argillic.clay.increase.depth: Return upper boundary of argillic horizon
Description
Returns the top depth of the argillic horizon as a numeric vector.
Uses crit.clay.argillic to determine threshold clay increase, and get.increase.matrix to determine where increase is met within a vertical distance of 30 cm.
Usage
argillic.clay.increase.depth(p, attr = "clay")
Arguments
p
A single-profile SoilProfileCllection object.
attr
OPTIONAL: horizon attribute name referring to clay content. default: `clay`
Value
A numeric vector containing top depth of argillic horizon, if present, or NA.