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Developing precision irrigation for field scale vegetable production, linking in-field moisture sensing, wireless networks and variable rate application technology - HL0196

Irrigation of field vegetables has changed relatively little over the last 3 decades. However, rising energy costs and supermarket demands for premium quality produce are forcing growers to address the impacts of irrigation variability (non-uniformity) on crop quality whilst simultaneously reducing energy and water consumption. This issue is important for the UK and internationally. Field vegetables are the most important crop in the UK after potatoes in terms of irrigated area and crop value. Nearly three-quarters are irrigated using overhead methods which are inefficient in energy and water use, with consequent impacts on crop quality. Whilst drip irrigation can improve water efficiency and crop quality in some sectors it is not the solution for field-scale horticulture, where sequential plantings and rotational cropping are better suited to portable overhead systems. Water regulation is also impacting on production, with water availability and reliability likely to become major constraints on horticultural businesses. Growers will have to demonstrate efficient and sustainable use of water to renew their abstraction licences and comply with supermarket grower protocols. Developing innovative approaches to combine knowledge of soil, crop and equipment management practices to reduce the variability in crop quality through precision irrigation is an industry priority.

The aim of this project is to develop an intelligent irrigation management system, integrating soil moisture sensing, wireless communication and variable delivery technology, to improve crop quality and reduce water consumption and other environmental impacts. Using irrigation trigger points at defined physiological set points combined with a precision application system will enable significant water savings in field-scale horticultural production, with an associated reduction in nutrient leaching and energy used for pumping.

We will use small-scale instrumented experimental sites to (i) design, develop and test a real time wireless soil moisture sensor array, and (ii) evaluate the role of plant water status measurement techniques (including thermal imaging) for monitoring varying levels of crop water stress, using lettuces and onions as reference crops. The crop measurements will be used to calibrate the soil moisture sensor readings to define trigger irrigation points. Technologies for applying water variably from booms and valved sprinklers and their associated control systems will be then developed and tested under bare soil conditions. The soil sensing, crop monitoring and variable application technologies will be coupled to form a ‘closed loop system’ which will be evaluated under contrasting crop, soil and agroclimatic conditions at two grower sites. This will include an assessment of system performance, practicality (ease of management), impacts on yield and post harvest quality, and economic appraisal. The fieldwork will inform decisions regarding technology transfer to other horticultural crops.
Project Documents
• Abstract : HL0196 Abstract   (14k)
Time-Scale and Cost
From: 2010

To: 2014

Cost: £320,249
Contractor / Funded Organisations
G Marketing, Plantsystems, PDM Produce (UK), UK Irrigation Association, AHDB-Horticulture, Briggs Irrigation, Wroot Water Systems, Elveden Estate Ltd, Adcon Telemetry, University - Lancaster, University - Harper Adams Agricultural College, University - Cranfield, VCS Agronomy, Horticultural Development Council