Effect of Acidification on Clay Minerals and Surface Properties of Brown Soil

Abstract

Globally, soil acidification is becoming a serious environmental and ecological concern, posing a major threat to ecosystem functions and services. In order to clarifying the acidification mechanism, evaluating acidification risk, and reconditioning soil acidification, the effects of acidification on clay mineral composition and soil surface properties should be evaluated. In this study, the surface charge, specific surface area (SSA), species and content of clay minerals were investigated using the ion adsorption method, methylene blue method, and X-ray diffraction (XRD) for brown soil samples, which collected from Muping, Shandong Province, China. The results showed that the clay mineral species and content varied with the degree of acidification. A small amount of montmorillonite was found in weakly acidic soils, and gibbsite was found in strongly acidic soils. Furthermore, although illite, kaolinite, vermiculite, and chlorite were commonly found in soils with different acidification degrees, their content differed. The negative charge (CEC8.2), permanent negative charge (CECP), variable negative charge (CECV), and SSA values decreased with increasing acidification, while anion exchange capacity values (AEC) decreased. The change of CECV was caused by soil organic matter, and the change of CECP was caused by illite content, which accounted for the largest proportion in clay minerals of brown soil.

Correlation between Element and Radionuclide Activity Concentrations in Soil and Beech Forests Growth Potential

“…These soils characterized a higher percentage of clay fraction in soil samples from BA and CZ developed on limestone and sandstone marlstone parent materials, respectively [52]. On granite, andesite, and conglomerate parent materials, a highly acidic reaction enables a certain destructive decomposition of clay minerals in the soil, so the percentage of clay is somewhat lower in the soil developed on this parent material [54]. The richness of organic matter is an important chemical characteristic of this type of soil [55].…”

“…Atmospheric deposition is one of the possible sources. Atmospheric deposition increases the concentration of elements in the upper horizon of the forest soil, due to the adsorption potential of the humus layer, which is present in northernmost European forests [46,47].…”

Metabolomics and physio-chemical analyses of mulberry plants leaves response to manganese deficiency and toxicity reveal key metabolites and their pathways in manganese tolerance

“…Soil acidification is becoming a serious environmental and ecological problem, posing a major threat to the functioning and structure of ecosystems in the world ( Yin et al., 2023 ). Almost half of potential arable land belongs to acidic soil, which severely hampers agricultural production ( Yin et al., 2023 ). One of the primary causes of soil acidification is the indiscriminate applications of chemical nutrients due to deficiencies.…”