不同肥料种类对连作烟草根际土壤微生物功能多样性的影响

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，施用不同肥料, 调查施肥后的土壤对连作烟草作物的生长、土壤微生物功能多样性的影响及其对土壤化感自毒的调节作用。结果表明，烟草根际土壤化感自毒潜力以施用常规复合肥最大，施用农家肥最小。基于Biolog平板法的微生物功能多样性研究表明，施用常规复合肥利于氨基酸类、胺类物质为碳源的微生物生长；施用有机肥利于羧酸类物质为碳源的微生物生长；而施用农家肥则利于糖类、脂肪酸、酚酸类物质为碳源的微生物生长。土壤微生物利用单一碳源的主成分分析结果表明，与碳源利用相关的主成分1、主成分2可分别解释变量方差的74.37%和25.63%。在主成分分离中有主要贡献的是糖类、脂肪酸类、酚酸类碳源。相关性分析结果显示，烟草土壤的化感自毒潜力与以糖类和酚酸类物质为碳源的微生物AWCD值呈显著正相关，而与以脂肪酸类物质为碳源的微生物AWCD值呈显著负相关。此外，农家肥施用最利于微生物生长，有机肥次之，常规复合肥最差。

Effects of Different Fertilizers on Functional Diversities of Microbial Flora in Rhizospheric Soil of Monoculture Tobacco

Tobacco is an intolerant continuous cropping crop. Continuous cropping obstacles restrict sustainable development of tobacco production, which are the most important issues in agricultural production that need to be solved urgently. In this study, tobacco was consecutively planted for twelve years in the same soil and the rhizospheric soil was sampled to investigate the changes in the functional diversities of microbial flora after different fertilizer treatments. The results showed that the autotoxic allelopathic potential was maximum for the monoculture soil treated with traditional compound fertilizer, and minimum for the soil treated with farmyard manure. BIOLOG analysis found that the traditional compound fertilizer was conducive to the growth of the microbial flora feeding on amino acids and amine as carbon sources. The commercial organic fertilizer was favorable to the growth of the microbial flora using carboxylic acids as a carbon source, and farmyard manure was good for the growth of the microbial flora feeding on carbohydrate, fatty acids and phenolic acids as carbon sources. Principal component analysis indicated that the first two components related to carbon sources accounted for 74.37% and 25.63% of the data variation, respectively. The carbon source of carbohydrate, fatty acids and phenolic acids made a mainly contribution to the separation of two principal components. Correlation analysis indicated that the autotoxic allelopathic potential of tobacco rhizospheric soil was positively correlated with the AWCD value of microbial flora feeding on carbohydrate and phenolic acids as carbon sources, and negatively correlated with that of the microbial flora using the carbon source of fatty acids. In addition, for the growth of microbial flora in monoculture soil, farmyard manure was the best, commercial organic fertilizer showed the medium effect, and traditional compound fertilizer was the worst.