What are redoximorphic features in soil primarily formed by?

Redoximorphic features in soil are primarily formed by reduction and oxidation processes. These features, which are often observed as color variations, mottling, or distinct layers within the soil, arise due to the dynamic interplay between oxygen availability and the microbial activity that influences the chemical state of various soil constituents.

In saturated or poorly drained soils, the lack of oxygen leads to reduction, a process where certain elements (like iron and manganese) lose electrons. This reduction often results in the leaching of iron, producing a grayish color in those areas where the reduction has occurred. Conversely, when oxygen is reintroduced during drier periods, oxidation takes place, converting reduced iron back to its oxidized form, which can create reddish or brownish hues in the soil.

These processes are critical in forming the characteristic patterns of redoximorphisms, which can indicate soil drainage conditions and help in interpreting the soil's water management capabilities. Thus, reduction and oxidation are the fundamental chemical reactions responsible for the development of these features in soil profiles.