为进一步明确大蒜连作障碍形成的原因,研究了连作0(对照)、10、20、30 a大蒜根际土壤养分含量、土壤微生物数量和土壤酶活性的动态变化。结果表明,随着连作年限的增加,大蒜鳞茎产量显著下降,与对照相比,连作10、20、30 a鳞茎产量分别下降22.74%、26.48%、27.16%;大蒜根际土壤p H值呈上升趋势,土壤有机质含量呈增加趋势,整体上土壤全氮、全磷、有效钾、碱解氮、有效锌含量呈下降趋势;土壤微生物数量呈先下降(0~20 a)后上升(30 a)趋势,且差异达极显著水平;土壤酶活性呈先降后升趋势,土壤脲酶和过氧化氢酶活性以连作20 a最低,碱性磷酸酶活性以10 a最低。相关性分析表明,整体上土壤微生物数量和土壤酶活性与土壤全氮、全磷、全钾、碱解氮、有效钾含量呈正相关,而与土壤p H值、有机质和缓效钾含量呈负相关;过氧化氢酶、碱性磷酸酶和脲酶活性与所测微生物数量(除真菌外)皆呈正相关,其中过氧化氢酶活性与放线菌数量相关性达显著水平,脲酶活性与固氮菌数量呈极显著正相关。综上,大蒜长期连作后,大蒜鳞茎产量降低,土壤有机质含量增加,土壤p H值上升,土壤养分失衡;连作20 a大蒜根际土壤微生物数量和土壤酶活性达到最低水平,而连作30 a土壤微生物数量和酶活性回升,但微生物结构并没有显著改变。 In order to further clarify the cause of continuous cropping obstacle in garlic, the dynamic changes of soil nutrient content, soil microbial quantity and soil enzyme activity in the rhizosphere soil of continuous cropping 0 (control), 10,20,30 a garlic were studied. The results showed that the bulb yield of garlic decreased significantly with the increase of continuous cropping. Compared with the control, the bulb yield of 10, 20 and 30 days decreased by 22.74%, 26.48% and 27.16%, respectively. The p H of rhizosphere soil increased Soil organic matter content tended to increase. Soil nitrogen, total phosphorus, available potassium, available nitrogen and available zinc showed a decreasing trend as a whole. Soil microbial biomass decreased first (0 ~ 20 a) and then increased (30 a) The trend of soil enzyme activity was the first and then increased. Soil urease and catalase activity were the lowest in 20 a continuous cropping and the lowest in 10 a soil alkaline phosphatase activity. Correlation analysis showed that soil microbial quantity and soil enzyme activity were positively correlated with soil total nitrogen, total phosphorus, total potassium, available nitrogen and available potassium, but negatively correlated with soil p H, organic matter and slow-acting potassium ; Catalase, alkaline phosphatase and urease activity and the number of tested microorganisms (except fungi) were positively correlated, of which catalase activity and actinomycetes number significant correlation, urease activity and the number of nitrogen-fixing bacteria There was a significant positive correlation. In conclusion, after long-term continuous cropping of garlic, garlic bulb yield decreased, soil organic matter content increased, soil p H value increased, soil nutrient imbalance; rhizosphere soil microbial biomass and soil enzyme activity reached the lowest level even for 20 a, The number of microbes and enzyme activity rose, but the microbial structure did not change significantly.