Lupins: pressing the case for better yields

A new lupin seeding technique can boost yields up to 20 per cent and also significantly reduce ryegrass germination.

The technique involves pressing the lupin seed into the soil but leaving the soil above the seed relatively loose, according to Glen Riethmuller of Agriculture Western Australia.

He said the research had been carried out in WA as part of a project supported by growers and the Federal Government through the GRDC and coordinated by Mohammad Amjad.

The seeding process involves the use of press-wheels to firm the seed into the furrow followed by rotary closers to drag soil back in, forming a loosely packed tilth cover. This ensured good seed-to-soil contact for the lupins but apparently not for inter-row ryegrass seed.

Researchers have also observed better weed control within rows as herbicide displaced by furrowing is dragged back into the rows by the rotary closers.

Mr Riethmuller said that in WA trials yield improvements had been recorded of up to 20 per cent, averaging 10 per cent, along with 58 per cent suppression of ryegrass.

The new system involves taking the seed boots from the seeding tines and mounting them, with a simple tube holder, directly in front of the press-wheels. The press-wheels then push the seed into the groove and the furrow is partially filled using light rotary closers.

Best suited to light soils Mr Riethmuller said that while the seed-pressing technique might not be considered applicable to heavy or sticky soils, its advantages in light soils over the conventional process of top-pressing the soil (not the seed) were:

  • increased plant establishment, vigour and crop growth
  • the suppression of ryegrass, and
  • higher crop yields.

Program 3.5.3

Contact: Mr Glen Riethmuller 08 9081 3111 Dr Mohammad Amjad 08 9083 1111