Research On Formula Fertilizer Of Reducing Nitrogen Application And Increasing Efficiency Of Summer Maize In Sandy Chao Soil

Sandy Chao soil area in the north of Henan Province located in the Huang-Huai-Hai Plain is one of the main areas of summer maize planting in China.In order to achieve high yield,a large amount of fertilizers was applied,which led to soil deterioration and water pollution.Excessive fertilization affected the quality of summer maize.In view of the above problems,this paper researched the new fertilizer technology to reduce nitrogen application and increase efficiency of summer maize in sandy Chao soil in the north of Henan Province.Screening of fertilizers through the field experiment of fertilizer efficiency and the new fertilizer technology of reducing nitrogen and increasing efficiency was studied and developed.The transformation and migration process in soil fertilizer microsite of formula fertilizer with different nitrogen application levels were studied through the indoor soil culture experiment,and the mechanism of efficiency enhancement of formula fertilizer was revealed to provide the basis for optimizing fertilizer formulation process.The research results are as follows.（1）The field experiment of fertilizer efficiency showed that the long-term coated slow-release urea could reduce nitrogen application and increase efficiency.When the application amout of N,P₂O₅ and K₂O were respectively 168,90 and 120 kg/ha,the yield of summer maize was 9564.75 kg/ha,the economic coefficient was 36.37%,and the partial productivity of nitrogen fertilizer was 56.93 kg/kg.The average contents of soil available nitrogen,available phosphorus and available potassium were 175.61,23.45 and 161.52 mg/kg,respectively.The accumulation of nitrogen,phosphorus and potassium in summer maize were 163.56,72.30 and 100.83 kg/ha,respectively.（2）The coated slow-release urea was coated with urea,monoammonium phosphate and potassium sulfate as raw materials to prepare new inorganic material coated complex fertilizer products with different nitrogen release rates.When the application amout of N,P₂O₅ and K₂O were respectively 168,75 and 75 kg/ha,the most suitable technological parameters of the new fertilizer were as follows,the binder concentration was 20 wt%,the drying temperature was 90°C,and the filler dosage was6.55 kg.At this time,the particle strength and rate of coated were 34.6 N and 97%,respectively.When the application amout of N,P₂O₅ and K₂O were respectively 210,75 and 75 kg/ha,the most suitable technological parameters of the new fertilizer were as follows,the binder concentration was 20 wt%,the drying temperature was 90°C,and the filler dosage was 10.42 kg.At this time,the particle strength and rate of coated were 33.7 N and 97%,respectively.The two new fertilizers had good quick release and slow release properties.The available nitrogen was completely released within 3 d.At14 d,the urea release rates of the two new fertilizers were 69.44%and 70.01%,respectively.The coating process was purely physical coating and products had great thermal stability.The coating layers were tightly combined with the core particles and there was no gap between them.The coating layer has a uniform thickness and a smooth surface,and the particle size was 3-4 mm.（3）Reducing the amount of nitrogen fertilizer could improve the effective use of nutrients and promote the migration of nutrients in soil fertilizer microsite.The p H of low nitrogen treatment soil was 8.34.The ratio of available nitrogen to total nitrogen application and migration distance were 69.00%and 62 mm,respectively,the ratio of available phosphorus to total phosphorus application and migration distance were48.43%and 26 mm,respectively,and the ratio of available potassium to total potassium application and migration distance were 78.55%and 44 mm,respectively.