Searching for "Win-Win" Solutions for Food-Water-GHG Emissions Tradeoffs across Irrigation Regimes of Paddy Rice in China
Abstract
Paddy rice cultivation is the main source of agricultural greenhouse gas emissions in China. The traditional flooded paddy rice field not only consumes large amounts of irrigation water, but also produces significant methane (CH4) emissions. To balance the food security with environmental impacts of rice production, many water-saving irrigations technologies have been developed in field experiments to increase the drainage period during the rice growth cycle. However, whether these experiments can be implemented at the regional scale needs to be proven. Because it is too time and resource intensive for field experiments to carry out across a large area, we opt to do the performance assessments of alternative irrigation schemes via modeling simulations by coupling the DSSAT model and DNDC model. Irrigation methods tested include the traditional Continuous Flooding (CF), Midseason Drainage (MD) and Alternate Wetting and Drying (AWD). Simulation results show that compared with CF, water-saving irrigation methods can significantly reduce the CH4 emission from paddy rice field, with slight or no rice yield loss. AWD had the greatest effect in reducing irrigation water amounts and CH4 emission. Compared with CF, CH4 emission under the AWD were 60% - 71% lower in the Northeast China sites and 34% - 65% less in the South China sites. At the same time, under AWD compared with CF irrigation water use was reduced by 23% - 34% in northeast China sites and 18% - 50% in south China sites. Our results suggest that policies that support expansion of AWD in paddy rice cultivation across China can lead to a "win-win" solution for the food-water-GHG emissions tradeoffs in paddy rice production, which has been a key concern of policy makers and stakeholders in China.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMGC066..07T
- Keywords:
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- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 1817 Extreme events;
- HYDROLOGY;
- 1834 Human impacts;
- HYDROLOGY;
- 1880 Water management;
- HYDROLOGY