Evaluation of water quality for agricultural suitability in the Benslimane region, Morocco.

Abstract

Morocco is basically a semiarid country with limited rainfall reducing the opportunities for rainfed agriculture. For feeding its ever growing population, irrigation is required. This study aims to evaluate the groundwater quality for irrigation in the Benslimane region by studying the main influencing chemical elements and characteristics. The main purpose is to provide the farmers and agricultural developers with a clear comprehension of the groundwater status. We focused on the determination and statistical analysis of physicochemical parameters and major elements (electrical conductivity, pH, Na+, K+,Ca2+, Mg2+, Cl-, SO42-, CO32-, and HCO3-) for 120 samples and the derivation of water quality indices like SAR, %Na, RSC, PI, KR, and MAR, along with graphical approaches such as Wilcox's and Richards's diagrams. Factors affecting groundwater hydrochemistry and quality were also discussed. The results show generally alkaline and shallow waters, with the majority of the samples belonging to the Na-Cl facies. Rock alteration, dissolution, ion exchange, evaporation, and anthropogenic activity are the main factors controlling water chemistry. Most prospected wells indicate high salinity problems due to salt water intrusion. With regard to the suitability of groundwater for irrigation, the majority of wells is of medium to poor quality and is therefore unsuitable. These types of water are found throughout the area, with a significant dominance on the coastal zone. The long-term use of this groundwater would therefore have negative impacts on soil quality and the sustainability of agricultural production. Therefore, we recommend proper agricultural management and irrigation practices in the Benslimane region, in order to increase agricultural production while preserving water and soil resources.