What is the criterion for redox marks if there is a depletion/concentration percentage?

Redox marks are indicators of soil conditions associated with the reduction and oxidation processes of iron and manganese, which are critical in understanding soil drainage and aeration. The criterion of 2% for the percentage of depletion or concentration in a soil profile is significant because it serves as a threshold to determine if redox features are prominent enough to influence the soil's classification.

When the concentration of redox features is at least 2%, it indicates that there is sufficient oxidation-reduction activity occurring in the soil. This percentage is also relevant because it allows for the differentiation between soils that experience regular wetting and drying cycles and those that may remain saturated for extended periods. Understanding this threshold aids soil judges in identifying soil horizons with significant redoximorphic features, which can affect land use, agricultural practices, and wetland designations.