Abstract :
Water and nitrogen are two importance factors in the growth and development of rice plant and have usually interaction together in which deficiency of them is being the decreasing of rice yield. For study of interaction of nitrogen and irrigation method on the growth and yield of rice, the field design as split plot in factorial form in deputy of rice research institute (Amol) was carried out in 2004-2005. Irrigation method with three level as a main plot and amount of nitrogen fertilizer (100,200,300 kg urea/ha) with split of nitrogen as a sub-plot were used as an factorial. The measurement of morphological characters such as plant height, tiller number, leaf area, leaf dry weight, stem dry weight and total dry weight were taken in maximum tillering, flowering and physiological maturity stages. At physiological maturing stage, which harvesting of 10 main stem of rice, yield component were measured. Yield of each plot with harvesting of 5 m2 and adjusted with 14% grain humidity changed to hectare. The obtained results showed interaction of nitrogen and irrigation methods was significant on the total dry weight in maximum tillering and physiological maturing stages. This interaction effect was observed in permanent irrigation method at high level of nitrogen. In this experiment, the others of interaction were not significant. The highest yield was obtained in the permanent and interval irrigation with using of 300 kg urea fertilizer with three times. Therefore, we suggest to farmer using interval irrigation instead to permanent irrigation without decreasing yield of rice.
