ArticleAPPLICATION OF CESIUM-137 IN A STUDY OF SOIL EROSION AND DEPOSITION IN SOUTHEASTERN BRAZILGuimarães, M. F.1; Filho, V.F. Nascimento2; Ritchie, J.3Author Information 1Universidade Estadual de Londrina, CCA, Depto de Agronomia, C.P. 6001, 86051–990 Londrina, PR - Brazil. 2CENA/USP, Laboratório de Instrumentação Nuclear, C.P. 96, 13400–970 Piracicaba, SP - Brazil 3USDA, ARS Hydrology and Remote Sensing Laboratory, BARC-West Bldg-007, Beltsville, MD 20705–USA Dr. Guimarães is corresponding author. E-mail: [email protected] Received May 20, 2002; accepted Aug. 29, 2002. DOI: 10.1097/01.ss.0000049730.22043.ca Soil Science: January 2003 - Volume 168 - Issue 1 - p 45-53 Buy Abstract A study using 137Cs, a component of radioactive fallout, was carried out to estimate soil erosion and deposition on a small watershed in Piracicaba District, São Paulo State, Southeastern Brazil. Soil samples were collected along three transects employing different land uses and conservation practices on different slopes. 137Cs concentration was measured with a high-resolution germanium semiconductor detector coupled to a multi-channel analyzer. The 137Cs estimates of soil movement and redistribution were related to slope, land use, and conservation practices, allowing the identification of sites with soil loss and accumulation. This study shows that the application of the 137Cs technique is viable for Brazil. A relationship between 137Cs concentration in soil profiles and soil losses or accumulations for Brazilian conditions needs to be established to avoid the use of equations developed for the Northern hemisphere. © 2003 Lippincott Williams & Wilkins, Inc.