Serradella can improve pasture productivity and crop yields from acidic sandy soils in low- and medium-rainfall areas.
Trials near Yelbeni, north-west of Merredin in Western Australia, examined productivity gains and the economic benefits of a mixture of three serradella varieties available to growers — Cadiz (French serradella Ornithopus sativus), and Santorini and Charano (Yellow serradella O. compressus). All three are acid- and aluminium-tolerant.
"The extra nitrogen made available by this legume has shown up as increased grain yields by 100-500 kg/ha from the first crop after a serradella improved pasture," says agronomist Brad Nutt of Agriculture WA.
Factoring in an increased livestock carrying capacity by up to 60 per cent (for sheep), with no loss in wool production per animal, this pasture looks like a winner for growers trying to make a living off the highly acidic wodjil soils that characterise the eastern wheatbelt of Western Australia.
The alternative that is currently available to some of these growers is a volunteer capeweed and ryegrass pasture. According to Mr Nutt, some soils are too acidic for pulses, leaving a limited range of options for growers wanting to introduce a legume phase into a cropping system.
"A big advantage of including serradella in a pasture is that it stays green for three to four weeks longer than a capeweed pasture," says Mr Nutt. "This gives a better green pick for livestock, and dries out the soil to allow it to soak up the summer rains."
The livestock and crop production benefits are reflected in the economic benefits, shown in these trials using the eastern wheatbelt version of MIDAS (Model of Integrated Dryland Agricultural Systems).
"The modelling showed an extra profit of up to $26 per hectare per year from increased wheat yields and protein levels when serradella is incorporated into the rotation," says Mr Nutt.
Also shown was an increased profit of $3-$6 per hectare per year from improved livestock production on paddocks that would be kept as serradella improved pastures. These analyses included all costs of establishing ($56/ha) and maintaining a serradella pasture using average 2000 commodity prices.
Mr Nutt says the next step is to closely monitor commercial plantings to watch the long-term performance of this alternative legume.
Contact: Mr Brad Nutt 08 9368 3870 email firstname.lastname@example.org