Use of geochemical fingerprints to trace sediment sources in an agriculture catchment of Argentina

Abstract

This research focuses on the identification of suitable soil tracers from hot spots of land degradation andsediment fate in an agricultural catchment of central Argentina with erodible loess soils. Using EnergyDispersive X-Ray Fluorescence (EDXRF) for geochemical characterization, element concentrations wereused as soil tracers.Tracers were identify using two artificial mixtures composed of known proportions of soil sources collectedin different sites with distinctive soil uses. Phosphorus, iron, calcium, barium, and titanium were identifiedfor obtaining a best suitable reconstruction of the source proportions in the artificial mixtures. Then, theseelements as well as the total organic carbon were applied for identifying critical hot spots of erosion in thecatchment. Feedlots were identified to be the main source of sediments, river banks and dirt roadstogether are the second most important source. This case study provides key information for improvingsoil conservation strategies and selecting land management practices and land uses that do not contributeconsiderably to sediment redistribution.