Irrigation water quality in the western Mitidja, Algeria: A case study of Sidi Rached watershed​

Abstract

The Sidi Rached watershed, located in the west of the Mitidja plain, is experiencing an important agricultural activity which is constantly increasing and is manifested by an excessive use of groundwater and inputs, in particular fertilizers. However, uncontrolled practices are observed and cause the deterioration of water and soil. To assess the consequences of these practices on the environment, a study was conducted in Sidi Rached watershed in the west of Mitidja plain, during 2008 and 2010 by conducting surveys involving agricultural institutions and farmers to establish the technical itineraries used by the farmers during the two years 2008 and 2010. Secondarily, analysis on the physico-chemical properties of the groundwater was carried out, which is mainly used for irrigation. The monitoring of the quality of this ground water was carried out on agricultural drillings from 50 water samples taken and analyzed. The main parameters analyzed were nitrate concentrations and mineralization rates. The results obtained are significant: more than 45% and more than 60% of the samples taken for the years 2008 and 2010 respectively exceed the norms of potability established by the World Health Organisation. Therefore, this could be a threat to public health and to the sustainability of the resource. These waters, although acceptable for irrigation, must be used on salt-tolerant crops and on well-drained or permeable soils to control salinity. The future of the agricultural plain depends on the quality of its resources, water and soil, and this is closely linked to the ability of managers and farmers to strike a balance between productivity and preservation of natural resources.