根围促生细菌配施生物质炭对辣椒生长和土壤理化性质的影响

Effects of PGPR Combined with Biomass Carbon on Capsicum annuum Growth and Soil Physical and Chemical Properties

为探究植物根围促生细菌(Plant growth-promoting rhizobacteria,PGPR)配施生物质炭对辣椒生长和土壤微环境的影响,盆栽条件下设置对辣椒接种PGPR以及不接种对照(NM)并分别配施生物质炭0、1%、3%、9%共8个处理。结果表明,PGPR处理对辣椒生长具有显著的促生效应,接种PGPR处理显著改善辣椒的根尖数、根分叉数、根系总投影面积和根系总体积,同时增加土壤中全氮含量,降低土壤速效磷、速效钾和有机质含量;3%生物质炭添加量下,接种PGPR处理的辣椒根系土壤中脱氢酶、酸性磷酸酶、过氧化氢酶、多酚氧化酶活性分别比对照增加了16.2%、4.5%、28.2%、28.3%,土壤微生物生物量碳和生物量氮含量分别是相应不接种对照的1.6、1.2倍;接种PGPR并施加生物质炭,可显著增加土壤细菌和放线菌数量,降低真菌数量;方差分析结果表明,不同生物质炭添加量与接种PGPR处理的交互作用对辣椒地上干质量、真菌数量影响极显著,对微生物生物量碳影响显著,对其余指标无显著影响。综上,PGPR配合生物质炭能够通过提高土壤相关酶活性和土壤养分含量,改善植物根系和微生物环境,从而促进植物生长,其中以PGPR配施3%生物质炭处理效果最优。

The effects of plant growth-promoting bacteria(PGPR)and biomass carbon on improving soil conditions and plant productivity have attracted much attention.The purpose of this experiment was to explore the effects of PGPR combined with biomass carbon on pepper(Capsicum annuum)growth and soil microenvironment.Pepper was inoculated with PGPR and non inoculated as a control(NM)under pot conditions,which were combined with biomass carbon of 0,1%,3%and 9%respectively.The results showed that PGPR treatment had a significant growth promoting effect on the growth of pepper,and inoculation treatment significantly improved the number of root tips,root bifurcation,total projected area and total root volume of pepper;at the same time,the content of total nitrogen in soil was increased,while the contents of soil available phosphorus,available potassium and organic matter were decreased.Under the treatment of 3%biomass carbon,the activities of dehydrogenase,acid phosphatase,catalase and polyphenol oxidase in pepper root soil inoculated with PGPR increased by 16.2%,4.5%,28.2%and 28.3%respectively compared with the control treatment;the contents of soil microbial biomass carbon and biomass nitrogen were 1.6 and 1.2 times those of the non inoculated control,respectively.Inoculation of PGPR and application of biomass carbon at the same time could significantly increase the number of soil bacteria and actinomycetes and reduce the number of fungi.Binary analysis of variance showed that the interaction of different biomass carbon addition and different inoculation treatments had a very significant impact on the aboveground dry mass of pepper and fungal content,had a significant impact on microbial biomass carbon,and had no significant impact on other indicators.The results above show that PGPR combined with biomass carbon could promote plant growth by increasing soil related enzyme activity and soil nutrient content,improving plant root and microbial environment,and the treatment effect of PGPR combined with 3%biomass carbon is the best.