Characteristics and influencing factors of carbon emissions of ecological farms in the Yangtze River Delta region

The construction of ecological farms is of great significance in promoting the green development of agriculture and rural ecological revitalization in China. Based on data from 94 ecological farms in the Yangtze River Delta region, the carbon emissions of ecological farms were calculated using the life cycle assessment method, which mainly included carbon emissions from the extraction of raw materials for agricultural production used in planting, during the production process of agricultural inputs for planting, from field management during crop planting, and from transportation links. The characteristics and factors influencing the carbon emissions intensity of ecological farms were analyzed. The results showed that the carbon emissions intensity of ecological farms in the Yangtze River Delta region was 3 903.74 kg(CO₂-eq)·hm⁻², and the main sources were organic fertilizer use, rice planting (CH₄), and field management (N₂O), which accounted for 31.65%, 23.01%, and 18.74%, respectively, accounting for more than 70%; the carbon emissions from fertilizer input sources were relatively low, only 6.50%. There were distinct differences in carbon emissions intensity among the provinces. Jiangsu Province had the highest carbon emissions intensity 4 586.40 kg(CO₂-eq)·hm⁻², followed by Shanghai and Zhejiang provinces. Anhui Province had the lowest carbon emissions intensity 3 282.15 kg(CO₂-eq)·hm⁻², which was 28.43% lower than that of Jiangsu Province. Differences in planting structure were the main source of carbon emissions intensity in ecological farms in the Yangtze River Delta region. The Gini coefficient was used to measure the imbalance in carbon emissions intensity of ecological farms. The closer the Gini coefficient is to zero, the smaller the difference between individuals. Within provinces, an imbalance in the carbon emissions intensity of ecological farms was evident. Zhejiang Province had the highest imbalance with a Gini coefficient of 0.46, and Shanghai Province had the lowest imbalance with a Gini coefficient of 0.23. The imbalance in carbon emissions intensity of ecological farms in Zhejiang and Anhui provinces was higher than that of the general population, whereas the imbalance in carbon emissions intensity of ecological farms in Shanghai and Jiangsu Province was lower than that of the general population. Based on the regression analysis, the factors influencing carbon emissions intensity of ecological farms were analyzed, and the control variables included the characteristics of ecological farm managers, farmland characteristics, technology adoption, and quality control systems. The empirical results showed that the carbon emissions intensity of ecological farms was affected by the farmland planting scale and proportion of rice planting area. In view of this, to promote the low-carbon development of ecological farms, we should continue to maintain the operation mode based on organic fertilizers, strengthen the substitution of organic fertilizers for chemical fertilizers, optimize the planting structure, reduce the proportion of rice planting, strengthen the water management of rice fields, improve fine field management and reasonable fertilization, improve the utilization rate of nitrogen, and strengthen the training of ecological farm operators. It is vital to reduce the regional imbalance in the carbon emissions intensity of ecological farms and enhance the comprehensive effect on the economy and environment of ecological farms.