Evaluation of Nitrate Distribution in Soil Irrigated by Treated Urban Wastewater under Corn and Tomatoes Cultivation

Treated municipal wastewater (TMW) as a non-conventional water resource¡ is well recognized as one of the most important factors of water resources management in arid and semi- arid religion. The main goal of this research is evaluating the effect of irrigation with TMW on nitrate distribution in the soil profile under greenhouse conditions. This experiment was carried out in randomized complete block design based on a factorial experiment with three replications. Three irrigation levels were considered consisting of TMW¡ alternative TMW- water and tap water. Soil samples extracted from four different depths (0¡ 7.5¡ 15 and 22.5 cm) and three horizontal distances into plant location (0¡ 5 and 10 cm). The results showed that nitrate of TMW had significantly greater amount in comparison with water (27.1 mg/lit for TMW¡ 19.6 mg/lit one among irrigation TMW- water and 4.5 mg/lit for water). Nitrate concentrations have largely been observed in the closest point of the plant. Also¡ diagrams¡ which have been drawn in order to compare the irrigation treatment on the cultivated plants¡ showed that amount of nitrate in the soil profile of tomato root’s region was significantly higher in comparison to corn. This could be due to plants unequal required nitrate. Based on the results obtained¡ using of TMW can reduce require nitrogen fertilizer for plants and it can also do to help reduce pollution of soil and water by nitrogen fertilizer.