In which soil layer is base saturation typically measured for udalls?

Base saturation is an important indicator in soil science that reflects the proportion of the soil's cation exchange capacity that is occupied by base cations, such as calcium, magnesium, potassium, and sodium. In udolls, which are a type of mollisol found in humid temperate regions, base saturation is typically highest in the upper soil layers where organic matter and weathering processes are more active.

Measuring base saturation in the 25-75 cm layer is significant because this depth often contains a well-developed accumulation of bases due to the leaching and translocation of materials from the upper layers. The accumulation of bases can be influenced by several factors, including parent material, soil formation processes, and vegetation type, which make the 25-75 cm layer a crucial zone for assessing nutrient availability and soil fertility.

Measurements taken from this depth are particularly indicative of soil health and productivity, as they represent a balance between leaching and accumulation processes that occurs within the profile. The other layers—0-25 cm, 75-100 cm, and above 100 cm—may not provide a complete picture of base saturation as they contain either very high organic matter and microbial activity (in the top layer) or are more influenced by the underlying parent material and