Agriculture Reference
In-Depth Information
issues of FAO World Soil Resources Reports (FAO, 1961Ï1971). The Ýnal Legend for the map
was published in 1974. The last and Ýnal map sheets for Europe appeared in 1981.
With the rapidly advancing computer technology and the expansion of geographical information
systems during the 1980s, the Soil Map of the World was Ýrst digitized by ESRI (1984) in vector
format, and contained a number of different layers of land resource-related information (vegetation,
geology), often incomplete and not fully elaborated upon. In 1984, a Ýrst rasterized version of the
soil map was prepared by Zbler, using the ESRI map as a base and using 1
grid cells. Only
the dominant FAO soil unit in each cell was indicated. This digital product gained popularity
because of its simplicity and ease of use, and is still considered a standard, particularly in the
United States, in spite of its drawbacks.
In 1993, FAO and the International Soil Reference and Information Centre (ISRIC) jointly
produced a raster map with a 30
×
1
ο
ο
cell size in the interest of the WISE (World Inventory of
Soil Emissions) project (Batjes et al., 1995). This database contains the distribution of up to ten
different soil units and their percentages in each cell.
In 1995, FAO produced its own raster version, which had the Ýnest resolution with a 5
'
×
30
'
'
×
5
'
cell size (9 km
9 km at the equator), and contained a full database corresponding with the
information in the paper map in terms of composition of the soil units, topsoil texture, slope class,
and soil phase in each of the more than 5000 mapping units. In addition to the vector and raster
maps discussed above, the CD-ROM contains a large number of databases and digital maps of
statistically derived (or expert guestimates of) soil properties (pH, OC, C/N, soil moisture storage
capacity, soil depth, etc.). The CD-ROM also contains interpretation by country on the extent of
speciÝc problem soils, the fertility capability classiÝcation results by country, and corresponding
maps. For more information, see
×
http://www.fao.org/WAICENT/FAOINFO/AGRI-
CULT/AGL/lwdms.htm
An overview of the publication stages of the paper Soil Map and its digitized version is given
in Table 12.1.
The development of the SOTER (SO = SOil, TER = TERrain) program started in 1986 (The
ISSS Congress in Hamburg) with the aim of providing the framework for an orderly arrangement
of natural resource data, in such a way that these data can be readily accessed, combined, and
analyzed. Fundamental in the SOTER approach is the mapping of areas with a distinctive, often
repetitive pattern of landform, morphology, slope, parent material, and soils at 1:1 million scale
(SOTER units). Each SOTER unit is linked through a geographic information system with a
computerized database containing, ideally, all available attributes on topography, landform and
terrain, soils, climate, vegetation, and land use. In this way, each type of information or each
combination of attributes can be displayed spatially as a separate layer or overlay or in tabular form.
The SOTER methodology was developed by the International Soil Reference and Information
Centre (ISRIC) in close cooperation with the Land Resources Research Centre of Canada, FAO,
Table 12.1
Important Dates in the Development of the Soil Map of the World
1960
1961
1971
1974
1981
1984
1988
1989
1991
1993
1995
1998
ISSS recommends the preparation of the soil maps of continents
FAO and UNESCO start the Soil Map of the World project
Publication of the first sheet of the paper map (South America)
Publication of the FAO Legend
Publication of the last sheet of the paper map (Europe)
ESRI digitizes the map and other information in vector format
Publication of the Revised Legend
Zöbler produces a 1
raster version
FAO produces an Arc/Info vector map including country boundaries
ISRIC produces a 30
º
x 1
º
'
'
raster version under the WISE project
FAO produces a CD ROM raster (5
x 30
'
'
) and vector map with derived soil properties
FAO-UNESCO reissues the digital version with derived soil properties, including corrections
x 5
