黄土塬区深剖面土壤水分垂直分布特征及其时间稳定性  

Vertical distribution characteristics and temporal stability of soil water in deep profile on the Loess Tableland,Northwest China

作　　者：韩晓阳[1,2] 刘文兆[1,3] 程立平[4] HAN Xiao-yang LIU Wen-zhao CHENG Li-ping(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, Shaanxi, China State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China Institute of Soil and Water Conservation, Northwest A＆F University, Yangling 712100, Shaanxi, China pingdingshan University, Pingdingshan 467000, Henan , China）.)

机构地区：[1]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [3]西北农林科技大学水土保持研究所,陕西杨凌712100 [4]平顶山学院,河南平顶山467000

出　　处：《应用生态学报》2017年第2期430-438,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41571036;41401015)资助~~

摘　　要：研究土地利用方式对深剖面土壤水分时空动态的影响,对于了解区域水循环在变化环境下的表现特征具有重要意义.本研究基于长期定位监测数据,对2012年9月至2015年12月黄土塬区4种土地利用方式0~15 m剖面土壤水分状况进行分析.结果表明:苜蓿草地(>7年)、休闲地、高产农田和低产农田平均土壤含水量分别为15.1%、22.0%、19.6%和21.1%(0~15 m、年度平均值);干湿交替层季节性失水和蓄水分别出现在3—6月和7—10月,其深度范围分别为0~2、0~4.6、0~3和0~4.2 m.深层土壤水分具有较好的时间稳定性,其垂直分布受土地利用方式的影响.观测年份内苜蓿产量和耗水量均呈逐年增加趋势,造成深层土壤的干燥化程度加大,2~10 m土层形成稳定土壤干层,阻断了降水补给地下水的途径.对于其他3种土地利用方式下的土壤水分平衡,冬小麦生长季农田与休闲地均表现为负平衡;玉米生长季高产农田表现为负平衡,而低产农田与休闲地表现为正平衡;在作物休闲期,农田与休闲地均表现为正平衡.通过施肥处理所形成的高产农田的作物水分利用效率是低产农田的3倍以上.Study of impacts of land uses on spatiotemporal dynamics of soil water content （SWC） is of great significance for understanding the performance characteristics of regional water cycling under changing environment. Based on long-term located field observations, this paper explored the temporal dynamics of soil water in 0-15 m soil profile under four land use types on the Loess Tableland from September 2012 to December 2015. Results showed that the annually averaged SWCs over the 0-15 m soil profile for alfalfa field, fallow field, fertilized cropland and unfertilized cropland were 15.1%, 22.0%, 19.6% and 21.1%, respectively. Soil water contents along the shallow soil profile exhibited seasonal and annual wetting and drying cycle from March to June and July to October, and the profile depths were 0-2, 0-4.6, 0-3 and 0-4.2 m, respectively. Soil water contents along the deep soil profiles had better temporal stability and were influenced by land-use types. During the observation years, the yield and water consumption in alfalfa field increased, which caused the increase of deep soil desiccation, the 2-10 m soil profile had become stable dry layer, blocking

关 键 词：土地利用方式 土壤水分 时空变化 土壤干层 黄土塬区 

分 类 号：S152.7[农业科学—土壤学]