Effects Of Drip Irrigation Rate On Growth And Water Consumption Of Winter-Sowing Spring Wheat In Northern Xinjiang

To determine the suitable drip irrigation amount for winter sowing spring wheat in northern Xinjiang.The experiment was carried out in Sanping Farm,Toutunhe District,Urumqi City,Xinjiang from 2020 to2021.The variety Xinchun 48 was used.The drip irrigation amount was set at 2625 m³·hm^-2,3150m³·hm^-2,3675 m³·hm^-2,4200 m³·hm^-2during the whole growth period of the field,which was expressed as W₁,W₂,W₃and W₄,respectively.The effects of different drip irrigation amount on growth,yield and water use efficiency of winter sowing spring wheat were studied.The main research results are as follows:1.Increasing drip irrigation mainly caused the change of soil water content in 0-60 cm soil layer.Soil water storage consumption decreased with the increase of drip irrigation amount,and W₁treatment was the largest,which increased by 97.20 m³·hm^-2,328.00 m³·hm^-2,558.74 m³·hm^-2respectively compared with W₂,W₃and W₄treatments.2.The growth period of the maximum drip irrigation amount W₄treatment was 6 days later than that of the minimum drip irrigation amount W₁.Increasing the amount of drip irrigation is conducive to improving the plant height of wheat.The difference between W₄treatment and W₁,W₂and W₃treatments at the filling stage is significant,which increases by 14.48%,9.64%and 5.92%,respectively.The difference in total stem number of each treatment in each period with the increase of drip irrigation amount was obvious.The total stem number of W₃treatment was the largest,showing an overall trend of first increase and then decrease.Before and after May 14,the maximum total stem number of W₁,W₂,W₃and W4 treatments was 630×10⁴·hm^-2,687×10⁴·hm^-2,718×10⁴·hm^-2and 695×10⁴·hm^-2,respectively.3.In the range of 2625-3675 m³·hm^-2drip irrigation,the photosynthesis of flag leaves increased with the increase of drip irrigation,and the photosynthesis of W₄treatment with more than 3675 m³·hm^-2drip irrigation decreased significantly.The leaf area index（LAI）of each drip irrigation treatment increased first and then decreased with the advance of growth period,and the peak value was on May 24.The LAI of W₃treatment was the largest,which was 4.24,increased by 15.19%,21.66%and 49.81%compared with W₄,W₂and W₁,respectively.The total photosynthetic potential was higher in W₃and W₄.W₃treatment was significantly higher than other treatments,190.04 m²·d·m^-2,increased by 8.55%,29.26%,57.02%compared with W₄,W₂,W₁.4.Increasing the amount of drip irrigation can improve the filling period duration（T）,W₃treatment reached the maximum of 42.98 d,compared with W₁,W₂,W₄treatment increased 6.34 d,5.34 d,0.92 d.However,excessive irrigation（W₄treatment）will lead to a slow decline in various indicators,so the appropriate irrigation amount is the key to improve the filling duration and increase grain weight.5.The amount of drip irrigation in the range of 2625-3675 m³·hm^-2had a promoting effect on the translocation of wheat pre-anthesis assimilates.The maximum amount of pre-anthesis assimilates was1940.32 kg·hm^-2in W₂treatment,which was 22.65%,6.09%and 35.18%higher than that in W₁,W₃and W₄treatment,respectively.The translocation of pre-anthesis assimilates in W₄treatment(4200 m³·hm^-2)with drip irrigation exceeding 3675 m³·hm^-2was weakened.6.There was a quadratic parabola relationship between drip irrigation amount and yield and water use efficiency.The highest water use efficiency of W₃treatment was 1.31 kg·m^-3.Comprehensive consideration showed that the suitable total drip irrigation amount for winter sowing spring wheat was 3150-3675m³·hm^-2,and the yield could reach 7075.83 kg·hm^-2.