland and central west NSW can access information on incorporating temperate and tropical companion legumes into their tropical grass pastures to lift production.
Research revealed the following:
Desmanthus was found to be a productive companion legume which does not compete with Digit grass, is bloat resistant, sets large quantities of seed and has a high proportion of hard seed with a slow breakdown providing persistence.
Leucaena (grown widely in northern Australia) can persist in northern inland and central west NSW if good preparation is undertaken before seeding. While it is not as productive as lucerne and provides forage for a shorter growing season, it can be grazed from December to May and produces green forage during low rainfall. Currently considered an environmental weed in these regions, producers need to wait for the development of a sterile line.
Temperate legumes sown in autumn, either before or after a tropical grass, achieved the highest productivity.
Tropical grass pastures with a plant density of 4–9 plants/m² are optimum for herbage production and water use efficiency.
Lucerne is productive in mixed pastures with tropical grasses but is highly competitive with tropical grass, which could reduce lifetime productivity.
Tropical grass pastures have increased risk of failure in central west NSW due to low seasonal rainfall.