Abstract

                                Experiments were conducted in sandyloam soils of Agricultural Research Station, Bhavanisagar for three years during 1996-2000 to evaluate the efficiency of drip system of irrigation and to assess the impact of fertigation of nitrogen in tapioca. The results revealed that scheduling irrigation through drip once in two days at 100 per cent of surface method of irrigation registered the highest mean tuber yield of 58.7 t ha-1 which was significantly superior over surface irrigation scheduled at 0.60 IW/CPE ratio. The tuber yields in surface irrigation and irrigation through drip at 50 per cent of surface method were comparable. Fertigation of N at different levels failed to reveal marked variation on yield. The per cent saving in irrigation water under drip scheduled at 50 per cent of surface irrigation was 48.4 per cent compared with that of surface method of irrigation. The water use efficiency was 20 to 60 per cent higher in drip irrigation treatments compared to that of surface irrigation method.

Key words : Tapioca, Drip irrigation, Fertigation of N, Water use efficiency.