Abstract

This paper presents the effect of recharge, irrigation and soil nature on the variation of nitrate in the groundwater of Wadi Nil (Jijel – North-East Algeria) where the intensive use of fertilizers and the recycling of irrigation water have resulted in an alarming increase in nitrate concentrations. In this plain, the groundwater is increasingly polluted by excessive use of fertilizers in agriculture. Indeed, in several areas cultured with irrigated vegetable crops, water contains nitrate levels which exceed the allowed standards for human consumption. The present study consists of a spatio-temporal monitoring of nitrate in groundwater in relation to the dilution caused by charging during the rainy season, on the one hand, and to the leaching caused by irrigation water during the dry season, on the other hand. The results obtained show an increase in the contamination of groundwater by nitrates and their seasonal variations under the effects of recharge, irrigation and soil nature.

Key words: Agricultural pollution, nitrates, recharge, irrigation, groundwater, soil nature.