For use in MLRAs 72 and 73 of LRR H; for testing in other MLRAs of LRR H.
In closed depressions that are subject to ponding, a mineral soil that has chroma of 1 or less to a depth of at least 35 cm (13.5 inches) and a layer at least 10 cm (4 inches) thick starting at a depth ≤25 cm (10 inches) from the mineral soil surface that has either:
a. One percent or more redox concentrations occurring as nodules or concretions, or
b. Redox concentrations occurring as nodules or concretions with distinct or prominent corona.
User Notes: This indicator is applicable in closed depressions (Food Security Act “playas”) in western Kansas, southwestern Nebraska, eastern Colorado, and southeastern Wyoming. It occurs in such soils as those of the Ness and Pleasant series. The matrix color of the 35-cm (13.5-inch) layer must have chroma of 1 or less; chroma-2 matrix colors are excluded; value generally is 3. The nodules and concretions are rounded, are hard or very hard, range in size from less than 1 mm to 3 mm, and most commonly are black or reddish black. The corona (halos) generally are reddish brown, strong brown, or yellowish brown. The nodules and concretions can be removed from the soil, and the corona will occur as coatings on the concentration or will remain attached to the soil matrix. Use of 10x to 15x magnification aids in the identification of these features.