Mulching Improves Water Productivity, Yield and Quality of Fine Rice under Water-saving Rice Production Systems

Water-saving rice production systems are inevitable in the wake of severe water shortage in rice-growing regions of the world. Mulches can improve water productivity, yield and quality of rice through increase in water retention. Studies were conducted for two consecutive years to assess the potential role of mulches (plastic and straw) in improving the performance of water-saving rice production systems in comparison with no mulch used and conventionally irrigated transplanted rice. Water-saving rice production systems in this study comprise aerobic rice and transplanted rice with intermittent irrigation. These systems saved water (18-27 %) with improved water productivity more than the conventional system. However, these systems caused a yield penalty of 22-37 %; nevertheless, these yield losses were compensated with the application of mulches under water-saving rice production systems. Both plastic and straw mulches were helpful in improving moisture retention and water productivity (0.18-0.25 kg grain m^-3 water) relative to non-mulch treatments (0.19-0.29 kg grain m^-3 water). Mulch application was also helpful in reducing the number of non-productive tillers and sterile spikelets, and improving the productive tillers, kernel number and size, and kernel quality. Plastic mulch was more effective than straw mulch in improving water retention, water productivity and reducing spikelet sterility. In conclusion, the mulching improved the soil moisture retention, and thus enhanced the rice water productivity, spikelet fertility, paddy yield and quality of rice. This signifies the importance of mulching in water-saving rice production systems.