Abstract:

Problems caused by continuous tobacco cropping were critical obstacles restricting the yield and quality of tobacco leaf. The trial was conducted in a filed, where tobacco was continuously planted for 12 years. By applying different fertilizers, we studied the effect of different fertilizers on the yield, quality and rhizospheric soil microbial biomass, enzyme activity of the rhizosphere. The results indicated that different fertilization treatments had different effects on leaf yield, soil microorganism and enzyme activity in continuous cropping, and farmyard manure application was favorable to improve the leaf yield. The result of soil microbial biomass analysis showed that microbial biomass C and N, and microbial respiration intensity ranked as farmyard manure>organic fertilizer>nitrogen fertilizer>compound fertilizer after different fertilizer treatments. Furthermore, the activity of neutral phosphatase, alkaline phosphatase, urease and sucrase in tobacco rhizospheric soil was the highest with application of organic fertilizer, and farmyard manure application had the highest acid phosphate activity. In addition, the activity of soil enzyme (polyphenol oxidase, peroxidase, catalase, dehydrogenase) involved in resistance ranked as farmyard manure>organic fertilizer>nitrogen fertilizer > compound fertilizer.

Key words: tobacco, continuous cropping impediment, soil microbial biomass, soil enzyme activity

摘要：

烟草连作障碍是制约烟草产量与品质的关键因素。以连作12年的烟草土壤为对象,通过施用不同肥料, 研究了不同肥料对连作烟草产量、根际土壤微生物量、土壤酶活性的影响。结果表明：不同施肥处理对连作烟草产量及土壤微生物及酶活性的影响存在一定差异,施用农家肥有利于提高连作烟草产量。土壤微生物量分析结果显示,不同施肥处理后烟草根际土壤微生物量碳、氮及微生物呼吸强度依次为：农家肥>有机肥>氮肥>复合肥。与土壤营养循环相关酶活性的分析结果表明,不同施肥处理后烟草根际土壤中性磷酸酶、碱性磷酸酶、脲酶、蔗糖酶活性以有机肥处理后活性最大,而酸性磷酸酶则以农家肥处理后活性最高。与土壤生物抗逆性相关的多酚氧化酶、过氧化物酶、过氧化氢酶、脱氢酶活性分析的结果显示,不同施肥处理后烟草根际土壤抗性相关酶活性大小依次为：农家肥>有机肥>氮肥>复合肥。

关键词: 烟草；连作障碍；土壤微生物量；土壤酶活性