Iron oxides as weathering indicator and the origin of Luvisols from the Vistula glaciation region in Poland

Abstract

Purpose The aim of the research was to determine the effect of lithogenic and pedogenic processes on the formation of Luvisols from the area of Vistula glaciation on the base of profile distribution of iron oxides and total iron in relation to texture and physicochemical properties. The indices of weathering of the soil material in genetic horizons were calculated, and changes in the content and forms of iron oxides were evaluated. Materials and methods The predominant type of soil in the study area is Luvisols under agricultural use, formed from silt formations on loam. The analyses were made applying the following methods: grain size composition using the sieve method and hydrometer method, the interpretation of the results was performed according to the World Reference Base for Soil Resources classification, the pH of soils was measured with the potentiometric method, C-organic with the WalkleyBlack dichromate method, the content of the following iron forms was determined (total iron (Fe t ) after the mineralization of soils in the mixture of HF and HClO 4 acids), free iron oxides were extracted using dithionite-citrate-bicarbonate method, and amorphous iron oxides after the ammonium oxalate extraction (using the Philips 9100PU apparatus). The clay mineralogy was estimated by X-ray diffraction analysis. Results and discussion It was observed that total iron enrichment occurs in argic horizons accompanied by iron depletion in luvic horizons, while the profile distribution of iron is similar to the distribution of clay. The (Fe d /Fe t ) ratio indicates a low degree of weathering; the highest values were observed in argic (Bt) horizons, which confirms the effect of the process of pedogenesis on the value of that index. In the soils investigated, crystalline iron oxides generally dominate over the amorphous forms. The mineralogical composition of clay fraction separated from the upper part of soils was different as compared to the underlying material. Conclusions The results of the study showed that iron contents (together with the other indicators) and its forms can be used to distinguish soil layers of different origin. The depth distribution of Fe d , Fe o and Fe t within soil profiles indicates that the soil material may be of different lithogenic origin in the studied pedons.

Effect of slope curvature and gradient on soil properties affecting erodibility of coastal plain sands in Akwa Ibom State, Nigeria

“…This could explain the concentration of the more active and mobile Am-Fe and Am-Al in CC soil and the accumulation of the less mobile Cr-Fe and Cr-Al in CV soil. These results are in consonance with reports by Olatunji et al (2015) and Jaworska et al (2015). However, the abundance of these oxides is important in the formation and stability of microaggregates in tropical soils reputed to be poor in organic matter (Pronk et al, 2011;Igwe and Obalum, 2013).…”

Impact of Texture on Sesquioxide Distribution in Southeastern Nigerian Soils

“…Also, Fed and Feox correlated significantly with other sesquioxide forms besides Mnd while Feac correlated significantly (P < 0.05) with all other sesquioxide forms exception being Sid and Mnd. (Jaworska et al, 2016), Feac with Feo, Fed, and Ald and Feo with Ald (Olatunji et al, 2015). Relationship between soil properties and sesquioxide forms (Table 7) showed that sand was significantly (P < 0.05) correlated with Ald and Feox, silt with Fed, Feox, Feac, Siox and Siac, clay with Ald, Feox and Mnd while MC was with Ald, Alac, Fed, Feox, Sid and Mnd.…”

“…Equally, whereas exchangeable Ca correlated significantly (P < 0.05) with all sesquioxide forms (Ald, Alox, Alac, Fed, Feox, Feac, Sid, Siox, Siac, Mnd, Mnox and Mnac), ECEC correlated significantly (P < 0.05) with only Ald, Feac, Siox, Mnd and Mnox. Significant correlation have been reported between clay and OC with Fed and Feo (Jaworska et al, 2016), sand and clay with Ald, OM and clay with Feo (Osodeke et al, 2005), OM and clay with all sesquioxide forms (Maniyunda et al, 2015) and various soil properties (sand, silt, clay, silt/clay ratio, TN, OM, P, Ca, K, Mg, Na, H, ECEC and % BS) with sesquioxide forms (Uzoho, 2014). Regression equation (Table 8) indicated that sesquioxide concentrations in soil particle size fractions accounted for more than 55% of 2/3 of that in the bulk soil.…”

Determination of Individual Magnetic Particle Sources in Sediments from the Wae Tomu River Estuary, Ambon City, Indonesia: Scanning Electron Microscope (SEM) and Energy-Dispersive X-Ray Spectroscope (EDX) Analysis

“…These natural processes occur through weathering and/or erosion of the parent rocks, which depend on the mineral composition, structure, and texture of the rocks, climate, and anthropogenic pressures (Marszałek et al 2014). In addition, during weathering, amorphous iron oxides are released and crystallize over time, and the rate of the process depends on the pedo-environmental conditions (Jaworska et al 2016).…”