关键词: 绿洲化, 土壤容重, 团聚体, 粘粒, 饱和水力传导度

Abstract: Oasisization is the process of converting natural desert to man-made oasis for satisfying social need under a certain economy and technical condition. This paper uses the method of space substituting for time to study the changing process of physical properties of oasis soil along the oasisization in about 1000-year period. This research focuses on providing the bases to better understand the process of oasisization. The results show: ①In about 1 000-year chronological scale, the bulk density and the saturated soil hydraulic conductivity of the surface layer (0~20 cm) significantly reduced with the increase of land reclamation year, at the same time, soil porosity, stability of aggregates, silt content significantly increased. The bulk density of the uncultured (0 year) and the cultured soil (for about 1 000 years) of the surface layer (0~20 cm) is separately 1.51 g·cm-3 and 1.35 g·cm-3, the soil total porosity is 43.16% and 49.27%, the capillary porosity is 38.73% and 47.10%, the water-stable aggregate (>0.25 mm) content is 24.60% and 49.59%, the soil sand content is 85.42% and 61.56%, the clay content is 3.93% and 4.80%, the specific surface area is 128 cm2·g-1 and 231 cm2·g-1, and the saturated soil hydraulic conductivity is 0.74 cm·h-1, 0.34 cm·h-1, respectively. ②In the first 30 years of the oasis reclamation, the changes are relatively fast, and the rates of the saturated soil hydraulic conductivity, dry aggregate (>0.25 mm) content, water-stable aggregate (>0.25 mm) content and specific surface area were 0.01 cm h-1·a-1, 0.58%·a-1, 0.50%·a-1 and 1.48 cm2·g-1·a-1, respectively.

Key words: oasisization, bulk density, aggregate, clay, saturated soil hydraulic conductivity