Pasture legumes in mixed farming zones
Research funded via the Feedbase Investment Plan also helped develop agronomy packages for hard-seeded annual pasture legumes such as serradella, arrowleaf clover, biserrula, bladder clover and gland clover.
The project found the following:
- In WA and NSW, these legumes can be established with summer dry sowing, as a standalone crop with autumn sowing or by twin-sowing with a cereal crop.
- They must be inoculated with rhizobia and protected from heat in the summer sowing operation to be successful and allow Nitrogen fixation.
- If established well, the alternative legumes increase animal weight gain and carrying capacity on suitable soils.
- These legumes are resilient in the face of intensification of cropping activities, but care must be taken with herbicide application in the crop phase.
- Most of the alternative legumes have much smaller seed than sub-clover and annual medics.
- Smaller seed size enables a higher proportion of ingested seed to escape digestion.
- As with any new pasture sowing, first-year focus should be on establishing a large and resilient seedbank for subsequent years of regeneration.
- Low weed pressure is essential in the establishment year.
- Sowing time can have a significant impact on seed production, hence the project recommends sowing as early as possible in the season to take advantage of warm, wet conditions.
- Plant growth habit has an impact on seed production under grazing, but under normal stocking rates this is not a threat to long-term persistence of the feedbase.
- Plant residues need to be grazed to encourage hard seed breakdown.
- Producers should aim to allow moderate seed set for seed bank replenishment at least every three years.
- The new pastures are deeper rooted than clovers and medics and provide some protection against false breaks and dry periods in the winter months.