Stagnic properties (WRB 2022)

Tests for stagnic properties (WRB 2022 Ch 3.2.14, p. 81) in a layer starting within the upper max_top_cm (default 100).

Usage

stagnic_properties(
  pedon,
  max_top_cm = 100,
  min_redox_pct = 5,
  decay_factor = 3
)

Arguments

pedon

A PedonRecord.

max_top_cm

Maximum top depth (cm) of candidate layers (default 100).

min_redox_pct

The oximorphic features are more than this % of the layer (default 5).

decay_factor

Not used since v0.9.312 (the decay test was removed); kept so that existing calls still work.

Value

A DiagnosticResult.

Details

Since v0.9.312 the layer reading is that of gleyic_properties (Hugo's reading for descriptions that do not say where the mottles sit): a layer with more than 5% oximorphic features that are not gleyic (criteria 1-3: the matrix has no reductimorphic colour, the layer does not lie directly on a layer with such a matrix, and the site records no groundwater within 150 cm that is not perched, or a claric layer lies directly above it); a layer with claric colours in 95% or more of its area above an abrupt textural difference or a layer of 1.5 kg/dm3 or more (criterion 4), or above a layer with stagnic oximorphic features (criterion 5). Mottles with neither colour nor water evidence leave the layer NA. Until v0.9.311 a layer with 5% redox features passed when the features decayed with depth, which is not in WRB 2022.

References

IUSS Working Group WRB (2022), Chapter 3.2.14, Stagnic properties.