Summer-sowing techniques revealed

An MLA-funded project is building on advances in pasture legume breeding and agronomy to expand the area where new, hard-seeded varieties can be sown.

As well as breeding highly productive, drought- and disease-resistant pasture varieties, researchers at Western Australia's Department of Agriculture and Food (DAFWA) and Murdoch University have developed summer-sowing techniques for some of the legumes.

Summer sowing involves using an unscarified seed with a high level of hard-seededness to prevent undesirable germination in summer.

Researchers have also developed a dry, granular rhizobium formulation that can be dry sown with the hard-seeded legumes.

Murdoch University's Professor John Howieson is leading the MLA project that will develop these new technologies for use in the drier regions of WA and NSW and the moister conditions of central and southern NSW.

He will also be investigating ways to dry sow the smaller-seeded varieties, such as biserrula and prima clover, which are more difficult to manage due to their size and very hard seed.

"While extending the knowledge of summer sowing of the larger-seeded species for farmers who want to accept that technology now, we'll also be researching ways to make summer sowing 'bullet proof' for the small and very hard-seeded species," Mr Howieson said.

Other aspects of the four-year project will include quantifying animal performance on the summer-sown legumes, developing optimal grazing strategies, and evaluating the option of grazing serradella pods as an alternative to summer feeding in Western Australia.

"In many parts of WA, producers have to supplementary feed lupins to sheep over summer, which is quite expensive," Mr Howieson said.

"We're looking at replacing lupins with serradella pod over summer. We have bits of data that say the pods are a good source of energy and protein, but we haven't done the right research to prove the exact benefit so that's what we'll be doing."

The project will also investigate the health of sub-clover rhizobia and try to understand, and overcome, its role in sub-clover decline.