Managing Water for System of Rice Intensification Paddy Fields to Mitigate Greenhouse Gas Emissions and Maintain Yield

The System of Rice Intensification (SRI) is known to boost rice yields while reducing water use, but its impact on greenhouse gas (GHG) emissions under different water management practices remains unclear. This research aims to determine the effective water management practices in SRI for mitigating greenhouse gas emissions by maintaining yield. This study, conducted from 2016 to 2018, evaluated three irrigation regimes—Flooded (FL: 2–5 cm water depth), WET (0–1 cm), and DRY (-5 cm) in Bogor, Indonesia. Methane (CH₄) and nitrous oxide (N₂O) emissions were measured weekly using a closed chamber system. Results showed an inverse relationship between CH₄ and N₂O: CH₄ was lowest under the DRY regime, while N₂O was lowest in the FL regime. The DRY regime had the lowest global warming potential (GWP), 28% and 33% lower than WET and FL, mainly due to a significant CH₄ reduction (42% and 57%, respectively). Despite reduced water levels, rice yields remained stable in the DRY regime, averaging 6.0–6.18 tons/ha across three seasons. These findings suggest that the DRY irrigation regime in SRI can effectively balance high rice productivity with reduced GHG emissions, offering a sustainable water management strategy.