中文摘要：

氮素矿化是土壤氮循环的重要环节,土壤氮矿化参数对于正确评价土壤供氮潜力和指导土壤氮素管理有重要意义。采用35℃淹水厌氧短期培养法研究了中亚热带典型红壤丘陵区五种土地利用方式土壤氮素的矿化作用。利用双一级动力学模型（双氮库模型）对矿化过程进行拟合与比较,并利用土壤理化性质对氮矿化动力学参数进行估测。结果表明,土壤氮素快速矿化主要在淹水培养前7 d,于28 d矿化曲线即趋于平稳;双氮库模型能很好的拟合氮矿化作用。菜地、稻田、荒地、林地和茶园土壤的易矿化氮库矿化势分别为85.9 mg/kg、184.4 mg/kg、64.5 mg/kg、37.0 mg/kg和11.4 mg/kg,其占全氮的比率分别为5.77%、8.65%、4.42%、3.31%和1.25%,其易矿化速率常数分别为0.31、0.58、0.15、0.07和0.17（1/d）。应用双氮库模型拟合的易矿化氮库矿化势和易矿化速率常数与土壤全氮、微生物生物量碳、微生物生物量氮、p H和碳氮比有显著相关性;利用全氮及p H两变量能较好地预测氮矿化势和矿化速率常数,但土壤微生物生物量碳对氮素矿化动力学参数估算具有更关键作用。

英文摘要：

Soil organic nitrogen mineralization is an important part of soil nitrogen cycle, and it is crucial for us to understand the soil organic nitrogen mineralization potential and advise the optimized fertilization. In this study, a short-term anaerobic incubation method at 35 ℃ was adopted to determine the soil nitrogen mineralization kinetics of five soils under different land use types in a typical hilly area of Jinjing town in Hunan province. We used a double first-order kinetic model （namely two-pool model） to fit the data of soil nitrogen mineralization kinetics. Then, the multivariate linear regression models for soil nitrogen mineralization kinetic parameters derived from two-pool model were developed based on basic soil properties. The results showed that the soil organic nitrogen was quickly mineralized in the early seven days and thereafter slowly, in particular for paddy soils. Two-pool models were fitted well to the soil nitrogen mineralization data. The soil nitrogen mineralization potentials （Nd） for different land use types were 85.9 mg/kg （vegetable land soil）, 184.4 mg/kg （paddy field soil）, 64.5 mg/kg （unused land soil）, 37.0 mg/kg （woodland soil） and 11.4 mg/kg （tea field soil）, and accounting for 5.77%,8.65% ,4.42% ,3.31%和1 1.25% of the total soil nitrogen, respectively. With regard to the mineralization rate constant （kd）, the paddy field soil had the greatest value of 0.58/d, the woodland soil the lowest value of 0.07/d, and vegetable land soil （0.31/d）, tea field soil （0.17/d） and unused land soil （0.15/d） in between. Both the fraction of soil total nitrogen in soil mineralization potential （fd） and kd were significantly related to soil total nitrogen, soil microbial biomass carbon （MBC）, soil microbial biomass nitrogen, pH and carbon nitrogen ratio, respectively. The multiple linear regression models for predicting fd and kd were successfully developed by using MBC, TN and pH. We also found that MBC played a very important role in determ