Purpose: Runoff caused by rainfall events contributes to the watercourses pollution through the export of OM, nutrients, and sediments from soils. This study aimed to assess the loss of OM, nitrogen, phosphorus, and sediments by the runoff of soils under agriculture and cattle farming. Materials and methods: Three pedons located on the top of the slope, in the backslope, and one close to the alluvial plain (CoAoMo) were selected as study sites. Experiments using a drop-forming rainfall simulator on runoff microplots were carried out under laboratory conditions. The physical and chemical characteristics of soils, sediments, and runoff waters were analyzed. Results and discussion: The rainfall took part in the soil acidification process through hydric erosion and lixiviation. Hydric erosion produced the loss of divalent cations associated with sediments transported by runoff waters, whereas the loss of monovalent ions (sodium) was linked with a leaching process. The losses of sediment, divalent cations, OM, NK, and P Bray were more marked in soils with a higher position in the landscape and higher slope. On the other side, CoAoMo showed the lowest sediments loss, OM, and NKj due to its high sodium concentration that decreases sediment detachment during the runoff processes. However, CoAoMo, which presented the highest TRP into runoff waters, would be the product of exogenous contamination. Sediments were enriched in fine materials, OM (EF: 1.16 – 1.32) and NK (EF: 1.31 – 1.69). Conclusion: According to these results, the particulate fraction represents the major proportion of nutrients in the runoff waters. Non - conservative management of these soils could conduct to a loss of plant cover that became them susceptible to intense erosion.
De Siervi, M. S.; Arreghini, S. & Fabrizio de Iorio, A. R. (2022). Losses of sediment, organic matter, and nutrients in the Argentinean pampas through rainfall simulation experiments. Journal of Soils and Sediments,22, (9),p.2485-2498
10.1007/s11368-022-03243-7
De Siervi, Marcelo Silvano, Arreghini, Silvana, Fabrizio de Iorio, Alicia Rosa. 2022. "Losses of sediment, organic matter, and nutrients in the Argentinean pampas through rainfall simulation experiments". Journal of Soils and Sediments 22, no.9:2485-2498.
Recuperado de http://ri.agro.uba.ar/greenstone3/library/collection/arti/document/2022desiervi