Accessing WoSIS-derived datasets

  1. Products
  2. Access data
  3. Tutorials
  4. Papers and documentation
  5. Soil properties
  6. Questions?

 

Products

Standardised datasets derived from WoSIS database are distributed in two ways. The most recent, WoSIS Latest (dynamic) version can be accessed through an OGC-compliant Web Feature Service (WFS). Further, WoSIS Snapshot (static) dataset in TSV (tab separated values) format are provided for consistent citation purposes and reproducible research.

WoSIS standardised data can be used in digital soil mapping (e.g. SoilGrids, GSP GSOC map), populate regional databases (e.g. GSP SISLAC), or to develop pedotransfer functions.

  • WoSIS Latest. This dynamic dataset contains the most recent standardised soil data served from WoSIS database. Being dynamic, the dataset will grow once new point data are standardised, additional soil properties are considered, and/or when possible ammendments are required.

  • WoSIS Snapshot. These static datasets are a representation of the standardised data available at a given point in time. For each snapshot is given a unique name and digital object identifier (doi) for consistent citation purposes.

 

Access data

  • WoSIS Latest can be accesses using Web Feature Service (WFS) by adding in your GIS application the following link http://maps.isric.org/mapserv?map=/map/wosis_latest.map . Learn how to add a WFS service in QGIS or ArcMap. It's also possible to download the layers at ISRIC Data Hub. After opening the previous link, choose the layer, scroll down to Download and links section then press the Download drop-down list and choose your favourite format (geojson, geopackage, shapefile, csv or gml). Bellow in this page, in the Soil properties section, there are also links to each one of these layers.
  • WoSIS Snapshot presently there are two snapshots: July-2016 and September-2019.
     

Find more ISRIC products with their fully described metadata at ISRIC Data Hub.

 

Tutorials

Here you can find R markdown scripts, as well as their compiled PDF, to access the two forms of WoSIS database products. Because of limitations of this web hosting environment, the R markdown script had to be saved with .txt file extension. If you want to run it in your own environment (most likely), download it and change the extension to .rmd, then load into your R Studio.

R markdown is explained by the R Studio project: https://rmarkdown.rstudio.com. You can also extract the R code from the compiled tutorial or the R markdown script and paste into your favourite R environment. These scripts were kindly prepared by David Rossiter.

 

Papers and documentation

 

Soil properties

The complement of soil properties provided in WoSIS Latest (since 2018) is presented in the table below. This list has grown since the original list, which focused on the soil properties defined in the GlobalSoilMap specifications.

 

Codes, properties, units of measurement and description as used in WoSIS Latest (since 2018)  

Code

Property 

Units

 Description

BDFI33 Bulk density fine earth - 33 kPa kg/dm³ Bulk density of the fine earth fraction*, equilibrated at 33 kPa
BDFIAD Bulk density fine earth - air dry kg/dm³ Bulk density of the fine earth fraction, air dried
BDFIFM Bulk density fine earth - field moist kg/dm³ Bulk density of the fine earth fraction, field moist
BDFIOD Bulk density fine earth - oven dry kg/dm³ Bulk density of the fine earth fraction, oven dry
BDWS33 Bulk density whole soil - 33 kPa kg/dm³ Bulk density of the whole soil including coarse fragments, equilibrated at 33 kPa
BDWSAD Bulk density whole soil - air dry kg/dm³ Bulk density of the whole soil including coarse fragments, air dried
BDWSFM Bulk density whole soil - field moist kg/dm³ Bulk density of the whole soil including coarse fragments, field moist
BDWSOD Bulk density whole soil - oven dry kg/dm³ Bulk density of the whole soil including coarse fragments, oven dry
TCEQ

Calcium carbonate equivalent total

g/kg

The content of carbonate in a liming material or calcareous soil calculated as if all of the carbonate is in the form of CaCO3 (in the fine earth fraction*); also known as inorganic carbon

ORGC

Organic carbon

g/kg

Gravimetric content of organic carbon in the fine earth fraction*

TOTC

Total carbon

g/kg

Gravimetric content of organic carbon and inorganic carbon in the fine earth fraction

NITKJD Total nitrogen (N) g/kg The sum of total Kjeldahl nitrogen (ammonia, organic and reduced nitrogen) and nitrate-nitrite
CECPH7 Cation exchange capacity - buffered at pH7 cmol(c)/kg Capacity of the fine earth fraction to hold exchangeable cations, estimated by buffering the soil at 'pH7'
CECPH8 Cation exchange capacity - buffered at pH8 cmol(c)/kg Capacity of the fine earth fraction to hold exchangeable cations, estimated by buffering the soil at 'pH8'
ECEC

Effective cation exchange capacity

cmol(c)/kg

Capacity of the fine earth fraction to hold exchangeable cations at the pH of the soil (ECEC). Conventionally approximated by summation of exchangeable bases (Ca2+, Mg2+, K+, and Na+) plus 1 N KCl exchangeable acidity (Al3+ and H+) in acidic soils

ELCO20 Electrical conductivity - ratio 1:2 dS/m Ability of a 1:2 soil water extract to conduct electrical current 
ELCO25 Electrical conductivity - ratio 1:2.5 dS/m Ability of a 1:2.5 soil water extract to conduct electrical current 
ELCO50 Electrical conductivity - ratio 1:5 dS/m Ability of a 1:5 soil water extract to conduct electrical current 
ELCOSP Electrical conductivity - saturated paste dS/m Ability of a water saturated soil paste to conduct electrical current (ECe)
CFGR

Coarse fragments gravimetric total

g/100g

Gravimetric content of coarse fragments in the whole soil

CFVO

Coarse fragments volumetric total

cm³/100cm³

Volumetric content of coarse fragments in the whole soil

CLAY

Clay total

g/100g

Gravimetric content of < X mm soil material in the fine earth fraction* (e.g. X = 0.002 mm as specified in the analytical method description)

SILT

Silt total

g/100g

X to Y mm fraction of the fine earth fraction; Y as specified in the analytical method description (e.g. Y = 0.05 mm)

SAND

Sand total

g/100g

Larger than Y mm fraction of the fine earth fraction; Y as specified in the analytical method description (e.g. Y = 0.05 mm to 2 mm*)

PHCA

pH CaCl2

 

A measure of the acidity or alkalinity in soils, defined as the negative logarithm (base 10) of the activity of hydronium ions (H+) in a CaCl2 solution, as specified in the analytical method descriptions

PHAQ

pH H2O

 

A measure of the acidity or alkalinity in soils, defined as the negative logarithm (base 10) of the activity of hydronium ions (H+) in water

PHKC

pH KCl

 

A measure of the acidity or alkalinity in soils, defined as the negative logarithm (base 10) of the activity of hydronium ions (H+) in a KCl solution, as specified in the analytical method descriptions

PHNF

pH NaF

 

A measure of the acidity or alkalinity in soils, defined as the negative logarithm (base 10) of the activity of hydronium ions (H+) in a NaF solution, as specified in the analytical method descriptions

PHPBYI Phosphorus (P) - Bray I mg/kg Measured according to the Bray-I method, a combination of HCl and NH4 F to remove easily acid soluble P forms, largely Al- and Fe-phosphates (for acid soils)
PHPMH3 Phosphorus (P) - Mehlich 3 mg/kg Measured according to the Mehlich-3 extractant, a combination of acids (acetic [HOAc] and nitric [HNO3]), salts (ammonium fluoride [NH4F] and ammonium nitrate [NH4 NO3]), and the chelating agent ethylenediaminetetraacetic acid (EDTA); considered suitable for removing P and other elements in acid and neutral soils
PHPOLS Phosphorus (P) - Olsen mg/kg Measured according to the P-Olsen method:  0.5 M sodium bicarbonate (NaHCO3) solution at a pH of 8.5 to extract P from calcareous, alkaline, and neutral soils
PHPRTN Phosphorus (P) - retention mg/kg Retention measured according to the New Zealand method
PHPTOT Phosphorus (P) - total mg/kg Determined with a very strong acid (aqua regia and sulfuric acid/nitric acid)
PHPWSL Phosphorus (P) - water soluble mg/kg Measured in 1:x soil:water solution (mainly determines P in dissolved forms)
WG1500 Water retention gravimetric - 1500 kPa g/100g Soil moisture content by weight, at tension 1500 kPa
WG0500 Water retention gravimetric - 500 kPa g/100g Soil moisture content by weight, at tension 500 kPa
WG0200 Water retention gravimetric - 200 kPa g/100g Soil moisture content by weight, at tension 200 kPa
WG0100 Water retention gravimetric - 100 kPa g/100g Soil moisture content by weight, at tension 100 kPa
WG0033 Water retention gravimetric - 33 kPa g/100g Soil moisture content by weight, at tension 33 kPa
WG0010 Water retention gravimetric - 10 kPa g/100g Soil moisture content by weight, at tension 10 kPa
WG0006 Water retention gravimetric - 6 kPa g/100g Soil moisture content by weight, at tension 6 kPa
WV1500 Water retention volumetric - 1500 kPa cm³/100cm³ Soil moisture content by volume, at tension 1500 kPa
WV0500 Water retention volumetric - 500 kPa cm³/100cm³ Soil moisture content by volume, at tension 500 kPa
WV0200 Water retention volumetric - 200 kPa cm³/100cm³ Soil moisture content by volume, at tension 200 kPa
WV0100 Water retention volumetric - 100 kPa cm³/100cm³ Soil moisture content by volume, at tension 100 kPa
WV0033 Water retention volumetric - 33 kPa cm³/100cm³ Soil moisture content by volume, at tension 33 kPa
WV010 Water retention volumetric - 10 kPa cm³/100cm³ Soil moisture content by volume, at tension 10 kPa
WV0006 Water retention volumetric - 6 kPa cm³/100cm³ Soil moisture content by volume, at tension 6 kPa
CFAO Soil classification FAO   Classification of the soil profile according to specified edition (year) of the FAO-Unesco Legend (up to soil unit level)
CWRB Soil classification WRB   Classification of the soil profile according to specified edition (year) of the World Reference Base for Soil Resources (WRB, up to qualifier level)
CSTX Soil classification Soil Taxonomy   Classification of the soil profile according to specified edition (year) of the USDA Soil Taxonomy (up to subgroup level)
DSDS Depth of soil - sampled cm Total depth of soil sampled
HODS Horizon designation   Horizon designation as provided in the source database**

 

*   The fine earth fraction is generally defined as being < 2 mm. However, an upper limit of 1 mm was used in the former Soviet Union  and its sattelite states (Katchynsky scheme). This has been indicated in the database.

** Where available, the 'cleaned' (original) layer/horizon designation is provided for general information; these codes have not been standardised. When horizon designations are not provided in the source data bases, we have flagged all layers with an upper depth given as being negative (e.g -10 to 0 cm that is using pre-1993 conventions; see WoSIS Procedures Manual 2018, p. 24, footnote 9) in the source databases as being 'litter' layers (i.e. organic layers at the surface of a mineral soil).

 

Questions?

If you have a WoSIS-related question that is not addressed in our FAQ, please post your question in our public mailing list by sending an email to isric-world-soil-information@googlegroups.com. You may join the group here.