If the aphorism “the Mallee was made by medics” is true, Ouyen grower Scott Anderson is hoping that serradella and other legumes could help shore-up its future.
Scott, who grows wheat, barley and oaten hay – as well as various legumes – on about 5500 hectares near Ouyen in the Victorian Mallee, says many local growers started moving away from medics about 15 years ago because they don’t perform well on poorer, sandy soils.
He is hosting trials as part of the $18 million Dryland Legume Pasture Systems (DLPS) project, led by GRDC, which sourced legume pasture species to evaluate their adaptation, rotational benefits, sowing methods and economics in different Australian growing areas.
The five-year DLPS project spanned medium to low-rainfall regions of Western Australia, central and southern New South Wales, South Australia and Victoria.
The trial on Scott’s property – which he runs with his wife Vanessa, parents Geoff and Sandra and farmhand “Jacko” – is overseen by local agronomist Michael Moodie (from Frontier Farming Systems) in collaboration with the Mallee Sustainable Farming organisation. Scott is into the fourth year of his involvement in the trials.
“We are trying to find a legume to grow on our poorer soils where the medics don’t persist,” Scott says. “We are watching the trials closely because we really want to find something that will grow well in our environment before we do anything on a larger scale.”
As well as serradella, the trials include rose clover, RM4 woolly pod vetch, biserrula, strand medic, hybrid disc medic and arrowleaf clover.
The work has shown that serradella and RM4 vetch are potentially strong performers as pasture legumes on the region’s nitrogen-deficient soils.
Replacement for lupins
Michael Moodie believes serradella could play a role as a replacement for lupins on deep sands in regions such as Ouyen. Serradella shares the same rhizobium as lupins and could have advantages if it can be established via twin-sowing with the previous crop, providing soil coverage over summer and then regenerating the following year – reducing the erosion risk in these systems.
Scott currently sows about 20 per cent of his land to pasture legumes and is not looking to increase this level, but rather to find combinations of species that perform better in terms of producing feed for his 1600 Merino ewes or returning nitrogen to the soil profile. His soil types are loamy clays through to deep sands.
“Some of the legume species produce more nitrogen and more feed than the medics, but there is also a cost to reseeding them, so we are looking for species that don’t need to be sown every year. However, we have done soil testing on vetch ground where the nitrogen levels are significantly better than medic ground, but nitrogen input is still very low on the poorer sands, which is the area we are trying to improve,” he says.
Mr Moodie believes further research will help demonstrate how the more promising species might fit into local growers’ systems. “The trials have narrowed down the species we would look at, but how they actually fit into the system needs more work,” he says. “Until you do that trial work locally, it can be hard for anyone to adopt it.”