北京山区典型土地利用方式对土壤理化性质及可蚀性的影响

Influence of Typical Land Use Types on Soil Physico-chemical Properties and Erodibility in Beijing Mountainous

延庆县地处北京市西北部,作为北京生态环境建设工程的重要组成部分,是北京五大风沙口之一,此区属于生态环境脆弱地带,加之人类对土地资源的不合理利用,导致了严重的土壤侵蚀性问题。针对北京市延庆县山区不同土地利用类型的土壤,通过室内测试分析,并运用统计和相关分析等方法,对研究区农田、果园、苗圃幼林地、山地灌木林和土路5种土地利用类型下土壤可蚀性及其理化性质进行研究,结果表明:各土地利用类型中,山地灌木林的土壤总孔隙、土壤贮水能力、土壤饱和持水量和有机质显著大于其它土地类型(P<0.05)。不同土地利用方式的土壤可蚀性K值存在差异,由大到小依次表现为:土路(0.047 4)>农田(0.043 5)>果园(0.042 1)>苗圃幼林地(0.040 8)>山地灌木林(0.034 2)。对土壤可蚀性和土壤理化性质进行相关性分析结果表明:土壤可蚀性与砂粒、粉粒含量、黏粒含量、非毛管孔隙、土壤贮水能力和容重相关性较好(P<0.05),可作为土壤可蚀性评价的指标。

Yanqing County as one of Beijing′s five sand sources is located in the northwest of Beijing.It is an important part of the Beijing ecological environment construction project.This area belongs to fragile zone,which has been influenced by human irrational use of land,leading to the serious soil erosion problems.Through laboratory test and analysis,and using different methods such as statistics and correlation analysis,soil erodibility and its physicochemical properties of five kinds of land use types（Farmland,Orchards,Nurseries of young forest,Mountain shrub forest and Dirt road）in Beijing mountainous of Yanqing County were studied.The results showed that among different land use types,total porosity,water holding capacity of the soil,soil saturated water content and organic matter of mountain shrub forest soil were significantly higher than those of other land types（P〈0.05）.Different land use types have the K value differences,which was followed in descending order：Dirt road（0.047 4）〉Farmland（0.043 5）〉Orchards（0.042 1）〉Nurseries of young forest（0.040 8）〉 Mountain shrub forest（0.034 2）.The correlation analysis on soil erodibility and soil physical and chemical properties showed that the soil erodibility K value was closely related to the factors such as silt content,clay content,noncapillary porosity,soil water storage capacity and bulk density correlation（P〈0.05）,which can be used as evaluation indices of soil erodibility.