The Effects of Different Nitrogen Levels and Irrigation Intervals on Yield and Water Productivity of Cotton Grown in the Eastern Mediterranean Region

Abstract

The experiment was conducted to determine the effect of nirogen levels and irrigation intervals applied with drip system on cotton yield, evapotranspiration and water use efficiency in the East Mediterranean Transitional Zone Agricultural Research of Institute Located in Kahramanmaras, Turkey during 2012 and 2013. In the experiment, 3 different nitrogen levels (N0:0, N15:150, N30: 300 kg ha-1) and 2 different irrigation intervals (I5: 5 and I10:10 days) were investigated on Erşan-92 cotton variety. The amount of irrigation water was estimated by replenishment of soil water deficit in 60 cm root-zone depth to the field capacity in the irrigation intervals of 5 and 10 days. The experimental design was split-plots with three replications. The amount of irrigation water applied to treatments in the research years varied between 511.9-633.8 and 498-611 mm respectively. Cotton yield values in the research years for irrigation and nitrogen applications ranged between 2520-3360 and 2360-3540 kg ha-1 respectively. Higher yields were obtained with 5-day irrigation frequency compared with irrigation every 10 days. The effects of different irrigation intervals and nitrogen application of interaction on yield, Water use efficiency (WP) and Irrigation water use efficiency (IWP) were found to be statistically significant at 1% level. I5 N15 generated the highest net income and the lowest income was found in I10 N0. As a result of the experiment, 150 kg ha-1 nitrogen dose in 5 days irrigation interval was recommended for cotton production in the region.