Effects of rice cultivar on the net greenhouse gas emission under continuous flooding and alternate wetting and drying irrigations in paddy field

Abstract

Rice production has been challenged by increasing food demand and water scarcity. Alternate wetting and drying (AWD) irrigation is a water-saving irrigation technique for paddy fields. The aim of this research was to determine the effects of rice cultivars on the net greenhouse gas emission under continuous flooding (CF) and AWD irrigations in paddy field. This experiment used randomized complete block design with combination of the water management systems and rice cultivars. There were two water management systems, namely (1) CF and (2) AWD irrigations and three rice cultivars, namely (1) Ciherang, (2) Inpari 32, and (3) Mekongga. The results showed that the AWD irrigation decreased global warming potential by 51%, 40% and 19% when combined Ciherang, Inpari 32 and Mekongga, respectively, compared to CF. The combination of AWD irrigation and Inpari 32 rice cultivar resulted the highest net GHG balance among all treatments approximately 7.9 t ha-1 and also showed the highest profit around IDR 18.3 million ha-1. This study clearly suggested the possibility of reducing GHG emission from the paddy field through appropriate selection of water management and rice cultivars to achieve a technically and economically feasible as a mitigation option.