植烟黄壤微生物生态特征与氮素的矿化和硝化作用

Microbial Ecological Characteristics and Nitrogen Mineralization and Nitrification in Tobacco Growing Yellow Soil

摘要: 在贵州省植烟黄壤上，进行了不同供氮水平的田间试验，对烤烟的根际微生物种群和数量动态变化，土壤微生物的活动对烟地土壤氮素的转化进行了研究。结果表明，烤烟根际细菌数量在旺长期剧增，成熟期剧减，而根际放线菌和真菌数量在成熟期剧增；氮素的矿化强度在4～8 月份逐渐升高，8 月最高（28.25 μg/g?d），9 月份以后下降，硝化强度随土壤水分及硝化基质的含量而变化，最高值出现在6 月份（29.95 μg/g?d）。微生物生物量碳、氮及Cmic:Nmic 值在植烟黄壤施肥或不施肥的变化基本一致。

Abstract: Field experiments were conducted to investigate the changes of microbial population and soil nitrogen in yellow soil. Results showed that the quantities of tobacco rhizosphere bacteria increased sharply in vigorous growth stage and decreased sharply in mature stage, while the quantities of rhizosphere fungi and actinomycetes increased sharply in mature stage；the rates of mineralization increased from April to August and reached the maximum in August with 28.25 μg/g?d, but declined after August. Nitrification changed with soil moisture and basic medium, and the peak rate appeared in July with 29.95 μg/g?d. No difference of changes of microbial biomass C, N, and the ratio of Cmic to Nmic appeared in nitrogen application treatment and the control.