Distribution of Magnetic Susceptibility in Relation to Iron Compounds in Some Selected Soils of Fars Province

Distribution of soil magnetic susceptibility (χ) and Fe compounds were studied in 14 soil profiles, reflecting key climatic conditions, land use, and drainage classes in Fars Province. Magnetic susceptibility was measured both on oven-dry basis (χod) and minerogenic basis (compensating for mobile diamagnetic materials such as carbonates and gypsum, χm). Magnetic susceptibility of eluvial horizons was greater than that of the illuvial horizons in most of the soils. This is probably a result of eluviation of diamagnetic materials as well as pedogenic formation of ferrimagnetic minerals in soil surface. Poorly and somewhat poorly drained soils had distinctly lower χm than well-drained soils. There was a positive significant correlation (P<0.01) between crystalline pedogenic Fe (Fed-Feo) and χm. Similar relationship was noticed between mean annual rainfall and χm.