Development of a novel dielectric tensiometer to deliver water savings in horticulture and agriculture

The sustainable and secure supply of water of adequate quality and in sufficient quantity is a major challenge for UK and global horticulture and agriculture. Blue water abstraction rates in many crop production areas are already unsustainable and despite the economic importance of scheduling irrigation effectively, almost 80% of UK irrigators used judgement not based on measurement in deciding when to irrigate. However, over-wet soil resulting from ineffective irrigation scheduling or ‘insurance’ irrigation reduces yields and post-harvest quality and increases the leaching of nitrates and other nutrients. In order to improve on-farm water use efficiency and water security, growers need to know when not to irrigate. To achieve this aim, a new soil moisture sensor that is accurate in the -5 to -30 kPa range will be developed and tested in this project; none of the current commercially available probes are sufficiently accurate within this range or suitably robust for growers.