% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/diagnostics-horizons-wrb.R
\name{mollic}
\alias{mollic}
\title{Mollic horizon (WRB 2022)}
\usage{
mollic(
  pedon,
  min_thickness = 20,
  min_oc = 0.6,
  min_bs = 50,
  surface_top_cm = 5
)
}
\arguments{
\item{pedon}{A \code{\link{PedonRecord}}.}

\item{min_thickness}{Minimum thickness in cm (default 20).}

\item{min_oc}{Minimum SOC \% (default 0.6).}

\item{min_bs}{Minimum base saturation \% (default 50).}

\item{surface_top_cm}{Maximum top depth (cm) for a horizon to be
considered "surface-related" (default 5). v0.1 uses this as a
proxy for the WRB rule that mollic must form continuously from
the soil surface (after mixing of upper 20 cm if required).}
}
\value{
A \code{\link{DiagnosticResult}}.
}
\description{
Tests whether any near-surface horizon meets the mollic horizon
criteria. The mollic horizon is the diagnostic surface horizon of
Chernozems, Phaeozems, Kastanozems, and several other RSGs; it
indicates a thick, dark, base-rich, organic-matter-enriched topsoil
formed under steppe or comparable vegetation.
}
\details{
Sub-tests called:
\itemize{
  \item \code{test_mollic_color} -- moist value <= 3, moist
        chroma <= 3, dry value <= 5.
  \item \code{test_mollic_organic_carbon} -- SOC >= 0.6\%.
  \item \code{test_mollic_base_saturation} -- BS (NH4OAc, pH 7)
        >= 50\%.
  \item \code{test_mollic_thickness} -- horizon thickness >= 20 cm.
  \item \code{test_mollic_structure} -- not simultaneously
        massive AND very hard when dry.
}

v0.1 limitations: cumulative thickness across contiguous mollic-
qualifying horizons is not yet supported -- this matters for profiles
where mollic criteria are met by an A1+A2 sequence but no single
horizon is >= 20 cm thick. Mixing of upper 20 cm before the test (per
WRB) is also deferred to v0.2.
}
\references{
IUSS Working Group WRB (2022). \emph{World Reference Base
for Soil Resources}, 4th edition. International Union of Soil Sciences,
Vienna. Chapter 3 -- Mollic horizon.
}
