[Effects of water-fertilizer integration on water use and photosynthetic characteristics of winter wheat].

In two growing seasons of wheat (2016-2018), a field trial with Jimai 22 as test mate-rial was conducted in Shijiawangzi Village, Yanzhou City, Shandong Province. Under three nitrogen levels of 150 (N ₁ ), 180 (N ₂ ) and 210 (N ₃ ) kg·hm ^-2 , two irrigation-fertilization methods were designed at jointing as border irrigation and broadcasting of fertilizer (W ₁ ), micro spraying irrigation and water-fertilizer integration (W ₂ ), to examine the effects of irrigation-fertilization methods on water use, photosynthetic characteristics, and dry matter accumulation and transport of wheat. The results showed that under the same nitrogen level, seven days average soil evaporation of W ₂ treatment in filling period was significantly lower than that of W ₁ treatment, and that soil water consumption in the 60-160 cm soil layer was significantly higher than that in W ₁ treatment. The flag leaf net photosynthetic rate, stomatal conductance and transpiration rate of W ₂ treatment were signi-ficantly higher than W ₁ treatment from 14 to 28 days after anthesis. The amount of dry matter in anthesis and maturity stage and the allocation to grain of post-anthesis assimilates of W ₂ treatment were significantly higher than those in W ₁ treatment. There was no difference in total water consumption between W ₂ and W ₁ treatments. Grain yield, water use efficiency and nitrogen use efficiency of W ₂ treatment were significantly higher than W ₁ treatment. The highest grain yield, water use efficiency and nitrogen use efficiency were obtained at the nitrogen level of 210 kg·hm ^-2 . By comprehensive considerations, under the same nitrogen level, treatment of micro spraying irrigation and water-fertilizer integration was better than border irrigation and broadcasting of fertilizer. The W ₂ N ₃ treatment under the nitrogen level of 210 kg·hm ^-2 and with the application of micro spraying irrigation and water-fertilizer integration at jointing was the optimal treatment to save water and fertilizer.