Revolutionising soil testing

A University of Southampton researcher has helped to develop a wireless network of sensors that is set to revolutionise soil-based salinity measuring.

Dr Nick Harris, from Electronics and Electrical Engineering, worked with a group of professors from the University of Western Australia (UWA) to produce a sensor capable of measuring the chloride (salt) in the soil moisture. Sensors can also be linked in a wireless networks that can collate and relay readings and also control the time intervals at which measurements are taken. Battery-powered, the unit can transmit data by short range radio, Bluetooth, satellite or mobile phone network and be logged to a memory card.

Dr Harris said “At plant level, probes can be positioned at continuous levels of depth to determine the salt concentration to which roots are exposed and whether this concentration changes with the depth of the soil or in different weather conditions. We can also measure how well a plant performs at a particular concentration and change the salt content for a few days and observe the effects.

 “On a bigger scale, sensors could be placed at different locations at catchment scale to observe any changes in the level of salinity within a field over time, having a direct impact on irrigation strategies. We have already been able to make some interesting observations on real world chloride concentration changes over just 24 hour periods, illustrating the dangers of relying on single point, single time measurements.”

Dr Harris’s sabbatical at UWA was supported with £2,000 of funding from the World University Network (WUN) with the sensor development work supported by the Biotechnology and Biological Sciences Research Council (BBSRC).

 He worked on the research project with Dr Andy Cranny from Electronics and Computer Science at the University of Southampton and Professors Keith Smettem, Neil Coles, Ed Barrett-Lennard and Mark Rivers from UWA.