A field experiment was conducted during rainy season of two consecutive years (2011 and 2012), in sandy loam soils of Warangal, Telangana State to study the response of aerobic rice (Oryza sativa L.) to drip irrigation and nitrogen fertigation under semi-arid environment. The experiment was laid out in split plot design with four replications. Three irrigation schedules viz. drip irrigation at 100% Pan Evaporation (PE); 150% PE and 200% PE were taken as main plots and three nitrogen levels through fertigation viz. 90, 120 and 150 kg/ha were taken as subplots. The data revealed that the growth parameters of aerobic rice like LAI, SPAD chlorophyll meter reading, tillers/m2 and drymatter accumulation were significantly higher in 200% PE schedule compared to that of 100% PE but comparable with 150% PE except for drymatter accumulation. Drymatter accumulation at maturity, root volume and dry weight were more at 200% PE compared to that of lower schedules. The number of panicles/m2 and filled spikelets/ panicle increased from 100% PE to 150% PE but not at 200% PE while sterility of spikelets was higher with 100% PE schedule. Higher grain and straw yield, nitrogen uptake and economics were recorded with 200% PE over the other two schedules. Irrespective of the irrigation schedules, growth parameters (plant height, LAI, SPAD meter reading, tillers/m2 and drymatter accumulation), yield attributes (panicles/m2, panicle length and filled spikelets/panicle) increased with level of N application from 90 to 120 kg N/ha while root volume and dry weight were higher at 150 kg N/ha. The number of days taken to reach 50 per cent flowering was not influenced by irrigation schedules but influenced by the nitrogen levels during first year in which the plots supplied with 150 kg N/ha flowered earlier than other N levels. The sterility of spikelets was higher at 90 kg N/ha compared to other doses. Grain yield, straw yield, nitrogen uptake and economic parameters were higher at 150 kg N/ ha compared to lower N levels. Water use-efficiency reduced with increased water input from 100% PE schedule to 200% PE but increased with the increase in N level from 90 to 150 kg N/ha during both the years of study. In contrary, nitrogen use efficiency was enhanced with the increase in water input in drip irrigation and reduced with the increase in N level of application. Gross returns, net returns and benefit: cost ratio were higher in drip irrigation schedule of 200% PE and 150 kg N/ha closely followed by that realized at 120 kg N/ ha in the same irrigation schedule.

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