Research on Carbon Sources and Sinks of Agricultural Ecosystems Based on Carbon Footprint: Evidence from Shaanxi Province, China

ABSTRACT The carbon footprint size of agricultural ecosystems in Shaanxi Province was evaluated using the input-output approach and the statistical data of agricultural output as well as agricultural modernization in Shaanxi Province from 2000 to 2019, then the characteristics and reasons for variations in its time series were analyzed. The results reveal that (1) over a 20-year period, the carbon sequestration of farmland systems in Shaanxi Province increased by 1,199.63 million t, with vegetables, maize, and wheat accounting for the majority of the increase; and (2) the carbon emissions caused by agricultural inputs in Shaanxi Province increased from 78.91 million t in 2000 to 98.64 million t in 2019, with agricultural irrigation accounting for the majority of the total carbon emissions. (3) The carbon footprint of agricultural ecosystems in Shaanxi Province was 0.106 ( $${10}^{6}{C\bullet hm}^{-2}\bullet {a}^{-1}$$ ) in 2019, indicating a downward trend, and the province has been in a carbon ecological reserve for 20 years. To diminish the carbon source, Shaanxi Province should improve the efficiency of fossil energy and agricultural chemicals; at the same time, measures such as straw return and crop management should be taken to improve the carbon sequestration efficiency of productive land and enhance the carbon sink, promoting the development of low-carbon agriculture in Shaanxi Province.