The economic value of gas exchange in a paddy field ecosystem using water-saving irrigation

Abstract

The ecosystem services value of paddy fields has received increasing attention in agricultural policy decisions. This paper presents the first study to investigate the effects of rice water-saving irrigation on the economic value of gas exchange in a paddy field ecosystem based on a field experiment. The results showed that, compared to traditional flooding irrigation (FI), controlled irrigation (CI) decreased irrigation water input while maintaining high rice yield. Irrigation methods showed no significant influence on O2 production and its value in paddy fields. CI significantly reduced CH4 emissions and its negative economic value by 81.80%, but increased N2O by 136.86%. The economic value of CO2 uptake far outweighed the absolute value of negative economic values caused by CH4 and N2O emissions. Therefore, the irrigation methods showed no significant difference in economic value caused by greenhouse gas emissions (GHGs) from rice paddies. CI management significantly decreased ammonia volatilization (AV) and its economic value by 19.56%. Overall, CI increased economic value of gas exchange (O2 production, GHGs emission, and AV) by 8.96% compared to FI paddies. Our results suggest that CI significantly increased the economic value of gas exchange in a paddy field ecosystem while drastically reducing irrigation water input and ensuring rice yields.