INFLUENCE OF ALTERNATE WETTING AND DRYING (AWD) IRRIGATION SYSTEM ON THE GROWTH AND YIELD OF BORO RICE (HIRA HYBRID dhan2)

Abstract

The experiment was conducted in the farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the period from December 2011 to April 2012 to study the influence of AWD (Alternate svetting and drying) irrigation system on the growth and yield of boro rice (1-ITRA HYBRID dhan2). The experiment consists of I factor that is irrigation. Nine levels of irrigations as T 1 : Continuous submergence (1 to 7 cm standing water).T 2 : Start irrigation when water table in the porous tube at 15 cm. 13: Start irrigation when water table in the porous tube at 10 cm, 1 4 : Start irrigation when water table in the porous tube at 5 cm, T 5 : Start irrigation when disappearance of water by naked eyes, 16: Start irrigation after 7 days disappearance of water, T: Start irrigation after 5 days disappearance of water, T 8 : Start irrigation after 3 days disappearance of water, 1 9 : Start irrigation after 1 days disappearance of water were used and there were 3 replications. Results revealed that different levels of irrigation had signilicant effect on the yield and yield parameters. The highest plant height (89.45 cm), total number of tillers per hill (26.67), number of effective tillers per hill (21.45), panicle length (31.50 cm). number of grains per panicle (215.5), 1000 grains wt. (24.00 g), grain yield (7.80 t/ha) and straw yield (7.52 t/ha) were found from T 3 treatment where irrigation was started when water table in the porous tube at 10 cm. On the other hand in most cases lowest values were obtained from T, treatment. Nutrient concentration in grain and straw of rice plant was significantly affected by application of different levels of irrigation water. The highest concentrations of grain N (1.20%), p (0.38%). K (0.39%) and S (0.10%) were recorded from 1 3 treatment and in all cases lowest value were observed in Tt. treatment and similarly the highest concentrations of straw N (0.69%), P (0.20%), K (1.87%) and S (0.10%) were recorded from 1 3 treatment and in other cases the lowest values were observed in T 6 treatment. The pH, organic matter and levels of N. P, K and S of post harvest soil were significantly affected by different levels of irrigation but P content of post harvest soil don't differ significantly. The highest pH (5.9), organic matter (1.26%) were recorded from Tj treatment and total N (0.075%). available P (19.89 mg/kg soil), Exchangeable K (0.12 meq/lOOg soil) and available S (14.66 mg/kg soil) were recorded from T 3 treatment and the lowest pH(5.4),organic matter (1.05%), total N (0.061%), available P (13.27 mg/kg soil), Exchangeable K (0.04 meq/lOOg soil) and available S (10.08 mg/kg soil) were recorded from 16 treatment.