These concretions are not considered plinthite unless there has been enough segregation of iron to permit their irreversible hardening on exposure to repeated wetting and drying. Plinthite is firm or very firm when the soil moisture content is near field capacity and hard when the moisture content is below the permanent wilting point.
These concretions are not considered plinthite unless there has been sufficient iron segregation for their irreversible hardening upon repeated wetting and drying cycles. Plinthite is a type of soil that becomes firm or very firm when soil moisture is near field capacity, and hardens further when moisture content falls below the permanent wilting point.