- - - The laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water, and Environment. Department of Chemistry, Faculty of Sciences, BP ۱۰۱۴, Rabat-Morocco
- - - Istituto di Produzione Vegetale, University of Udine, P. le M. Kolbe ۴, ۳۳۱۰۰ Udine, Italy
- - - The laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water, and Environment. Department of Chemistry, Faculty of Sciences, BP ۱۰۱۴, Rabat-Morocco
- - - INRA-CRRA Agadir Morocco, B.P.۱۲۴.Inezgane, ۸۰۳۵۰, Morocco
- - - INRA-CRRA Rabat Morocco, Avenue Mohamed Belarbi Alaoui B.P ۶۳۵۶, Morocco
- - - The laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water, and Environment. Department of Chemistry, Faculty of Sciences, BP ۱۰۱۴, Rabat-Morocco
- - - The laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water, and Environment. Department of Chemistry, Faculty of Sciences, BP ۱۰۱۴, Rabat-Morocco
- - - The laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water, and Environment. Department of Chemistry, Faculty of Sciences, BP ۱۰۱۴, Rabat-Morocco
- - - INRA-CRRA Rabat Morocco, Avenue Mohamed Belarbi Alaoui B.P ۶۳۵۶, Morocco

Purpose Soil salinization is one of the most severe abiotic stresses which threaten sustainable agriculture in arid and semi-arid regions including Morocco. The application of organic amendments like composts to saline soils has been confirmed to alleviate soil salinity stress. The present work aims to study the effect of humic acids (HA), as one of the products resulting from organic matter decomposition, on soil salinity reduction. Methods In this perspective, four composts made from mixtures corresponding to initial C/N ratios of ۲۵, ۳۰, ۳۵ and ۴۰ were tested. The four composts were made from mixtures of different proportions of greenhouse wastes, olive mill waste and sheep manure in Souss-Massa region. Representative samples underwent physicochemical analysis, extraction, purification and analysis of HA. The maturity of compost was assessed through some maturation index, prior to the main trial of the interaction between extracted HA and sodium carbonates salt (Na۲CO۳), largely encountered in saline soils. Results The results showed that the compost with initial C/N ratio of ۳۵ is the most recommended for application as an amendment to alleviate soil salinity. Conclusion The salt stress alleviating effect of compost may be advocated to compost humic acids and their ability to chelate sodium on their carboxylic sites.

Alkalinity, C/N ratio, compost, Humic acid, Soil salinity