Issue link: https://read.dmtmag.com/i/657340
42 APRIL 1, 2016 Good Fruit Grower www.goodfruit.com W hen we talk about water in fruit coun- try in the West, we usually mention those things that are key to irrigation: snowpack, reservoir capacity and stor- age, the elements of supply. The 2015 season is a stark reminder of why, as drought reduced water availability across the West and forced curtailment of irrigation in some orchards. But Dr. Lee Kalcsits of Washington State University took a few minutes during the Washington State Tree Fruit Association's meeting in December in Yakima, Washington, to discuss demand, offering practical approaches to limit or reduce water use in an orchard. After all, sooner or later, there will be another drought similar to 2015, said Kalcsits, an assistant professor of tree fruit physiology at WSU's Tree Fruit Research and Extension Center in Wenatchee, Washington. "They're going to come along again," he said. So, here are Kalcsits' six tips for reducing water use in an orchard: —Maintain a weed-free strip. Weeds compete for water and nutrients with tree roots. The shallow root zones of dwarfi ng rootstocks give those weeds an advan- tage. Give your trees about 3 to 4 feet of weed-free buffer, which should be plenty for dwarfi ng rootstock roots. —Use mulches to hold in moisture and reduce soil temperature, as well as to improve the overall nutritional quality of your ground. Good mulching techniques can reduce a tree's water demand by 25 percent, earlier stud- ies have shown. —Mow cover crops. Growing grass between rows is important for keeping down dust and for other practical reasons, but the more leaf area of a cover crop, the more evapotranspiration occurs and the more water it uses. Studies have shown cover crops can consume more than 1 acre-foot of water. Keep it short. Better ways to IRRIGATE WSU researcher offers tips for reducing water use. by Ross Courtney Water Management Lee Kalcsits