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A basis for soil profile modelling in a geomorphic context
Author(s) -
KIRKBY M. J.
Publication year - 1985
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1985.tb00316.x
Subject(s) - weathering , soil science , soil horizon , leaching (pedology) , saprolite , context (archaeology) , nutrient cycle , soil water , denudation , geology , mixing (physics) , environmental science , mineralogy , geomorphology , nutrient , chemistry , physics , paleontology , tectonics , organic chemistry , quantum mechanics
SUMMARY A mathematical model for soil profile evolution is developed in three parts; respectively for the weathering profile, the organic profile and for the inorganic profile associated with nutrient cycling. Processes modelled are percolation, equilibrium solution, leaching, ionic diffusion, organic mixing, leaf fall, organic decomposition and mechanical denudation. In each sub‐model some of these processes may be neglected, and time‐scales differ, so that they are best separated. Each leads to a second‐order linear partial differential equation with non‐constant coefficients. Equilibrium profiles are derived for the simplest cases, and numerical models exemplify profile evolution in more realistic cases. Modelled weathering profiles generally show a zone of near‐constant composition at the surface, with saprolite developing in deep profiles. Nutrient‐cycling profiles show the variable development of B‐horizons, and may be classified according to the relative depths of rooting, organic soil, and organic mixing processes.