Agricultural Production Can Be a Carbon Sink: A Case Study of Jinchang City

In the context of China’s commitment to the “double carbon” goal, promoting agricultural carbon emission reduction is currently an important research topic. Assessing the carbon sequestration level of crops has a positive impact on enhancing agricultural carbon sinks and reducing carbon emissions. The carbon budget for agricultural planting on the arid oasis of Jinchang, northwest China, is quantitatively calculated from 2018 to 2020. The average value of total carbon absorption by crops in Jinchang was greater than the average value of total carbon emissions in the past three years. In 2020, the total carbon absorption was the highest (1,744,725 t CO2-eq), and the carbon emission was 102,641 t CO2-eq. The crops had a strong carbon absorption function. Among the investigated crops, the largest average annual carbon sequestration was found in corn, which accounted for 45% of the total carbon sequestration in the city. Among the carbon emission pathways, chemical fertilizer and agricultural film were the main carbon sources, accounting for more than 40% of total carbon emissions. The carbon budget analysis in the region clearly showed that the structure of agricultural cropping and the planting area proportion of crops significantly affected the carbon balance of the whole agricultural region and that increasing the proportion of the area planted with corn was beneficial in enhancing regional carbon sequestration.