Water-saving mechanism and efficiency of vertical partial-rootzone alternative controlled drip irrigation of tomato(Lycopersicon Esculentum)

Vertical Partial-rootzone Alternative Controlled Drip Irrigation (VPRADI) is one of the fields operating methods of Controlled Partial-rootzone Alternative Irrigation (CRAI). At present, VPRADI has not been researched and used. Tomato is a primary vegetable of greenhouse in China. Research on the new water-saving irrigation method of tomato that can save water resources and increase the rate of commercial fruit is important. So VPRADI on tomato was studied. The treatment included middle water on VPRADI, low water of VPRADI and middle water of DI. The result showed the VPRADI can form alternative drought and wet soil zones in vertical profile of tomato rootzone. And VPRADI can reduce the intensity of water consumption and smooth the process of water consumption in appropriate irrigation schedule. It can control redundant growth of tomato, increase the stem diameter and the roots of underlayer. The tomato's yield dropped a few in VPRADI_M than in DI_M, but the water consumption of VPRADI_M was saved by 46.5% in comparison with DI. VPRADI under the higher soil moisture limited is feasible to irrigate tomato in order to save water and operational expenditure of greenhouse.