Balancing legume N with fertiliser inputs can be tricky. Legumes can affect soil N dynamics in unexpected ways. For example, chickpeas grown in low N soil can fix a large amount of N. But in high N soils, chickpeas use the soil N and fix less from the atmosphere. They can even have a negative impact on total soil N stocks.
More farmers are growing legumes now than in the past. This means managing soil nitrogen dynamics is a growing issue.
‘Managing Legume and Fertiliser N for Northern Grains Cropping’ helps growers and advisors manage N in soils. Thirty years of experiments in New South Wales and Queensland inform the manual. It is the most comprehensive guide on the subject for the region.
Key topics include:
- Organic matter. How it delivers N to crops and dealing with declining SOM levels.
- Legumes. What practices affect N2 fixation, inoculants, and the rotational benefits of N.
- Nitrogen cycling.
- Mineral and organic N fertilisers. What are the different types and when to apply them?
- The fate of N fertilizer.
- N-Budget calculator. What it is and how to use it to work out your nitrogen budget.
Download the manual free here.
David Herridge from the University of New England produced the manual, funded by the GRDC project UNE00014. The manual was last updated in 2013. There are plans for an update in 2018.