中山市不同土地利用方式下土壤肥力特性的剖面分布特征

了解不同利用方式下土壤肥力状况,揭示影响土壤肥力的障碍因子,对区域土壤资源管理及合理施肥具有重要意义.调查了中山市不同土地利用类型(水田、菜地、林地)土壤,测定了不同发生层次土壤的颗粒组成、pH值、有机质、氮、磷、钾、阳离子交换量等特性,分析了土壤肥力特性的剖面特征,评价了耕层(表层)土壤肥力状况.结果表明:供试的水田、菜地土壤黏粒、粉粒含量高,林地土壤以砂粒、黏粒为主,土壤颗粒组成与成土母质类别密切相关.菜地、水田土壤耕层呈现酸化特征,具有含硫层的土壤酸性极强.林地土壤CEC最低,水田和菜地土壤CEC较高,人为管理和成土母质类型影响土壤CEC.土壤有机质、氮、磷含量随土层深度的增加而降低,菜地耕层土壤有效磷极为丰富,林地土壤碱解氮、有效磷、速效钾含量最低.土地利用方式深刻影响耕层(表层)土壤有机质、氮、磷的积累,钾含量主要受成土母质的影响.针对中山市土壤肥力特性,提出了合理管理土壤的建议.

Profile distribution characteristics of soil fertility properties under different land use patterns in Zhongshan city

Understanding soil fertility status under different land use patterns and finding out limiting factors affecting soil fertility are of great importance for regional soil management and rational soil fertilization. Soil under different land use patterns including paddy field, vegetable field and woodland in Zhongshan city were investigated, soil particle composition, pH, organic matter, N, P, K, cation exchange capacity (CEC) in different soil horizons were analyzed, soil fertility in soil profile and plough/surface horizon were assessed in this paper. The results indicated that clay and silt were high in soil of paddy and vegetable fields, and sand and clay were high in soil of woodland, soil particle composition closely related with parent materials. Soil in plough layer of paddy and vegetable fields had acidification tendency and soil with a sulfic horizon had strong acid. The CEC was the lowest in woodland soil, and was higher in soil of paddy and vegetable fields, human management and parent materials influenced soil CEC. Soil organic matter, N, P decreased with the increase of soil depths, soil available P in plough horizon of vegetable field was very abundant, and soil available N, P and K in woodland were the lowest. Soil organic matter, N, P contents in plough (surface) layer were affected by land uses patterns, and K content was affected by parent materials. Soil management suggestions were put forward according to soil fertility properties in Zhongshan city.