Effects of temperature increase on water use and crop yields in a pea-spring wheat-potato rotation

A greenhouse experiment on a pea-spring wheat-potato (Pe-Sw-Po) rotation system was conducted at the Guyuan Experimental Station (lat. 36°02′N, long. 106°28′E), in a semiarid region of China, during 2000-2005. The mean daily temperature was designed to increase 0.5-2.0 °C, in the Pe-Sw-Po rotation system. When mean daily temperature increased by 1.2 °C, water use efficiency (WUE) decreased by 7.3%, the summed length of the growing period of the rotation was shortened by 23 days, and the total yield of the rotation decreased by 7.8%. With a 2.0 °C increase, WUE decreased by 12.5%, the growing period was shortened by 42 days, and the total yield decreased by 9.4%. Supplemental irrigation was beneficial to crop yields in the rotation with temperature increase. With 130 mm of supplemental irrigation spread over all growth stages and a 0.5-2.0 °C in mean daily temperature, the total yields of all crops improved by 8.3-12.7%. Consequently, in this region, supplemental irrigation may play an important role in maintaining yields of crops in a Pe-Sw-Po rotation system affected by climate warming.