Effects of Irrigation and Nitrogen Application Rates on Nitrate Movement and Corn Yield



For a determination of optimum levels of water and Nitrogen fertilizer, as regards corn yield and nitrate movement in soil, a split-plot experiment, using a randomized complete block design of three replications was conducted in Safiabad Agricultural Research Center, on a silty clay loam soil. Three irrigation levels (50, 75, and 100% of water requirement) and three Nitrogen fertilizer levels (150, 225, and 300 kg N ha-1) were applied through fertigation in three equal splits of first irrigation, 6 to 8 leaf and flowering stages. The results revealed that the treatment of 100% water requirement with 932 mm of water consumption and 0.75 kg m-3 of water productivity displays a significant difference as compared to the other treatments. In addition, nitrate concentration in the 0-30 cm of soil layers was significantly higher than those in the other layers. The NO3-N leaching in soil layer deeper than 60 cm was not observed in any of the fertilizer level and fertigated stages for the schedueled irrigation in heavy textured soil, and in the climatic conditions of the North of Khouzestan Province.