WoSIS Soil Profile Database

The World Soil Information Service (WoSIS) aims to serve the user with a selection of standardised and ultimately harmonised soil profile data.  The quality-assessed data may be used to underpin digital soil mapping and a range of global assessments. WoSIS is an important building block of ISRIC’s evolving, searchable data infrastructure.

Aims

The aims of the World Soil Information Service are to:

  • Safeguard world soil data 'as is' (especially for soil legacy data)
  • Share soil profile (point) data upon their standardization and  harmonization
  • Provide quality-assessed, standardised soil data for digital soil mapping and a range of environmental applications.

 

General workflow

All data submitted for consideration in WoSIS are first preserved ‘as is’ in the ISRIC WDC-Soils Data Repository. Subsequently, they are quality-assessed (i.e. plausibility checks), standardised, imported into the WoSIS data model itself and, where possible, harmonised using consistent procedures (Fig. 1).

We presently consider the following soil chemical properties (organic carbon, total carbon, total carbonate equivalent, total nitrogen, phosphorus (extractable-P, total-P, and P-retention), soil pH, cation exchange capacity, and electrical conductivity) and physical properties (soil texture (sand, silt, and clay), bulk density, coarse fragments, and water retention), grouped according to analytical procedures (aggregates) that are operationally comparable. Further, for each profile, we provide the original soil classification (FAO, WRB, USDA, and version) and horizon designations insofar as these have been specified in the source databases. WoSIS workflow

                                         Figure 1. Workflow for processing data in WoSIS

 

Measures for accuracy

Soil profile data that underpin WoSIS were derived from a wide range of sources. Three measures for the (inferred) accuracy of the data are presented:

  • geographical accuracy (i.e. location) of the point data
  • a first approximation for the uncertainty associated with the operationally defined analytical methods
  • date of sampling.

These measures are provided for possible consideration in digital soil mapping and subsequent earth system modelling.

Further, when specified by the data providers, additional information is provided on the analytical methods themselves (e.g. class size limits for soil textural fractions or the fine earth fraction, see documentation). This extra information provides the basis for eventual harmonisation, the ultimate long-term goal of WoSIS.
 

Serving standardised data

Some 215,000 geo-referenced, standardised point data are currently served from WoSIS via WFS (Fig. 2). This corresponds with more than 6 million soil records. The number of measured data for each property varies between profiles and with depth, generally depending on the purpose of the initial studies. Further, in most source data sets, there are fewer data for soil physical as opposed to soil chemical attributes. There also are fewer measurements for deeper than for surficial horizons. Generally, limited quality information is associated with the various source data. Further, standardised data set for some 45,000 profiles can not be distributed to the international community due to license restrictions. For a full description, see here.

 

                       Figure 2. Location of soil profiles provided from WoSIS via WFS (September 2019)

 

Full data harmonization in a global context, the ultimate objective, will first become feasible once results of extensive, comparative proficiency testing programmes become available, for example in the framework of Pillar 5 of the Global Soil Partnership and GLOSOLAN (Global Soil Laboratory Network), and a common set of ’international’ reference methods (e.g. ISO procedures or SOP’s developed by GLOSOLAN) has been accepted by the international soil community.

 

Data download

Data served from WoSIS are supplied in compliance with the license specified by each data provider.

The standardised data can be accessed here

 

Applications

An important application of the WoSIS-standardised data at ISRIC, in collaboration with partners, is the generation of soil propery maps for the world using digital soil mapping (see SoilGrids) and other products derived from adavanced data processing (e.g. aps, visualizations). The resulting producs are freely available to the international community through ISRIC's Soil Data Hub.

 

Sharing data to support global modelling

If you wish to share soil profile data for consideration/processing in WoSIS please see here. The WoSIS team will be happy to assist!

 

Technical documentation and data papers

  1. Batjes NH, Ribeiro E and van Oostrum AJM, 2020. Standardised soil profile data to support global mapping and modelling (WoSIS snapshot 2019).  Earth System Science Data (paper).
  2. Batjes NH, Ribeiro E and van Oostrum AJM 2019. Standardised soil profile data for the world (WoSIS snapshot - September 2019).  ISRIC WDC-Soils (dataset).
  3. Ribeiro E, Batjes NH and van Oostrum AJM 2020. World Soil Information Service (WoSIS) - Towards the standardization and harmonization of world soil data. Procedures Manual 2020. ISRIC report 2020/01, ISRIC - World Soil Information, Wageningen, 166 p. (report).