Effects Of Application New Nitrogen Fertilizers On Water And Nitrogen Utilization And Yield Of Spring Maize Under Plastic Film Mulching

The mulching film is the main cultivation mode for improving crop yield and water and nitrogen use efficiency in the dry farming area of Weibei,but the mulching cultivation increases the difficulty of late fertilizer application.One-time fertilization reduces fertilizer utilization and increases the risk of resource waste,soil nitrogen loss and environmental pollution.The new nitrogen fertilizer has the characteristics of long-lasting fertilizer effect,which can effectively reduce the loss of nitrogen and increase the utilization rate of nitrogen fertilizer.Therefore,the application of new nitrogen fertilizer under the condition of film mulching in the dryland of Weibei is expected to be an effective way to achieve weight loss,increase efficiency and increase income in the region.In this study,spring maize was used as a research object in the field experiment in Ecological test station of Changwu County,Shaanxi Province.There are five kinds of new nitrogen fertilizers,including urease inhibitor,nitrification inhibitor and coated slow-release nitrogen fertilizer.To explore the effects of 20%nitrogen reduction on the grain yield,growth traits,nitrogen accumulation,nitrogen use efficiency,soil water use efficiency and soil nitrate nitrogen accumulation in spring maize under mulching cultivation.The aim is to screen out the new nitrogen fertilizer varieties and dosages suitable for the application of spring maize in the region,and provide theoretical guidance and technical support for reducing the fertilizer,increasing yield and efficiency of spring maize in the region.The main results are as follows:1.Under the mulching cultivation,20%nitrogen reduction combined with stable nitrogen fertilizer NBPT had the best grain yield and yield components,and the yield was as high as 13223.3 kg·hm^-2,and the yield increased by 30.5%.Nitrogen reduction of 20%with new nitrogen fertilizer can not only reduce fertilizer input but also increase spring corn yield,thereby improving economic benefits.The economic benefits of NBPT,DMPP and DCD treatment increase by 131-1568?·hm^-2.2.Under the condition of plastic film mulching,the nitrogen reduction of 20%combined with new nitrogen fertilizer could increase the dry matter accumulation,leaf area index,plant height and SPAD value in different growth stages,and NBPT treatment was the best.3.Application of new nitrogen fertilizer under mulching cultivation can significantly increase nitrogen accumulation during silking and maturity,increase nitrogen translocation amount and translocation proportion after silking,and contribute to the grain.Compared with N₂₅₀ and N₂₀₀,the translocation amount of 20%nitrogen reduction combined with new nitrogen fertilizer treatment increased by 0.7%-34.6%and 13.4%-51.5%,respectively,and the nitrogen partial productivity was the highest with NBPT treatment(66.12 kg·kg^-1),compared with the treatment of equal nitrogen application N₂₀₀,the increase was 8.4%,and the nitrogen utilization rate was the highest?67.07%?with NBPT treatment.4.The application of new nitrogen fertilizer under mulching cultivation did not significantly increase the water consumption during the growth period,but had a significant impact on the water consumption at different stages.Under the condition of plastic film mulching,the average WUE of spring maize was 28.5 kg·hm^-2·mm^-1,the nitrogen reduction of 20%combined with new nitrogen fertilizer treatment significantly improved soil water use efficiency,and the WUE increased by 15.7%-36.0%.5.The application of new nitrogen fertilizer under mulching cultivation significantly reduced the accumulation of nitrate nitrogen in the 0-100 cm,100-200 cm and 0-200 cm soils at maturity.In the 0-100 cm,0-200 cm soil layer,In the 0-100 cm,0-200 cm soil layer,20%of nitrogen reduction combined with DMPP and NBPT in the treatment of new nitrogen fertilizers had the lowest accumulation of nitrate nitrogen in the mature stage,which was significantly different from other treatments?P<0.05?.The application of new nitrogen fertilizer?except SCN?under mulching condition can significantly reduce the loss of nitrogen,which is reduced by 42.6%-52.1%compared with the same application of nitrogen treatment,of which DCD and NBPT treatment are lower,respectively 38.2 kg·hm^-2,41.3kg·hm^-2.In summary,under the mulching cultivation,the nitrogen reduction of 20%combined with the new nitrogen fertilizer once applied can stabilize the yield of spring maize,increase the utilization of water and nitrogen,reduce the soil nitrate nitrogen residue and nitrogen loss during harvest,and increase Revenue,saving labor costs.Under the conditions of this study,it is suggested that NBPT,DMPP and RCN in the new nitrogen fertilizer can be used as a way to achieve high yield and high efficiency,and increase fertilizer and increase income.