Plastic mulch cultivation of rice (Oryza sativa) in India in light of dwindling water resources

A field investigation was carried out during 2 winter seasons (rabi) of 201213 and 201314 at the ICAR-Direc- torate of Rice Research, Hyderabad, Telangana to assess the impact of mulching and moisture regime treatments on transplanted rice (Oryza sativa L.) productivity and economics. Results revealed that saturation moisture re- gime affected 35% irrigation water economy but reduced rice grain yield by 7.8% (0.38 t/ha) on account of greater weed pressures over standing water rice culture (4.86 t/ha). Saturation moisture when combined with plastic mulching, reduced yield penalty by 56.6% (0.22 t/ha), thus became at par with transplanted rice with standing wa- ter. Additional irrigation water economy (23%, i.e. 15 cm) and elimination of weeding were seen in plastic mulch- transplanted rice. There was minimal weed biomass production (4.9% of standing water 125.3 and 3.1% of satura- tion moisture: 194.5 g/m2). Transplanted rice with standing water was highly economical with net profit of 43,220/ ha to saturation moisture ( 31,360/ha) when irrigation water is free and upon pricing of irrigation water @ 400/ ha-cm, saturation moisture-transplanted rice became more economical than standing water. High cost of plastic mulch ( 23,000/ha) masked the gains in irrigation water, saving weeding cost and higher yield irrespective of irri- gation water pricing. Saturation moisture- transplanted rice could be adopted without any challenges but for adding plastic mulch to saturation moisture, reducing its cost and evolving biodegradable plastics (making environment friendly) including N management options need to be evolved.