Experiences with WRB in the 1:250,000 mapping in Italy

1. Experiences with WRB in the 1:250,000 mapping in Italy • Numerous authorities are active in many fields involving soil information issues: • at national level (e.g. the Agricultural and the Environmental Ministries; the Environmental and Technical Services Agency) • at regional level (only a few regions have a permanent staff consisting of more than one or two soil scientists) Institutional Framework and Soil Classification Systems • At national levelboth a Soil Survey Service and a Soil Classification System are lacking. • In the sixtiesthe French (CPCS) classification system was the main reference • Subsequently the USDA Soil Taxonomy and the Legend for the FAO World Map were the main references. • Over the last few years the FAO Legend was replaced by WRB.

2. 1:250,000 mapping through subsequent stages • The 1:250,000 soil maps are implemented through a series of approximations, • which correspond to subsequent quality levels • aimed at taking into account urgent matters and priorities • without the intention of describing the soil in a definitive manner • The “1st approximation” of the 1:250,000 soil map. • Concerning the whole Italian territory. • Carried out by the European Soil Bureau on behalf of the Italian Environment Ministry. • Works started in 1998 and ended in 2001. • Main purposes: analyses about relations between soil and vegetation and soil erosion risk assessments • An initial means of dealing with the problems encountered by the users of data for applications; • Concrete starting point to direct future approximations in order to fulfil the users’ demands. • A “2nd approximation”, i.e. the “1:250,000 Soil Map of Italy”. • Concerning the great part of the Italian territory. • Carried out by regional teams (ref. at national level: Agriculture Ministry). • Some Regions started in 1999 and others are going to start now (http://web.tiscalinet.it/adanto/forum/) • Related project: “Pedological Methodologies”, aimed at defining methods and procedures for soil survey, soil mapping and soil information disseminating (http://www>issds.it/cncp/)

3. Using WRB for the different 1:250,000 soil mapping projects • For the 1st approximation project • the soil classification was mostly achieved by conversion of Soil Taxonomy • (or FAO Legend) to WRB. • The use of only one or two qualifiers to designate the lower level units • has been considered to be acceptable. • As for the 2nd approximation project, • most of the regional teams are achieving the WRB soil classification: • first by defining local typological soil units (STU) that, as best as possible, ~ fit the spatial organization of the soil cover within the landscape; ~are relevant to main actual applications (e.g. they are useful for predictions about use or management of land) • andthen by allocating the STU to the WRB (and Soil Taxonomy) classes.

4. Using WRB for the different 1:250,000 soil mapping projects (continued) • The local STU are not entirely independent of WRB (and of Soil Taxonomy). • But, when the STU do not perfectly belong to the WRB classes, • most of the soil survey regional staffs • describe as "not perfect" the STU linkages to WRB classes, • rather than to change their definition in order to make them coinciding with the WRB classification. • This way of working is based on the grounds that it is important to keep: • both the STU predictive power for practical purposes • and the STU coherence with the soil cover structure • (prominent soil-landscapes limits should not be split) • The WRB lower level units: • specificity and adequacy for predictions about use or management of land • bridging the gap with local STU • (Examples from Calabria, Piemonte and Veneto regional soil teams)

5. Harmonising the use of WRB • The development of comparable guidelines and procedures is facilitated by the • broad conceptual coherence of soil information in Italy, • which is a consequence of the either direct or indirect • links with the same pedological school (Prof. Mancini, University of Florence). • A manual for soil description has been worked out at interregional level <http:/www.soilmaps.it/fr-down-load.htm>, • which is coherent with the Manual of Procedures for the European Georeferenced Soil Database and with FAO guidelines for field soil description. • Official standard methods for chemical, physical and microbiological soil analyses • have been prepared by the Committee for the National Observatory for Soil and Soil Quality (supporting the Agricultural Ministry). • Correlation analysis with ISO-formats has to be improved. • Harmonisation of sampling strategies, field soil description guidelines, sample preparation and laboratory analyses: • crucial for the comparability of the WRB classification • among different regional teams • towards more effective comparative evaluation • and accreditation systems (QA and QC)

6. Harmonising the use of WRB(continued) Beyond the manuals, the field correlation is indispensable to effectively harmonise the classification. Soil maps and data bases can express only a part of the knowledge acquired in the field during the survey (the other “tacit knowledge” remains in the mind of the field soil surveyor). Because of the importance of the local experience of the soil surveyor, it is crucial to find ways to guarantee the continuity of its work Problems related to small permanent staff of the regional soil services: only partly solved by co-operating with best quality professionals and private companies. Since the trend is to reduce public technical services, the small permanent staffs demand for more continuity in the co-operation with professionals.