Old Man Saltbush Five-year trial
GroundCover™ Issue: 56
Three hundred and forty hectares of the Condobolin Research Station is being set up for alley farming. A five-year trial will develop the management practices needed to incorporate Old Man Saltbush into the business of mixed farming.
Part of the broadly based Grain and Graze project, the trial will see 15-metre strips of saltbush interspersed with 60-metre strips of crop or pasture in a five-year rotation. Peter Milthorpe, a research scientist with the NSW Department of Primary Industries, believes that if properly managed saltbush has the potential to increase the profitability of mixed farms in a wide arc of the lower rainfall grain and grazing area.
Mr Milthorpe says saltbush is an ideal complementary pasture species to stubble or dry pasture. It is high in protein and responds to out-of-season rainfall. That makes it an ideal species to fill the summer-autumn feed gap in southern areas and the winter-spring feed gap further north. It forages for deep water more effectively than any of the native grass species and unlike lucerne does not drop its leaves under stress. This means that at a critical time of the year a grazier can accurately assess the amount of green feed available and plan stocking rates accordingly.
Mr Milthorpe warns however that there is much to be learned about the technique of grazing saltbush. He says stock have to be "taught" to eat it. They need to learn to browse rather than to graze and it is important that the shrub not be allowed to get away.
A series of 10ha paired paddocks is being established for the trials. The standard rotation will be two cereal crops followed by three years of a sub-clover, medic and lucerne-based pasture with the saltbush remaining undisturbed. The experiences of some 20 producers who have included saltbush in their farming systems will be incorporated in the trials, which are backed by the Central West-Lachlan Grain and Graze group.
Grain and Graze is a joint initiative of the GRDC, Meat and Livestock Australia, Land and Water Australia and Australian Wool Innovation. It aims to increase the profitability of crops and livestock while helping to better manage water, soil and biodiversity.
Tagasaste, also called tree lucerne, is a hardy leguminous shrub. In a temperate climate it can provide green fodder which is palatable and protein-rich (23 to 27 per cent crude protein). It has only 18 to 24 per cent indigestible crude fibre and even when grown on poor coastal soils (properly fertilised) can maintain these protein levels.
Benefits reported by Australian farmers include shade and shelter, erosion control, nitrogen fixation, reductions in salinity-causing water tables, and habitat for native birds that eat crop and pasture pests. Tagasaste can withstand long, dry periods and thrives on a variety of soil types, provided they are well drained.