Effect Of Water-fertilizer Optimization Management On The Yield, Water And Nitrogen Use Efficiency And Soil Quality Of Whibei Plateau Winter Wheat

Winter wheat is the main crop in Weibei dryland, Water shortage and nutrient deficiencyrestrict the development of agriculture in arid areas, so the key issues is how to strengthen themanagement of water and fertilizer. Searching for effective measures to improve the waterand nutrient use efficiency, obtain high and stable yield and improve soil quality is the focusof this paper.In this study, we set winter wheat field experiments in Chengcheng County, ShaanxiProvince during September2009to June2012. The treatments contained farmers’ patternswith traditional fertilization application and irrigation patterns and optimized water andfertilizer management patterns. The field experiment was carried out to study the effects ofthe farmers’ patterns and optimized patterns on the winter wheat yield, water and nitrogen useefficiency, soil quality. The research was to provide theoretical basis for the cultivationmeasures of grains yield and resource using efficiency and the sustainable in arid areas. Themain conclusions included:1The yield was increasing year by year. Three-year results showed that, the averageyield of optimized patterns increased by107.5%,93.5%and74.1%, compared with thefarmers’ patterns, respectively. In the yield components, the spike number and kernel numberper spike made the greater contribution to the grain yield in yield components than the kernelweight, especially in the abundant precipitation conditions.2The population amount of the treatments were all increased after seeding, reached thehighest at reviving stage, and decreased afterwards. Dry biomass showed the tendency of“slow-quick-slow” and the accumulation rate was biggest from jointing stage to filling stage.In the whole growth period, the average dry biomass of optimized patterns was21.8%and31.0%higher than control and farmers’ patterns respectively.3Compared with traditional farmers’ patterns, the average WUE of optimized patternswas11.1kg·hm^-2·mm^-1, that increased by25.0%in the year of2009^-2010. The second year,the average WUE of optimized patterns was12.5kg·hm^-2·mm^-1, that increased by25.5%. Inthe last year, the average WUE of optimized patterns was10.9kg·hm^-2·mm^-1, that increased by11.1%. The N application and irrigation can improve the total water consumption of winterwheat. The topdressing N and supplementary irrigation in jointing stage, straw mulch andorganic fertilizer application could improve the water use efficiency more.4The results of N use efficiency showed that, drought and irrigation in reviving stagecould significantly promote the nitrogen accumulation in0²00cm soil, while the strawmulch could decrease the residual nitrate N in the soil profiles. The topdressing nitrogen andsupplementary irrigation in jointing stage could significantly promote nitrogen accumulationand nitrogen use efficiency, that increased by37.2%、32.7%and32.2%compared with thefarmer’ patterns in the three years. Combined with straw mulch and organic fertilizerapplication can promote winter wheat N, P, K uptake.5In the0²0cm soil, compared with the farmers’ patterns and CK, the organic mattercontent of optimized pattern3-1,3-2which combined with straw mulch and organic fertilizerapplication significantly increased by5.84%and17.96%, and the available P, K weresignificantly higher than other treatments, the total N of optimized patterns increased by17.91%and29.51%. While there were not significant differences in20⁴0cm soil. Bulkdensity of optimized pattern3-1,3-2was lower. The urease activity of optimized patterns was20.1%higher than farmer’s made, and31.8%higher than CK. The enzymatic activity ofoptimized patterns3-1,3-2was higher. The urease, sucrase and phosphatase activity weresignificantly positive correlation with organic matter, total N and available P, while there was notsignificant correlation with available K.The results showed that optimized patterns could improve the economic benefitssignificantly compared to famers’ patterns in Weibei dryland. The optimized pattern3-2which integrate optimized nitrogen with supplementary irrigation, straw mulch and organicmanure was ideally efficient water and fertilizer management cultivation pattern. It was worthto expending...