Get fixated on nitrogen fixation

Author: Natalie Lee | Date: 15 Apr 2014

Correct legume inoculation is a key consideration for Western Australian growers looking to plant pastures and grain crops such as lupins, field peas and chickpeas this year.

Inoculating legumes with rhizobia can enhance nitrogen fixation and represents a minor production cost with a potentially substantial payoff in terms of increases in legume nodulation, grain and biomass yield, nitrogen fixation and post-crop soil nitrate levels.

Each year Australian growers sow inoculated legume seed on about 2.5 million hectares, equivalent to 50 per cent of the area sown to legumes.

A recently released Grains Research and Development Corporation (GRDC) publication recommends growers:

  • Use quality inoculants (the Green Tick logo is a trademark of Australian Inoculants Research Group approval);
  • Match the correct inoculant group to each legume;
  • Inoculants contain live bacteria. Make sure they are kept in moderate temperatures (less than 30°C, not frozen) away from sunlight and chemicals;
  • Sow freshly inoculated seed as soon as possible and definitely within 24 hours of inoculation;
  • Use clean potable water for dilution when using liquids or slurries, and make sure holding tanks are free from chemical and fertiliser residues;
  • Many pesticides, mineral and organic fertilisers are toxic to rhizobia and should never be mixed with rhizobia;
  • Rhizobia can be compatible with seed pickles or dressings for a limited time prior to sowing - always apply the seed dressing first and allow it to fully dry before applying the rhizobia as a second process;
  • Always use inoculants before their expiry date;
  • Reseal opened bags of peat inoculant and use them within two weeks of first opening the bag.

Inoculating legumes – The Back Pocket Guide can be downloaded at

The GRDC has also published a booklet Inoculating Legumes: A Practical Guide which is available at and the Rhizobial Inoculants Fact Sheet, available at

Information is also contained in a GRDC GroundCover TV video about legume inoculation and sowing preparation, available at

Contact Details 


Natalie Lee, Cox Inall Communications
08 9864 2034, 0427 189 827

GRDC Project Code COR0022

Region West