Cold and Arid Regions of Environmental and Engineering Research Institute, Chinese Academy of Sciences, 320 Donggang West Road, Lanzhou, 730000, China.
Environ Monit Assess. 2013 Jul;185(7):6013-21. doi: 10.1007/s10661-012-3002-5. Epub 2012 Nov 24.
Water is a limiting factor to plant growth in Horqin Sand Land of China. Knowledge of soil saturated hydraulic conductivity (K(sat)) is of importance because K(sat) influences soil evaporation and water cycling at various scales. In order to analyze the variation of K(sat) along with sand types and soil depths, and its relationship with soil physiochemical properties, six typical lands were chosen, including mobile dune, fixed dune, pine woodland, poplar woodland, grassland, and cropland, and K(sat) was measured in situ by Guelph Permeameter at each type of land. Soil bulk density, organic matter content, and soil particle size distribution were determined in parallel with K(sat) measurement. The results showed that (1) The averaged K(sat) was decreased in the order: mobile dune > fixed dune > pine woodland > poplar woodland > grassland > cropland; changes in K(sat) varied considerably as soil depth increased, e.g., the changes of K(sat) along with soil depth in fixed dune was fitted by exponential model, but it was fitted by parabola model in the pine woodland and grassland. (2) The K(sat) values of fixed dune and mobile dune were varied considerably among three slope positions (dune top, windward slope, and leeward slope). (3) The relationships of K(sat) and soil physiochemical property revealed that soil bulk density, organic matter content, and coarse sand fraction (2∼0.1 mm) were the key factors affecting K(sat) in Horqin Sand Land. Compared with clay and silt content proportion, sand fraction in this region showed a more significant positive correlation with K(sat).
水是中国科尔沁沙地植物生长的限制因素。土壤饱和导水率（K(sat)）的知识很重要，因为 K(sat) 影响不同尺度的土壤蒸发和水循环。为了分析 K(sat) 随沙体类型和土壤深度的变化及其与土壤理化性质的关系，选择了 6 种典型土地类型，包括流动沙丘、固定沙丘、松树林地、杨树林地、草地和耕地，并在每种土地类型中使用 Guelph 渗透仪原位测量 K(sat)。同时平行测量土壤容重、有机质含量和土壤粒径分布。结果表明：（1）K(sat)平均值的顺序为：流动沙丘＞固定沙丘＞松树林地＞杨树林地＞草地＞耕地；随着土壤深度的增加，K(sat)的变化相当大，例如，固定沙丘的 K(sat)随土壤深度的变化拟合为指数模型，但在松树林地和草地中拟合为抛物线模型。（2）固定沙丘和流动沙丘的 K(sat)值在三个坡位（沙丘顶部、迎风坡和背风坡）之间有很大差异。（3）K(sat)与土壤理化性质的关系表明，土壤容重、有机质含量和粗砂粒级（2∼0.1mm）是影响科尔沁沙地 K(sat)的关键因素。与粘粒和粉粒含量比例相比，该地区的砂粒级与 K(sat)呈更显著的正相关。
