The Effect of Water Saving Irrigation and Nitrogen Fertilizer on Rice Production in Paddy Fields of Iran

Abstract

Rice production in Iran needs to increase to feed a growing population whereas water for irrigation is getting scarce. There are 230000 ha paddy fields in Guilan province in north of Iran. About 73% of paddy fields irrigated by Sepeedrood dam. Shortage of water for rice production will be a problem in near future. In order to investigate the best irrigation regime and nitrogen level an experiment was conducted in split plot based on completely randomized block design with 3 replications at the rice research institute of Iran in 2008. Four levels of nitrogen (N1= 0, N2 = 90, N3 = 120 and N4 = 150 kg ha-1) w ere splited on 4 different irrigation managements (I1= con tinuous submergence (CS), I2 = 5, I3 = 8 and I4 = 11 days interval). The results clearly indicate that nitrogen levels and irrigation management in most of studied characteristics had very significant differences. Not only grain yield was statistically the same under CS and 8 days interval but also water consumption decreased 18%. Thus, concluded that water limited irrigation can lead to reduce water consumption in paddy fields and minimum 150 million m3 water of Sepeedrood dam saved annually.