Towards a mechanistic understanding of disease suppressive soils

This project is based at University of Sheffield

Current agricultural systems are unsustainable. Crop diseases cause estimated yield losses of 20-40% annually. Disease is likely to increase with climate change and loss of agrochemicals, hence alternative methods of crop protection are essential. Plants release root exudates that can lead to the generation of disease-suppressive soil microbiomes, but our understanding of these processes is limited. This studentship will explore how soils can be managed to be more suppressive. We have identified a pair of soils, differing only in their plant communities, with contrasting suppressive capabilities. The project will both explore the mechanisms driving increased disease suppression and screen treatments from field experiments in the UK and Denmark using our existing model system and testing efficacy using field-relevant pathogen screens. This will provide a mechanistic understanding that will aid the development of production systems with reduced environmental impact.

Objectives:

1. Explore the interaction between plant cover and disease suppression using combinations of species grown on previously identified uppressive soil.

2. To use modelling-based approaches to better understand the formation of disease suppressive communities.

3. To apply microcosm- and field-based experimentation to explore management options driving suppressiveness in arable soil.

4. To confirm efficacy of disease suppression through assessment of UK/Danish field relevant diseases.

Novelty: Whilst suppressive soils have been known for some time there remains no mechanistic understanding of how suppression develops. Our data provides unique insight into one such mechanism since our paired soils differ only in plant cover history offering both an opportunity to dissect mechanisms and a route to suppression through plant management.

Timeliness: We need to generate novel methods to improve crop resistance whilst aiding improvement of overall system health. Rational use of selected lay or cover crops may provide an opportunity to generate disease suppressive soils reducing crop losses and reducing reliance on agrochemicals

Skills: The project will use a combination of soil and plant ecological and plant disease related methods in both greenhouse and field based experiments.  We expect to appoint a candidate who has a strong biological background with a keen interest in improving the sustainability of agricultural production.  The project will provide a firm foundation in a key future subject area placing the successful student in an enviable position for a future career.