丘陵紫色土砾石的性质及其空间分布

Characteristics and spatial distribution of rock fragments in hilly purple soils of Sichuan Basin

丘陵紫色土中含有大量的砾石，本文对重庆丘陵紫色土中砾石的理化性质进行了测定。结果表明，不同类紫色土砾石的容重、比重、孔隙度、饱和含水量、水分特征曲线及化学组成含量有明显的差异。不同类紫色土的砾石含量为5．27％～57．78％，且粗暗紫泥〉棕紫泥〉红棕紫泥〉灰棕紫泥，不同尺寸的砾石含量随粒径的增大而下降；同一岩性山坡，砾石含量随坡位的上升而增加，在同一台土上，台后砾石含量高于台前砾石含量；剖面上的砾石含量基本上是随土层的加深而减少。此结果为研究山地丘陵土壤中砾石对土壤的物理、化学和农学特性的重要影响奠定了基础。

There were abundant rock fragments in soils of hilly regions, and the article determined the physical and chemical properties of rock fragments in soils of hilly regions in Chongqing,The results showed that：there are obvious differences of mineral components, density, specific gravity ,porosity, saturated water content, water retention characteristic curves and the content of chemical components in the different rock fragments. The total rock fragments contents were 5.27 % -57.78 % in different purple soils,and coarse dark purple soils 〉 brown purple soils 〉 red-brown purple soils 〉 grey-brown purple soils,and the rock fragments contents descent with the increasing size. The rock fragments contents represent increased tendency with the slope gradient at the same lithological slope. At the same soil platform, the rock fragments contents were the back more than the before. The rock fragments contents basically decreased with soil deeper in profiles. The results established a base for researching the influence of the soil physical and chemical properties and the agronomical characteristics with rock fragments in hilly regions.