Novel application of Compound Specific Stable Isotope (CSSI) techniques to investigate on-site sediment origins across arable fields

The main grazed waterway of the basin, identified as one of the four sources of the sediment, was evaluated to have contributed 55.1 ± 5% (IsoSource), 53.9 ± 2.7% (SIAR), 53.9 ± 2.7% (MixSIAR) and 54.0 ± 2.7% (SIMMR) to the sediment. The estimated contributions of the sources to the sediment are consistent with the land use information and the distance of the sources to the outlet. More than 80% of the sediment deposited at the basin exit originates from the two sources which had maize cultivation, one of the more erosive crops, in particular at the beginning of the growing season. This study emphasizes that CSSI and 137Cs techniques are complementary for establishing land sediment redistribution. Their combined use could provide key decision support knowledge for optimised decision-making of land managers to ensure the sustainability of agro-ecosystem management.