WEST Australian growers have renewed interest in seeding pastures this autumn due to improved livestock returns, the need to reduce crop inputs and the use of pastures as a weed management tool.
Department of Agriculture and Food (DAFWA) researcher Brad Nutt said a number of pasture species could be produced for seed cheaply on-farm, dramatically reducing seed costs associated with a large-scale pasture improvement program.
“Access to this low cost seed allows growers to use higher sowing rates which are more competitive with weeds, and provides the high amounts of seed needed for alternative uses of pastures such as twin or summer sowing,” he said.
The research into cost effective legume production was conducted by DAFWA and supported by Pastures Australia, a collaboration between the Grains Research and Development Corporation (GRDC) and other stakeholders.
Mr Nutt stressed that farmers considering producing their own pasture seed should firstly check the commercial status of the cultivar – for example, obligations under point of sale contracts – to confirm what they could do with the seed.
While a number of pastures such as sub-clovers and medics are not suited to on-farm seed production, some other pastures are and can be harvested with a conventional harvester.
Mr Nutt said species suited to on-farm seed production included the soft-seeded forms of French serradella including Cadiz and the recently released, earlier maturing Eliza, which was less dependent on spring rainfall.
“Other cultivars which can be produced cheaply on-farm include the hard-seeded French serradellas Erica and Margurita, which each have a maturity similar to Cadiz,” Mr Nutt said.
“Additional pastures suitable for on-farm production include Yellow serradella and Bartolo Bladder clover.”
Mr Nutt said that the hard-seeded French serradellas, Yellow serradella and Bartolo Bladder clover needed processing to remove the seed from the pod and scarification before they were seeded, if grown conventionally.
“But growers who choose to produce these varieties for seed can opt to use it for twin and summer sowing techniques, which actually capitalise on the high level of hard-seeded dormancy,” he said.
“Twin sowing refers to sowing the pasture seed with a cereal or canola crop, where little of the legume will emerge in the crop due to the hard-seed dormancy, but will gradually become non-dormant over the following summer and autumn.
“A similar principle applies with summer sowing but the seed is sown after the cereal or oilseed crop is harvested.
“Twin and summer sowing have the advantage of making full use of rainfall, and can provide two to three times the dry matter production of pasture compared with that produced from normal pasture seeding – this is because the pastures emerge early when soil temperatures are still warm.
“Twin sowing has the additional benefit of being a one-pass operation for seeding the grain and pasture crops.
“High sowing rates are required with these techniques but production of seed on-farm can keep the associated seed cost to below $50 per hectare.”
Mr Nutt stressed that pasture crops grown for seed required careful management including good weed and insect control.
He is continuing pasture research within the project ‘Putting the focus on profitable break crop and pasture sequences in WA’, which is being conducted by DAFWA as part of the GRDC’s national Crop Sequencing Initiative.
“Our work aims to put a value on having a high legume component in a whole farm system,” Mr Nutt said.