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Potassium takes a vital role in the progress and improvement of traditional T. Aman rice. The experiment consisted of four potassium levels and four rice cultivars. Four different potassium levels viz, (i) K0 = 0 kg per hectare, (ii) K15 = 15 kg per hectare, (iii) K30 = 30 kg per hectare and (iv) K45 = 45 kg per hectare were considered as factor A, while four rice cultivars viz, (i) C1 = Sadamota, (ii) C2 = Lalmota, (iii) C3 = Moulata, and (iv) C4 = Lalchicon were considered as factor B. The highest plant crown at harvest (153.20 cm), number of effective tillers hill-1 (11.68), panicle length (20.67 cm), number of grain (90.52), 1000 grains weight (25.01 g), grain yield (3.95 t ha-1), biological yield (10.29 t ha-1) and harvest index (37.99%) as well as minimum lodging (4.25), recorded from 30 kg per hectare. The total tillers hill-1 (14.42), effective tillers hill-1 (13.02), panicle length (21.04 cm), grain panicle-1 (92.49), 1000-grain weight (24.98 g), grain yield (3.93 tons per hectare) and harvest index (38.37%) were found highest in Sadamota cultivar. Sadamota is also less susceptible to lodging (4.58). The maximum number of total tillers hill-1 (15.70), effective tiller hill-1 (15.00), panicle length (21.87 cm), number of grain panicle-1 (94.74), 1000-grain weight (27.00 g) and grain yield (4.19 t ha-1) as well as minimum lodging (2.67) found at K30C1 (30 kg per hectare with Sadamota cultivar) treatment. The lowest number of total tillers hill-1 (8.67), effective tillers hill-1 (6.00), panicle span(17.03 cm), number of grain panicle-1 (77.13), 1000 grain weight (20.04 g), and grain yield (3.33 tons per hectare) were observed for K0C4 (0 kg per hectare with Lalchicon cultivar). Therefore, 30 kg per hectare with Sadamota cultivar will be compare the best treatment synthesis for cultivar of Traditional Aman rice in tidal ecosystem.