The Practical Effectiveness of Nitrogen-Fixing Crops: Policy Briefing

In the 2018 Climate Change Plan, the Scottish Government committed to a reduction in emissions from the use of synthetic nitrogen fertiliser, which currently accounts for around 25% of the GHG emissions from agricultural soils. One approach is to increase cultivation of nitrogen-fixing crops also known as legumes, which convert nitrogen from the air into a form that is biologically useful.


The evidence base for the effectiveness of nitrogen fixing crops is largely based on research and experience at a UK and European level. ClimateXChange was asked by Scottish Government to explore the current state of confident knowledge for their application, and their potential benefits for farm business (commercial as well as on-farm) under Scottish circumstances (i.e. soil, climate, markets, etc). 


80% of current demand for legume products in Scotland is imported, mainly for animal feed, but also for human consumption.

There is a long history of growing legumes in Scotland and a considerable potential to increase legume production. However, there is limited opportunity to access commercial seed stock as current markets are focused on more-temperate climates, and there is also a lack of processing facilities in Scotland.

An increase in legumes grown in place of another crop as part of a rotation and with no added fertiliser, could give significant savings in terms of fertiliser-offset depending on the crop.