吕文星　唐洪波　刘东旭等

摘要 由于受气候、生物、土壤属性等因素的影响，土壤基本物理性质垂直剖面分布也表现出相应的层次性。该研究对青海省大峡灌区典型地块土壤基本物理性质分层次进行测定和分析。结果表明，土壤容重随土层深度的增加呈先增大后减小趋势；土壤孔隙度随土层深度的增加呈先减小后增加趋势，整个土壤层次中0～40和90～150 cm两处为高孔隙度区，其他土层属于低孔隙度区；土壤持水性能指标中的土壤饱和持水量、毛管持水量及田间持水量均随土层深度的增加呈先减小后增加趋势，且三者变化趋势基本一致，均呈近等差递减的趋势。大峡灌区典型样地土壤在垂直方向呈现出上部（0～40 cm）疏松，40～60 cm范围较紧实，下部（60～200 cm）再次趋于疏松。

关键词 大峡灌区；土壤物理性质；垂直变异

中图分类号 S152 文献标识码 A 文章编号 0517-6611（2015）15-099-03

Vertical Variation Characteristics of Basic Physical Properties in the Daxia Irrigated Area of Qinghai Province

LV Wenxing1， TANG Hongbo2， LIU Dongxu1 et al

（1.Yellow River Institute of Hydrology and Water Resources， Zhengzhou， Henan 450004； 2. Qinghai Hydrographic and Water Resources Survey Bureau， Xining， Qinghai 810008）

Abstract Due to the influence of such factors as the climate， biology and soil properties， the vertical section distribution of soil basic physical properties also show the corresponding hierarchy. Basic physical properties of typical field in the Daxia irrigation area in Qinghai Province layer were determined and analyzed in this study. The results showed that soil bulk density increased with the increase of soil depth first and then decreased； Soil porosity increased with the increase of soil depth first and then decreased. The soil layers in 0-40 cm and 90-150 cm were high porosity zones， other soil layer belongs to low porosity area； Soil waterholding performance index such as soil saturated water holding capacity， capillary water holding capacity and field capacity showed increased first and then decreased trend with the increase of soil depth. These three indexes almost showed the same nearly evenly spaced degressive trend. The soil of the typical sample plots in Daxia irrigation area presents the upper vertical （0-40 cm） is loose， the 40-60 cm layer is relatively tight， and the lower part （60-200 cm） tend to loose again.

Key words Daxia irrigated area； Soil basic physical properties； Vertical variation

大峽渠灌区位于河谷平原川水区。该区沿湟水干流及其一级支流呈带状分布，由河滩和1～5级阶地坡洪积扇组成，土体构型较好，质地松，是全县的主要产粮区。该地区属半干旱的高原大陆性气候类型。寒冷和干旱是区内主要气候特点。由于受气候、生物、土壤属性等因素的影响，土壤水分的剖面分布也表现出相应的层次性[1-2]。该研究通过对大峡灌区200 cm土体的基本物理性质的测定分析，探讨其在垂直方向上的变异特征，以期为青海省大峡灌区土壤资源的进一步研究提供理论依据。

1 材料与方法

1.1 研究区概况

该试验布设在位于青海省黄河流域大峡灌区，地处E102°15′～102°24′和N36°13′～36°30′，海拔范围在1 650～4 400 m之间。……