WISE Soil Property Databases

Harmonised sets of soil property estimates are necessary for a wide range of environmental studies at a global scale: agro-ecological zoning, assessments of crop production, soil vulnerability to pollution, soil carbon stocks and change, and soil gaseous emission potentials. The WISE project has developed a range of harmonised world soil databases (point and grid-based) that may be used to underpin such broad scale studies, pending the availability of regionally and globally more detailed datasets.

^{Soil auger profile sampling and analysis, Maguvani, Tanzania (Credit: Prof. Ray Weil, University of Maryland)}

There are two types of WISE databases. The first comprises a set of harmonised soil profile data considered to be representative for the soil units of the FAO Soil Map of the World, and later the Harmonised World Soil Database (HWSD). These profiles were used to develop consistent taxo-transfer rules to estimate soil property estimates, by FAO soil unit and depth zone, including: organic carbon, total nitrogen, pHwater, cation exchange capacity, base saturation, aluminium saturation, calcium-carbonate and gypsum content, exchangeable sodium, electric conductivity, bulk density and the sand, silt and clay fractions. In the second type of WISE databases, the above soil property estimates were linked to the spatial data of the 1:M FAO Soil Map of the World respectively used to fill gaps in SOTER databases (so-called SOTWIS databases), using the FAO soil classification as main ‘carrier-of-soil information’.

WISE-derived databases can be used to address a range of global issues, assessments of crop production, soil vulnerability to pollution, soil carbon stocks and change, and soil gaseous emission potentials. Examples of such studies, by various groups, are provided here.

Numerous organizations and scientists have contributed in various ways to WISE-related activities; we gratefully acknowledge their contributions.

A brief history of the WISE project, and main funding agencies, is given here.

Point and raster datasets

A selection of WISE-derived data sets (point and raster) is available through our soil data hub. We recommend using the latest dataset as shown in the table below.

^{Overview of WISE-derived soil databases (point and grid)}
^{Soil geographical data}	^{WISE version & reference}	^{Main elements of taxotransfer procedure}
^{HWSD, 30”x30”*}	^{WISE30sec, v1.0 (Batjes 2016; metadata)}	^{Soil profiles: ~21,000} ^{Layer model: 7, i.e. 5 x 20 cm up to 100 cm depth, and 2 x 50 cm up to 200 cm depth} ^{Textural classes: 5 (SOTER conventions: Coarse, Medium, Medium Fine, Fine, and Very Fine)} ^{Co-variates: climate (Peel et al. 2007)} ^{Soil variables: 19} ^{Measure of uncertainty: mean ± std by map unit; descriptive statistics per soil ‘cluster’ including 10% and 25% percentiles}
^{DSMW, 5’x5’}	^{WISE5min, v1.2 (Batjes 2012; metadata)}	^{Soil profiles: ~11,000} ^{Layer model: 5 times 20 cm up to 100 cm depth)} ^{Textural classes: 5 (SOTER conventions)} ^{Soil variables: 19} ^{Measure of uncertainty: descriptive statistics by soil ‘cluster’}
	^{WISE5min, v1.0}	^{Soil Profiles: ~10,250} ^{Layer model: 5 times 20 cm up to 100 cm depth} ^{Textural classes: 3 (DSMW conventions: Coarse, Medium, Fine)} ^{Soil variables: 19} ^{Measure of uncertainty: descriptive statistics by soil ‘cluster’}
^{DSMW, 0.5°x0.5°}	^{WISE30min, v3.0 (Batjes 2005; metadata)}	^{Soil Profiles: ~9,600} ^{Layer model: 2 (0-30 and 30-100 cm)} ^{Textural classes: 3 (DSMW conventions)} ^{Soil variables: 22 soil variables} ^{Measure of uncertainty: descriptive statistics by soil ‘cluster} ^{Binned and un-binned GIS layers’}
	^{WISE30min, v2.0}	^{Soil Profiles: ~9,600} ^{Layer model: 2 (0-30 and 30-100 cm)} ^{Textural classes: 3 (DSMW conventions)} ^{Soil variables: 10 soil variables} ^{Measure of uncertainty: descriptive statistics by soil ‘cluster’}
	^{WISE30min, v1.0}	^{Soil profiles: ~4,350} ^{Layer model: 2 (0-30 and 30-100 cm)} ^{Textural classes: 3 (coarse, medium,fine; DSMW conventions)} ^{Soil variables: soil organic carbon, carbonate carbon, and pH_water}
	^{IGBP-DIS gridded soil surfaces (IGBP-DIS 1995)}	^{Soil profiles: ~1,000 from WISE} ^{Layer model: 2 (0-30 and 30-100 cm)} ^{Soil variables: soil-carbon density, total nitrogen density, field capacity, wilting point, profile available water capacity, thermal capacity, and bulk density.}

WISE30sec_SOC_P3_2015une29_440dpi_Legendadded_CLIPPED.png