The challenge

Agriculture is the largest source of anthropogenic N2O, and more than half of the agriculturally emitted N2O (4.1 Tg N2O-N) is coming from permanent grasslands. Mitigation measures that reduce N2O emissions from agriculture are urgently needed and can make the difference in combating climate change.  

Utilising the soil microbiome could hold the key to reducing N2O emissions. Symbiotic Rhizobia that are Nitrogen-fixers and form nodules in the roots of clover plants, could also be capable of reducing N2O if they possess the gene for encoding nitrous oxide reductase (nosZ).

What we're doing

This interdisciplinary project will investigate the potential of clover-rhizobia associations to mitigate N2O emissions by isolating native grassland soil rhizobia strains to investigate the presence of the N2O-reducing genotype, using genetic fingerprinting combined with biogeochemical measurements of N2O reduction in a mesocosm experiment. The ambition of our project is to form a new interdisciplinary research team and generate a proof-of-concept.

How it helps

Our long-term goal is to develop a rhizobial inoculum, with the potential for commercial use, to be applied across grasslands and grassland/arable rotations as a unique ‘biofertiliser’ that will not only reduce the use of chemical fertilisers but will also mitigate the emission of the deleterious greenhouse gas nitrous oxide, offering a globally important new tool for combating climate change. 

Investigators

• Dr Fotis Sgouridis, School of Geographical Sciences 
• Dr Chris Williamson, School of Geographical Sciences 
• Dr Tom Williams, School of Biological Sciences