Abrupt textural difference (WRB 2022 Ch 3.2.1)

Sharp clay-content increase between two superimposed mineral layers meeting all of (WRB 2022 3.2.1, p. 72):

• underlying clay \>= 15% AND thickness \>= 7.5 cm;

• underlying starts \>= 10 cm below the mineral soil surface;

• underlying has, vs overlying: 2x clay if overlying < 20%, OR \>= 20pp (absolute) more clay if overlying \>= 20%;

• transitional layer, if any, \<= 2 cm.

Since v0.9.312 criterion 5 is read from the distinctness of the lower boundary of the overlying layer (boundary_distinctness): abrupt (2 cm or less) or very abrupt passes, clear, gradual or diffuse fails, and a boundary not recorded leaves the pair undecided (NA). Criterion 2 is counted from the mineral soil surface (below organic layers).

Usage

abrupt_textural_difference(pedon)

Arguments

pedon

A PedonRecord.

Value

A DiagnosticResult recording whether the diagnostic is present, the qualifying layers, and the supporting evidence.