Effects Of Cover Crop Usage On Yield And Soil Ecological Environment Of Continuous Cropping Pepper

Pepper which is one of the main facility crop have been widely planted around China.In the long-term continuous cultivation,however,the soil farming environment became worse,the plant diseases and insect pests increased,and the yield of pepper decreased.Consequently,it is urgent to find a green ecology way to solve the above problems.Previous studies have proved that filling in the blanks is one of the effective measures to solve the above problems.In this study,through two years of field experiments and pot experiments,wheat,vicia faba and rocket were used as cover crops to study the effects of single cover crop,two and three cover crops mixed covering on pepper growth,yield,Phytophthora Blight and soil microbial community structure.The purpose of this study was to clarify the benefits of cover crop and the effects of cover crops on soil microorganisms,which can provide scientific basis and technical support for solving the continuous cropping obstacles of pepper in Greenhouse.The main results are as follows:(1)As the results of two years'field experiments,the yield of pepper was significantly increased under three treatments:wheat mixed with vicia faba(MD),wheat mixed with rocket(MC),wheat mixed with vicia faba and rocket(MDC)covering,and the effect in 2020 was better than that in 2019.(2)As the research of the effects of cover crops on soil chemical properties of pepper continuous cropping system,all treatments significantly reduced soil available phosphorus content and soil EC value,and increased soil p H;the content of soil NO₃-N was significantly increased in wheat mixed with vicia faba(MD)and wheat mixed with vicia faba and rocket(MDC)covering;wheat(M)covering significantly increased soil available potassium content;soil organic matter content was significantly increased in three treatments of rocket(C),wheat mixed with vicia faba(MD)and wheat mixed with rocket(MC)covering.(3)As the results of q PCR,all treatments significantly increased the abundance of soil bacteria in 2019.In 2020,all treatments significantly increased the abundance of soil bacteria,fungi,bacillus and pseudomonas.(4)As the results of Miseq sequencing,the Shannon index of soil bacteria was significantly increased in the three mixed treatments of rocket(C),wheat mixed with rocket(MC),vicia faba mixed with rocket(DC)covering;wheat(M),vicia faba(D),wheat mixed with vicia faba(MD)and wheat mixed with vicia faba and rocket(MDC)covering treatments significantly reduced the inverse Simpson index of soil bacteria.All the treatments significantly increased the contents of nitrospirota phylum,vicinamibacteria class,norank?c??KD4-96 order,micromonosporales family and Arthrobacter genus.(5)Principal component analysis showed that the contribution rate of PCo A1 and PCo A2 was13.02%and 16.85%respectively to the bacterial community structure.There were differences in bacterial community structure between 3 treatments of wheat(M),wheat mixed with rocket(MC)and wheat mixed with viaia faba and rocket(MDC)covering and the control.(6)The results of LEf Se analysis showed that Saccharimonadales,Myxocaceae,Entomoplasmatales,Erysipelotrichaceae,Streptomycetaceae,Streptomycetaceae and Saccharimonadaceae are the main microflora that cause the differences among microflora.To sum up,the results showed that the three filling patterns of wheat and vicia faba(MD),wheat and rocket(MC),wheat,vicia faba and rocket(MDC)covering were the best cover crop patterns of continuous cropping pepper.