Reflections on Available Soil Databases Freddy Nachtergaele

10-12 November "Reducing the costs of GHG Estimates in Agriculture to inform low emissions development”

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

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

Introduction

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

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

FAO/UNESCO Soil Map of the World

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

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

Harmonized World Soil Database

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

Harmonized World Soil Database (2006-2012)

Soil  moisture  holding  capacity  based  on  HWSD  

Soil Organic Carbon pool (t/ha)

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

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)

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    

Soil  A9ributes  present    in  HWSD    (For  top-­‐  and  subsoil  where  appropriate)  

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    

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)

Additional information contained in HWSD

Globsoilmap.net (2009-Now)

Globsoilmap.net

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

http://www.africasoils.net/

(ISRIC and ICRAF with some African partners)

Organic carbon estimate (0-5cm)

African Soil Information System (AfSIS)

AfSIS

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)

Soil Grids 1km (2013-now)

Global Soil Databases – Evolution

Evolution

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

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

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

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…

Thank you for you attention J

http://www.fao.org/soils-portal