关键词: 耕地利用, 净碳汇量, 时空演进, 河南省县域

Abstract:

Drawing on statistical data spanning from 2006 to 2020, four key aspects were analyzed in this study: inputs of agricultural production materials, soil conditions, carbon emissions from wheat and rice cultivation, and carbon sequestration by crops. The carbon emission coefficient method was used to calculate the net carbon sink of cultivated land use across 104 counties in Henan province, and its spatiotemporal distribution characteristics were examined. The findings offer scientific insights for the low-carbon transformation of cultivated land use and the pursuit of carbon peaking and neutrality goals in Henan province. The results indicate that: (1) carbon emissions from cultivated land use in Henan province initially rose and then declined, while carbon absorption increased steadily, leading to a fluctuating increase in net carbon sinks. Notably, chemical fertilizers emerged as the primary carbon source. Compared to 2006, by 2020, most counties in Henan province experienced growth in carbon emissions, carbon sinks, and net carbon sinks, with respective county proportions of 65.4%, 78.9%, and 77.9%. In eastern Henan led in increments of carbon emissions, carbon sinks, and net carbon sinks, while northern Henan showed a faster growth rate in carbon emissions. In southern Henan, on the other hand, exhibited significant growth rates in carbon sinks and net carbon sinks. (2) In terms of spatial distribution, the net carbon sink of cultivated land use in Henan province displayed a pattern of “higher in the east and lower in the west.” Spatial agglomeration was evident, with notable regional differences. However, low−value areas of net carbon sinks were gradually transitioning towards high−value areas, indicating a trend of narrowing regional disparities. Most counties fell into the category of moderate net carbon sink areas. Counties exhibiting homogeneity in net carbon sink values accounted for over 95% of the aggregated counties. The center of gravity for net carbon sinks was situated in Yanling county, with a tendency to shift eastward. (3) Natural conditions, including climate, soil, and terrain, as well as national policies, influenced the crop planting structure, the level of agricultural mechanization, and the input of agricultural materials, thereby impacting carbon emissions and carbon absorption from cultivated land use. In the future, crop carbon sinks should be integrated into the decision−making framework for crop planting structure adjustment in Henan province. Efforts should also continue to reduce and enhance the efficiency of chemical fertilizers. Additionally, increasing investment in agricultural machinery technology innovation in Henan province and fostering inter−regional agricultural technology exchange and cooperation will fully harness its potential for emission reduction and carbon sequestration enhancement, ultimately promoting green agricultural development.

Key words: Cultivated land utilization, Net carbon sink capacity, Spatio?temporal evolution, Counties in Henan province