How should water retention be assessed when estimating characteristics of the B horizons?

When estimating characteristics of the B horizons in relation to water retention, it is essential to focus on the specific properties and thickness of the horizon itself. Selecting half the top of the B horizon down to the underlying bedrock or restricting layer (often noted as 150/rock) provides a more accurate assessment. This is because the B horizon typically accumulates clay, iron, and other minerals leached from the overlying layers, which can significantly influence its ability to retain water.

By assessing this portion of the B horizon, you gain insights into the quantitative and qualitative properties that directly affect water retention capabilities. This method acknowledges that the B horizon can act differently based on its depth and composition, as well as the influence of the overlying layers. Ignoring or summing the thickness of all horizons, for example, does not differentiate the unique characteristics of the B horizon that are vital for understanding its water retention attributes.