典型黑土区农业小流域不同坡向和坡位的土壤水分变化特征

土壤水分变化受地形地貌、土壤质地、土地利用方式等多种因素的影响.为了分析东北典型黑土区土壤水分变化规律,以该区农业小流域为研究对象,采用野外实验的方法,从坡向和坡位出发,系统分析土壤水分在不同坡向和坡位的变化特征.结果表明：1）半阴坡平均土壤含水量低于阳坡和半阳坡;各坡向土壤水分剖面变化趋势不同,坡向仅对0 ～ 35 cm深度范围内土壤含水量变化有显著影响.2）3坡向（阳坡、半阳坡和半阴坡）土壤含水量均为下坡位＞上坡位＞中坡位,各坡向不同坡位土壤含水量剖面变化呈现不同趋势,坡位对测量范围内的阳坡和半阴坡,以及25 ～ 100 cm范围内的半阳坡土壤水分变化有显著影响,但对半阳坡0～ 25 cm土壤水分影响不显著.研究结果可对该地区小流域农作物合理配置及农田土壤水分管理提供科学依据.

Variation of soil moisture with slope aspect and position in a small agricultural watershed in the typical black soil region

Soil moisture is affected by land use type,topography and geomorphology,soil texture and other factors.A small agricultural watershed in the typical black region was selected as the study area to analyze the variation of soil moisture at different slope aspects and positions by field experiment.The results were as follows.1） In the depth range of 0-100 cm,soil moisture content on the semi-shady slopes was lower than that on sunny and semi-sunny slopes; profile variation trends of soil moisture content on the three types of slopes differed,and the effect of slope aspect on soil moisture content was significant only in the depth 0-35 cm.2） On each type of slope,the soil moisture content followed the order of lower slope ＞ upper slope ＞ middle slope,the profile variation of soil moisture content presented different trends at different slope positions of each slope aspect,and the effect of slope position on soil moisture content of sunny and semi-shady slopes was significant within the measurement range,and it was also significant on the semi-sunny slope in depth 25-100 cm,but not significant in 0-25 cm in this slope aspect.Our research results could provide theoretical basis for reasonable allocation of crops and management of farmland soil moisture.