X.Z. Shi1*, D. S.Yu1, E.D. Warner2*, W.X. Sun1, G.W. Petersen2 , Z. T. Gong1 1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China 2Office for Remote Sensing of Earth Resources, The Pennsylvania State University, University Park, Pennsylvania, USA

ABSTRACT Soil classification systems are not consistent between countries or organizations thereby hindering the communication and organizational functions they are intended to promote. The development of translations between systems will be critical for overcoming the gap in understanding that has resulted from the lack of a single, internationally accepted classification system. This paper describes a case study of categories for soil order and great group, which resulted in the translation of the Genetic Soil Classification of China (GSCC) to Soil Taxonomy (ST). A brief history of soil classification in China is also provided to familiarize readers with GSCC and its origins. Three soil datasets used in the study are introduced, which include information on 2,540 soil species of “Soil Species of China (six volumes)” and provincial soil species from locations throughout China, and the newly created digital version of the 1:1,000,000 scale soil map of China. The translation from GSCC to ST was based on profile descriptions, physical and chemical analysis data of 2,540 soil species. During the translation, the 2,540 soil species were classified to their equivalent soil order, suborder, great group and subgroup according to ST and GSCC subgroup descriptors. GSCC order and great group names and ST order names were then linked to corresponding map units in the 1:1,000,000 digital soil map of China using a geographic information system. GIS tabulation made possible the summary and display of the distribution of Chinese soils according to GSCC and ST classification units. Cross-reference benchmarks between GSCC and ST soil orders were established. The reference compatibility between the GSCC great groups and the ST soil orders was developed. According to maximun referencibility, it is believed that GSCC 22 great groups with ST soil orders are of high referencibility with maximum referencibility > 90%; 24 great groups have intermediate referencibility with maximum referencibility in the range of 60-90%, which can be cited as reference benchmarks; The remaining 14 GSCC great groups are less compatible, with maximum referencibility <60% and need further study, or require referencing at lower classification levels or at a regional level to help to improve the accuracy of the reference.

ACKNOWLEDGEMENTS We gratefully acknowledge support for this research from The National Natural Science Foundation of China (No. 40471081), the Innovation Project of the Chinese Academy of Sciences ISSASIP0201 and the Key Innovation Project of Chinese Academy of Sciences (KZCX3-SW-427).