Impacts of the controlled roots-divided alternative irrigation on water and nutrient use of winter wheat

Impacts of three-irrigation methods, i.e., all soil area irrigation (CK), the controlled roots-divided alternative irrigation (CRDI) and fixed half of root area irrigation on water and nutrient use of winter wheat were studied with the potted method. Results showed that there were a big root-canopy ratio and dry weight when the lower limit of controlled soil water content decreased at the same irrigation treatment. There were an obvious improving role for winter wheat root system growth with CRDI irrigation, representation of well-distributed root in soil and a large root density. When the lower limit of soil moisture changed from 65% field capacity to 55% field capacity, water consumption dropped by 35%, which showed an remarkable water-saving effect. Analysis of the nutrient uptake of winter wheat with different irrigation methods showes that the high soil water content benefits nutrient absorption by winter wheat. At the same lower limit of soil water content, there were decrease trends of soil H₂PO^-₄ and NH⁺₄-N concentration within growth period and soil profile under different irrigation methods, but NO^-₃-N concentration was in increase trend, The nutrient uptake of winter wheat with CRDI was more than those by other irrigation methods at the same soil water content.