Year of publication
2025
Excerpt
This report describes general principles for standardizing and coding soil observations/properties considered in WoSIS (World Soil Information Service); ultimately, the standardized data are served to users following FAIRdata principles. Data for nominally similar soil properties, collated from disparate sources, are grouped according to major features of the corresponding analytical methods; that is, the properties are grouped according to ‘operational definitions’ i.e. a given combination of ‘property-procedure-method options’. For example, major features for defining soil pH are the extractant solution (water or salt solution), and in case of salt solutions the salt concentration (molarity), as well as the soil/solution ratio. A further descriptive element may be the type of instrument used for the actual laboratory measurement.
The following chemical and physical properties are currently considered during the standardization process:
a) Chemical properties: organic carbon, total carbon, total carbonate equivalent, total nitrogen, phosphorus, soil pH, cation exchange capacity, and electrical conductivity. To which have been added, in 2025, the following: Calcium (Ca), Magnesium (Mg), Potassium (K), Sodium (Na), Aluminum (Al), Hydrogen (H+), Acidity (Al3+ + H+) and Sulfur (S), as well as Arsenicum (As), Boron (Bo), Bromine (Br), Cadmium (Cd), Chrome (Cr), Copper (Cu), Iron (Fe), Lead (Pb), Manganese (Mn), Molybdenum (Mo), Nickel (Ni), Selenium (Se), Zinc (Zn), as well as soluble salts (anions and cations) for saline soils.
b) Physical properties: soil texture (sand, silt, and clay), bulk density, coarse fragments, water retention, and hydraulic conductivity.
Full data harmonization in a global context, the ultimate objective of WoSIS, will first become feasible once results of extensive proficiency testing programs become freely available and a common set of ’international’ reference methods has been accepted as the common standard by the international soil community; such would provide the basis for method validation between laboratories with their actual/adjusted method. Results of such ‘harmonization’ transformations should be managed in a separate set of databases tables.
Note: This report supersedes ISRIC Report 2023/01.
DOI landing page for: https://doi.org/10.17027/isric-wdcsoils-1nh7-zr51
The following chemical and physical properties are currently considered during the standardization process:
a) Chemical properties: organic carbon, total carbon, total carbonate equivalent, total nitrogen, phosphorus, soil pH, cation exchange capacity, and electrical conductivity. To which have been added, in 2025, the following: Calcium (Ca), Magnesium (Mg), Potassium (K), Sodium (Na), Aluminum (Al), Hydrogen (H+), Acidity (Al3+ + H+) and Sulfur (S), as well as Arsenicum (As), Boron (Bo), Bromine (Br), Cadmium (Cd), Chrome (Cr), Copper (Cu), Iron (Fe), Lead (Pb), Manganese (Mn), Molybdenum (Mo), Nickel (Ni), Selenium (Se), Zinc (Zn), as well as soluble salts (anions and cations) for saline soils.
b) Physical properties: soil texture (sand, silt, and clay), bulk density, coarse fragments, water retention, and hydraulic conductivity.
Full data harmonization in a global context, the ultimate objective of WoSIS, will first become feasible once results of extensive proficiency testing programs become freely available and a common set of ’international’ reference methods has been accepted as the common standard by the international soil community; such would provide the basis for method validation between laboratories with their actual/adjusted method. Results of such ‘harmonization’ transformations should be managed in a separate set of databases tables.
Note: This report supersedes ISRIC Report 2023/01.
DOI landing page for: https://doi.org/10.17027/isric-wdcsoils-1nh7-zr51