关键词: 土壤分类系统 , 土壤调查 , 土壤功能性状 , 世界土壤资源参比基础（WRB）

Abstract: During China Second Soil Survey, a soil classification system developed by hundreds of soil scientists was used as the normative standard in the survey. Since then, the system has been recommended and applied as the national standard. The first integration of county data from the survey showed that there were differences between the soil names extracted from county data and the names of the national system. In order to revise soil names which did not match with the national classification system, to clarify the differences among the two existing soil classification systems in China at present and the system recommended in World Reference Base for Soil Resources (WRB), research works on soil classification in last decades were reviewed and discussed in this paper.It was showed in the study that soil genesis has been applied as the common basis for soil classification in different countries. Although the theoretical basis is the same, different countries developed different soil classification systems, as the concepts, the naming conventions, the ground survey methods and the soil sampling density are different in different countries. Main reasons for that were large differences in climatic zones, richness of soil types, levels of economic and technological development at different continents and countries. Because of the language custom, the influences of already existing classification systems and the declining demand in understanding pedogenesis in soil surveys in recent years, the impact of efforts made for integrating different soil classification systems has not been obvious.Comparison among soil classification systems in different languages has been showed that the officially issued national soil genesis classification system is more in line with Chinese language characteristics. Main features of the main soil types of China are well extracted and expressed with names of the 60 Soil Great Groups of the system. These names have been approved to be easy for both the soil classification experts and the soil scientists to distinguish and cognize the dominating soil formation processes, the main futures and the spatial distributions of main soil types of the country. Since the system has been officially recommended and applied for more than 30 years and had a great impact on country-wide, so the authors suggest that the system should be used continually. Problems of the classification system, in regard with mismatching with names of soil taxonomy of WRB, should be solved by establishing the relationships between 60 Soil Great Groups of China and the soil names of WRB. The review showed that it would be conducive to the stability of the classification system and the cognition of major forming process of soil types by soil scientists, if the naming of soil types were confined to soil formation. Changing classification system in the hierarchy or introducing parameters besides soil formation process into the system may lead to burdensome soil names, weakening the cognition of soil formation process. On the other hand, information of soil genesis and classification can supply crucial supplementary information to evaluate and understand soil functionalities such as soil fertility, environment and health properties. According to the points mentioned above, soil names extracted from county data in the survey were revised and summarized. According to China National Classification System, the soil great groups were merged to 60. The names of soil sub groups were moderately merged. Names of soil genus and species, which contained rich soil forming information from survey works, were maintained as far as possible.

Key words: soil classification system , soil survey , soil functionalities , WRB