The Distribution Of Nitrogen,Phosphorus In Soil And Greenhouse Pepper,The Emission Flux Of Greenhouse Gases And The Economic Benefits Under Different Fertilization Model

Agricultural non-point source pollution has been the main factors of the present environmental pollution.In order to explore the environmental risks in the process of planting greenhouse vegetables,greenhouse pepper has been the research object in this experiment.The environment and economic benefits and the distribution of nitrogen?N?,phosphorus?P?in soil and pepper of several treatments?Treatment 1:Conventional fertilization;Treatment 2:Optimization of reducing herbicide;Treatment 3:Optimization of reducing pesticide;Treatment 4:Integration of water and fertilizer?were compared in order to filtrate a better fertilization model.The best fertilization model was filtrated in order to provide a reference for pepper cultivation.1.Indicators of N and P decreased layer by layer in different imbed depth,with the times of fertilization the accumulation of NH₄⁺-N and NO₂^--N in different imbed depth increased not obviously and the accumulation of NO₃^--N,PO₄^--P,TN and TP in different imbed depth increased obviously,the downward leaching of NO₃^--N may bring the loss of nitrogen.2.The TN,TP in pepper was significantly higher than the other three treatments in last harvest time?P<0.05?.In the growth of pepper,the growing rate of accumulation of N,P in pepper in treatment 4 was higher than the other three treatments,which promoted the absorption and utilization of nitrogen and phosphorus.The nitrogen in pepper in four treatments accounted for 47.56%,46.43%,44.85%,62.00%of the whole plant and the phosphorus in pepper in four treatments accounted for 47.56%,46.43%,44.85%,62.00%of the whole plant 65.79%,67.41%,68.62%,73.29%,which indicated a high distribution of nitrogen and phosphorus under treatment 4.3.As time went by,the accumulation of N,P in pepper of each treatments increased rapidly in the late.At the last harvest time,the accumulation of N,P in pepper were121.16%¹73.36%and 27.13%⁷5.31%higher than the first sampling.The accumulation of N in pepper of treatment 4 was 123.79%,57.99%,30.55%higher than the other treatments respectively,and he accumulation of P in pepper of treatment 4 was 150.14%,72.85%,26.88%higher than the other treatments respectively.There was no difference of the index of N and P among four treatments?P<0.05?.The absorption of N and P was higher under treatment 4.4.The contents of VC in pepper increased as the increase of maturity,the amplification of which reached the maximum in turning stage to red stage.The contents of VC in pepper reached the maximum at last harvest time in four treatments,which were significantly higher than the other three harvest times?P<0.05?.The contents of VC in pepper in four treatments were among 36.67⁴1.67mg·100g^-1,42.33⁴5.57mg·100g^-1 with no difference in the earlier harvest time?P<0.05?,but in the later and last harvest time,the contents of VC in pepper of treatment 4 was 61.2mg·100g^-1,69.23 mg·100g^-1 which was significantly higher than the other three treatments?P<0.05?.Treatment 4 could promote the contents of VC in pepper effectively.5.The emission flux of CO₂ and N₂O of treatment 1 were significantly higher than the other three treatments at the first sample?P<0.05?.The emission flux of CO₂ of treatment 1 were significantly higher than the other three treatments and the emission flux of N₂O of treatment 2 were significantly higher than the other three treatments?P<0.05?,which suggest conventional fertilization might bring more greenhouse gas emission.6.The PFP_N?Partial Factor Productivity of applied N?of treatment 4 was 135.33%,85.33%,52.84%significantly higher than the other three treatments respectively?P<0.05?,which suggest the fertilizer using efficiency could reach the maximum in treatment 4.7.The yield of treatment 4 was 79.37%,41.25%,16.49%significantly higher than the other three treatments respectively?P<0.05?,and the input-output ratio of treatment 4 was 3.23produced the best economic benefit and market prospect,which was 28.17%,31.3%,16.61%significantly higher than the other three treatments respectively.8.In combination with the increment of NO₃^--N and PO₄^--P in soil surface layer from first sample to last sample and the yield,the best fertilization model was selected as treatment 4,which brang the lower environmental risks in the condition of yield increase dependable crop and high quality.