Family of a soil under the Australian Soil Classification

Places a soil in the family classes of its order (Australian Soil Classification, 3rd edition, the 'Family Criteria' of each order page). The family is not a level of the key: each criterion is a class of its own, given by a one- or two-letter code. Most orders use the thickness of the A1 horizon (of the whole A horizon in the Kurosols, Sodosols and Chromosols and in the Kurosolic, Sodosolic and Chromosolic Hydrosols, as the book's general rule has it), with any organic horizon over it; gravel (2-60 mm) of the surface and A1 horizon (the larger of the estimate of the ground surface, site$surface_gravel_pct or site$surface_coarse_fragments_pct, and that of the A1); the field texture of the A1 (its major part, peaty under organic surface horizons) and the most clayey field texture of the B; soil depth; and water repellence of the surface soil (water_repellence). The Vertosols use laboratory clay (upper 0.1 m and the B), the Calcarosols the depth of the first Bk horizon, the Arenosols and Rudosols the surface soil, and the Organosols the kind and thickness of their organic materials and the texture under them. Soil depth is the depth to rock, a cemented pan (not a thin ironpan), another cemented layer or saprolite; otherwise, in a soil with a B horizon, the depth to the C below it, and in a soil without one, the depth described. The Anthroposols have no family, nor do the Subtidal, Subaqueous and Intertidal Hydrosols. The readings where the text is silent are in system.file("rules", "asc3", "readings.yaml", package = "soilKey") (topic "Families").

Usage

classify_asc3_family(pedon, order = NULL, suborder = NULL, great_group = NULL)

Arguments

pedon

A PedonRecord.

order, suborder, great_group

Codes of the soil's classes (as in levels of a classify_asc3 result). When order is NULL the soil is classified first.

Value

A named list of FamilyAttribute, one per criterion of the order that applies, in the order of the book's family name: value is the class name (NULL when undecided or when no class fits), evidence$code the class code ("YY" undecided, "ZZ" no class of the order fits). An empty list when the soil has no family.

References

Isbell, R.F. and the National Committee on Soil and Terrain (2021). The Australian Soil Classification, 3rd ed. CSIRO Publishing, Melbourne. Online version: www.soilscienceaustralia.org.au/asc.

See also

classify_asc3.

Examples

fam <- classify_asc3_family(make_asc3_example("chromosols"))
vapply(fam, function(a) a$evidence$code, "")
#>        thickness           gravel       a1_texture        b_texture 
#>              "C"              "E"              "L"              "O" 
#>            depth water_repellence 
#>              "W"             "YY"