黄土丘陵半干旱区土壤水资源利用限度  

Soil water resource use limit in semi-arid loess hilly area

作　　者：郭忠升[1,2] 

机构地区：[1]西北农林科技大学 [2]中国科学院-水利部水土保持研究所,陕西杨凌712100

出　　处：《应用生态学报》2010年第12期3029-3035,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41071193);国家"十一五"科技支撑计划项目(2006BAD09B08)资助

摘　　要：以柠条为对象,采用中子水分仪对黄土丘陵半干旱区人工植被恢复过程中土壤水分与植物生长进行长期定位观测.结果表明:撂荒地播种后,随着时间推移,植物群落保持水土能力增强,根系吸收利用水分的土层深度增加、土壤含水量下降.林地土壤出现干层,且干层土壤的深度和厚度逐年增加.植物对土壤水资源的利用限度为干层土壤深度等于最大补给深度时的土壤储水量.在黄土丘陵半干旱区人工柠条林地土壤水资源利用限度是0～290cm土层的土壤储水量为249.4mm.当人工林地土壤水资源接近或等于土壤水资源利用限度时,需要采取措施降低土壤水分消耗,或增加土壤水分补给,维持根系吸收利用水资源的相对稳定.Taking Caragana korshinskii as test object,and by using neutron probe,a long term observation was conducted on the soil water and plant growth during the process of vegetation restoration in semi-arid loess hilly area. The results showed that after seeding on waste land,the capability of plant community in conserving soil and water was promoted with time,with the depth of roots to absorb and use soil water increased and the soil water content reduced. Then,the dried soil layer appeared,and its deepness and thickness increased with increasing plant age. Therefore,the plant use of soil water had a limit,soil water resource use limit,i. e. ,the soil water storage when the deepness of dried soil layer was equal to the largest depth that rain could recharge. In the C. korshinskii woodland in semi-arid loess hilly area,the soil water resource use limit in 0 - 290 cm layer was 249. 4 mm. When the soil water storage in woodland was close or equal to the soil water resource use limit,effective measures should be taken to decrease soil evapotranspiration or increase soil water supply to ensure the sustainable water use of plant roots.

关 键 词：黄土丘陵半干旱区 植物 土壤水资源 土壤干层 土壤水资源利用限度 

分 类 号：S152.7[农业科学—土壤学]