植煙黃壤微生物生態(tài)特征與氮素的礦化和硝化作用
Microbial Ecological Characteristics and Nitrogen Mineralization and Nitrification in Tobacco Growing Yellow Soil
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摘要: 在貴州省植煙黃壤上,，進(jìn)行了不同供氮水平的田間試驗(yàn),，對烤煙的根際微生物種群和數(shù)量動態(tài)變化，土壤微生物的活動對煙地土壤氮素的轉(zhuǎn)化進(jìn)行了研究,。結(jié)果表明，烤煙根際細(xì)菌數(shù)量在旺長期劇增,，成熟期劇減,，而根際放線菌和真菌數(shù)量在成熟期劇增；氮素的礦化強(qiáng)度在4～8 月份逐漸升高,，8 月最高（28.25 μg/g?d）,，9 月份以后下降，硝化強(qiáng)度隨土壤水分及硝化基質(zhì)的含量而變化,，最高值出現(xiàn)在6 月份（29.95 μg/g?d）,。微生物生物量碳、氮及Cmic:Nmic 值在植煙黃壤施肥或不施肥的變化基本一致,。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.
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