| The experiment was performed in an experimental farm at the Shandong Agricultural University during the wheat growing seasons in 2013~2014 and 2014~2015. According to the water content of 0~40cm soil layers, five treatments were installed, i. e., zero-irrigation in growth stages, zero-irrigation at overwintering stage, target soil relative water content was70% in the overwintering stage, target soil relative water content was 75% at overwintering stage, irrigation 60 mm at overwintering, jointing and anthesis stages with W0, W1, W2, W3 and W4 said, and in the treatment W1,W2 and W3, the target soil relative water content of the three treatments at jointing and anthesis were 65% and 70%, respectively. We set Jimai 22 for test wheat cultivars. In order to study the effects of supplemental irrigation based on measuring soil moisture in the overwintering stage on water consumption characteristics and water use efficiency, the main results as follow:1 Effect of different treatments on water consumption in wheatIn the growing seasons of winter wheat in 2013~2014 and 2014~2015, the highest irrigation amount in the overwintering stages was obtained by W4 treatment, followed by W3?W2 and W1 treatment. The total irrigation amount and its proportion of the total water consumption showed the following trend: W4 > W3 > W2 > W1 > W0. The total water consumption in the whole stages, soil water consumption in the 60~120 cm soil layers and water consumption and daily water consumption from anthesis to maturity in W4 were the highest, followed by W2, W3 and W1, those in W0 treatment were the lowest. In addition,there was no significant difference between W2 and W3 treatments.2 Effect of different treatments on photosynthetic characteristic and dry matter accumulation and transportation of wheatIn the two growing seasons of wheat, from 14 DAA to 21 DAA, the flag leaf netphotosynthetic rate Pn, transpiration rate Tr and stomatal conductance Gs were ranked as W4> W2 or W3 > W1 > W0, and there was no significant differences between W2 and W3 treatment. At 14 DAA and 21 DAA, the flag leaf chlorophyll content and the actual maximum photochemical activity ?PS?were ranked as W4>W2 or W3>W1>W0 and W2 or W3>W4>W1>W0, repectively, and there was no significant differences between W2 and W3 treatment. Dry matter accumulation at anthesis and maturity in W4 was the highest, followed by W2, W3, W1 and W0 treatments. The contribution rate of dry matter translocation amount from vegetative organs to grain after anthesis were ranked as W0>W1>W2?W3>W4. The dry matter accumulation to grain in maturaty stage and its distribution ratio in W4 treatment was the highest, followed by W2, W3 and W1, the lowest in W0 treatment. Flag leaf sucrose content and the activity of sucrose phosphate synthase from 14 DAA to 21 DAA were ranked as W4>W2>W3>W1>W0. In the 28 DAA and maturaty stage, amylopectin and total starch content in grain in W4 were the highest, followed by W2, W3 and W1, the lowest in W0 treatment.In the 2013~2014 growing season, from 14 DAA to 21 DAA, superoxide dismutase(SOD)and catalase(CAT) activity of winter wheat flag leaves in W2 were significantly higher than W1 and W0 treatment, lower than W4, and had no differ with W3 treatment. From 7 DAA to28 DAA, malondialdehyde(MDA) content and soluble protein content were ranked as W0>W1 > W2 or W3 > W4 and W4 > W3 > W2 > W1 > W0, repectively. In the 2014~2015growing season, from 14 DAA to 21 DAA, SOD and CAT activity of winter wheat flag leaves in W4 were the highest, followed by W3, W2, W1 and W0 treatments. From 7 DAA to 28 DAA, MDA content and soluble protein content were ranked as W0>W1>W2 or W3>W4and W4>W2 or W3>W1>W0, repectively. In the two growing seasons, from 14 DAA to21 DAA, the grain-filling rate in W4 were the highest, followed by W2, W3 and W1, the lowest in W0 treatment. In addition, there was no significant differences between W2 and W3 treatments.In both growing seasons of 2013~2014 and 2014~2015, canopy PAR interception rate after anthesis in W4 were the highest, followed by W2, W3 and W1, the lowest in W0 treatment. It was contrary with those in the PAR reflect ratio. The canopy PAR pernetration loss ratio inW0 was signicantly higher than other treatments. In the 2013~2014 growing season, canopy PAR conversion rate in W2 was the highest, followed by W1, W4 and W0, and had no differ with W3 treatment. In the 2014~2015 growing season, canopy PAR conversion rate was ranked by W4>W2>W3>W1>W0.3 Effect of different treatments on nitrogen accumulation and transportation of wheatIn both growing seasons of 2013~2014 and 2014~2015, nitrogen accumulation amount of grain in maturaty stages was ranked by W4>W2 or W3>W1>W0, and its ratio of the tatol nitrogen accumulation amount in maturaty stages in W2 was significantly higher than other treatments. Nitrogen accumulation amount in vegetative organs of anthesis stages in W4 were the highest, followed by W2, W3 and W1, the lowest in W0 treatment. In addition, there was no significant differences between W2 and W3 treatments. Nitrogen accumulation amount in maturaty stages and its contribution to grain in W2 was significantly higher than other treatments.4 Effect of different treatments on yield and water use efficiency of wheatIn both growing seasons of 2013~2014 and 2014~2015, the grain yield in W4 were the highest, followed by W2, W3 and W1, those in W0 treatment were the lowest. In addition,there was no significant difference between W2 and W3 treatments. Irrigation efficiency was ranked as W2 > W3 >W1 > W4 > W0. In the 2013~2014 growing season, the water use efficiency was ranked as W2>W3>W1>W4>W0. In the 2014~2015 growing season,water use efficiency was ranked as W2 and W3>W1>W4>W0. Those all indicated that the supplemental irrigation based on the soil moisture in the 0~40 cm soil layers, W2 treatment which relative water content in the overwintering stage was 70% was the best irrigation treatments under this test condition with lower irrigation amount and higher grain yield and water use efficiency than other treatments. |
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