Effects Of N And Topdressing Ratios On Biological Effects And Soil Properties Of Winter Wheat In Different Soil Textures

Wheat and maize are important guarantees for my country’s food production and people’s livelihood,and the two-crop rotation is the main planting mode in the North China Plain.In view of the large different properties of different soil textures in the Hei-long-gang area of Hebei province,the application of Nitrogen(N)fertilizer is unreasonable,and the N utilization rate is lower.Using a combination of field trials and laboratory analysis,in Baimu Village,Jiajiakou Town,Ningjin County,Xingtai City,winter wheat was as the main research object,and three soils,such as sandy loam,light loam and clay loam were selected.Each soil texture was separately set six treatments,such as without N(T1),and the N fertilizer base to dressing ratio was 3:7(T2),4:6(T3),5:5(T4),6:4(T5),and 7:3(T6),four crop trials were conducted for 2 years,the winter wheat growth characters,dynamic accumulation of nutrients and dry matter,yield formation,soil physical and chemical properties,and the after-effect yield of summer maize were studied.The results of the study optimize the method of N application for winter wheat,provide a basis for reasonable application of N fertilizer for wheat production on different soil textures in the region.The main results obtained were as follows:1.On sandy loamy soil,compared with no N(ST1),the photosynthetic characteristics,dry matter accumulation and flag leaf N content of wheat with different N fertilizer base and topdressing ratios were significantly improved,and the nitrate and ammonium Ns of each soil layer(ST1)were lower,and the contents of soil available P and K were higher than those in other treatments.The yields of wheat in the two seasons were the highest in the treatment of N topdressing ratio of 3:7,which were 5847 and 6127 kg/hm2,respectively,increased by 6.1%-58.2%compared with other treatments,the subsequent maize yield was also the highest.2.On light loamy soil,the above-ground growth index of wheat and the soil N content in each treatment were more than 7%higher than that in no N treatment.The difference in photosynthetic characteristics of wheat between LT2-LT6 treatments was small,and the dry matter and N accumulation in wheat flag leaves,N,P,K accumulation in plants,N utilization efficiency and other indicators showed the treatments of N fertilizer base to dressing ratios 4:6 and 5:5 were significantly higher than others,and the N accumulation of these two treatments was 4-5 times as LT1.The highest yield of the two seasons of wheat was the N fertilizer base to dressing ratio of 4:6,were the highest 8265 and 8400 kg/hm2,respectively.Yield and economic benefits of the subsequent maize were the highest with the base to dressing ratio of 4:6 and 5:5.3.On clay loam soil,the SPAD value of chlorophyll,leaf area index,chlorophyll fluorescence parameter and total N content of flag leaf in wheat treated with different N fertilizer base to dressing ratios were significantly higher than those in no N treatment(CT1)above 5%,the nutrient accumulation of wheat plant was also significantly higher than that of CT1,and the soil available P and K contents of CT2-CT6 treatments were lower than those in without N treatment.The two-year highest wheat yields were the base to dressing ratio 5:5 at 8363 and 8811 kg/hm2,respectively,and the highest maize yields in the subsequent crop were 11363 and 11758 kg/hm2.In summary,N fertilizer has an important effect on wheat growth,and N fertilizer management methods on different soil textures should be different.Due to the different nature of soil texture,the highest yield of wheat under no N application and reasonable N fertilizer ratio was clay soil>light soil>sandy soil,indicating that light soil and clay soil were more conducive to wheat growth and yield formation,it has good potential for high yield.The highest yield of wheat in different soil textures were:sandy soil with a N fertilizer base to dressing ratio in 3:7,a light loam soil with a N fertilizer base to dressing ratio of 4:6,and a clay soil soil with a N fertilizer base to dressing ratio of 5:5.Therefore,choosing the appropriate N fertilizer base dressing ratio according to the soil texture can ensure the better growth of wheat in each growth period,promote nutrient absorption and utilization,which is conducive to the formation of yield and increases net income.