Source: GRDC's The Crop Doctor

Biserrula, a promising pasture legume for crop rotations in most Western Australia's wheatbelt rainfall zones, holds a trifecta of benefits by controlling herbicide resistant weeds, producing excellent seed yields and fixing nitrogen.

The two commercial varieties currently available are Casbah, a mid-season cultivar suited to areas with 325 to 500 mm annual rainfall and Mauro, a mid to late maturing cultivar suited to areas with 450 to 700 mm annual rainfall.

Department of Agriculture and Food (DAFWA) researcher, Dr Angelo Loi said biserrula was a prolific seed producer, yielding up to 1500 kilograms per hectare.

Biserrula was developed by University of Western Australia based Centre for Legumes in Mediterranean Agriculture and the Grains Research and Development Corporation supported National Annual Pasture Legume Improvement Program, now effectively part of Pastures Australia.

Its high levels of dry matter digestibility, metabolisable energy and crude protein make it an attractive stock feed, however there is a risk of photosensitisation occurring in spring (particularly for lambs and bare shorn animals).

With high fertiliser costs reducing growers’ margins, biserrula is an excellent source of nitrogen and Dr Loi adds that grazing biserrula is the best tool for controlling herbicide resistant weeds because sheep can develop an aversion to biserrula and graze the non-legume pasture components.

Biserrula cultivars suit fine textured acidic and alkaline soils, including sandy loams and clay loams.

Spring herbage yields of biserrula have reached 11 tonnes per hectare in WA, which compares favourably with the more established French serradella, yellow serradella and subterranean clover.

Photosensitivity and aphid susceptibility are the only real limitations to consider and are currently being investigated by DAFWA.

The Crop Doctor is GRDC Managing Director, Peter Reading, Ph 02 6272 5525.