Impact of podzolization on lamellae transformation in sandy soils in a temperate climate – A case study from southern Poland

Abstract

Lamellae occur in Podzols around the world, mostly in illuvial horizons and parent material, while in eluvial horizons they are often absent or very rare. While many studies have been conducted on lamellae origins, there has been little research focused on their transformation in the soil profile, including the disappearance of lamellae in the course of soil formation. Some studies show that the transformation of lamellae toward physical degradation over time occurs frequently. However, there still exists a lack of studies on lamellae transformation in soils occurring in similar environmental conditions, formed from the same parent material, and varying only in terms of type of dominant soil-forming process. The main aims of this study were: (1) to determine the mechanism of lamellae transformation in sandy soils in a moderately humid climate in southern Poland in relation to progressing podzolization and (2) to compare lamellae transformation mechanisms in well-developed sandy soils affected and not affected by podzolization. The obtained results indicate that soil lamellae commonly occur in the sandy soils of southern Poland – and are characterized by very diverse morphology as well as diverse physical and chemical properties. Soil lamellae exhibit a higher content of fine fractions, iron, aluminum and total organic carbon compared with interlamellae. Soil lamellae are affected by different mechanisms of transformation that depend on their position in the soil profile, predominant soil-forming process, and stage of soil development. Soil lamellae in the upper part of initial sandy soils are mainly transformed by mechanical degradation related to bioturbation. Mechanical degradation of soil lamellae due to clay translocation as well as chemical degradation due to dissolution of iron compounds occur in the upper part of well-developed sandy soils in which podzolization takes place and the eluvial horizon is well-developed. Mechanical degradation of soil lamellae due to bioturbation and clay translocation occurs in the upper part of well-developed sandy soils, which do not exhibit podzolization. Soil lamellae occurring in the lower part of initial and well-developed sandy soils develop progressively due to the illuviation and accumulation of clay and iron compounds as well as lack of biological activity.