Spatial-temporal variations of externality value of rice production environment in the Yangtze River Economic Belt

Evaluating the external value of rice production environment in the Yangtze River Economic Belt can make up for the lack of attention to the pre-production link of rice in literature, and thus provide a basis for promoting agricultural green production. Based on the panel data of rice production in the Yangtze River Economic Belt from 2000 to 2024, we used the functional value method and the equivalent factor method to calculate the 20 environmental externalities across 11 provinces and cities in the Yangtze River Economic Belt, and analyzed the spatial and temporal variations. The results showed that the annual environmental positive, negative externality and net value of rice production from 2000 to 2024 in the Yangtze River Economic Belt were 344.476 billion, 284.605 billion, and 59.871 billion yuan, respectively. The positive externality value was mainly composed of water conservation (50.1%) and gas regulation (21.7%). The negative externality value was mainly composed of water consumption (27.8%), fertilizer pollution (27.2%), and greenhouse gas emissions (22.2%). During the study period, the overall value of positive externality showed a downward trend, and the value of negative externality showed a trend of increasing first and then decreasing with 2012 as the demarcation point. The average annual net external value of rice production environment in the lower, middle, and upper reaches of the Yangtze River Economic Belt was 7.892 billion, 46.679 billion, and 6.099 billion yuan, respectively. The net external value of rice production in Jiangxi and Hunan was the highest, which together contributed more than 2/3 of the whole study area. The net external value of Yunnan was the lowest. Our results could provide scientific basis for the optimal layout and green transformation of rice production in the Yangtze River Economic Belt.