Hardseeded legumes are proving to be more productive than traditional legume pastures thanks to varieties which allow harvest without special equipment and sowing in summer or before the conventional cropping program.
Legume pastures are typically sown after cereals, canola and lentils. This limits biomass and subsequent pod production in the year of establishment. Along with intensified cropping rotations, less reliable seasons and a changing climate, conditions for persistence can be less than ideal. As well, harvesting some legumes can be a slow, laborious and soil damaging task, especially if they require specialist suction harvesting like sub clover and medics often do.
These factors, coupled with periods of drought, have resulted in eroded seedbanks of legume pastures on many farms. Despite the outlook for livestock remaining positive, and the benefits legume pastures deliver to cropping rotations, pasture renovation rates on low-medium rainfall farms remains low.
The Dryland Legume Pasture Systems (DLPS) project is evaluating the regional performance of commonly grown legumes including new medic and vetch varieties, as well as recently developed pasture legumes such as serradella, biserrula and bladder clover.
Indications so far are:
- On neutral to alkaline soils of upper Eyre Peninsula and SA Mallee, annual medics continue to be the best pasture option.
- On neutral to alkaline soils of the Victorian southern Mallee Margurita French serradella (also performs well in west Wimmera), Rose clover, Bartolo bladder clover, PM250 medic (to be released 2021) and Studenica vetch performed well.
- On acidic soils in NSW, the climate suits summer sowing of arrowleaf clover, biserrula, bladder clover, gland clover and serradella (French and yellow).
- On acidic soils in WA, summer sowing only suits French serradella and bladder clover.
Management strategies for successful establishment include:
- Farm harvested seed reduces seed costs after the initial purchase.
- Summer sowing requires minimally processed seed, retaining high hardseed proportion. Scarified seed should only be sown once the risk of a false break has passed.
- Alternative pasture establishment methods, eg. summer sowing, are viable in the Mallee, but are not suitable for all legume species.
- Aim to maximise pasture legume seed set in the establishment year. Legumes with very high hard seed levels (>90%) are best cropped in the year following establishment.
Vic: Dryland legume pasture systems: legume adaptation, Dryland legume pasture systems: pasture feed value
SA: New pasture opportunities to boost productivity of mixed farms in low/medium rainfall areas
NSW: Developing pasture-crop rotation systems with hard seeded self-regenerating legume species to fix more N for crops and feed livestock in medium and low rainfall zones