Effect of irrigation with brackish water on photosynthesis characteristics and yield of winter wheat

Abstract

In order to obtain the suitable alternative of saline water irrigation pattern and reveal the physiological and growth response mechanism for winter wheat, a field experiment was conducted in Yellow River Delta, Shandong, North China. Four irrigation treatments(irrigating 80 mm with fresh water each at jointing and heading stages, irrigating 80 mm with fresh water each at jointing, heading and milking stages, irrigating 80 mm with fresh-saline water each at jointing and heading stages, irrigating 80 mm with fresh-saline-saline water each at jointing, heading and milking stages) were designed. The collected datum were used to analyse the effects of saline water irrigation on photosynthesis characteristics, biomass and yield of winter wheat. The results show that, the winter wheat leaf stomatal regulation under saline water irrigation caused decreasing in plant transpiration rate, through improving the non-stomatal limitation factor, while ensuring a high net photosynthetic rate at milky stage, thus high efficiency of leaf water use efficiency significantly. Compared with the treatment of fully irrigated with fresh, plant height and biomass of winter wheat were inhibited, also yield decreased by 3%-13% and fresh water saved 50%-67% under the treatment with fresh-saline water. If saline water irrigation schedule is rational and rainfall reaches to the average level, the utilization of saline water for winter wheat could be prospective, which have important practical significance for the sustainable agriculture in the region.