Evaluation of Drip Fertigation System for Aerobic Rice in Western Zone of Tamil Nadu

Abstract

The productivity of rice is in decreasing trend due to non-availability of irrigation water. Hence, rice cultivation with minimum water which paves way for the research on aerobic rice (i.e., growing in the non-flooded and non-puddled situation). Field experiments were conducted at Agricultural Research Station, Bhavanisagar during 2013-14 and 2014-15 to evaluate the drip fertigation system and to work out the economics in aerobic rice at different irrigation and nitrogen levels. The treatments included four irrigation levels (irrigation at 100%, 125%, 150% PE daily and conventional irrigation at IW/CPE = 1.25) with a combination of three fertigation levels (100,150 and 200 kg N ha-1) of nitrogen. The experiment was laid in split plot design replicated thrice. The test variety is PMK 3, with a duration of 130-135 days. Entire quantity of phosphorus and 50 per cent of potassium was applied basally. Different doses of nitrogen and remaining 50 per cent of potassium was applied as fertigation in weekly intervals from 21 days after sowing. Irrigation was given daily basis with daily Pan Evaporation rate. Concerning different irrigation levels, 150 per cent 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 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 and B:C ratio of 1.53. For aerobic rice, the irrigation at 150 per cent 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 and B:C ratio of 2.03.