Six reasons to green manure

Research has shown that adding organic matter to the soil through green manuring can be a profitable strategy that improves soil fertility for farmers with weed management problems or low soil fertility, or for those who run little or no stock along with a cropping rotation. In other words, it is an alternative to a legume pasture to control weeds and lift fertility.

The strategy is to grow a legume crop which is ploughed in or sprayed and left. It is best used every five or six years in intensive cropping rotations. Some researchers call it sabbatical cropping.

Green manuring:

  • increases grain yield up to 30 per cent and grain protein 1 per cent in the wheat the following year
  • increases organic matter
  • enriches the soil with nitrogen up to 0.2 t/ha
  • provides a disease break for crops
  • adds water retention to the fallow
  • encourages better water penetration, thanks to better soil structure and more soil organisms, notably earthworms.

Contact: M r Maurice Amato, CSIRO Soils 08 8303 8531 Dr Pichu Rengasamy, Mr Andrew Lake or Mr Jake Howie, SARDI08 8303 9400 Dr Sam Jarwal, VIDA, Horsham 03 5362 2111 Dr Allan Mayfield 08 8842 3230