INFLUENCE OF AWD (ALTERNATE WETTING AND DRYING) IRRIGATION SYSTEM ON THE GROWTH AND YIELD OF BORO RICE (BRM dhan29)

Abstract

The experiment was conducted in the farm of' Sher-e-Bangla Agricultural University. Dhaka. Bangladesh during the period from December 2011 to May 2012 to study the influence of AWD (Alternate Wetting and Drying) irrigation system on the growth and yield of born rice (BRRI dhan29). The experiment consists of I factor that is irrigation. Nine levels of irrigations as 'l': Continuous submergence (1 to 7 cm standing water),T 2 : Start irrigation when water table in the porous tube at 15 cm.T3 : Start irrigation when water table in the porous tube at 10 cm, 1i: Start irrigation when water table in the porous tube at 5 cm,Tc: Start irrigation when disappearance of water by naked eyes. Ti,: Start irrigation after 7 days disappearance of water.T 7 : Start irrigation after 5 days disappearance of water.T8: Start irrigation after 3 days disappearance of water.T 9: Start irrigation after I days disappearance of water were used and there were 3 replications. Results revealed that different levels of irrigation had significant effect on the yield and yield parameters. The highest plant height (88.20 cm), total number of tillers/hill (26.60), number of effective tillers/hill (21.50) were found from T 5 T1 T4 treatments respectively. The highest paniele length (31.53 cm), number of grains/panicle (215.73), 1000 grain wt. (24 g), grain yield (7.70 tlha) and straw yield (7.53 tJha) were found from i' 4 treatment where irrigation was started when water table in the porous tube was at 5 cm followed by •I t treatment. On the other hand in most cases lowest values were obtained from 16 treatment. Nutrient concentration in grain and straw of rice plant was significantly affected by application of different levels of irrigation. The highest concentration of grain N (1.197%). p (0.379%), K (0.395%) and S (0.097%) were recorded from l treatment and in all eases lowest value were observed in T6 treatment. Similarly the highest concentration of straw N (0.567%), p (0.198%). K (1.873%) and S (0. 100%) were recorded from T4 treatment and in all cases the lowest values were observed in T,-, treatment. The p1-I, organic matter and levels of N and S of post harvest soil were significantly affected by different levels of irrigation but P and K content of post harvest soil do not differ significantly. The highest p1-1 (5.5) and organic matter (1.28%) were observed from T T treatment and highest total N (0.075%). available P (12.92 ppm), exchangeable K (0.19 meq/100 g soil) and available S (11.05 ppm) were recorded from 1' 4 treatment. The lowest pH (5.9), organic matter (1.03%), total N (0.061%), available P (10.28 ppm), K (9.31 ppm) and available S (8.70 ppm) were recorded from T 6 treatment in all the cases.