雅鲁藏布江江当宽谷区固沙措施对流沙理化性质的改良效应

目的]分析雅鲁藏布江江当宽谷区流沙治理技术(砾石覆盖+人工植被+围封)对流沙理化性质的改良效应,为区域荒漠化治理工作提供理论指导。方法]对比分析固沙区和流动沙丘土壤机械组成、有机质和养分等指标开展研究。结果]采用植物和工程相结合的固沙措施,在流沙表面覆盖砾石、播种固沙植物,并对该区域进行围封后,沙丘表面植被盖度增加,流沙基本固定。与流动沙丘相比,固沙区土壤的黏粒、粉粒明显增多。固沙区土壤的有机质、全氮、碱解氮、全磷、速效磷、速效钾含量比流动沙丘高;尤其是土壤表层0—5cm,分别比流动沙丘高出634.3%,268.0%,506.5%,38.3%,343.8%,66.7%。固沙区0—5cm土层的pH值比流动沙丘降低了11.5%;电导率比流动沙丘增加了268.1%。结论]该项流沙治理技术(砾石覆盖+人工植被+围封)的固沙和改良土壤理化性质作用明显,适宜在该区推广使用。

Improvement Effects of Sand Fixing Measures on Shifting-sand Physical and Chemical Properties in Jiandang Wide Valley Area of Yarlung Zangbo River

Objective] Analyzing the responses of shifting-sand physical and chemical properties improvement to sand control technologies(gravel cover+artificial vegetation+enclosure) in Jiandang wide valley area of Yarlung Zangbo River, to provide theoretical guidance for regional desertification control.Methods] Soil mechanical composition, organic matter and nutrients, etc. were comparatively analyzed between the samples of the sand fixed region and the ones of the mobile sand dune.Results] After combined plantation and engineering measures were applied, such as gravel laying over the mobile dune surface,sand-fix-capable plant seeds sowing and enclosing, the sand of dune surface was fixed and the vegetation cover increased. As compared with the mobile sand dune, the contents of clay and silt particles increased significantly. The contents of soil organic matter, total nitrogen, alkaline hydrolytic nitrogen, total phosphorus, available phosphorus and potassium in sand fixed region were higher than those of the corresponding values of mobile sand dune. Especially in 0-5 cm soil layer, greater improvements of 634.3%,268.0%,506.5%,38.3%,343.8%,66.7% of the fixed dune were obtained against the ones of the mobile sand dune, respectively. pH value at 0-5 cm soil layer in sand fixed region decreased by 11.5% in comparison with the one of the mobile sand dune; whereas the value of conductivity at 0-5 cm soil layer in sand fixed region increased by 268.1% than the value of the mobile sand dune.Conclusion] The sand control technologies(gravel cover+artificial vegetation+enclosure) obviously fixed mobile sand and improved the soil physical and chemical properties, and were suitable for popularization and application in these region.