Estimation of soil erosion and deposition rates at an agricultural site in Bavaria, Germany, as derived from fallout radiocesium and plutonium as tracers

摘要

In the near future, the use of 137Cs from global fallout (Cs) as a tracer for erosion studies will no longer be possible in areas with a substantial deposition of Chernobyl-derived 137Cs. Therefore, we have used 239+240Pu from global fallout (Pu) as a tracer as well as 137Cs in order to determine long-term soil redistribution rates for an agricultural field (inclination about 20%, area approx. 3 ha) in Scheyern, Bavaria. The mean erosion and deposition rates derived from Cs were –37 and +52 t·ha–1·year–1, respectively; those from Pu were –32 and +39 t·ha–1·year–1. We found no statistical difference between the means obtained by the two tracers. In contrast to Pu, however, the rates obtained by Cs were not accurate enough to assure the presence of a net soil redistribution. Modeling of soil translocation in the field by water and tillage erosion resulted in estimates which were in reasonable agreement with the rates derived from Pu.