Assessment of water quality of drains from irrigation district in a semiarid agricultural zone

Abstract Worldwide wastewater is used for agriculture, because of water scarcity. Also, there are increasingly fewer sources of good quality water because of widespread contamination (Ramirez-Fuentes et al., 2002; Rutkowski et al., 2007, Qadir et al., 2010).Agronomic water quality effects on soil, crops and management; major problem with the use of wastewater are salinity, soil permeability and toxicity (Ayers and Westcott, 1994).Wastewater with a high salt concentration leads to increased soil salinity and reducing the availability of water to the plant and induces a drought condition (osmotic effect), that varies with the plant growth stage (Kirda, 1997). The symptoms in plants exposed to high salt concentration are marginal burn, necrosis and sometimes defoliation. Seed germination is also affected by the presence of salts, mainly sodium, chloride and occasionally boron (George, 2004). On the other hand, some specific ions from wastewater may accumulate in plant and reduce yields. Irrigation district 024 (DDR024) is main source of water for agricultural irrigation in Cienega de Chapala. In this zone there is a high demand of water for irrigation; 46,743 ha planted with grains and vegetables, and 1,722 thousands of m3 from drains are used mainly in dry season (Conagua, 2005), the scarcity of water for this production leads to use drainage water (Sandoval and Ochoa, 2010), which is a risk of human and environmental health, furthermore, the soils irrigated with wastewater in this area have become salty (Silva-García et al. 2002) which can lead to low productivity.Water quality is a very important concern both for crop irrigation and for soil. The aim of this study was to characterize the physical and chemical composition of drainage water used for agricultural irrigation and assess the suitability and to review the possible salinization and alkalinization involved when using such water for agriculture.