Effects Of Soil Moisture Content On Water Use And Yield Characteristics Of Wheat Under Different Nitrogen Base Dressing Ratios And Wide Sowing Width

Wide-sowing water-saving and high-yield cultivation technology of wheat is a water-saving and high-yield cultivation technology of wheat created by Professor Yu Songlie in our research group.In this paper,the physiological basis of wide-sowing water-saving and high-yield cultivation technology of wheat is studied,and the test results are shown below:During the wheat growth seasons of 2016-2017 and 2017-2018,field experiments were conducted at the Shiwang Village Wheat Experiment Station in Xiaomeng Town,Yanzhou District,Jining City,Shandong Province（35°40’N,116°41’E）.Using a split zone design,the main zone was treated with a nitrogen base dressing ratio.Under a total nitrogen application rate of 240 kg·hm^-2,the ratios of nitrogen base dressing and top dressing during the jointing were 7:3（N1）,5:5（N2）,and 3:7（N3）,totaling 3 treatments;The sub area was treated with soil moisture content,and the relative moisture content of the 0-40 cm soil layer was replenished to 70%（W70）and 90%（W90）during the wheat jointing and anthesis,with a total of 2 treatments.Study the effect of soil moisture content on water use and yield characteristics of wheat with different nitrogen base dressing ratios,providing a theoretical basis for water-saving and high-yield cultivation of wheat.Field experiments were conducted at the Shiwang Village Wheat Experiment Station in Xiaomeng Town,Yanzhou District,Jining City,Shandong Province during the wheat growth seasons of 2019 2020 and 2020 2021（35°40’N,116°41’E）.Adopting split zone design,the main zone is treated with sowing methods,including wide width seeder（K）and conventional drill seeder（T）,with a total of 2 treatments;The sub zone was treated with soil moisture content,and the relative moisture content of the 0-40 cm soil layer was replenished to 65%（W65）,70%（W70）,75%（W75）,80%（W80）,and 85%（W85）during the wheat jointing and anthesis,totaling 5 treatments;The 2BJK-8 wheat wide width seeder（Yuncheng Gongli Co.,Ltd.）is used for the wide width seeder,with a broadcasting width of 8 cm;The conventional drill uses the 2BXF-12 wheat conventional drill（Renqiu Shuangyin Agricultural Machinery Manufacturing Co.,Ltd.）,with a broadcasting range of 3 cm.To study the effects of different soil moisture content on water use and yield characteristics of wheat under wide sowing and conventional sowing conditions,and to provide a theoretical basis for water-saving and high-yield cultivation of wheat in wide sowing.1 Effects of soil water content on water use and yield characteristics of wheat with different nitrogen base/topdressing ratioWater consumption characteristics.In two growing seasons,N2W70 treatment had significantly higher water consumption from anthesis to maturity and soil water storage consumption in the 160-200 cm soil layer than other treatments.It indicates that N2W70treatment provides sufficient water for grain filling.Photosynthetic characteristics and dry matter production.In two growing seasons,the net photosynthetic rate of flag leaves in N2W70 treatment was significantly higher than that in N1W70 and N3W70 treatment,and the dry matter allocation in grain after anthesis was significantly higher than that in N1W70,N3W70,N1W90 and N3W90 treatment.The results showed that N2W70 treatment was beneficial to increase photosynthetic capacity of leaves and dry matter accumulation of grains.Nitrogen accumulation and distribution.After anthesis,the transport of stem and leaf sheath in N2W70 treatment was significantly higher than that in other treatments.The nitrogen accumulation in grains was N2W70,N3W70>N1W70,N2W90,N3W90>N1W90.It indicates that N2W70 treatment is beneficial for improving grain nitrogen accumulation.Grain yield,water content,and nitrogen utilization efficiency.In two growing seasons,1000-grain weight and water use efficiency of N2W70 treatment were significantly higher than other treatments.The grain yield and nitrogen fertilizer partial productivity were N2W70,N2W90>N1W70,N1W90,N3W70,N3W90.It indicates that N2W70 treatment is the optimal treatment for high yield and efficiency under the conditions of this experiment.2 Effects of different soil moisture content on water use and yield characteristics of wheat under wide sowing conditionsWater consumption characteristics.Soil water storage consumption in 60-120 cm soil layer,water consumption from anthesis to maturity and soil water storage consumption in KW75 treatment were significantly higher than those in other treatments in two growing seasons.The results showed that KW75 treatment could promote the absorption and utilization of soil water,meet the water demand during grain filling and reduce water consumption.Photosynthetic characteristics and dry matter production.In two growing seasons,the net photosynthetic rate of flag leaf and photosynthetic active radiation interception rate of canopy in KW75 were significantly higher than those in KW65,KW70,TW65,TW70,TW75,TW80and TW85 treatments.KW75 treatment after anthesis dry matter distribution in grain,grain filling rate in the middle and late stages were significantly higher than other treatments;The grain dry matter accumulation of KW75 at maturity was significantly higher than that of KW65,KW70,TW65,TW70,TW75,TW80 and TW85 treatments.The results showed that KW75 treatment was beneficial to improve the photosynthetic capacity and increase the transport of photosynthate to grain after anthesis.Nitrogen accumulation and distribution.In two growing seasons,KW75 treatment significantly increased stalk+leaf sheath,leaf nitrogen transfer and grain nitrogen accumulation at maturity compared with other treatments.The results showed that KW75treatment was beneficial to increase nitrogen accumulation in anthesis plants and nitrogen transport capacity in vegetative organs,and increase nitrogen accumulation in grains.Aging characteristics of flag leaf and root system.In two growing seasons,the superoxide dismutase activity of flag leaves 21 and 28 days after anthesis,and the superoxide dismutase activity under KW75 treatment were significantly higher than those under KW65,KW70,TW65,TW70,TW75,TW80 and TW85 treatment.The results showed that KW75treatment delayed the senescence of flag leaf and root.Grain yield and water use efficiency.The 1000-grain weight,grain yield and nitrogen partial productivity of KW75 treatment were significantly higher than those of KW65,KW70,TW65,TW70,TW75,TW80 and TW85 treatments,and the water use efficiency of KW75treatment was significantly higher than that of other treatments.The results showed that KW75 treatment was the best treatment for both grain yield and water use efficiency.