One row per site property that soilKey recognises (the named elements of
PedonRecord$site), with the section it belongs to, its type, unit
and description, the values a categorical property takes where the keys
compare it with a fixed set, and the classification keys that read it. The
properties of the last section, reference classes and provenance,
are stored by the loaders and reports and read by no key. The metadata
come from inst/schemas/site-attributes.yaml; the attribute reference
inst/ATTRIBUTES.md lists them after the horizon attributes.
Value
A data.frame with the columns name, type,
section, unit, description, and allowed and
systems (comma-separated, empty when none).
Examples
s <- site_attribute_spec()
s[s$name %in% c("drainage_class", "soil_moisture_regime"),
c("name", "type", "description")]
#> name type
#> 26 drainage_class character
#> 28 soil_moisture_regime character
#> description
#> 26 Drainage class, in English or Portuguese; a range ('imperfectly to poorly drained') is read by the end each test asks for. Read by the WRB Drainic, Subaquatic and Tidalic qualifiers (which also look for words such as 'artificial', 'submerged' and 'tidal'), the SiBCS horizonte glei (after drainage), the CSSC Folisol and Vertisol great groups, the ASC key (Hydrosols, organic materials, Folic Organosols, Aquic Vertosols, the Podosol and Hypersalic suborders) and the NZSC Organic Soils.
#> 28 USDA soil moisture regime, compared in lower case (aridic and torric are the same). Read by the USDA key (the Aridisols, and the ustic, xeric, udic and torric suborders, great groups and subgroups) and by the CSSC key when soil_moisture_subclass is absent (Chernozemic climate, the subhumid Solonetzic subgroups). The Chinese Soil Taxonomy 2001 adds the stagnic (perched water), anthrostagnic (irrigated paddy) and peraquic (water table always at or near the surface) regimes (pp. 51-55); the USDA key reads all three as aquic.