Effects Of Optimum Fertilization Practices On Yield And Nutrients Utilization Of Winter Wheat In Guanzhong Irrigation District

Rational application of nitrogen fertilizer is an important measure to regulate nitrogen cycle and balance of soil-crop system,and it plays an indispensable role in improving nutrient utilization of crops and improving environmental quality.Guanzhong Irrigation District is an important production area for grain in Shaanxi Province.The unreasonable application of nitrogen fertilizer has become an important factor limiting the sustainable development of agriculture in this area.Different optimized fertilization practices are widely used in various grain producing areas,which can give full play to the different advantages of various fertilizers in crop production.This experiment was conducted in2017-2018 at the Tuokou Experimental Station in Jingyang,Shaanxi Province,which used Xiaoyan 22 as winter wheat experimental materials.In order to reduce the environmental damage caused by nitrogen fertilizer application,achieve the goal of exploring the fertilization measures suitable for winter wheat production in Guanzhong irrigation area,and promote the sustainable development of grain production in Shaanxi.This experiment sets five treatments:Conventional fertilization CK(nitrogen application rate:270kg·hm^-2);Urea application N1(nitrogen application rate:210 kg·hm^-2);urea+slow release fertilizer N2A(nitrogen application rate 210 kg·hm^-2);Urea+bacterial fertilizer N2B(nitrogen application 210kg·hm^-2;bacterial fertilizer 3600 kg·hm^-2);urea+biochar N2C(nitrogen application 210kg·hm^-2,biochar 22.5t·hm^-2).This study discussed the effect of different fertilization measures to soil physical and chemical properties,population structure of winter wheat,yield,quality and nutrient utilization in Guanzhong irrigation area,so as to provide a theoretical basis and practical support for the application and promotion of rational fertilization measures in agricultural production in guanzhong irrigation area.The main test results are as follows:1.Under different fertilization treatments,the organic matter content of 0-60 cm soil layers was the highest under N2C treatment,and the total nitrogen content of 40-60 cm soil layers was the highest.Among 80-100 cm soil layers at maturity stage of winter wheat,N2C treatment had the lowest ammonium nitrate nitrogen content,which was 67.18%and27.12%lower than CK,respectively.N2A treatment increased the total nitrogen content of0-20 cm soil layers at maturity stage.Compared with N1,N2A,N2B and N2C all increased the content of nitrate nitrogen in soil layers of 0-60 cm at flowering stage.N2A increased the content of total nitrogen in soil layers of 0-60 cm,N2B and N2C increased the content of organic matter in soil layers of 0-60 cm and total nitrogen in soil layers of 20-60 cm,which indicated that the combination of urea and slow-release fertilizer could increase the content of total nitrogen in soil.Soil organic matter content can be increased by applying bacterial fertilizer and biochar separately.2.Under different nitrogen treatments,the yield of N2B and N2C treatments were significantly higher than that of CK,N1 and N2A.N2B and N2C treatments increased the yield of winter wheat mainly by increasing the number of spikes and grains per spike,and the yield of N2C treatment was the highest.The yield increase of N1,N2A and N2B treatments was 8.31%-30.69%,which was the best for improving crop yield.Compared with N1,N2A,N2B and N2C treatments all increased leaf area index and dry matter accumulation in the middle and late growth stages of winter wheat,and increased grain yield,among which N2A,N2B and N2C treatments increased grain yield by 8.81%,17.04%and 22.03%respectively.3.Under different fertilization treatments,N1,N2B and N2C treatments could improve the milling quality of winter wheat grains,while N2A treatment could improve the nutritional quality and processing quality of winter wheat grains.4.Under different fertilization treatments,the nitrogen accumulation,phosphorus accumulation,nitrogen use efficiency and phosphorus use efficiency of the above-ground part of N2C treatment were the highest,and the nutrient utilization performance of winter wheat was the best.The nitrogen accumulation and partial productivity of the above-ground part of N2A and N2B treatments were higher than CK and N1 treatments.Compared with N1,N2A,N2B and N2C treatments could increase nutrient accumulation and nutrient use efficiency of winter wheat.In summary,under nitrogen reduction treatment,urea combined with slow-release fertilizer,bacterial fertilizer and biochar can improve soil fertility,increase nutrient accumulation and nutrient use efficiency of above-ground parts of crops,and play a positive role in improving crop growth,development,yield and quality.Among them,urea+biochar treatment can improve soil organic matter and total nitrogen content,reduce nitrogen loss at maturity stage,increase nutrient utilization of winter wheat and grain yield.It is a suitable fertilization measure in agricultural production in Guanzhong irrigation area.