Drought-resistance rice variety with water-saving management reduces greenhouse gas emissions from paddies while maintaining rice yields

Abstract

Rice paddies are a major anthropogenic source of greenhouse gas (GHG) emissions due to the flooding management. Water saving practices often reduce the GHG emissions from rice paddies, yet increase the risk of rice yields loss due to drought stress. Water-saving and drought-resistance rice (WDR) has high drought-tolerant, suggesting that WDR with water-saving management could reduce GHG emissions while maintaining rice yields. However, the effect of WDR on GHG emissions is still unclear. Therefore, we conducted a 2-yr field experiment to assess the effect of WDR on rice yields and GHG emissions under continuous flooding (F), alternate wetting and drying (AWD), and dry cultivation (D) conditions, using a WDR variety and a common variety. Compared to the common variety, the WDR did not affect the rice yields under F and AWD treatments, but increased rice yields by 24% under D treatment. The methane (CH4) emissions and nitrous oxide (N2O) emissions of the two rice varieties were similar. Compared to the F treatment, AWD treatment reduced CH4 emissions by 7%−64% and area-scaled global warming potential (GWP) by 9%−39% and D treatment reduced CH4 emissions by 70%−90% and area-scaled GWP by 65%−74%. The WDR with dry cultivation (D-WDR mode) had the lowest area- and yield-scaled GWP. Our findings indicate that it is possible to produce optimal rice yields with low GHG emissions in the D-WDR mode, and suggest that drought-resistance rice variety breeding may benefit climate change mitigation and adaptation efforts.