| The experiment was conducted in Xuanzhuang Village?E116 54',N 36 12'?of Daolang Town,Tai'an City,Shandong Province during the wheat growing season from 2016 to 2018.Shannong 29,a high-yielding winter wheat variety widely popularized in Shandong Province,was used as experimental material.Two treatments,micro-sprinkling supplemental irrigation?MSI?and traditional border irrigation?BI?,were set up in split plot design with irrigation mode as the main area.Nitrogen level was the sub-area,and two treatments were set up,which were 192 kg ha-1?N1,20%less than traditional nitrogen application?and 240 kg ha-1?N2,traditional nitrogen application?.To explore the effects of different water and nitrogen management methods on water and nitrogen use efficiency of winter wheat,the main results are as follows:1 Effects of Water and Nitrogen Management on Winter Wheat Yield and Its ComponentsAt the same nitrogen application level,there were no significant differences in number of spikes,grain per spikes,1000-grain weight and grain yield between micro-sprinkling and border irrigation treatments.Under the same irrigation mode,the amount of nitrogen application was reduced by 20%compared with traditional nitrogen application,which had no significant effect on the grain yield of winter wheat.2 Effects of Water and Nitrogen Management on Water Consumption Characteristics and Water Use Efficiency of Winter WheatUnder the same nitrogen application level,compared with border irrigation,micro-sprinkling supplemental irrigation promoted the absorption and utilization of deep soil water by winter wheat,reduced the evaporation between trees,and significantly improved water use efficiency,irrigation use efficiency and irrigation benefit.Under the same irrigation mode,the amount of nitrogen application was reduced by 20%,the consumption of soil water by winter wheat was reduced,the total water consumption was reduced,and the soil water use efficiency and irrigation benefit were significantly improved.3 Effect of Water Management on Soil Physical Properties in 0–40 cm Soil LayerUnder the same nitrogen application level,compared with border irrigation treatment,micro-sprinkling supplemental irrigation treatment reduced soil bulk density of 0-20 cm soil layer,increased soil total porosity of 0-15 cm or even 0-20 cm soil layer,increased soil capillary porosity of most 0-40 cm soil layer,increased the proportion of soil macro-aggregates and field water holding rate of corresponding soil layer,and accelerated the recovery of soil temperature after revival,which indicated that micro-sprinkling supplemental irrigation could increase soil capillary porosity of 0-40 cm soil layer.It can improve the physical properties of wheat field soil,increase the soil water storage capacity of the main root layer,and coordinate water,fertilizer,gas and heat.4 Effects of Water and Nitrogen Management on Spatial and Temporal Distribution of Nitrate Nitrogen in Winter WheatAfter irrigation at jointing,under the condition of reducing nitrogen by 20%,the content of nitrate nitrogen in upper soil layer of micro-sprinkling supplemental irrigation treatment was higher than that of border irrigation treatment.Under the same nitrogen application level,the nitrate leaching from soil at jointing and anthesis by micro-sprinkling supplemental irrigation was less than that by border irrigation,and the nitrate nitrogen residues in soils of60-160 cm in maturity stage were less.5 Effects of Water and Nitrogen Management on Root Morphology and Physiological Characteristics of Winter WheatUnder the condition of reducing nitrogen by 20%,compared with border irrigation,micro-sprinkling supplemental irrigation treatment increased root length density of 0-20 cm soil layer from jointing to anthesis rapidly,increased significantly root length density of 0-60cm soil layer at anthesis,maintained a higher level of root activity in 0-40 cm soil layer at the early and middle grain-filling stage,which was conducive to the absorption of soil moisture and nutrients in the main root layer.6 Effects of Water and Nitrogen Management on Population Development and Dry Matter Accumulation and Distribution of Winter WheatAt the same nitrogen application level,compared with border irrigation,micro-sprinkling supplemental irrigation could reduce tillering in spring,promote the transport of storage assimilates from vegetative organs to grains before anthesis,and increase the contribution rate of redistribution assimilates to grains after anthesis.Under the same irrigation mode,20%reduction of nitrogen application increased the transport of storage assimilates from vegetative organs to grains and their contribution to grains before anthesis.7 Effects of Water and Nitrogen Management on Nitrogen Absorption,Accumulation and Distribution and Nitrogen Use Efficiency of Winter WheatUnder the condition of 20%nitrogen reduction,compared with the border irrigation treatment,the nitrogen accumulation of plants in the mature stage of micro-sprinkling supplementarl irrigation treatment had no significant change,promoted nitrogen accumulation after anthesis and significantly increased nitrogen accumulation in grains.Under the traditional nitrogen application condition,compared with the border irrigation treatment,micro-sprinkling supplemental irrigation significantly increased nitrogen accumulation after anthesis and compensated for the deficiency of nitrogen transfer in vegetative organs before anthesis,thus obtained and compared with the border irrigation treatment.The grain nitrogen accumulation of border irrigation was the same.Under the same nitrogen application level,compared with the border irrigation treatment,the nitrogen harvest index and nitrogen fertilizer agronomic efficiency of micro-sprinkling supplemental irrigation treatment were improved.8 Ecological and Economic BenefitsUnder the same level of nitrogen application,micro-sprinkling supplemental irrigation treatment reduces the input of irrigation water,saves electricity,reduces the input of labor and labor costs,and greatly increases the output value by increasing the effective planting area,thus achieving remarkable ecological and economic benefits. |
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