怀来盆地不同土地利用方式对土壤质量的影响分析

Effects of Land Use on Soil Quality in Huailai Basin,Hebei Province

基于对河北省怀来县官厅水库南北两岸8种主要土地利用类型的土壤养分、pH值和土壤容重等的分析,讨论了不同土地利用方式对土壤质量的影响,并评价了不同土地利用方式下的土壤退化程度。结果表明:怀来县官厅水库北岸的防护林地,由于合理的土地利用管理与保护措施,土壤容重最低,土壤养分含量高于其它几种土地利用方式;而由坡耕地撂荒后演替而来的草地,由于当地干旱寒冷多风的气候环境,土壤的母质条件以及缺乏有效的恢复措施等原因引起土壤质量继续退化;在长期不合理的土地管理措施影响下位于水库南岸的防护林地及葡萄园、果园、玉米地等土壤也发生较严重退化,表现为土壤容重、pH值显著增加,大部分土壤养分显著降低。土壤退化指数的计算结果也表明草地及南岸的玉米地、葡萄园的土壤发生了较严重的退化。在对数据进行处理分析过程中发现,土壤有机质、有机碳与全氮之间存在显著正相关关系。

It is essential to use rationally the lands in ecologically vulnerable environment to preserve soil quality and develop sustainable land use model. This study was undertaken to evaluate the effects of land use on soil nutrients and pH value as well as soil bulk density in Huailai basin of Hebei province. Eight dominating land use types were collected from two representative regions which respectively lie to the north and south of Guanting reservoir, second largest drinking water source for Beijing city. Moreover the soil degradation degree of different land use types was evaluated by soil degradation index (DI). The results show: Under rational land management and effective conservation practices, compared to other 7 land use types, the bulk density value of shelter-forest land in the north of Guanting reservoir is least and most of its soil nutrients showed significant increase. However, because of local formidable natural conditions and void restoration measures, soil quality of grassland which although developed from discarded field for 8 years was still at the degradation stage. Moreover, the soils under shelter-forest, vine and cherry-apple trees as well as corn in the south of Guanting reservoir were also subject to severe soil degradation andgreat decline of soil quality without appropriate soil and water conservation practices. The bulk density and pH value in these lands increased and most soil nutrients significantly decreased. The soil degradation index shows that severe degradation occurred to grassland and farmland and vine yard land in the south ofGuanting reservoir. On the whole, there was significant correlation between soil quality and land use model. Irrational land management approaches and measures, such as over-grazing, deforestation and over-irrigation and so on, led to soil degradation and greatly diminished soil quality.