Causes of Low Yield of Rice in Acidic Alluvial Tract of West Bengal

Pot culture and laboratory experiments were conducted with a view to find out the causes of low yield of rice in acidic alluvial soils of northern West Bengal. Significant increase in grain yield was obtained by liming. Response of grain yield to N was more in limed soils. The best response was, however, obtained by application of N in combination with P. When N and P were applied in combination, liming was of little significance. No significant increase in grain yield was obtained by K treatment but chemical analysis of rice plant at harvest showed that the minimum ratio of K/N = 2.5 for healthy growth of rice was not maintained in it. Application of N disturbed this N: K balance to a large extent, which influenced the outbreak of Aogare disease. Application of micronutrients showed no response. The minimum fixation of P was observed at pH value 6.0 and 7.1.