Test CEC (1M NH4OAc, pH 7) per kg clay <= threshold

Default threshold is 16 cmol_c/kg clay (WRB 2022 ferralic horizon).

Usage

test_cec_per_clay(h, max_cmol_per_kg_clay = 16, candidate_layers = NULL)

Arguments

h

Numeric threshold or option (see Details).

max_cmol_per_kg_clay

Numeric threshold or option (see Details).

candidate_layers

Numeric threshold or option (see Details).

v0.9.69 ECEC fallback (opt-in)

Brazilian / SOTERLAC / BDsolos profiles often record the exchange complex as separate Ca, Mg, K, Na, Al cmol values without an explicit "Valor T" CEC column, so cec_cmol is NA for the entire profile. With options(soilKey.ferralic_ecec_fallback = TRUE) the test falls back to the ECEC sum (ca_cmol + mg_cmol + k_cmol + na_cmol + al_cmol) on layers where cec_cmol is missing but the components are present. Default is FALSE (canonical WRB behaviour preserved).

Note: ECEC is typically smaller than CEC at acidic pH because it omits H+; using ECEC against the same threshold is therefore conservative (MORE permissive) – it should not produce false positives, only recover Latossolos that lacked Valor T.

v0.9.86 engine="aqp" auto-enables the ECEC fallback

soilKey.diagnostic_engine = "aqp" now auto-enables the v0.9.69 ECEC fallback (the user can still suppress it explicitly by setting soilKey.ferralic_ecec_fallback = FALSE). The rationale: the aqp engine is the "data-quality-aware" mode, designed for field-described datasets like BDsolos / Redape where Valor T is rarely recorded. Bundling these two opt-ins lifts BDsolos RJ Latossolo recall from 14.9\ 28.1\