Document Type : Research Paper
M.Sc. Student, Department of Water Engineering, Aburaihan Campus, University of Tehran, Tehran, Iran
Associate Professor, Department of Water Engineering, Aburaihan Campus, University of Tehran, Tehran, Iran
Assistant Professor, Department of Horticultural, Aburaihan Campus, University of Tehran, Tehran, Iran
Associate Professor, Department of Water Engineering, Aburaihan Campus, University of Tehran, Tehran, Iran.
Water crisis is one of the most important problems in arid and semi-arid areas such as Iran. Also, in these areas indiscriminate use of nitrogen fertilizer have had severe environmental consequences. Thus, assessment of plant responses to water stress, the amount of nitrogen and, estimation of production function for determining optimal use of water and fertilizer is inevitable. The objective of this study was to investigate the interrelations of yield, irrigation depth and, applied nitrogen fertilizer of Radish (Raphanus sativus L.). For this purpose, the study was conducted in the College of Aburaihan (Southeast Tehran, Pakdasht, Iran) in 2020. Experiment was arranged based on randomized complete block design with two treatments of nitrogen fertilizer and irrigation water depths with three replications. In this study the Levels of irrigation depth were 120% (I1), 100%(I2), 80%(I3) and 60%(I4) of irrigation requirement the levels of applied nitrogen fertilizer were 120%(N1), 100%(N2), 80%(N3) and, 60%(N4) of nitrogen use requirement. In this study four equations of of linear, Cobb-Douglas, quadratic and transcendental were used to determine the water-nitrogen production function production. The results showed that the quadratic equation simulates the dry yield of radish with a higher accuracy. The results showed also, the I3 (142 mm) and N2 nitrogen (150 Kg per hectare) treatments, were yielded the highest yield and irrigation water use efficiency.