Impact of nitrogen fertilizers on the natural weathering-erosion processes and fluvial transport in the Garonne basin

• Published in: Applied Geochemistry
• Main Authors: Semhi, Khadija, Amiotte Suchet, Philippe, Clauer, Norbert, Probst, Jean-Luc
• Other Authors: Centre de géochimie de la surface (CGS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Ecole et Observatoire des Sciences de la Terre (EOST), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2000
• Subjects: N-fertilizers; Rural weathering-erosion process; Nitrification; Soil erosion; Garonne river; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; Carbonic acid
• Online Access: https://hal.science/hal-04260556; https://doi.org/10.1016/S0883-2927(99)00076-1

International audience Knowledge of the impact of N-fertilizers on the weathering-erosion processes of soils in intensively cultivated regions is of prime importance. Nitrification of NH4− fertilizers produces HNO3 in the basin of the Garonne river, enhancing soil degradation. Their influence on the weathering rates was determined by calculating the consumption rate of atmospheric/soil CO2 by soil weathering and erosion, and its contribution to the total dissolved riverine HCO3−. This contribution was found to be less than 50% which corresponds normally to a complete carbonate dissolution by carbonic acid, suggesting that part of the alkalinity in the river waters is due to carbonate dissolution by an acid other than carbonic acid, probably HNO3.