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

1
Experiences with WRB in the 1250,000 mapping in
Italy

• Institutional Framework and Soil Classification
  Systems

• 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)

At national level both a Soil Survey Service and
a Soil Classification System are lacking.

• In the sixties the 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
1250,000 mapping through subsequent stages

• The 1250,000 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 1250,000 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 1250,000 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/foru
  m/)
• Related project Pedological Methodologies,
  aimed at defining methods and procedures for soil
  survey, soil mapping and soil information
  disseminating (http//wwwgtissds.it/cncp/)

3
Using WRB for the different 1250,000 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)

• and then by allocating the STU to the WRB (and
  Soil Taxonomy) classes.

4
Using WRB for the different 1250,000 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 lthttp/www.soilmaps.it/fr-d
  own-load.htmgt,
• 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.