The Effects of the Quality of Irrigation Water Used on Agricultural Soils in Coastal Chaouia, Morocco

Abstract

The Coastal Chaouia region is located south of the Casablanca city (Morocco). Since the 1970s, groundwater has been used intensively for irrigation, previously for growing citrus and currently for vegetables and forages. The increase of irrigated soils by pumping has induced environmental problems such as the degradation of groundwater quality and salt water intrusion. For these reasons, this work aimed to study the impact of the irrigation water quality upon the agricultural soils. During the study, 71 samples of well water and soil were taken to represent the whole considered area, which comprised 3 different zones (0–1.8 km, 1.8–4.5 km, and 4.5–11 km from the coast). The analyzed parameters were salinity and pH. The results showed firstly that the soil pH average values decrease for the three zones with 7.73, 7.57, and 7.52, respectively. However, the water pH averages vary from 7.24 to 7.49. For the soil electrical conductivity, it represents a light decrease moving from the nearest zone to the sea to the far one (average of 3.54, 2.66, and 2.33, respectively). A similar result is for observed water electrical conductivity with average of 6.83, 5.30, and 2.06, respectively, for the three zones. The analyses of the soil and water salinity show that both salinities decreased moving from the coast to inland. Richard and Wilcox charts have confirmed the strong mineralization and the poor quality of most of the well water which are close to the sea.