Soil and water salinity evaluation in new agriculture land under arid climate, the case of the Hassi Miloud area, Algeria

Abstract

The food security challenge requires exploring new agricultural lands almost belonging to the arid and Saharian climate zones. An experimental trial was carried out in 2011 in southern Algeria (Hassi Miloud) where agricultural practices started a few years ago. Investigations of the soil at different depths (vadose and saturated horizon) and waters sampled from two irrigations bore holes were made. Irrigation water and subsoil water solution salinity values were close (EC = 3.07 and EC = 3.16 dS/m, respectively) but the saturated horizon salinity was clearly higher (EC = 9.11 dS/m). The saturation index and concentration factor were defined to predict possible trends of each type of water. Irrigation waters were undersaturated in gypsum, anhydrite and halite and close to equilibrium in aragonite, calcite and dolomite. In the vadose and saturated horizon, the waters were close to the oversaturation state. A correlation matrix was developed to analyze ionic interactions between the solutions from the vadose and saturated horizon. An important exchange between the two horizons was observed involving mainly sodium, chlorides and sulfates. We conclude that the use of these waters requires more attention to sustain agricultural development because they require processes never observed before in dry areas.