Abstract

Results of field experiment on the economics of water and N management practices on low land rice indicated that grain yield increased upto 150 kg N ha' in the South West Monsoon (SWM) and Summer seasons. Continuous 5 em submergence (1) or recouping submergence one day after disappearance (12) did not influence grain yield during SWM whereas continuous submergence was necessary to record more grain yield during summer. Straw yield recorded were highest with continuous submergence in both the seasons and with 225 kg N ha in SWM season and 150 kg N ha-1 in summer season. Gross and net returns as well as benefit cost ratio were highest with 150 kg N ha-1 in both the seasons. A gruss return of Rs.7121/- and 7432 ha were obtained with continuous submergence in SWM and summer seasons, respectively, whereas, net return and benefit cost ratio were highest with submergence one day after disappearance of water. The variety IR 50 outyielded CO37 in all the aspects of study. Recouping submergence one (SWM) or three (Summer) days after disappearance of water recorded more return per rupee invested on water and N in both the seasons. Application of N at 150 kg ha-1 gave higher retum per rupee on water, whereas, the net return per rupee on N decreased beyond 75 kg N ha-1.

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