摘要
为研究黄土丘陵缓坡风沙区不同土地利用类型下的土壤水分变化规律,采用时域反射仪TDR在山西省五寨县分别对玉米农地、柠条林地、苜蓿草地0-100 cm土层进行连续3年的土壤水分观测,掌握不同土地利用类型土壤含水量的季节变化规律和垂直分布特征。结果表明:(1)农林草地土壤水分随时间的变化曲线基本呈"M"形分布,三者季节变化规律相似,但土壤含水量差异达到极显著水平(P<0.01),表现为苜蓿草地>柠条林地>玉米农地;(2)玉米农地与柠条林地土壤含水量随土层深度的增加呈"S"形分布,苜蓿草地的变化趋势与两者完全相反,玉米农地仅土壤表层0-20 cm含水量与降水存在显著相关性,柠条林地和苜蓿草地0-60 cm土壤含水量均与降水显著相关;(3)土壤含水量具有明显的垂直分布特征,在0-100 cm土层层中,随着土层深度的增加,玉米农地CV先逐渐降低后保持稳定,柠条林地CV始终持续降低,苜蓿草地CV先呈现波动变化后明显降低,三者整体表现为表层土壤含水量变异系数大于深层;(4)0-100 cm范围内,玉米农地的土壤层自上而下依次可划分为速变层、活跃层2个层次,柠条林地和苜蓿草地的土壤层划分为速变层、活跃层和次活跃层3个层次。本研究结果表明林地和草地在涵养土壤水分方面优于农田,林地和草地为黄土丘陵缓坡风沙区适宜的土地利用方式,为该区域土壤水分管理及水土资源的合理开发利用提供理论依据。
In order to study the variation characteristics of soil moisture under different land use types in the moderate slope sandy area of loess hilly region, time domain reflectometry(TDR) was used in three land use types, which were maize farmland, Caragana korshinskii forest land and alfalfa grassland, in Wuzhai County, Shanxi Province. The soil moisture of 0-100 cm soil layer was observed for three years, and the seasonal variation and vertical distribution of soil water content of different land use types were grasped. The results showed that the seasonal variation curves of soil moisture in the three kinds of lands all showed M type distribution. The seasonal variations of the three kinds of lands were similar, but the difference of soil water content reached an extremely significant level(P<0.01), which showed as follow alfalfa grassland > C. korshinskii forest > maize farmland. The soil water content of maize farmland and C. korshinskii forest showed S distribution with the increasing of soil depth, while the variation trend of alfalfa grassland was completely opposite to the other two lands. There was a significant correlation between the soil water content of 0-20 cm soil layer and precipitation in maize farmland, and there was a significant correlation between the soil water content of 0-60 cm soil layer and precipitation in C. korshinskii forest and alfalfa grassland. The soil water content had obvious vertical distribution characteristics. In 0-100 cm soil layer, with the increasing of soil depth, the CV of maize farmland decreased gradually and then remained stable, however, the CV of C. korshinskii forest decreased continuously, the CV of alfalfa grassland fluctuated at first and then decreased obviously. The coefficient of variation of surface soil water content was higher than that of deep layer. In the range of 0-100 cm, the soil layer of maize farmland could be divided into rapid change layer and active layer from top to bottom, and the soil layers of C. korshinskii forest and alfalfa grassland could be divided into three layers, which were rapid change layer, active layer and sub-active layer. The results of this study showed that forest land and grassland were better than farmland in conserving soil moisture, and forest and grassland were suitable land use patterns in the moderate slope sandy area of loess hilly region. It provided a theoretical basis for the management of soil moisture and the rational development and utilization of soil and water resources in this area.
作者
张敏
刘爽
刘勇
张红
ZHANG Min;LIU Shuang;LIU Yong;ZHANG Hong(Institute of Loess Plateau ,Shanxi University ,Taiyuan 030006;College of Environment and Resource Sciences ,Shanxi University ,Taiyuan 030006)
出处
《水土保持学报》
CSCD
北大核心
2019年第3期115-120,128,共7页
Journal of Soil and Water Conservation
基金
山西省自然科学基金项目(201601D021117)
国家自然科学基金项目(41871193,41401618)
山西省“1331工程”土壤污染生态修复学科群项目(20181401)
关键词
黄土丘陵缓坡风沙区
土地利用类型
土壤水分
变异系数
moderate slope sandy area of loess hilly region
land use type
soil moisture
coefficient of variation