NEW HARD SEEDED PASTURE LEGUMES FOR WESTERN NSW

SeedcropNyabing2023

  Since the turn of the century pasture researchers have been selecting and breeding annual legumes that perform better, as climate change and more intense cropping rotations exert pressure on sub-clover and medic seedbanks. A suite of new winter legume varieties has gradually been released to farmers over the last decade. They cover a broad range of soils and climates common to the western plains of NSW and the Wheatbelt of WA. These newer generations of winter legumes produce their seed aerially, unlike subclover and medic, and can then be header-harvested when the seed matures. This means farmers can grow their own seed for large-area pasture renovation.

A selection criteria for researchers has always been to select hard-seeded breakthrough legumes. This hard seed protects the legume from false breaks and sets it up for crop rotations, during which it can self-regenerate. But in a huge breakthrough, researchers have now released several varieties whose seed can be sown off the header without the need to first process or scarify this hard seed. A great example of this remarkable type of pasture legume is the new bladder clover just released in NSW called Diaman2ti. The way to sow the directly harvested seed is called “Dormant Summer Sowing.". In simple terms, the hard seed collected off the header can be sown the next season into dry soil in late February or early March in NSW.

he day/night temperature fluctuations then act to soften the seed in time for an autumn break. This “natural” breakdown of most of the seed provides for very good early germination in the year of establishment. But first, to set this up, farmers must sow a special “nursery paddock” with high-quality, certified, and certified seed (ideally after a weed control exercise) to produce their seed for dormant summer sowing in the following years.

Diaman2ti bladder clover is suited to medium soils in the pH range 5-8 and grows exceptionally well with growing season rainfall as low as 275 mm. Diaman2ti is a very high nitrogen fixer, which means it enriches the soil for the following season. It is well suited to a 1:1 pasture crop rotation.The combination of header harvesting a nursery paddock, then dormant summer sowing this seed the next season into a larger paddock, allows farmers to produce sufficient seed after the initial purchase to rapidly sow large acreages.