EUROPEAN SOIL BUREAU RESEARCH REPORT NO. 7 A Comparative Study of the Latvian Soil Classification with WRB

A comparative study of three different soil classification systems: Latvian Soil Classification, World Reference Base for Soil Resources (WRB) and USDA Soil Taxonomy was performed. The objective of the study was to investigate the possibilities to make comparison of soil taxa, which has importance for international communication and information exchange. The focus was put on the comparison of Latvian system with WRB, which is supposed to be a reference base for correlation of national soil units and a tool for international information exchange. The methods used were soil pedons ’ descriptions according to the internationally used guidelines and soil classification according to the above mentioned systems. Additionally, analysis of soil classification principles and criteria were used within each of the system. In the higher categorical level WRB consists of 30 major soil groups (Reference soil groups), Latvia soils are supposed to correspond to 14 of them. Similarly WRB defines 39 soil diagnostic horizons, 12 diagnostic properties and 7 diagnostic materials. For characterization of Latvian soils currently we found relevant 13, 8 and 6 respectively of them. For differentiation of the lower categorical level WRB uses predefined so called formative elements the total number of which is 120. For characterization of Latvian soils 56 presumably might be used. We should recognize that some of them are found very rarely, but th