% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/diagnostics-orders-usda.R
\name{ultisol_usda}
\alias{ultisol_usda}
\title{Ultisols (USDA Cap 15): argillic/kandic horizon + base saturation < 35\%.}
\usage{
ultisol_usda(pedon)
}
\arguments{
\item{pedon}{A \code{\link{PedonRecord}}.}
}
\description{
v0.9.17 graceful BS handling: when \code{bs_pct} is missing in the
argillic layers, the diagnostic falls back to two equivalent
indirect criteria before failing:
\itemize{
  \item \code{al_sat_pct >= 50} (high Al saturation mathematically
        forces BS < 50, and BS < 35 in essentially all tropical
        soils with this profile);
  \item \code{ph_h2o < 5.0} (the empirical threshold below which BS
        exceeds 35 in fewer than 5 % of tropical B horizons).
}
The fallback only fires when the direct measurement is missing, so
lab-grade profiles always use the canonical KST 13ed gate.
}
