S20 Eurasian Soil Science, Vol. 38, Suppl. 1, 2005, pp. S20–S26. Original Russian Text Copyright © 2005 by Napoli, Costantini, Castellani, Gardin. English Translation Copyright © 2005 by MAIK “Nauka /Interperiodica” (Russia). INTRODUCTION The World Reference Base [12] is a soil classifica- tion system that has been indicated as an international reference for soil classification; however, in the past few years, the WRB was not only chosen as a reference for the exchange of soil profiles information, but also for characterizing soil types in soil cartography. This is the case for several EU countries, which followed the suggestions of the European program aimed at soil mapping of the continent at a 1 : 250000 scale, to rec- ognize and establish soil typologies (soil bodies) by means of the WRB [2]. However, the actual WRB application in small-scale soil maps has produced inconsistent results, for the attribution of soil type to soil cartographic units, because different methodologies were adopted. Some- times, a simple identification (soil taxonomic unit = soil map unit) was chosen; in other cases, a more detailed description of the soil type, before assigning it to the related map unit, was preferred [1, 13–16]. If we analyze the solutions taken on in the cited national experiences, we can see that, although the cor- relation mechanism for single soil profiles is tested, it seems very difficult if not impossible to correlate soil maps, because of the lack of a common system of rules guiding the gathering and grouping of soil properties into a soil map unit. In Italy, the program of soil mapping on the 1 : 250000 scale is based on a work procedure that defines soil typologies with both the WRB and ST–USDA sys- tems and with adjunctive specific soil functional char- acters and qualities, which are more detailed than those comprised in the soil body concept [3, 4]. The mapping program is led by regional soil services, which tune the methodology according to local experiences and needs. This work reports the solutions adopted in applying the WRB to benchmark soils and mapping units of the Tuscany region (central Italy) and the suggestions for a modification of the WRB system that could improve its performance in soil mapping. MATERIALS AND METHODS Reference Databases for the Tuscany Region The Tuscany region occupies an area of about 22 990 sq. km in the central part of Italy. A series of soilscapes on different scales were built, on behalf of the National Soil Mapping project belonging to the “Agriculture and Quality” Measure of the Italian Min- istry for Agricultural and Forestry Policies [3]. The Soil Regions (1 : 1 M) level was provided by the national working group in the European area [18], whereas the New Proposals toward a WRB System for Soil Cartography: The Soil Map at 1 : 250 000 Scale of the Tuscany Region (Central Italy) R. Napoli 1 , E. A. C. Costantini 1 , F. Castellani 2 , and L. Gardin 3 1 Experimental Institute for Soil Study and Conservation, Soil Genesis, Classification, and Mapping Dept., P.O.BOX 50121—30, M.D’Azeglio, Firenze, Italy e-mail: napoli@issds.it 2 Private Consultant, Environmental Technical Office, P.BOX 53100, Siena, Italy 3 Tuscany Regional Agro-Forestry Service—26, Novoli, Firenze, Italy Abstract—In the course of the last years the World Reference Base system (WRB), considered a reference for correlation of single pedons, has been widely used to make soil cartography and produce soil maps. This kind of use of a soil classification system highlights some conceptual problems, like finding rules for the setting up of typological units and cartographic units from the classified pedons. A possibility is to treat characters and properties important for management separately from the genetic. The soil cartography at 1 : 250000 of the Tuscany Region (central Italy) was a useful test for the application of a WRB new proposal. Some new concepts were proposed, like (i) the introduction of a pragmatic level, coherent with the WRB architecture, for the conveying of soil information from the pedon to the map unit, (ii) the defi- nition of concepts and thresholds related to functional characters, for the differentiation of “similar” from “dis- similar” soils, and (iii) the setting up of rules for the number of qualifiers to be used in this kind of soil maps. All pedons were classified according to both current and modified WRB systems; the comparison showed the improvement obtained with the new method, while the soil map displayed soil typological variability more faithfully. DEVELOPMENT OF THE WORLD REFERENCE BASE FOR SOIL RESOURCES