Keys a PedonRecord through the New Zealand Soil
Classification, 4th edition (Manaaki Whenua - Landcare Research 2026),
following its Key to Soil Orders and keys to groups and subgroups.
Experimental: this release keys the 15 orders (Organic, Gley,
Ultic, Podzol, Allophanic, Pumice, Melanic, Semiarid, Oxidic, Granular,
Pallic, Brown, Anthropic, Recent, Raw Soils), their 77 groups (since
0.9.298, e.g. Orthic Brown Soils, Perch-gley Pallic Soils) and their 336
subgroups (keyed from 0.9.299 to 0.9.302, e.g. Peaty Orthic Gley Soils,
Humose Orthic Podzol Soils, Mottled Fragic Pallic Soils, Typic Orthic
Brown Soils); seven groups have no subgroups and keep the group name. The
Cryic Soils of the appendix are not keyed.
Usage
classify_nzsc4(
pedon,
rules = NULL,
on_missing = c("warn", "silent", "error"),
gapfill = FALSE
)Arguments
- pedon
A
PedonRecord.- rules
Optional pre-loaded rule set (
load_rules("nzsc4")).- 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
"nzsc4", the deepest class in name (the subgroup, or the
group where no subgroup is keyed yet), the order in
rsg_or_order, the classes of each level in levels, the key
trace, and provisional_because (classes before the assigned one
that could not be decided).
Details
The NZSC reads horizon notations and field tests. The diagnostics read
the New Zealand notation (Ah, E, Bw, Bt, Bg, Bh, Bs, Bo, Bx, Bw(g), Bhm,
Bsm, Blm, CR, R, Of, Om, Oh, Lm, Lh, an e prefix for anthropic soil
material; FAO designations are read by the same letters), moist Munsell
colours, texture (field_texture words or codes, or lab clay, silt
and sand), pH, P retention (phosphate_retention_pct), dry bulk
density, volcanic glass, coarse fragments and their origin, structure,
clay coatings, carbonate, ESP, and the field tests naf_test
(reactive-aluminium test: none, slight, moderate, strong),
childs_test, sensitivity_class, fluidity_class,
stickiness and strength_moist. From the site it reads
drainage_class, parent_material (Melanic Soils),
anthropic_truncation and overthickened_a (the note to the
key on overthickened A horizons), and designation_system. The
groups also read the packing (packing_degree), Ksat
(ksat_mm_h), penetration resistance, where the redox segregations
are (redox_segregations_location), sulfate S, roots, a Maori
cultural layer (maori_cultural_layer) and the colour of coatings;
and, on the site, soil_temp_30cm_C, mean_annual_air_temp_C,
surface_water, methane_odour,
mechanical_mixing_depth_cm and artificially_drained. The
subgroups also read sulfidic S (sulfidic_s_pct), the EC of a 1:5
extract (ec_1to5_dS_m), the share of Sphagnum in the fibres
(sphagnum_fibres_pct), a shelly layer (shelly_layer),
exchangeable Ca and Mg, clay films, the colour of coatings on pores
(pore_coatings_hue_moist, pore_coatings_value_moist,
pore_coatings_chroma_moist), the weathering of rock fragments
(weathering_stage, weathered_fragments_pct) and the
cementation class; on the site, mechanical_mixing_purpose and
acid_neutralising_amendment (Mixed and Fill Anthropic Soils).
Features
a describer records when met (stratification, nodules, cracks, refuse or
cultural layers, permafrost, surface water) are absent when not recorded.
The choices where the text is silent are listed in
system.file("rules", "nzsc4", "readings.yaml", package = "soilKey").
References
Manaaki Whenua - Landcare Research (2026). New Zealand Soil Classification. 4th ed. doi:10.7931/dl1-lrss-4-2026 .
Examples
res <- classify_nzsc4(make_nzsc4_example("brown"), on_missing = "silent")
res$name
#> [1] "Typic Orthic Brown Soils"