Study On The Application Effect Of Slow Release Fertilizer On Maize Under Plastic Film Mulching

The northwestern region has abundant light and heat conditions,but the shortage of water resources and low soil nutrient content are prominent.The local water conservation through film-mulching cultivation mode increases the difficulty of top dressing in the later stage.Therefore,excessive application of base fertilizer is not only a waste of resources but also polluted environment.In order to study the application effect of black mulch film in Northwest China and solve outstanding problems in Northwest China,a series of studies have been carried out.In this study,spring maize was used as the research object.Field trials were carried out in Gansu Province,Ningxia Hui Autonomous Region,Shanxi Province and Qinghai Province.There were eight treatments in the experiment:no nitrogen treatment（N₀）and farmer’s traditional mode treatment(N₂₅₀).),nitrogen reduction 20%treatment(N₂₀₀),nitrogen reduction 20%combined with 1%nitrification inhibitor DMPP（3,4-dimethylpyrazole phosphate）treatment,nitrogen reduction 20%combined with 5%nitrification inhibition DCD（dicyandiamide）treatment,20%nitrogen reduction combined with 1%urease inhibitor NBPT（n-butyl thiophosphoric triamide）treatment,nitrogen reduction 20%combined with sulfur-coated urea treatment（70%Urea+30%sulfur-coated urea）,reduced nitrogen by 20%and treated with resin-coated urea（70%urea+30%resin-coated urea）.To explore the effects of black and white mulching film and 20%nitrogen reduction combined with slow-release nitrogen fertilizer on spring maize grain yield,above-ground dry matter quality,plant nitrogen content,nitrogen effect and soil nitrate-nitrogen distribution under the film-mulching cultivation mode The selection of nitrogen fertilizer varieties,dosage and color of mulching film suitable for the four provinces of northwest dryland areas will provide technical and theoretical support for achieving nitrogen reduction and fertilizer saving,high efficiency and environmental protection of spring maize in the four northwestern provinces.The research results of this experiment are as follows:1.The use of different colors of mulching film in the four northwestern provinces has an impact on the yield of spring maize.The white mulching film is better in Gansu,Ningxia and Qinghai,and the black mulching film is better in Shanxi.Combined application of new nitrogen fertilizers under the condition of reducing nitrogen by 20%can increase spring maize grain yield and yield components.In 2018,the treatments with the highest yields in Gansu,Ningxia,Shanxi and Qinghai were DCD,NBPT,DCD,and NBPT,respectively,which were 12739 kg·hm.^-2,16922kg·hm^-2,14676kg·hm^-2,11666kg·hm^-2,compared with the farm mode,the output increased by 4.7%,6.5%,3.1%,12.5%,respectively,and the economic benefits were increased by 816.6￥·hm^-2,2082.2￥·hm^-2,571.5￥·hm^-2,2589.5￥·hm^-2.In 2019,Gansu,Ningxia,Shanxi and Qinghai under their respective better mulching types,the highest treatment is DCD,NBPT,RCN,DCD,respectively10211.3kg·hm^-2,10583.8kg·hm^-2,12297.8kg·hm^-2,7481.3kg·hm^-2,which are 10.4%,21.3%,9.7%,and 22.8%higher than the farm household model,and economic benefits are increased by 1671.5￥·hm^-2respectively.￥·hm-2,3775.7￥·hm^-2,475.9￥·hm-2,2515.5￥·hm^-2.2.In the four provinces of northwest arid region,black and white plastic film mulching is used for cultivation,and there is no big difference in the dry matter quality of spring maize between the two.However,the treatment of reducing the amount of urea by 20%and adding new nitrogen fertilizer can significantly improve the dry matter quality of spring maize.In2018,the four provinces of Gansu,Ningxia,Shanxi and Qinghai were treated with DCD,NBPT,DCD,and NBPT respectively.In 2019,the white film coating was treated with DCD,NBPT,NBPT,and DCD,and the black film coating was treated with DMPP,DMPP,RCN,and DCD.3.There is no significant difference in the effects of different colors of mulching films on the nitrogen content of spring maize grains in the four northwestern provinces under the film mulching cultivation mode.A 20%reduction in nitrogen combined with a new type of nitrogen fertilizer can increase the nitrogen content of spring maize grains,and the difference is significant（p<0.05）,and it will also greatly improve the nitrogen use efficiency of spring maize.4.There is no significant difference in the effect of different colors of mulching films on the soil nitrate nitrogen content in the four northwestern provinces under the film mulching cultivation mode.Nitrogen reduction combined with a new type of nitrogen fertilizer can significantly reduce the soil nitrate nitrogen content of 0-100cm soil layer.In2018,in Gansu,Ningxia,Shanxi and Qinghai provinces,the highest grain yields were treated with 0-20cm soil nitrate nitrogen content at the harvest stage,which was reduced by38.3%,44.3%,27.7%and 13.13%,respectively,compared with N₂₅₀treatment.In 2019,the highest grain yields under white film mulching in the four northwestern provinces were treated.The nitrate nitrogen content of 0-20 cm soil during the harvest period was reduced by 33.9%,9.72%,85.1%,9.8%,respectively,compared with N₂₅₀treatment.Compared with N250 treatment,the soil nitrate nitrogen content in the 0-20cm soil during the harvest period was reduced by 39.65%,32.7%,20.1%,42.9%,respectively.5.To sum up,in the northwest dryland area,the use of different color mulching films and new nitrogen fertilizers can increase spring maize yield,dry weight of the above-ground plant,nitrogen content in the grain,and nitrogen absorption and utilization efficiency.Reduce soil nitrate nitrogen content during spring maize harvest.In this study,it is recommended to use white plastic film mulch in Gansu,Ningxia and Qinghai provinces,and black plastic film mulch in Shanxi province.Based on this,new nitrogen fertilizer treatments such as DCD,NBPT,DCD and RCN can be used to reduce nitrogen and increase efficiency of spring maize in dry farming areas in northwestern China.,High yield and green purpose.