Regulation Effects Of Fertilizer Nitrogen Reduction With Nitrification Inhibitor And Bacteria Agent On Nitrogen Loss From Greenhouse Cucumber System

At present,low utilization and serious losses of nitrogen in greenhouse vegetable production lead to a series of problems such as waste of resources and negative environmental effects.With fruit vegetables cucumber(Tianjin green 20-10)as the research object,combining indoor aerobic incubation and field in situ experiment methods,to explore the effects of different nitrification inhibitor and microbial agent application on transformation of soil nitrogen morphology and nitrification inhibition in the greenhouse.The experiment was aim to select the most suitable inhibitor type,dosage and the amount of germ administering agent,to explore the comprehensive effects of fertilizer nitrogen reduction with nitrification inhibitor and microbial agent on soil-vegetables-atmosphere system,and to select the effective regulation program of controlling nitrogen loss and improving the utilization rate of nitrogen in greenhouse vegetable fields,which could provide scientific theoretical and technical supports for the goal of "High-efficiency,Environmentally-friendly,and High quality" in greenhouse cucumbers production.The main results are as follows.(1)The inhibition effects of three different nitrification inhibitors on soil nitrogen conversion were identified,and suitable nitrification inhibitors and their dosages were selected.Under the condition of 25? and 60%field water holding capacity,the effect of nitrification inhibitors and microbial agent application on the basis of nitrogen reduction on transformation of soil nitrogen morphology was obviously different.The nitrification inhibition effect of the 3 nitrification inhibitors was shown in the ordor of DMPP>DCD>MHPP.Compared with the conventional nitrogen application treatment,the fertilizer mitrogen reduction with nitrification inhibitor(2%DMPP of pure nitrogen)treatment can increase NH4+-N in soil by 40.85%?73.61%,and reduce the NO3--N content in soil by 24.61%?33.8%,respectively,which showed better nitrification inhibition effect;the effect of fertilizer nitrogen reduction with inhibited nitrification(2%DMPP of pure nitrogen)and microbial agent(75L/hm2)was better,which can reduce the NO3--N content in soil by 38.88%?43.91%.(2)Clarified the effects of fertilizer nitrogen reduction with nitrification inhibitor,microbial agent on yield and quality of greenhouse cucumber.Fertilizer nitrogen reduction with nitrification inhibitor and microbial agent can promote cucumber growth and development,increase the yield,improve fruit quality significantly,and promote crop nitrogen absorption,significantly improve the utilization rate of nitrogen.Compared with the conventional nitrogen application treatment,fertilizer nitrogen reduction with nitrification inhibitor and microbial agent can ensure the steady yield of cucumbers,and increase the yield of cucumbers by up to 7.50%.The utilization rate of nitrogen was increased from 7.50%to 20.32%?25.30%,the nitrate content in cucumber fruit was reduced by 7.38%?18.28%,and the content of Vc,soluble sugar and soluble protein were also increased and the quality of the cucumber fruit was improved.(3)The effect of controlling soil nitrogen gaseous loss by fertilizer nitrogen reduction with nitrification inhibitor,microbial agent of greenhouse cucumber was proved.Fertilizer nitrogen reduction with nitrification inhibitor and microbial agent can significantly reduce N2O emissions and NH3 volatilization,and reduce the total gaseous loss.The total loss of gaseous(N2O and NH3 volatilization)loss maily caused by nitrogen application of greenhouse cucumbers was relatively small,which was only 3.31%?3.67%of applied nitrogen.Compared with the conventional nitrogen application treatment,fertilizer nitrogen reduction with nitrification inhibitor and microbial agent can reduce N2O emissions by 30.01%?41.40%,and NH3 volatilization by 28.85%-37.71%,respectively.(4)The effect of controlling the soil nitrate leaching by fertilizer nitrogen reduction with nitrification inhibitor,microbial agent of greenhouse cucumber was determined.Fertilizer nitrogen reduction combined application nitrification inhibitor or microbial agent can significantly reduce the accumulation amount of NO3--N in soil profile.Compared with the conventional nitrogen application treatment,nitrification inhibitor and microbial agent application on the basis of nitriogen reduction can reduce the accumulation of NO3--N in the 0-120 cm soil profile by 12.62%?74.58%.(5)The microbiological effect of regulating the rhizosphere soil by fertilizer nitrogen reduction with nitrification inhibitor,microbial agent of greenhouse cucumber was revealed.Fertilizer nitrogen reduction with nitrification inhibitor and microbial agent can improve the functional diversity of soil microbiome,improve the soil microbial environment,which is an environmentally friendly nitrogen regulation measure.Comprehensive evaluating,fertilizer nitrogen reduction with nitrification inhibitor DMPP and microbial agent(topdressing nitrogen 316 kg N/hm2,with 2%DMPP of pure nitrogen,75 L/hm2 liquid microbial agent of functional bacteria for Paenibacilus mucilaginosus)is an effective measure to resistance control loss of nitrogen and improve nitrogen utilization in greenhouse vegetable production,showing environmentally friendly,which could achieve "win-win" economic and environmental outcomes.Compared with the conventional nitrogen application treatment,fertilizer nitrogen reduction with nitrification inhibitor and microbial agent can increase the yield of cucumbers by up to 7.50%,the nitrate content in cucumber fruit was reduced by 18.28%,and the utilization rate of nitrogen was increased from 7.50%to 25.30%.And it can reduce N2O emissions by 41.40%,NH3 volatilization by 28.85%,and the accumulation of NO3--N in the 0-120 cm soil profile by 36.06%?52.00%.