What happens to the minimum thickness required if the arg/camb horizon exceeds 25 cm?

When determining the minimum thickness requirement for horizons in soil classification, specific criteria are set based on the characteristics of those horizons. In the case of argillic (arg) or cambic (camb) horizons, if the thickness exceeds 25 cm, the established standard indicates that the minimum thickness requirement for that horizon becomes 25 cm.

This is crucial because horizons that are sufficiently thick demonstrate more developed properties and greater soil functionality, which can affect its classification and potential use in agriculture and land management. Thus, once the argillic or cambic horizon reaches a thickness beyond 25 cm, it aligns with the classification guidelines that raise the minimum required thickness to ensure adequate representation of the soil's characteristics.

The other possibilities would misrepresent the thickness requirements, either retaining a lower threshold that's not applicable when the horizon exceeds 25 cm, suggesting a higher threshold unnecessarily, or invalidating the consideration of thickness altogether, which would compromise systematic soil classification approaches.