Potato Review

www.potatoreview.com POTATO REVIEW MAY/JUNE 2020 13 IRRIGATION Is your programme water-tight? Specialist agronomist Andy Alexander discusses irrigation scheduling to help manage water resources better. M any growers could be better managing their irrigation programmes and making better use of precious water resources according to specialist potato agronomist Andy Alexander. Andy believes it’s necessary to make tailored decisions on a case-by-case basis because, although pre-prepared irrigation schedules are available, he stresses that these are based on average values, and there is no ‘one size ts all’. Rather, getting the timing right and knowing when to start and stop, is crucial, he said, pointing out that it was important to know your soil type and structure, which could even di er within the same eld. “Too many growers start irrigating for cosmetic reasons, and then continue, wasting a precious commodity, and too much water can have a detrimental e ect, such as growth crack in the tubers,” Andy said. “Understanding how much water a soil can hold, and what the in ltration rate is, determines how much is available to the crop and is key to deciding when - and how much - to irrigate. “For example, we know that clay soils are normally considered as moisture retentive, but, as they dry out, they can fracture, and the water quickly lters away through the cracks.” “It is often better to irrigate at night because there is less wind, and the crops will not transpire so fast either.” ➜