中文摘要：

为了研究放牧对内蒙古典型草原土壤氮矿化的影响,本研究采用室内培养的方法,分析了平地和坡地两种地形中不同放牧强度下的土壤氮矿化时间动态,同时结合动力学模型的应用,得出氮矿化潜力（N0）。结果表明,地形和放牧强度对累积净氮矿化量都有极显著影响（p〈0.01）,且地形的影响要大于放牧处理的影响。不同时期的累积净氮矿化量、N0及矿化速率常数k没有随放牧梯度表现出规律性变化,在不同地形中差异较大。但N0整体表现为,坡地系统高于平地系统,平地系统中以中度放牧下较大,而在坡地系统中则随放牧强度增大而降低。在平地系统中,中度和重度放牧下的k值较大,而在坡地系统中则相反。

英文摘要：

To study the effect of grazing on nitrogen mineralization in the typical steppe of Inner Mongolia,soils were sampled from flat and slope sites respectively with different grazing intensities and cultured.Dynamics of soil net nitrogen mineralization were measured,and nitrogen mineralization potential（N0） were calculated with application of model.The results showed that the accumulated net nitrogen mineralization was significantly affected by topography and grazing intensities（p〈0.01）,but topography had stronger effect than grazing.No consistent differences in accumulated net nitrogen mineralization,nitrogen mineralization potential（N0） and nitrogen mineralization rate constant（k） were observed between grazing intensities.In general,N0 were higher in the slope sites than the flat sites,and were higher in moderate grazing plots in flat site,while decreased with grazing intensities in slope site.k values were higher in moderate and heavy grazing plots in flat site while conversely in slope site.