Rice cultivation using plastic mulch under saturated moisture regime and its implications on weed management, water saving, productivity and profitability

摘要

A Rabi season (2012-13) field investigation was carried out at Directorate of Rice Research, Hyderabad to assess the impact of saturated moisture regime (SMR) with and without plastic mulching (black and transparent) in transplanted rice (TPR) on weedmenace, water saving, productivity and economics as compared to 5 cm standing water regime (SWR) rice in RBD with six replications. Results revealed that no-mulch SMR rice has 37.3 and 80.2% higher weed count and thus 26.8 and 114.1% lower weed controlefficiency than SWR rice culture at 20 and 40 days after transplanting. Plastic mulching (PM) with SMR has reduced the weed count and weed biomass in rice by over 90% as compared to no-mulch-SWR rice. Labour days required for weeding were enhanced by 50%under SMR (30 man days) as compared SWR (20 man days). SMR had 35% irrigation water (IW) economy but with 7.1% grain yield penalty (0.34 t/ha) as compared to SWR (100 cm IW use and 4.79 t/ha grain yield). When SMR was combined with plastic mulching (PM), there was aless yield depression (0.10-0.18 t/ha) when compared to SWR. SWR has more net returns (IR/s 42,160/ha) than SMR (X 30,750). High cost of PM (IR/s 23,000/ha) with SMR has masked gains in IW, weeding costs saving and higher yields. SMR can beadopted without any challenges but weed management through PM is desired with added advantage of water economy. Reducing cost of plastic mulches and evolving biodegradable plastics may make SMR rice culture a reality.