Evaluation of ferrolysis in soil formation

Abstract

Summary The concept of ferrolysis as defined in the 1970s by Brinkman and co‐workers is mentioned in the recent literature as a dominant process to explain clay disintegration, interlayering of clay minerals, and strong texture contrast of duplex soils, in which bleaching and mottling are predominant features. Ferrolysis is based on biochemical reduction of free iron(III) oxides to Fe2+ and re‐oxidation of Fe2+ during alternating reducing and oxidizing conditions in the soil. The acidity produced during the oxidation is assumed to release cations from silicates which results in the destruction of clay minerals. A detailed analysis of data from chemical analyses, laboratory experiments, and mineralogical and micromorphological investigations, which have been considered to sustain the ferrolysis theory, has been carried out. Some soils in Belgium and France, which have been considered to be formed mainly by ferrolysis, show strong textural contrast or albeluvic features. It has been shown that the development of these soils is due to clay translocation rather than to clay destruction by ferrolysis. Fine quartz and chlorite, assumed to be secondary minerals formed during ferrolysis, are more likely formed by disintegration of larger quartz and chlorite particles.

Origin of mounds in the Pantanal wetlands: An integrated approach between geomorphology, pedogenesis, ecology and soil micromorphology

“…The dissolution voids observed on the thin sections from the upper part of the Bt horizon and in the abrupt transition between E/Bt horizons, provide clear evidence of this process. This situation is the opposite of that observed by Van Ranst and De Coninck [ 53 ], which associated contrasts in soil texture to argilluviation. With the advance of the ferrolysis, coalescence of the voids can also be observed ( Fig 10C and Fig 10D ), resulting in voids with mamelonar wall arrangements with Fe coatings, which is clear evidence of temporary hydromorphism at this position of the soil profile [ 54 ].…”

Assessing lithologic discontinuities and parent material uniformity within the Texas sandy mantle and implications for archaeological burial and preservation potential in upland settings

“…The E-Bt boundary distinctiveness trends within the investigated pedons may be partially attributed to a process known as ferrolysis, in which seasonal oxidation and reduction cycles between Fe 3+ and Fe 2+ iron states result in increased acidity (Brinkman, 1970). During this biochemical process in seasonally wet soils, cations released through silicate weathering can cause disintegration of clay minerals in Bt horizons, resulting in abrupt and wavy E-Bt boundaries (Van Ranst and De Coninck, 2002).…”

Low Cotton Yield is Associated with Micronutrient Deficiency in West Africa

“…The poor nature of the soils, low and erratic rains in the arid and semiarid regions, and intense monsoonal rains in the humid regions coupled with high air and soil temperatures are responsible for the high rates of soil degradation (Bationo et al, 1998). Leaching is so intense that it does not only include the translocation of ions from the clay exchange sites but also the disintegration of the clay lattices and the subsequent formation of Fe and Al oxides (Van Ranst and De Coninck, 2002). The outcome of low soil fertility is therefore addressed by addition of manure and chemical fertilizers, and by the rotational practice of cultivation, during which soils are left uncultivated (fallow) for years, aiming to regain fertility (Esse et al, 2001).…”