Studies have indicated that after the application of paddy-upland rotation, the adverse effects in the long-term-flooded paddy fields have shown slight improvements, such as increased soil granular structure and capillary porosity, improved redox potential of soil, and removed secondary
gleization. For instance, Huang and Ding [12] showed that soil water-stable aggregate increased by 12.54% after paddy-upland rotation is applied.
By noting the presence or absence of
gleization (a process involving the reduction of iron in saturated soils, commonly indicated by black Fe-Mn films and mottlings), and the concentration and character of clay coatings, it is possible to recognize four types of B horizons.
The reduction and leaching of iron, which commonly leaves behind zones of grey (low chroma) depletions, is termed
gleization. The process of sulfur reduction is involved in sulfidization; the oxidation of sulfides is involved in sulfuricization (Fanning et al.