土地利用方式对桂西北石漠化地区土壤理化性质的影响

在广西壮族自治区凌云县典型石漠化地区对7种不同土地利用方式土壤理化性质进行了调查分析.结果表明,不同土地利用方式对土壤容重、含水量、总孔隙度、毛管孔隙度、非毛管孔隙度存在极显著差异(p＜0.01),有机质、全氮、全磷、全钾、速效氮、速效磷、速效钾及交换性Ca2+含量差异极显著(p＜0.01).相对阔叶林地土壤,灌木林、针叶林、退耕台地、草地、退耕坡地、农田土壤的退化程度依次增加.农田土壤质量最低,针叶林地、草地、退耕坡地、退耕台地土壤质量为中等,灌木林地与阔叶林地土壤质量较高.人为干扰是影响土壤理化性质的主导因素,干扰强度大,土壤理化性质退化严重.控制不合理的人为干扰及恢复结构良好的地上植被对改善土壤质量具有重要意义.

Effects of Different Land Use Systems on Soil Physical and Chemical Properties in Karst Rocky Desertification Area of Northwest Guangxi Province

Soil physiochemical properties for 7different landuse types were investigated in the typical karst rocky desertification area of Lingyun City,Guangxi Zhuang Autonomous Region.Results showed that different landuse systems had significant effects(p <0.01)on the bulk weight,water content,total porosity,capillary porosity and non-capillary porosity,as well as the organic matter,total N,P and K,effective N,P and K,and exchangeable Ca²⁺.Compared with the soil in broad-leaf forest,the degrees of soil degradation in shrub land,coniferous forest land,fallow terrace farmland,grassland,fallow sloping land and farmland became serious in turn.Among them,soil quality was he worst in farmland and it was in middle in coniferous forest land,grassland,fallow sloping land and fallow terrace farmland,while it was better in shrub land and broadleaf forest land.Human disturbances were the dominant factor affecting soil physiochemical properties. Hence,the degrees of soil degradation were changed with disturbance intensity.It is significant to control unreasonable disturbances and restore good vegetation for soil quality improvement in the region.