Anthropogenic

Used of soils, landscapes, or ecological systems generally, to indicate modification by human activities. Recognized as the group Anthrosols in the WRB System of Soil Classification, in terms of diagnostic anthropogenic horizons:

A terric horizon (from L. terra, earth) results from addition of earthy manure, compost or mud over a long period of time. The terric horizon has a non‐uniform textural differentiation with depth. The source material and/or underlying substrates influence the color of the terric horizon. Base saturation (in 1 M NH ₄OAc at pH 7.0) is more than 50%.

An irragric horizon (from L. irrigare, to irrigate, and agricolare, to cultivate) is a light colored (Munsell color value and chroma, moist, both greater than 3), uniformly structured surface layer, developed through long‐continued irrigation with sediment‐rich water. Clay and carbonates are evenly distributed and the irragric horizon has more clay, particularly fine clay, than the underlying soil material. The...