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作 者 ：张国桢 李世清 邓震义 张清杉 黄占斌

期 刊 ：植物营养与肥料学报 2011年 17卷 5期 页码：1147-1155

关键词：石灰性土壤；外源氮源；硝化作用；Michaelis-menten动力学方程；

Keywords:limy soil, exogenous nitrogen sources, nitrification, Michaelis-menten kinetics,

摘 要 ：为了揭示外源氮源对石灰性土壤硝化作用的影响机理，以钙积半干润均腐土（Cal-Ustic Isohumasols）为材料，采用室内培养方法研究了不同添加量和不同氮源对土壤硝化作用的影响，并建立了对应的硝化模型。结果表明，NH4+-N消耗速率和NO3--N增加速率呈“S”曲线变化，NH4+-N消耗速率高于NO3--N增加速率。氮素添加量与NH4+-N消耗速率和NO3--N增加速率呈正相关，硝化菌外的因子对NH4+-N和NO3--N的吸收与NH4+-N添加量呈正相关；不同氮素添加量对硝化作用影响程度不同，当氮素添加量为N 75 mg /kg，干土时，硝化作用较彻底。SO42-可加快硝化作用速率，同时也可改变其他因子对NH4+-N和NO3--N的利用。

Abstract:In order to understand the mechanism of nitrification in limy soil for different exogenous nitrogen sources, the study was conducted to investigate the effects of different additive amounts and nitrogen sources on the nitrification in fresh Cal-Ustic Isohumasols by using the plot experiment, and the corresponding model was obtained. The results show that the curve between the ammonium nitrate consumption rate and nitrogen nitrate increasing rate can be described as an S shape, and the ammonium nitrate consumption rate is higher than the nitrogen nitrate increasing rate. The ammonium nitrate consumption rate and nitrogen nitrate increasing rate are positively correlated with the nitrogen addition. Except the nitrifying bacteria, other organisms’ absorptions of ammonium nitrate and nitrogen nitrate are positively related to the addition of nitrogen nitrate. Applications of different nitrogen amounts have great influences on the nitrification in soils. When the nitrogen addition is 75 mg N/kg soil, the nitrification is more completely. SO42- can hasten the nitrification rate and can also improve the bio-availabilities of ammonium nitrate and nitrogen nitrate for other organisms.

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