% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/diagnostics-gelisols-usda.R
\name{lithic_contact_usda}
\alias{lithic_contact_usda}
\title{Lithic contact within X cm of the surface (USDA Subgroup helper)}
\usage{
lithic_contact_usda(pedon, max_top_cm = 50)
}
\arguments{
\item{pedon}{A \code{\link{PedonRecord}}.}

\item{max_top_cm}{Default 50 cm.}
}
\value{
A \code{\link{DiagnosticResult}}.
}
\description{
Pass when a horizon designation matches an R contact within
\code{max_top_cm}. Default 50 cm (Subgroup-level depth bound).
For Gelisols organic soil materials (Folistels), the depth is
50 cm; for Fibristels/Hemistels/Sapristels and other Gelisols,
it is 100 cm (KST 13ed, p 46).
}
\references{
Soil Survey Staff (2022), KST 13ed, Ch. 3, p 45;
  Ch. 9 various Subgroups.
}
