Get the shallowest depth of description out of all profiles in a SoilProfileCollection. Data missing one or more of: bottom depth, profile ID, or any optional attribute are omitted using complete.cases
.
# S4 method for SoilProfileCollection
min(x, v = NULL, na.rm = TRUE)
a SoilProfileCollection
optional: a vector of horizon attribute names to refine calculation
remove NA
? default: TRUE