中文摘要：

以贵州毕节撒拉溪镇下小寨小流域为研究单元,分析了土壤中砾石含量以及不同土地利用方式对土壤容重的影响。结果表明,土壤中砾石含量与土壤总容重、细土容重之间均呈显著负相关关系。不同土地利用方式下,0～100 cm不同土层土壤总容重、细土容重未表现出一致的大小顺序。不同土层林地细土容重、总容重与菜地、玉米地、人工草地三者之间均存在显著性的差异,退耕地40～100 cm各土层细土容重、总容重与林地细土容重、总容重均无显著差异,说明减少人为干扰,采取休耕措施可以改善土壤物理性状。

英文摘要：

With the karst watershed of Xiaxiaozhai in Bijie district as the research unit, influences of gravel content and land use patterns on soil bulk density were analyzed. The reaults showed that the gravel content was negatively related to total soil bulk density and bulk density of fine earth significantly. The orders of total bulk density or bulk density of fine earth were not same in different soil layers from surface to 100 cm depth. Total bulk densities and bulk densities of fine earth in different soil layers in woodland were significantly different from vegetable plot, cornfield and artificial grassland. There was no significant difference in total bulk densities and bulk densities of fine earth in different soil layers of woodland and returned land. These meant that soil physical feature might be improved by reducing disturbances and leaving farmlands lay fallow.