Effects Of Supplemental Irrigation Based On Measuring Soil Moisture In Different Soil Layers On Grain Yield And Their Physiological Basis Of Wheat

Taking winter wheat cultivar Jimai 22 and Tainong 18 as test material, a field experiment was conducted to study the effect of supplemental irrigation based on measuring soil moisture in different soil layers on light interception, photosynthetic characteristics of flag leaf, dry matter accumulation and distribution, nitrogen accumulation and translocation, grain yield and water use efficiency of wheat according to measuring soil moisture in different soil layers in Shiwang village, Yanzhou, Shandong, China, in the 2013~2015 growth season. Five soil layer depths(D20:0~20cm; D40:0~40cm; D60:0~60cm; D80:0~80cm; D140:0-140cm)were used to calculate the amount of supplemental irrigation, and the same target soil relative moisture content at jointing stage(target soil relative moisture content was 70%) and anthesis stage(target soil relative moisture content was 75%), was set in each soil layer depth.Zero-irrigation(W0) and conventional irrigation(W60, water of 60 mm at jointing and anthesis) as the control treatment. the main results as follow:1 Effect of supplemental irrigation based on measuring soil moisture in different soil layers on grain yield and water use efficiency of wheat1.1 Effect of different treatments on the grain yield and component of wheatMaking supplemental irrigation in 0-40 cm soil layer enhanced the grain yield, spike grain weight and number per hectare than that of making supplemental irrigation in 0-20 cm in Jimai 22, the grain yield, spike grain weight in Tainong 18, when making supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm the grain yield, spike grain weight and number per hectare without significant increasing in Jimai 22 and Tainong 18. The grain yield, spike grain weight and number per hectare of W40 had no signifficent difference with Wck in Jimai 22 and Tainong 18. under no irrigation, the grain yield and spike grain weight of Jimai 22 were lower than those of Tainong 18, the number per hectare of Jimai 22 was higher than Tainong18; under the irrigation, the grain yield of Jimai 22 had no significant difference with Tainong18, the spike grain weight of Jimai 22 was lower than that of Tainong 18, the number per hectare of Jimai 22 was higher than Tainong 18.1.2 Effect of different treatments on the total water consumption, water use efficiency and irrigation benefit of wheatMaking supplemental irrigation in 0-40 cm soil layer enhanced the water use efficiency and irrigation benefit than that of making supplemental irrigation in 0-20 cm, 0-60 cm, 0-80 cm and 0-140 cm in Jimai 22 and Tainong 18. The irrigation benefit of Jimai 22 was higher than Tainong 18; under no irrigation condition,the total water consumption and water use efficiency of Jimai 22 had no significent difference with Tainong 18; making supplemental irrigation in 0-20 cm, 0-40 cm and 0-80 cm,the total irrigation quantity of Jimai 22 was higher than Tainong 18; making supplemental irrigation in 0-60 cm and 0-140 cm and Wck, the total irrigation quantity and water consumption of Jimai 22 were lower than Tainong 18 but the water use efficiency was significant higher than Tainong 18. It showed that W40 treatment was the optimum treatment obtaining higher grain yield and water use efficiency.2 Effect of supplemental irrigation based on measuring soil moisture in different soil layers on canopy light interception of wheat2.1 Effect of different treatments on leaf area index of wheatMaking supplemental irrigation in 0-40 cm soil layer, leaf area index was higher than that of making supplemental irrigation in 0-20 cm and zero-irrigation when making supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm without significant improvement.The leaf area index of each treatment in Jimai 22 was higher than that in Tainong 18 at 0 days,10 days and 30 days after anthesis, under the condition of W0 and W20, the leaf area index of Jimai 22 was lower than that of Tainong 18 at 30 days after anthesis and other conditions there were no significant between Jimai 22 and Tainong 18. The results suggest that, the leaf area index of Jimai 22 was higher than that of Tainong 18.2.2 Effect of different treatments on canopy light interception rate of wheatMaking supplemental irrigation in 0-40 cm soil layer, canopy light interception rate was higher than that of making supplemental irrigation in 0-20 cm when making supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm without significant improvement. There were no significant differences between the canopy light interception rate of W40 and Wck at 0 days,10 days, 20 days and 30 days after anthesis. The canopy light interception rate between Jimai22 and Tainong 18 had no significant difference at 0 days, 10 days, 20 days and 30 days after anthesis.2.3 Effect of different treatments on canopy apparent photosynthetic rate of wheatMaking supplemental irrigation in 0-40 cm soil layer, canopy apparent photosynthetic rate was higher than that of making supplemental irrigation in 0-20 cm when making supplemental irrigation in 0-60 cm without significant improvement. There were no significant differences between the canopy apparent photosynthetic rate of W40 and Wck at 10 days and20 days after anthesis. The canopy apparent photosynthetic rate between Jimai 22 and Tainong 18 had no significant difference at 10 days and 20 days after anthesis.3 Effect of supplemental irrigation based on measuring soil moisture in different soil layers on flag leaf photosynthetic characteristics of wheat3.1 Effect of different treatments on flag leaf photosynthetic rate of wheatMaking supplemental irrigation in 0-40 cm soil layer, flag leaf photosynthetic rate was higher than that of making supplemental irrigation in 0-20 cm when making supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm without significant improvement. There were no significant differences between the flag leaf photosynthetic rate of W40 and Wck at 0 days, 7days, 14 days, 21 days,28 days and 35 days after anthesis. The flag leaf photosynthetic rate between Jimai 22 and Tainong 18 had no significant difference at 0 days, 7 days, 14 days, 21 days and 28 days after anthesis but the flag leaf photosynthetic rate of Jimai 22 was lower than Tainong 18 at 35 days after anthesis.3.2 Effect of different treatments on flag leaf chlorophyll content of wheatMaking supplemental irrigation in 0-40 cm soil layer, flag leaf chlorophyll content was higher than that of making supplemental irrigation in 0-20 cm when making supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm without significant improvement. There were no significant differences between the flag leaf chlorophyll content of W40 and Wck at 10 days and 20 days after anthesis. The flag leaf chlorophyll content between Jimai 22 and Tainong 18 had no significant difference at 10 days and 20 days after anthesis.3.3 Effect of different treatments on the flag leaf RUBP carboxylase activity of wheatMaking supplemental irrigation in 0-40 cm soil layer, flag leaf RUBP carboxylaseactivity was higher than that of making supplemental irrigation in 0-20 cm when making supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm without significant increasing. The flag leaf RUBP carboxylase activity in W40 and Wck had no significant difference of Jimai22 and Tainong 18 at 0 days, 7 days, 14 days, 21 days and 28 days after anthesis. The flag leaf RUBP carboxylase activity between Jimai 22 and Tainong 18 had no significant difference at0 days, 7 days, 14 days, 21 days and 28 days after anthesis but the flag leaf RUBP carboxylase activity of Jimai 22 was lower than Tainong 18 at 35 days after anthesis.4 Effect of supplemental irrigation based on measuring soil moisture in different soil layers on Dry matter accumulation and distribution of wheat4.1 Effect of different treatments on the dry matter accumulation of wheat at anthesis and maturityMaking supplemental irrigation in 0-40 cm soil layer was more benefit for dry matter accumulation than that of making supplemental irrigation in 0-20 cm when making supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm without significant increasing at maturity. The dry matter accumulation in W40 and Wck had no significant difference of Jimai22 and Tainong 18 at maturity. The dry matter accumulation between Jimai 22 and Tainong18 had no significant difference at anthesis but lower than Tainong 18 at maturity.4.2 Effect of different treatments on the dry matter distribution and contribution rate in grain of wheat at maturityMaking supplemental irrigation in 0-40 cm soil layer was more benefit for the dry matter distribution and contribution rate in grain than that of making supplemental irrigation in 0-20 cm when making supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm without significant improvement after anthesis. The dry matter distribution and contribution rate in grain of W40 had no significant difference with Wck in Jimai 22 and Tainong 18. The dry matter distribution and contribution rate in grain of Jimai 22 were lower than those of Tainong 18 before anthesis but higher than Tainong 18 after anthesis.5 Effect of supplemental irrigation based on measuring soil moisture in different soil layers on the nitrogen accumulation and transportation of wheatMaking supplemental irrigation in 0-40 cm soil layer enhanced the nitrogen accumulation and transportation than that of making supplemental irrigation in 0-20 cm whenmaking supplemental irrigation in 0-60 cm, 0-80 cm and 0-140 cm without significant increasing at anthesis and maturity. The nitrogen accumulation and transportation of W40 and Wck had no significant difference in Jimai 22 and Tainong 18. The nitrogen accumulation and transportation between Jimai 22 and Tainong 18 had no significant difference at anthesis and maturity.