Nitrogen and irrigation requirements of potato in alluvial soils of Patna (Bihar)

Field experiments were conducted on sandy loam alluvial soils at Patna during rabi 1977, 1978, 1979 to find the optimum levels of irrigation and nitrogen for potato cv. Kufri Chandramukhi. There was a positive interaction between the irrigation and nitrogen levels for potato production. The optimum nitrogen level increased with the increase in irrigation level. Nitrogen application increased the production of large and medium size tubers but irrigation had positive effect only on the yield of medium size tubers. The NO₃-N in upper and lower layers of soil increased with increasing levels of nitrogen and frequency of irrigation. The cost benefit ratio was the highest (1.38) when irrigation was given at 15 mm CPE and nitrogen was applied at 180 kg/ha.