Case study : Influence of groundwater irrigation on Agricultural salty soils in a hyper-arid region (In Salah) Algeria
Agriculture in the In Salah region, located south of the Algerian Sahara, relies entirely on groundwater for irrigation. Proper management and sustainable development of this resource are essential to ensure satisfactory and sustainable agricultural production. However, soil degradation has been observed, resulting from the natural characteristics of the environment, agricultural practices and irrigation management methods. The objective of this study is to assess the type of soil degradation in this region and to analyze the impact of the quality of groundwater irrigation on this degradation. To do this, eight soil profiles were studied, and the characteristics of the associated irrigation water were analyzed. The results reveal soil salinization, characterized by electrical conductivity greater than 15 dS/m and a significant accumulation of soluble salts, mainly sodium, calcium and magnesium. Irrigation water has a high concentration of dissolved salts, with high TDS values, very high sodium contents and moderate concentrations of calcium and magnesium. Their electrical conductivity remains below 4 dS/m, classifying them in the category (C4-S4) according to the water classification diagram [1] which indicates a high risk of alkalinity for soils. This study highlights that the use of groundwater for irrigation, whether from wells or boreholes, leads to secondary salinization of agricultural soils in this region.