Study On The Mechanism Of Increasing Yield And Nitrogen Efficiency Of Corn By Applying Controlled Release Fertilizer In Combination With Deep Loose

Deep loosening can change soil structure,improve soil physical and chemical properties,improve soil temperature and humidity,promote maize growth and development and release nutrients of controlled release fertilizer,and then regulate the release rate of controlled release fertilizer and the rule of maize growth and development.In order to explore the response mechanism of spring maize growth and development to the application of controlled release fertilizer in deep pine,a field orientation experiment was conducted in Tumote right Banner,Baotou City,from 2017 to 2018 with Xianyu 696 as material.A total of 10 treatments were set up in the experiment:under the two tillage methods of deep loosening and shallow rotation,the model of without nitrogen fertilizer application(CK)were set up respectively,the model of the high yield(HY),Release fertilizer model(DN),and the control of nitrogen reduction model(CN),controlled release fertilizer nitrogen reduction model(DCN).The effects of controlled release fertilizer on nutrient release and maize growth were studied.From the soil environment,nutrient release rate and release rate of controlled release fertilizer,plant root structure characteristics,photosynthetic physiological characteristics,material accumulation,yield and yield composition,etc.The relationship between nutrient release of controlled release fertilizer and maize growth under shallow rotation and deep loose tillage was systematically analyzed,which provided technical support for rational application of controlled release fertilizer in maize production and provided theoretical basis for further realization of high yield and high efficiency of maize.The main results of this study are as follows:(1)Effects of controlled release fertilizer on maize growth and soil physical and chemical properties:After deep tillage,the soil bulk density in 0-60cm soil layer and the soil compactness in 15-35cm soil layer decreased significantly.The loose soil environment and suitable soil structure increased the field water content and soil temperature of 0-15cm soil layer,promoted the release rate of controlled release fertilizer nutrients,and increased the release rate of controlled release fertilizer nutrients in different growth stages of maize.At the same time,with the improvement of soil structure and physical and chemical properties,the growth of naize root system was promoted,and the total root dry weight,root length,root surface area and root volume were significantly increased.Leaf area index and unit leaf area index of plant leaves at different stages The relative content of chlorophyll also increased significantly,and accelerated the net photosynthetic rate of maize at different stages,significantly increased the accumulation of dry matter and nitrogen,and increased the yield of maize by 4.35%and 11.9%.Nitrogen use efficiency increased by 0.66-6.4kg/kg.Moreover,the leaching of nitrate nitrogen in the soil after harvest was reduced,and the pollution of fertilizer to the environment was reduced.(2)the response relationship among matter accumulation of spring maize and nutrient release of controlled release fertilizer was studied:The regression equations of cumulative release rate and soil temperature of controlled release fertilizer,dry matter accumulation per plant and nitrogen accumulation per plant were obtained by fitting.2017:Y=-0.0042x~2+0.38x+15.39(R~2=0.9714),and the relationship between the cumulative release rate of controlled release fertilizer and soil temperature,dry matter accumulation per plant and nitrogen accumulation per plant was obtained:Y=0.175x~2-17.55x+450.97(R~2=0.962*),Y=0.003x~2-0.323x 9.294(R~2=0.981*);2018:Y=-0.0067x~2+0.8x+2.84(R~2)0.9999),Y=0.003x~2-0.327x+8.346(R~2=0.961*),Y:=0.164x~2-15.895x+445.656(R~2=0.988*).Through the improvement of soil environment,the nutrient release of controlled release fertilizer coincided with the rule of maize growth and development,and the fertilizer effect of controlled release fertilizer could be enhanced.It was a new effective measure for increasing yield and increasing planting efficiency of maize.