The usefulness of 137Cs as a tracer for soil erosion assessment: A critical reply to Parsons and Foster (2011)

A large number of geoscientists worldwide from different disciplines have recognized and have adopted the Cs-137 method as an effective tracer to assess soil erosion rates during the last decades. The recent review of Parsons and Foster (2011) challenged the usefulness of this radioisotopic method primarily by questioning the assumption of the representativeness of the reference inventory and its conservative behavior and the Cs-137 data conversion into erosion rates. While there are many studies published on Cs-137 method, Parsons and Foster (2011) have not evaluated the full range of the existing literature. We present additional highly relevant studies, assessing and applying the Cs-137 method successfully. While we agree that the applicability of the Cs-137 method to assess soil erosion magnitude needs careful planning as well as expert knowledge, we highlight in our reply that if the method is based on suitable and statistically sound sampling, Cs-137 is a very effective soil tracer to assess soil erosion magnitude. (C) 2013 Elsevier B.V. All rights reserved.