关键词: 西藏, 酸性土壤, 交换性盐基组成, 离子饱和度

Abstract: According to the analysis data of 76 soil profiles of 9 soil great groups in Tibet, exchangeable base and change trend of acid soil are discussed. The results indicate that the change of BIS(Base Ion Saturation) is the same as those of BS and pH(which is decided by BS) generally. The change of BS and pH are mainly attributed to the change of Ca²⁺, but little affected by the change of Mg²⁺, K⁺, Na⁺. As a whole, the compositive percentage of each exchangeable base ion varies with BS and pH. The ratio of Ca²⁺ is in positive relation with that of BS and pH, and the change range is broad, on the contrary, the compositive ratio of Mg²⁺, K⁺, Na⁺ is negative relation with that of BS and pH, and the change range is narrow, especially in the soil with low values of BS and pH.

Key words: Tibet, acid soil, compositive percentage of exchangeable bases, ion saturation percentage