开垦对退化沙质草地土壤机械组成及有机碳分布的影响  

The Effect of Cultivation on Soil Aggregates and SOC in Degraded Sandy Grassland of Farming-Grazing Transition Zone

作　　者：李顺江[1] 胡霞[2,3] 刘连友[2,3] 

机构地区：[1]北京市农林科学院植物营养与资源研究所,北京100097 [2]北京师范大学减灾与应急管理研究院,北京100875 [3]环境演变与自然灾害教育部重点实验室,北京100875

出　　处：《水土保持研究》2011年第4期150-152,共3页Research of Soil and Water Conservation

基　　金：北京市优秀人才计划"不同肥源对土壤重金属污染及蔬菜品质的影响"(2010D002020000004);北京师范大学自助创新基金"机动车碾压对干草原土壤风蚀的影响机理研究";地表过程与资源生态国家重点实验室开放基金(2001-KF-09)

摘　　要：分析了退化沙质草地开垦耕种40,15,6 a的草地的土壤理化性状的特征和变化。结果表明:草原土壤开垦后,土体自然结构基本消失,分散成单粒或由不同单粒结合的微团聚体,力学稳定性降低,表层土壤粒径<0.02 mm的黏粉粒的显著降低,0.002～0.02 mm和<0.002 mm显著增加,随着开垦年限的延长,土壤进一步向粗粒化和单粒化演变;当草地开垦为农田后及转化为林地后,土壤质地又会逐渐逆转,林地中0-2 cm和2-4 cm深度土壤中<0.002 mm的颗粒又会增加。同时开垦还会导致土壤有机碳下降,土壤肥力严重下降。草地开垦后土壤粒级分布的显著变化,可以反映出开垦导致的强烈土壤结构破坏和受风蚀影响的程度。Cultivation is the other factor influencing grassland soil degradation.Soil structure could be changed by cultivation.And contents of clay and silt would be decreased greatly,and the particles of 〈0.002～0.02 mm and 0.002 mm increased obviously.With ages of cultivation,soil structure would evolve to be coarse.When cultivated grassland was transformed to forest land,the particles of 0.002 mm in the 0-2 cm and 2-4 cm layers increase.Moreover,soil fertility was decreased greatly,such as depletion of soil organic constituents.In addition,the loss rate of SOC was also accelerated by cultivation.The change of soil structure of the cultiveated grassland can indicate the extent of destruction of soil structure due to cultivation and erosion.

关 键 词：开垦 沙质草地 机械组成 有机碳 

分 类 号：S152.3[农业科学—土壤学] S153.621[农业科学—农业基础科学]