Gross nitrogen mineralization-, immobilization-, and nitrification rates as a function of soil C/N ratio and microbial activity
Gross nitrogen mineralization-, immobilization-, and nitrification rates as a function of soil C/N ratio and microbial activity
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DOI：
10.1016/s0038-0717(02)00248-1
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发表时间：
2003-01-01
影响因子：
9.7
通讯作者：
Månsson, KF
中科院分区：
文献类型：
--
作者：
Bengtsson, G;Bengtson, P;Månsson, KF
一个实验室实验的目的是挑战的想法，森林土壤的ON比可以控制总氮固定，矿化和硝化速率。土壤中的C/N比在15和27之间变化的落叶林网站收集。它们被风干并重新润湿以诱导微生物活性的爆发。通过同位素稀释和富集的方法计算了氮素转化率，其中（NH_4Cl）-N-15或（NaNO_3）-N-15在培养的7天内反复添加到土壤中。试验结果表明，不同土壤氮素固定和矿化速率的差异与呼吸速率和ATP含量的相关性大于与C/N的相关性。呼吸和ATP含量的峰值之后，高矿化率和固定化，延迟1-2天。NH 4+的总固定量依赖于总矿化量，比NO3-的总固定量大1 ~ 2个数量级。总硝化速率与ATP含量和C/N比呈显著负相关，且显著高于净硝化速率。两者合计，观察表明，从森林土壤中的硝酸盐淋溶可能在很大程度上取决于密度和活性的微生物群落。(C)2003爱思唯尔科技有限公司版权所有。
A laboratory experiment was designed to challenge the idea that the ON ratio of forest soils may control gross N immobilization, mineralization, and nitrification rates. Soils were collected from three deciduous forests sites varying in C/N ratio between 15 and 27. They were air-dried and rewetted to induce a burst of microbial activity. The N transformation rates were calculated from an isotope dilution and enrichment procedure, in which (NH4Cl)-N-15 or (NaNO3)-N-15 was repeatedly added to the soils during 7 days of incubation. The experiments suggested that differences in gross nitrogen immobilization and mineralization rates between the soils were more related to the respiration rate and ATP content than to the C/N ratio. Peaks of respiration and ATP content were followed by high rates of mineralization and immobilization, with 1-2 days of delay. The gross immobilization of NH4+ was dependent on the gross mineralization and one to two orders of magnitude larger than the gross NO3- immobilization. The gross nitrification rates were negatively related to the ATP content and the C/N ratio and greatly exceeding the net nitrification rates. Taken together, the observations suggest that leaching of nitrate from forest soils may be largely dependent on the density and activity of the microbial community. (C) 2003 Elsevier Science Ltd. All rights reserved.