Dr Ian Dodd

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My research aims to understand the mechanisms by which plants sense changes in the soil physical environment, how they communicate this information to the shoot to regulate water use, growth and crop yield, and how this knowledge can be exploited to maximize agricultural profit while sustainably using resources.

When agricultural water use is limited by root-to-shoot signalling, biomass (and yield) can also be limited. Since different signals control water use and growth, reconciling these agricultural objectives may require retention of signalling that restricts water use, with selective attenuation of signalling that restricts growth.

Although this can be achieved by genetic modification, an alternative is "rhizosphere engineering", using naturally occurring soil-borne bacteria that produce or break down the same chemical signals used by plants.

 

Deficit irrigation is when crops will receive less water than considered optimal. My research has shown that heterogeneous placement of available water (partial rootzone drying) can ensure crop water use is restricted. By pioneering a novel grafting procedure to measure the output of root-to-shoot chemical signals from different parts of the root system and developing a simulation model of whole root system output, I have determined when soil moisture heterogeneity is advantageous in saving water.

These principles will assist irrigation managers to optimise partial rootzone drying within their specific soil-plant systems.