PhD research studentFrancesc

Project: Developing novel seed treatments for grain legumes: optimising sustainable outcomes in agricultural systems

Funding acknowledgements: PhD funded by University of Stirling, Legume Technology Ltd, Processors and Growers Research Organisation (PGRO) and The James Hutton Institute.

Agronomic sustainability can be facilitated by incorporating legumes into crop rotations. Symbiotic root-nodule bacteria associated with legumes (collectively known as rhizobia) are able to fix atmospheric nitrogen through the process of biological nitrogen fixation (BNF), and thus reduce the need for synthetic fertiliser input. Additionally, this symbiosis is also able to improve legume crop establishment and production.

Successful root nodulation relies upon agricultural soils having a sufficiently high inoculum potential. However, intensively farmed soils are often lacking in adequate populations of rhizobia due to the rotation of non-leguminous crops and high application rates of synthetic nitrogenous fertilisers which also disfavour root nodulation.

Therefore, the overarching aim of this project is to develop strategies to coat seeds with rhizobia prior to sowing. However, during storage seed-borne rhizobia can desiccate and die, thereby reducing their effective population density. To test intraspecific variation in desiccation tolerance, our field trials will initially focus on trapping rhizobia from soils of arid regions. These isolates will be screened for desiccation tolerance alongside other strains from the JHI collection.

We aim to:

  • Identify a set of desiccation-tolerant bacterial strains and determine the metabolic and genetic basis for this stress tolerance.
  • Develop commercial inoculant products with improved storage and field performance.