长期大蒜连作复种秋白菜种植模式对土壤酶活性及微生物区系的影响

Effect on the Soil Microorganism and Enzyme Activities Under Long-term Continuous Cropping Garlic Multiple Cropping Fall Chinese Cabbage

研究长期大蒜连作复种秋白菜对土壤酶活性和根际土壤微生物数量的影响。采集15、25、35、45年大蒜复种秋白菜连作土壤,分别测定大蒜生育期根际土壤微生物区系和酶活性的变化并探讨二者相互作用的关系。结果表明:在整个生育期土壤酶及微生物区系的变化以25年作为分割点,土壤脲酶、多酚氧化酶、过氧化氢酶均表现为,连作25年以下,随生育期的变化呈"Z"字形,连作25年以上变化趋势为先升后降。随着种植年限增加根际土壤蔗糖酶活性下降分别为82.3%、63.6%、72.6%、53.7%;连作45年的土壤酸性磷酸酶活性下降幅度为10.9%。随着连作年限的增加,土壤中细菌和真菌的数量和比例变化表现为15年为较低值,随后表现为回升趋势,微生物三相比例趋于均一化。连作15年以上的土壤,微生物种群结构失调,表征土壤健康状况的土壤酶的活性开始下降,连作25年以上的土壤连作障碍极其显著。

In order to study the long-term continuous cropping garlic revaccination autumn cabbage effected on soil enzyme activity and the number of rhizosphere microorganisms.15 years,25years,35 years,45years garlic revaccination autumn cabbage continuous cropping soil were gathered,rhizosphere soil microorganisms and enzyme activity changes were separately measured in different garlic growth period and discussed the interaction relations.The results showed that the soil enzymes during whole growth period and the changes of microorganisms in 25 years as a division point.Soil urease,polyphenol oxidase,catalase,continuous cropping under 25 years,was characterized by ‘Z＇glyph with the change of growth period.The trend for more than 25 years was increasing at first then was falling.With increasing years of planting,rhizosphere soil invertase activity fell by 82.3%,63.6%,72.6%,53.7%;less than 45 years of continuous cropping,soil acid phosphatase activity declined of 10.9%.With the increasing time of continuous cropping,the number of bacteria and fungi in the soil and the change of proportion of 15 years were lower,then showed the upward trend.Microbial three-phase proportion was homogenization.More than 15 years of continuous cropping soil,microbial population structure was imbalance,characterization of soil enzyme activity represented soil health began to decline,and more than 25 years of continuous cropping soil continuous cropping obstacles were extremely significant.