Abstract:

As an important part of cultivated land, slope farmland is the agricultural production fundamental resource in mountain areas. Particularly in the hilly areas of central and western China, slope farmland accounts for a significant proportion of the total cultivated land. Slope farmland has become one of the land use types with the highest intensity of soil and water erosion and the greatest risk of agricultural non-point source pollutant migration due to the limitation of natural conditions and farming practices. This study analyzed the influencing factors of soil organic carbon (SOC) loss in slope farmland, elaborating on both environmental and anthropogenic factors. The main environmental factors include water erosion, wind erosion, frost-thaw erosion and their interactive erosive processes, while the human factors mainly include farming, fertilization, and irrigation. Given that soil and water loss from slope farmland leads to organic carbon loss, from the perspective of carbon sequestration/carbon emission reduction in sloping farmland, this study proposed improvements in agronomic practices such as tillage, fertilization, irrigation, straw mulching and biochar application. These improvements aim to modify slope characteristics, reduce surface runoff, enhance soil quality, and increase crop yields. Finally, the study summarized research on soil carbon pool reserves and carbon sequestration algorithms, fostering consensus on the accounting of SOC sinks in slope farmland and determining the technical methods for accounting organic carbon sinks in slope farmland under the influence of soil and water loss.

Key words: slope farmland, soil and water loss, carbon emission reduction, carbon sink accounting