非洲菊连作对土壤理化性状与生物性状的影响

摘要

[Objective] The objective of the experiment is to study the effect of Gerberajamesonii continuous cropping on soil physical-chemical and biological characters. [Method] Using conventional methods, an experiment was conducted to investigate the changes of Gerbera jamesonii continuous cropping on soil physical-chemical properties , soil microbial and enzyme activities. [Result] Results showed that compared with control, soil salt content was increased by 4.00%, 72.80%, 24.00% and 88.00%, respectively, under 1-7 years continuous cropping, while soil pH and bulk density began to decline. With the increasing of continuous cropping years, soil organic matter content and available N content was remarkably raised, but the soil available P and available K content was decreased. The activities of urase and sucrase increased in 1-3 years continuous cropping, while those enzyme activities decreased in 5-7 years, the soil catalase and phosphatase activity decreased with the continuous cropping year increasing, while the protease activity increased by 9.09%, 50.00%, 63.64%, 93.18%, respectively, under 1-7 years continuous cropping, compared with control. With the time of continuous cropping increasing, soil fungi number increased gradually, the number of 7 years continuous cropping increased by 192.04%, the number of bacteria decreased, but the number of other microorganisms increased in 1-3 years continuous cropping and decreased in 5-7 years. [Conclusion] Under continuous cropping, soil pH and bulk density decreased, soil salt content increased, while soil N, P, K proportion was imbalanced. The quantities of bacteria and actinomycetes and the enzyme activities of soil decreased under 5-7 years continuous cropping, but soil fungi number increased, the obstacles of continuous cropping were obvious.%[目的]研究非洲菊连作土壤物理化学性状、土壤微生物区系和土壤酶活性动态变化.[方法]以未种植过非洲菊的土壤作对照,测定连作非洲菊1、3、5和7年土壤的理化性质、酶和微生物活性的变化.[结果]随着连作年限的增加,土壤pH和容重下降,连作1、3、5和7年的土壤总含盐量分别比对照增加4.00％、72.80％、24.00％和88.00％.土壤有机质和速效氮含量随着连作年限的增加而上升,土壤速效磷和速效钾含量呈下降趋势. 土壤脲酶和蔗糖酶活性呈先升后降的趋势,连作1年和3年土壤酶活性降低,连作5年以后又升高,土壤过氧化氢酶和中性磷酸酶活性呈下降趋势,连作1、3、5、7年土壤蛋白酶活性分别比对照增加9.09％、50.00％、63.64％、93.18％.土壤真菌数量随着连作时间延长而增加,连作7年的土壤真菌数与对照相比增加了192.04％,细菌数量呈下降趋势,其它微生物类群的数量呈先升后降的趋势.[结论]非洲菊连作后土壤pH降低,土壤总合盐量逐渐增加,有次生盐渍化的趋势,土壤中氮、磷、钾比例失调.连作5-7年,土壤真菌数量上升,细菌和放线菌数量和土壤酶活性下降,连作障碍明显.