菠萝不同连作年限对土壤理化性状和微生物群落丰度的影响

Effects of Different Years of Continuous-cropping of Pineapple on Soil Physiochemical Properties and Microbial Community Abundance

以未种植菠萝的空地土壤为对照,研究分析了连续种植菠萝5 a和15 a的土壤理化指标、酶活性及微生物群落丰度的变化及其规律。结果表明,与对照相比,连续种植菠萝5 a和15 a的土壤pH分别降低了0.39和0.57个单位,酸化明显;有机质、全氮、铵态氮、有效磷含量显著增加;土壤速效钾及交换性Mg、Ca含量降低;有效B、Na含量升高;土壤微生物生物量碳较对照提高了1.74倍和1.71倍;土壤微生物生物量氮较对照提高了56.01%和72.96%,但差异不显著。连续种植菠萝5 a的土壤酸性磷酸酶活性升高1.60倍,差异显著;土壤细菌、真菌丰度提高了1.56倍和26.54倍,放线菌丰度降低了35.39%。连续种植菠萝15 a的土壤过氧化氢酶活性较对照降低了52.63%;土壤细菌、放线菌丰度分别降低37.18%和13.78%,真菌丰度提高了40.74倍。

In this study,uncultivated soil was taken as the control(TR0),and then the differences in soil physiochemical characteristics,enzyme activities and microbial community abundances were compared between TR0 and continuous-cropping pineapple for 5 and 15 years(TR5 and TR15).The results indicated that,compared with TR0,TR5 and TR15 decreased soil pH by 0.39 and 0.57 unites,respectively,showing obvious acidification.TR5 and TR15 significantly increased the contents of organic matter,total nitrogen,ammonium nitrogen and available phosphorus,increased the contents of available boron and sodium,while decreased the contents of available potassium and exchangeable calcium and magnesium.TR5 and TR15 increased the content of microbial biomass corbon by 1.74 and 1.71 times,respectively;increased the content of microbial biomass nitrogen by 56.01%and 72.96%,respectively;but neither significant difference was observed.TR5 significantly increased the activity of soil acid phosphatase by 1.60 times,increased the abundances of soil bacteria and fungi by 1.56 and 26.54 times,respectively;while decreased that of actinomyces by 35.39%.TR15 decreased the activity of catalase by 52.63%and the abundances of bacteria and actinomyces by 37.18%and 13.78%,respectively;while increased that of fungi by 40.74 times.