The Effect Of Slow And Controlled Release Urea On The Yield, Quality And Environmental Effects Of Fresh Corn And Seed Corn

?Objective?Tt is an urgent need for agricultural production to achieve the coordination of crop yield,quality and environmental protection,reduce agricultural gas emissions and improve the utilization rate of nitrogen fertilizer.This paper studied the application effect of different slow and controlled release urea on fresh and seed corn.?Methods?The experiment was conducted in the field in fangshan district,Beijing from April to October,2018.The study was divided into three experiments :(1)the effect of slow controlled release urea on fresh corn;(2)effect of slow and controlled release urea on seed corn;(3)simulation experiment of new synergistic urea nutrient release with different inhibitor ratios.Experiments 1 and 2 were field experiments.The slow and controlled release urea was used as double-effect inhibitor urea(D),resin-coated urea(C)and biochar inhibitor urea(B).In experiment 1,conventional treatments U,D:U= 2:1,C:U=1:2,C:D:U= 1:1:1,blank control CK were used for 5 treatments.In experiment 2,there were 5 treatments including conventional treatment U,D:U= 1:2,C:U= 2:1,B:U= 1:2,and blank control CK.Experiment 3 was carried out in the laboratory.Fertilizer was made before the experiment,and the proportion of double-effect inhibitor was 0.5%,1%,1.5% and 2% of nitrogen respectively.Conventional treatment U,DN0.5,DN1,DN1.5 and DN2 were used in the experiment,and blank control CK was used.?Results?One-time reduction of 25% slow controlled release urea could stabilize the yield of fresh food and corn for seed,and the agricultural efficiency and partial productivity of nitrogen fertilizer with dual-effect inhibitor were both higher.In terms of the three quality indexes of Vc,soluble sugar and soluble protein content in fresh corn,compared with U,the grain quality of DU increased by 30.4%,27.8% and 10.9% respectively,while that of CU increased by 19.6%,61.2% and 23.4% respectively.The seed quality of CDU increased by 18.2%,33.2% and 29.0%,respectively.Compared with U,the soil ammonia emissions of DU,CU,CDU and BU were reduced by 45%-78%,43%-81%,80% and 39%,respectively.Fresh corn test after harvest U deal with 80-100 cm,the highest soil no3--n concentrations of 51.6 mg/kg,with a higher risk of nitrogen leaching,and the slow controlled release urea is beneficial to reduce the risk of nitrogen leaching,and seed corn harvest after U deal with soil no3--n content is higher,shows that the processing efficiency is low,no3--n any more.The addition of dual-effect inhibitors delayed the release of urea nutrients,but when the proportion of the addition was >=1%,there was no significant difference in the results of the treatment of synergistic urea.?Conclusion?Slow/controlled release urea can improve the yield and quality of maize.The application of slow controlled release urea can significantly reduce soil ammonia volatilization,improve fertilizer utilization rate,reduce the risk of nitrate nitrogen leaching,and reduce the gaseous loss and leaching loss of nitrogen and its pollution to the atmosphere and water environment.One-time fertilization and reduced fertilization further reduce the cost of fertilization and labor costs;The fertilizer with inhibitor coating has good effect,low cost,and greater synergistic potential when used together with biochar;Due to the high proportion of dual-effect inhibitors added is not obvious,so the amount of added nitrogen is recommended for 1% coating.