The document discusses several global and regional soil databases. It notes that the Harmonized World Soil Database is currently the most appropriate freely available global soil database, though it is no longer being updated. Efforts like Globsoilmap aim to map soils at higher resolutions but have not achieved global coverage yet. Regional databases like AfSIS for Africa provide more detailed information. National databases also exist but availability varies. New techniques involving spectroscopy, remote sensing, and statistics aim to improve soil mapping.

1. Reflections on Available
Soil Databases
Freddy Nachtergaele
10-12 November "Reducing the costs of GHG Estimates in
Agriculture to inform low emissions development”

2. Ø Introduction
Ø Global Soil Databases.
Ø FAO/UNESCO Soil Map of the World
Ø Harmonized World Soil Database
Ø Globsoilmap.net/Afsis
Ø Soil Grid – ISRIC World_Soil
Ø Regional and National Soil Databases.
Ø Access: Soils Portal
Ø Point Databases.
Ø Conclusions

3. Introduction
u Soils have received less attention than other natural
resources, partly because they are largely invisible
and partly because they are much more complex than
air and water.
u As with all data, there is a difference for soil
databases between what exists and what is available.
This is particular a problem in Europe and for point
data, but the problem is becoming more widespread.
u Remote sensing has great capabilities for monitoring.
However for soils, although progress has been made,
RS cannot determine (yet) soil properties in time and
space with sufficient accuracy.
u Soil monitoring by field sampling over large areas is
near impossible because of time and resource
constraints.
Introduction

4. Global Soil Databases
u Excelent for global modeling (in combination with GCM or other
models eg GAEZ).
u Relatively high number of soil properties available (7-20) at
different depths (2-6) depending on type of global database.
Disadvantages of Global Soil Databases
u Those based on classical soil maps present polygon or raster data
with associations of soils. Consequently there is no unique value
for a soil property but several values are given, one of which is
dominant. Point-based global soil databases present unique
values with a(n) (un) reliability estimate attached.
Inherent Difficulties related to soil property monitoring
u Soil properties cannot be measured over very large areas within a
limited time frame. Hence no baseline values for a single year
globally are available.
u Most soil properties change slowly in time, however some show
fluctuations seasonally (soil moisture, salinity) or change
drastically after a land use change (SOC, pH after deforestation).
u Laboratory methods may have sometimes a higher error range
than the change in time of soil properties.
Global Soil Databases

5. FAO/UNESCO Soil Map of the World (1971-1980)
FAO/UNESCO Soil Map of the World

6. FAO/UNESCO Soil Map of the World (1971-1980)
http://www.fao.org/geonetwork/srv/en/resources.get?
id=14116&fname=DSMW.zip&access=private
u Is still the only, fully consistent, harmonized global
soil inventory
u The paper map (1980) is polygon based and contains
info on soil unit associations, topsoil texture and
slope class.
u The digitized version (1995) is also raster based and
contains estimated values for 10 soil properties.
u It is a soil database of historical value superseded
by the Harmonized World Soil Database.
FAO/UNESCO Soil Map of the World

7. Harmonized World Soil Database (2006-2012)
Harmonized World Soil Database

8. Harmonized World Soil Database (2006-2012)
http://www.fao.org/soils-portal/soil-survey/soil-maps-and-databases/
harmonized-world-soil-database-v12/it/
u It is the most used global soil dataset.
u Raster resolution of 1km by 1km
u 20 soil properties for two soil depths (0-30 cm and
30-100cm).
u Includes SOC pool and soil moisture storing
capacities.
u Is not fully harmonized.
u Is part of GAEZ approach that models anticipated
yields for hundreds of crops worldwide.
http://www.fao.org/nr/gaez/about-data-portal/en/
u Updates no longer funded
Harmonized World Soil Database

9. Soil
moisture
holding
capacity
based
on
HWSD

10. Soil Organic Carbon pool (t/ha)

11. Soil and Terrain Suitability for Maize in Africa
(based on HWSD/GAEZ)

12. FAOSTAT Emission Database
http://faostat.fao.org/site/705/default.aspx
u Presents country data for emissions of cultivated organic soils and
grassland organic soils.
u Organic soils are derived from HWSD data.
Histosols (peat soils)

13. Soil
A9ributes
present
in
HWSD
(For
top-­‐
and
subsoil
where
appropriate)
u Soil
depth
u Organic
Carbon
u pH(H2O)
u CEC
soil
u CEC
clay
frac;on
u Total
Exchangeable
Bases
(TEB)
u Base
satura;on
u Exchangeable
Sodium
Percentage
(ESP)
u Calcium
carbonate
u Gypsum
u Sand
frac;on
u Silt
frac;on
u Clay
frac;on
u Ece
(salinity)
u USDA
Texture
Class
u Bulk
Density
u Reference
Bulk
Density
u Soil
Drainage
class
u Presence
of
Gelic
proper;es
u Presence
of
Ver;c
proper;es
u Soil
Phase
informa;on

14. Additional information contained in HWSD
1.Land cover/land use shares (5’grid based on GLC 2000)
Rain-fed cultivated land, Irrigated cultivated land,
Forest land, Pasture land, Barren/slightly vegetated
land, Water, Urban land.
2. Terrain slope and aspect distributions (5’grid)
3. Soil qualities for agriculture (5’grid)
Nutrient availability, Nutrient retention capacity, Rooting
conditions, Oxygen availability, Excess salts, Toxicity
and Workability, Soil erodibility.
4. Rural and urban population distribution (5’grid)

15. Globsoilmap.net (2009-Now)
www.globalsoilmap.net
u Project undertaken by ISRIC, CSIRO, USDA, JRC
etc…
u Funded by the Bill and Melinda Gates Foundation
Intends to predict soil properties at a very fine
spatial resolution (~100 m),
u Digital Soil Mapping (DSM) techniques with
infrared spectroscopy, radar, hyperspectral
imagery, advanced modelling, GIS and statistical
techniques.
u After 5 years, the project has produced a new
regional database for Sub-Saharan Africa (AfSIS) at
a resolution of 1 by 1 km with 7 soil properties at 6
different depths.
u Work in (slow) progress
Globsoilmap.net

16. African Soil Information System (AfSIS)
http://www.africasoils.net/
(ISRIC and ICRAF with some African partners)
Organic carbon estimate (0-5cm)
AfSIS

17. Soil Grids 1km (2013- Now)
http://soilgrids1km.isric.org/
u ISRIC’s Experimental global soil database
u Resolution 1km by 1km
u Uses advanced statistics
u Maps for 7 soil properties at six standard
depths
u Predicts also soil types
Soil Grids 1km (2013-now)

18. Global Soil Databases – Evolution
Evolution

19. Global Soil Databases – conclusions
1. The Harmonized World Soil Database is the most
appropriate global soil database freely available at the
moment. It is produced with “old” technology and is no longer
updated.
2. The Globsoilmap.net project is far from achieving world
coverage and is unlikely to do so at a resolution of 100 meters
for a long time to come.
3. Enhanced regional soil databases are being produced such as
AfSIS.
4. SoilGrids1km is an experimental product with a limited
number of soil parameters.
All global soil databases suffer from inherent limitations
related to the sometimes high variability of soil properties in
space and time and the impossibility to create a base-line for
large areas.
Conclusions

20. National and Regional Soil Databases
A multitude of regional and national soil databases exist and are accessible on-line:
FAO: http://www.fao.org/soils-portal/it/
JRC: http://eusoils.jrc.ec.europa.eu/library/maps/country_maps/list_countries.cfm
ISRIC: http://www.isric.org/content/data
AFRICA
Contact National Soil Information Centers
Sub-regional Soil Information
• Soil Atlas for Africa
• New generation soil property maps for Africa
• Soil and Terrain database for North Eastern Africa
• Soil and Terrain database for Central Africa
Country Soil Maps and Geographic Databases
• EUSDAM (all African Countries)
• Burkina Faso
• SOTER Kenya
• SOTER Senegal and Gambia
• SWALIM - Somalia Water and Land information management
• South Africa Natural Resources Atlas
• SOTER Tunisia
• Soil and Terrain database for Southern Africa

21. Soil Profile Databases
u Provide Geo-referenced soil information
u Often not, or not freely available. Good sources below:
u http://www.isric.org/data/isric-wise-global-soil-profile-data-ver-31
u http://worldsoilprofiles.org/nl-nl/profile/search/#search

22. New techniques
u Mid-infrared (MIR) and near-infrared
(NIR) spectroscopy techniques are used
for chemical analysis and are based on
diffuse-reflectance.
u Remote sensing allow better modeling of
soil properties: Digital Elevation Models,
Land Cover Share, Population etc…
u Advanced statistical techniques:
krigging, co-krigging, use of splines etc…

23. Thank you for you attention J
http://www.fao.org/soils-portal