黄土丘陵区退耕还林草对深层土壤水分动态的影响  

Changes in Subsoil Water Content After Withdrawing Crop Production in the Hilly Loess in Northwestern China

作　　者：孟婷婷 王欢元 刘金宝 杨亮彦 石磊 MENG Tingting;WANG Huanyuan;LIU Jinbao;YANG Liangyan;SHI Lei(Shaanxi Provincial Land Engineering Construction Group Co.,Ltd.,Xi’an 710075,China;Institute of Land Engineering and Technology,Shaanxi Provincial Land Engineering Construction Group Co.,Ltd,Xi’an 710075,China;Key Laboratory of Degraded and Unused Land Consolidation Engineering,Ministry of Natural Resources,Xi’an 710075,China;Shaanxi Provincial Land Consolidation Engineering Technology Research Center,Xi’an 710075,China)

机构地区：[1]陕西省土地工程建设集团有限责任公司,西安710075 [2]陕西地建土地工程技术研究院有限责任公司,西安710075 [3]自然资源部退化及未利用土地整治工程重点实验室,西安710075 [4]陕西省土地整治工程技术研究中心,西安710075

出　　处：《灌溉排水学报》2021年第12期78-84,共7页Journal of Irrigation and Drainage

基　　金：陕西省自然科学基金资助项目(2019JQ-945);陕西省土地工程建设集团科研项目(DJNY2021-30,DJNY2021-15)。

摘　　要：【目的】量化黄土丘陵区退耕还林草植被恢复下深层土壤储水量和耗水量,弄清植被恢复类型对深层土壤水分动态的影响,为优化该区植被管理和土壤水资源调控提供理论依据。【方法】采用室外调查和室内检测的方法,研究了黄土丘陵区园则沟小流域坡耕地,草地和枣林0~1000 cm剖面土壤含水率和深层(200~1000 cm)耗水量。【结果】(1)0~1000 cm土层,土壤含水率为枣林<草地<坡耕地。0~200 cm土层,坡耕地、草地和枣林土壤含水率均呈先增加后减少的趋势,均值分别为11.91%、11.23%和9.99%;200~1000 cm土层,土壤含水率缓慢下降趋于稳定,均值分别为11.77%、11.62%和9.96%。(2)200~1000 cm土层,土壤储水量坡耕地>草地>枣林,均值分别为148.78、145.28和121.11 mm;各土层坡耕地和草地土壤储水量显著大于枣林(p<0.05),但坡耕地储水量和草地土壤储水量无显著差异。(3)200~1000cm土层,枣林存在明显的深层土壤耗水量并显著高于草地(p<0.05),枣林耗水量范围为21.67~32.97 mm,均值为27.67 mm,草地耗水量范围为-4.47~10.32 mm,均值为3.50 mm。(4)各样地土壤深层含水率与黏粒呈显著正相关,与砂粒呈显著负相关,与有机碳质量分数呈负相关。【结论】枣林存在明显的深层土壤水分消耗量,且显著高于草地;草地在深层土壤虽然也出现土壤水分消耗,但消耗量较低。【Background and objective】Withdrawing crop production to restore ecological functions of the loess plateau in northwestern China has greatly increased vegetation coverage since 1999,but there is a lack of understanding of how subsoil water content responded to such land use changes.The purpose of this paper is to fill this knowledge gap.【Method】Soil water content in the depths from the soil surface to 1000 cm was measured from slopped farmland,grassland and jujube orchard at a small watershed in the Yuanzegou waterhead in a loess hilly region.【Result】(1)The average moisture content in the 0~1000 cm soil in different ecosystems was ranked in the order of jujube orchard<grassland<sloping farmland.In the 0~200 cm soil,soil water content in the farmland,grassland and jujube orchard increased with depth first followed by a decline,with their average water content across the soil profile being 11.91%,11.23%and 9.99%,respectively.In the depth from 200 to 1000 cm,soil water content decreased asymptotically with depth,with the average soil water content over the profile being 11.77%,11.62%and 9.96%for the farmland,grassland and jujube orchard,respectively.(2)Water stored in the 200~1000 cm soils was ranked in the order of farmland>grassland>jujube orchard,with their associated average value being 148.78 mm,145.28 mm and 121.11 mm,respectively.Waters stored in the farmland and grassland were comparable,both being significantly higher than that in the jujube orchard(p<0.05).(3)Jujube took up more water from the 200~1000 cm soil than the grasses(p<0.05),with the water consumed by the jujube ranging from 21.67 mm to 32.97 mm compared to-4.47 mm to 10.32 mm used by the grasses.(4)Subsoil water content was positively correlated with clay while negatively related to sand particles and organic carbon mass fraction,all at significant levels.【Conclusion】Withdrawing crop production significantly reduced soil water content and water storage in the subsoil,especially when returning to forests.Jujube took a significant

关 键 词：退耕还林草 深层土壤水分 草地 枣林 

分 类 号：S15[农业科学—土壤学]