摘要
晋西北是我国北方旱作农田沙化土地较严重的地区之一,开展不同地类土壤的机械组成、有机质及其二者之间关系的研究,以期为该区沙化土地类型和程度评价及其防治效益评估提供科学依据。对研究区农田、人工林地(乔木)和荒地的表层(0—20cm)和下层(20—40cm)土样进行粒度和有机质分析,结果表明:不同地类土壤的机械组成均为粉粒(0.002～0.05mm)>极细砂(0.05～0.1mm)>细砂(0.1～0.25mm)>黏粒(<0.002mm),中砂及以上粒级(>0.5mm)含量极少,其中粉粒、极细砂和细砂为优势粒级组分,三者含量之和在90%以上。农田受翻耕影响,其表层和下层土壤机械组成差异不大;人工林地中林间表层受草本植被影响,其表层颗粒明显细于下层;荒地由于受冬春季风蚀影响,其表层则略粗于下层。不同地类土壤有机质的积累均表现出表层含量大于下层,总体上有机质含量表现为农田>荒地>人工林地。不同地类的土壤机械组成与有机质的关系,呈现出粉粒和黏粒与有机质含量呈正相关关系,而细砂和极细砂与有机质则呈负相关关系,在相关程度上,粉粒和细砂与有机质含量的正、负相关性最大,是研究区不同地类土壤有机质积累与否的关键粒级。
Northwest of Shanxi Province is one of the severe desertification areas in northern China.The samples of topsoils(0-20 cm)and subsoils(20-40 cm)collected from cropland,planted forest land and wasteland in the northwest of Shanxi Province,were analyzed for particle sizes and organic matter in the laboratory.The results showed that the contents of particle sizes decreased in order:silt(0.002～0.05 mm)>very fine sand(0.05～0.1 mm)>fine sand(0.1～0.25 mm)>clay(<0.002 mm)in the study area,and the content of>0.5 mm particle size was very few.The contents of dominant size fractions which were silt,very fine sand and fine sand exceeded 90%.The soil mechanical composition was not significant difference between topsoil and subsoil in cropland due to plowing;the fractions of topsoil was finer than subsoil in the planted forestland because of the function of dispersing soil parent material of herbage which were grown in the topsoil under forest;and the soil in wasteland was less covered by vegetation layer in the winter and early spring when the wind erosion is the strongest in the year.The contents of organic matter from different land types in this area appeared greater in the topsoils than subsoils.The content of organic matter decreased in the order:cropland>wasteland>planted forest land.In terms of correlativity between soil mechanical composition and the content of organic matter,the fine particles(silt and clay)are positively correlated with the content of organic matter,while the coarse particles(fine sand and very fine sand)are negatively correlated with the content of organic matter.From the viewpoint of relevance degree,silt and fine sand are significantly positively and negatively correlated with the content of organic matter,respectively,which indicates that silt and fine sand are the key size fractions determining the organic matter accumulation.
作者
苏志珠
刘蓉
梁爱民
马义娟
王国玲
高君亮
哈斯
SU Zhizhu;LIU Rong;LIANG Aimin;MA Yijuan;WANG Guoling;GAO Junliang;HA Si(Historical Culture School,Shanxi University,Taiyuan 030006,China;College of Geography Science, Taiyuan Normal University,Jinzhong,Shanxi 030619,China;Northwest Institute of Eco-environment and Resources, Chinese Academy of Sciences,Lanzhou 730000,China;College of Environment and Resources,Shanxi University, Taiyuan 030006,China;Experimental Center of Desert Forestry,Chinese Academy of Forestry,Dengkou,Inner Mongolia 015200,China;College of Resources Science and Technology,Beijing Normal University,Beijing 100875,China)
出处
《水土保持研究》
CSCD
北大核心
2018年第6期61-67,共7页
Research of Soil and Water Conservation
基金
国家重点研发计划项目"京津冀风沙源区沙化土地治理关键技术研究与示范"第5课题(2016YFC0500805)
山西省研究生教育创新项目(2016SY056
SYYJSJC1604)
关键词
沙化土地
机械组成
有机质
晋西北
desertification land
soil mechanical composition
organic matter
northwest of Shanxi Province
