Influence of garlic continuous cropping on rhizosphere soil microorganisms and enzyme activities | 大蒜连作对其根际土壤微生物和酶活性的影响

Китайский. 【目的】研究大蒜长期连作对其根际土壤微生物数量和酶活性的影响。【方法】采用大蒜连作0（CK）、5、10、15和20年的土壤再分别盆栽大蒜,以大蒜根际土壤为研究对象,分别测定根际土壤微生物区系和酶活性的变化以及两者间的相互关系。【结果】随连作年限的增加,根际真菌数量持续上升,连作20年的土壤约为对照的2.88倍。而其它微生物类群的数量及土壤酶活性只在短期内（5―10年）呈上升趋势。与对照相比,连作10年的大蒜根际土壤中的细菌、放线菌各增加了8.72%和25.81%,氨化细菌、硝化细菌和芳香族化合物降解菌分别为对照的5.63、11.60和3.35倍。连作10年的大蒜根系分泌物对过氧化氢酶、多酚氧化酶、脲酶、磷酸酶和蔗糖酶等土壤酶活性具有促进作用,比对照分别增加了26.67%、41.67%、203.13%、23.73%和43.65%,但长期连作（15―20年）后均呈现下降趋势。相关分析表明,氨化细菌与脲酶、多酚氧化酶均呈显著正相关;芳香族分解菌与脲酶、过氧化氢酶呈极显著正相关;细菌、微生物总量分别与磷酸酶呈显著、极显著正相关。【结论】大蒜连作5―10年,根际土壤微生物数量和土壤酶活性上升,未发生连作障碍;但连作15―20年,根际土壤微生物结构失调,土壤酶活性下降,连作障碍明显。

Английский. 【Objective】 The objective of the experiment is to study the effect of garlic continuous cropping on rhizosphere soil microbial and enzyme activities. 【Method】 With the soils cropped garlic for 0(control), 5, 10, 15 and 20 years as test materials, a pot experiment was conducted to investigate the influence of garlic continuous cropping on rhizosphere soil microbial and enzyme activities. 【Result】 With the increasing of continuous cropping years, fungi number in rhizosphere soil increased gradually, the number of 20 years continuous cropping was 2.88 times higher, but the number of other microorganisms and the enzyme activities in the garlic rhizosphere soil were increased at the short-term (5-10 years) continuous cropping. The quantities of bacteria and actinomycetes were increased by 8.72% and 25.81%, respectively, and in the meantime, the ammonifier, nitrifying bacteria, and aromatic compounds-degrading bacteria increased by 5.63, 11.60 and 3.35 times. The root exudates of successively cropped garlic for 10 years increased the activities of catalase, polyhenoloxidase, urease, phosphatase and sucrase in rhizosphere soil by 26.67%, 41.67%, 203.13%, 23.73% and 43.65%, respectively, but long-term (15-20 years) continuous cropping showed a downward trend. Correlation coefficients between ammonifying bacteria and urease, polyphenol oxidase, bacteria and phosphatase, total microbe quantity were significant at 0.05 levels, and correlation coefficients between aromatic decomposing bacteria and urease, catalase, phosphatase and total microbe quantity were significant at 0.01 levels. 【Conclusion】 The balance of rhizosphere soil microbial flora was destroyed and the enzyme activities of rhizosphere soil decreased in a long period of time (from 15 to 20 years), the obstacles of continuous cropping were obvious.