Evaluation of Irrigation Regimes and Seedling age Effects on Rice (Oryza sativaL.) Yield and Yield Components in Conventional and Ecological Systems

The System of Rice Intensification (SRI) is one of the farm management methods that reduces inputs such as seeds, irrigation water, fertilizers and chemical pesticides while increases yield. Considering the economic importance of rice, this research was carried out in a split plot design with two irrigation managements at three levels (A1: flooding, A2: saturated and A3: low irrigation) and plant age at two levels (B1: 39 days, B2: 46 days) in three replications to evaluate the effects of irrigation methods and seedling ages on yield and yield components of rice under conventional and ecological systems. Combined treatments including A1B2 and A3B1 were the conventional and the ecological methods, respectively, and the other treatments were compared as intermediate. The average number of tiller per hill in flood irrigation treatment (37.85) was higher compared to other treatments (30.73 and 27.28 for saturated irrigation and deficit irrigation, respectively). It was observed that the highest biological yield (15313 Kg ha-1) was recorded under flooding irrigation treatment and the lowest value (12764.6 Kg ha-1) was realted to deficit irrigation. Mean comparison of the tiller number showed that the highest (32.48) and the lowest (31.44) tiller number per hill were related to 39 and 46 days plant age, respectively. Water consumed under deficit irrigation was about 42 percent lower than that of flooding irrigation treatment and its water productivity was 0.63 Kg ha-1. Based on the results, in order to increase rice production and water saving, it is recommended to use ecological systems (deficit irrigation and plant age of 39 days).