Real-time scheduling of supplemental irrigation for potatoes using a decision model and short-term weather forecasts

Recent droughts in the UK have highlighted the fragile balance that can exist between the needs of the water environment and those of abstractors. Sustainable development concerns therefore dictate that irrigators must use water wisely through proper scheduling. Given the special circumstances of supplementary irrigation demand, the use of short-term weather forecasts should be considered in order to ensure more efficient use of rainfall during the growing season. This paper therefore presents an approach to real-time scheduling of supplemental irrigation, which makes use of short-term weather forecasts and an optimising decision algorithm. The utility of the approach is demonstrated for potatoes grown in eastern England under conditions that represent wet, dry and average years. The advantage of the model in wet years would be due to cost and water savings from unnecessary irrigation, resulting in increased profit and efficiencies of irrigation water-use. In average and dry years, the benefit of the approach would derive from improved efficiency in the use of limited water supply. The model is used to explore the consequences of decision options available to farmers given a range of water and crop price conditions.