Not enough nodules: impact of herbicides, pesticides and other farm management tactics

The Issue

close up of Biserrula in flower

Recent surveys of commercial pasture paddocks have shown more than 90% have inadequate legume nodulation. Without adequate nodulation, legumes respond poorly to applied phosphorus restricting pasture production and therefore feed supply to livestock can be significantly restricted. Additionally, poorly nodulated legumes will not contribute to building the soil nitrogen pool. Herbicides and their residues have been implicated in contributing to poor nodulation. Investigation of the role of herbicides and other farm management tactics in impacting nodulation is required to enable better pasture management systems to be developed

close up of legume roots with good nodulation


lush green pasture with hills in distance

  1. Develop a literature review identifying known impacts and gaps in knowledge in relation to the use of herbicides, pesticides and other farm management tactics on nodulation
  2. Develop an RDE&A investment framework and prioritisation for Meat and Livestock Australia in this area


  • Increase nodulation and nitrogen fixation by pasture legumes
  • Increase efficiency of use of other farm management inputs for boosting pasture production


Murdoch University Centre for Rhizobium Studies

Meat and Livestock Australia


Dr. Belinda Hackney