ABSTRACT
The present investigation was carried out to study the influence of irrigation levels and nitrogen doses on aerobic rice under drip irrigation in sandy loam soils. Field experiments were conducted at Agricultural Research Station, Bhavanisagar, Tamil Nadu, India. The treatments included four irrigation levels (irrigation at 100%, 125%, 150% PE daily and conventional irrigation at IW/CPE = 1.25) and three fertigation levels (100,150 and 200 kg N ha–1) of Nitrogen. The experiment was laid in Split-plot design replicated thrice with the test variety as PMK 3, with a duration of 130–135 days. Irrigation was given daily based on daily Pan Evaporation rate. With reference to different irrigation levels, 150% PE on daily basis recorded significantly higher grain yield (5069 kg ha–1), WUE (7.37 kg/ha-mm) and net income of Rs. 33607 ha–1 (560.12 US$/ha) and B:C ratio of 1.88. For nitrogen levels, 150 kg N per ha recorded significantly higher grain yield (4146 kg ha–1), WUE (6.69 kg/ha-mm) and net income of Rs. 20464 ha–1 (341.07 US$/ha) and B:C ratio of 1.53. For aerobic rice, the irrigation at 150% PE on daily basis combined with 150 kg N per ha recorded significantly higher grain (5483 kg ha–1), WUE (8.18 kg/ha-mm) and higher net income of Rs. 39448 ha–1 (657.47 US$/ha) and B:C ratio of 2.03.
