Impact of Nitrogen Fertilization on Soil Nitrate Concentrations in an Onion Field in the Saiss BasinChaimae Nessah, Abdellah El Hmaidi, Abdelhakim Lahjouj, El mâti El Faleh and Karima BouhafaE3S Web Conf., 489 (2024) 08001DOI: https://doi.org/10.1051/e3sconf/202448908001