半干旱黄土丘陵区小流域横断面土壤水分生态特征  

Soil water ecological characteristics in a cross section of small watershed in a semi-arid loess hilly area

作　　者：刘文兆[1] 胡梦珺[2] 侯喜禄[1] 李凤民[3] 

机构地区：[1]中国科学院水利部水土保持研究所西北农林科技大学资源环境学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所西北师范大学地理与环境科学学院,甘肃兰州730070 [3]兰州大学生命科学学院,甘肃兰州730000

出　　处：《干旱地区农业研究》2003年第4期95-100,共6页Agricultural Research in the Arid Areas

基　　金：国家"973"前期研究专项"半干旱黄土植被景观覆盖格局与生态系统功能调控";国家自然科学基金项目(90202011)资助

摘　　要：在半干旱地区甘肃榆中北部中连川流域取一横断面,根据地形部位与利用条件布设11个测点,用土钻法监测土壤水分剖面分布与动态,测深到5m。各立地条件年内4月到12月土壤水分动态趋势多样。流域横断面的土壤湿度均较低,2～5m平均值一般都小于10%,其中以坡地苜蓿与半阳坡柠条林地最干燥。该地区土壤干燥化层是普遍存在的,不仅存在于人工植被,也存在于天然植被。径流富集叠加可显著改善土壤水分状况,隔坡水平梯田是其重要途径。退耕还草中要考虑各类草地的比例、苜蓿种植的适宜规模及其持续性问题。Soil moisture was measured to a depth of 5 m in eleven sites with different landform and landuse in a cross section of the Zhonglianchuan watershed during 2002. The watershed is located in a semiarid and loess hilly area, Yuzhong County of Gansu Province, China. There were different types of soil moisture variation within the year of 2002 in eleven sites. Soil moistures were lower in all sites, and the averages of 2 m to 5 m depth were usually lower than 10% (dry mass water percentage), in which the smallest water contents were in soils of the sloping land under Medicago sativa and the sloping land under Caragana korshinskii. The dried soil layer exists in this area widespreadly, not only in the artificial vegetation but also in the natural vegetation. The soil moisture could be increased in a site which collects the surface runoff from its neighboring area. One of important ways to harvest runoff is the terrace alternated with sloping land. The proportion of various grasslands, the appropriate acreage under alfalfa and its sustainable development should be further studied during returning cultivated land to grassland.

关 键 词：半干旱黄土丘陵区 小流域横断面 土壤水分 生态特征 土壤干层 退耕还草 集雨农业 

分 类 号：S152.7[农业科学—土壤学]