晋西黄土区林草复合界面土壤水分养分分布规律研究

通过对晋西黄土区刺槐林与天然草带的复合界面及其对照（林地、草地）生长季土壤水分和养分（有机质、全氮、速效氮和速效钾）的测定，分析比较了其水分和养分的空间分布特征及其变化规律。结果表明，不同土壤层次的土壤含水量在水平方向上存在差异，在浅层土壤（0-20cm），土壤含水量从大到小依次为:草地、林地、林草界面，在深层土壤（20-100cm），土壤含水量从大到小依次为:草地、林草界面、林地；在垂直方向上，随着土层深度的增加，研究区林地、草地、林草界面的土壤含水量表现为逐渐降低的趋势，刺槐林地在60-100cm土层中土壤含水量有少许回升。研究区复合类型内土壤养分分布不均衡，水平方向上有机质平均含量为林草界面<草地<林地；全氮平均含量为林草界面最小，草地与林地相差不大；速效磷平均含量为林地<草地<林草界面；速效钾平均含量为草地<林草界面<林地；垂直方向上，各个生态类型的有机质含量、全氮含量、速效钾含量随着土壤层次的加深逐渐减少，而速效磷含量在土壤的不同层次呈现不同的变化。

Distribution of Soil Moisture and Nutrients at the Grassland-Forestland Interface in the Loess Region of West Shanxi Province

Based on the determination of soil moisture and nutrients at the grassland-forestland interface in the Loess Region of West Shanxi,comparative analysis of soil moisture and nutrients distribution and spatial variability were carried out.The results indicated that: the soil moisture between different soil layers under interface in horizontal direction presented different for different kinds.In 0-20cm soil layer the soil moisture content is grassland>forestland>grassland-forestland,and in 20-100cm soil layer the soil moisture content is grassland>grassland-forestland>forestland.With increasing soil depths,the soil moisture showed reducing tendency but increased in forestland in 60-100cm soil layer.The soil nutrients were unevently distributed.In horizontal direction,the average content of organic matter is grassland-forestland