Keys a PedonRecord through the FAO-Unesco legend of the Soil
Map of the World. Experimental: this release keys the 28 major
soil groupings of the Revised Legend (FAO 1988, World Soil Resources
Report 60; the text of the ISRIC reprint of 1997, Technical Paper 20),
chapter X, pp. 75-89, and their 153 soil units, in the key's order
(Histosols, Anthrosols,
Leptosols, Vertisols, Fluvisols, Solonchaks, Gleysols, Andosols,
Arenosols, Regosols, Podzols, Plinthosols, Ferralsols, Planosols,
Solonetz, Greyzems, Chernozems, Kastanozems, Phaeozems, Podzoluvisols,
Gypsisols, Calcisols, Nitisols, Alisols, Acrisols, Luvisols, Lixisols,
Cambisols), on the 16 diagnostic horizons and 27 diagnostic properties of
chapters IV and V read on the data. Under its grouping a soil keys to
the first soil unit whose gate passes, in the key's order; the last unit
of each grouping is the key's "Other ..." residual (Haplic, Eutric, and
the Terric Histosols and Urbic Anthrosols, whose descriptions are shown,
not tested). Since v0.9.386 the result also gives the 16 phases of
chapter VIII (pp. 67-71) and the texture and slope classes of the map
symbol (Appendix 2, p. 107) in $phases, beside the unit, which
they never change. Since v0.9.389, edition = "1974" keys the
Legend of 1974 (FAO-Unesco, Soil Map of the World, Vol. I, Unesco Paris),
pp. 43-53: its 26 major soil groups in the key's order (Histosols,
Lithosols, Vertisols, Fluvisols, Solonchaks, Gleysols, Andosols,
Arenosols, Regosols, Rankers, Rendzinas, Podzols, Ferralsols, Planosols,
Solonetz, Greyzems, Chernozems, Kastanozems, Phaeozems, Podzoluvisols,
Xerosols, Yermosols, Nitosols, Acrisols, Luvisols, Cambisols) and their
106 soil units (the Lithosols, Rankers and Rendzinas are single units),
on the diagnostic horizons and properties of 1974 read on the data; its
registry id is fao1974 (classify_fao1974). Since
v0.9.390 its result gives in $phases the 12 phases of 1974 (pp.
5-7: stony, lithic, petric, petrocalcic, petrogypsic, petroferric,
phreatic, fragipan, duripan, saline, sodic, cerrado) and the texture and
slope classes of its map symbol (pp. 4-5), in the same form.
Arguments
- pedon
A
PedonRecord.- edition
"1988"(the Revised Legend, default) or"1974"(the Legend of 1974).- rules
Optional pre-loaded rule set (
load_rules("fao1988"), orload_rules("fao1974")withedition = "1974").- on_missing
One of
"warn"(default),"silent","error".- gapfill
Opt-in within-pedon gap-fill, as in
classify_usda.
Value
A ClassificationResult with system_id
"fao1988" ("fao1974" for the Legend of 1974);
name holds the soil unit as printed ("Haplic
Luvisols") and rsg_or_order the major soil grouping
("Luvisols"); levels has one row per level (major_groups,
units) with the code ("LV", "LVh"), name, page of the key and
soilKey's Portuguese gloss (name_pt); the key trace of both
levels and provisional_because; and phases, a
data.frame with one row per phase and one per class of the map
symbol (kind "phase", "texture_class",
"slope_class"), its status ("present",
"absent", "undecided", or "not shown" for a
unit the text excludes), present and criterion
(TRUE, FALSE, NA), page, basis, flags and the
attributes that would decide an undecided phase (missing).
Details
The tests are three-valued: a measurement not recorded leaves its
criterion undecided, a field observation not recorded is absent. A
grouping or unit tested before the assigned one that the data leave
undecided makes the result provisional (provisional_because,
"major_groups:<code>" or "units:<code>": the candidates).
The key has no
residual grouping after the Cambisols: a soil that no gate takes is
"[Not classified in the FAO-Unesco Revised Legend (1988)]", in
brackets because the name is soilKey's, with the gates that failed in the
warnings; when no gate passes but some are undecided, the name lists them
in brackets as the candidates. Depths are read from the soil surface, H
and O horizons included. The readings where the text is silent are in
system.file("rules", "fao1988", "readings.yaml", package =
"soilKey").
References
FAO (1988). FAO/Unesco Soil Map of the World, Revised Legend, with corrections and updates. World Soil Resources Report 60, FAO, Rome. Reprinted with updates as Technical Paper 20, ISRIC, Wageningen, 1997.
Examples
res <- classify_fao(make_fao_example("LV"), on_missing = "silent")
res$name
#> [1] "Albic Luvisols"
res$rsg_or_order
#> [1] "Luvisols"
res$levels
#> level code name name_pt page
#> 1 major_groups LV Luvisols Luvissolos (Luvisols) 88
#> 2 units LVa Albic Luvisols Luvissolos Álbicos (Albic Luvisols) 88
res$phases[res$phases$status != "absent", c("kind", "code", "name", "status")]
#> kind code name status
#> 6 phase inundic Inundic phase undecided
#> 9 phase phreatic Phreatic phase undecided
#> 17 texture_class 2 Medium textured present
#> 18 slope_class <NA> <NA> undecided
classify_fao(make_fao_example("Lc", edition = "1974"), edition = "1974",
on_missing = "silent")$name
#> [1] "Chromic Luvisols"