Agricultural activities increased soil organic carbon in Shiyang River Basin, a typical inland river basin in China

Oasis agriculture is one of the main forms of agriculture in the world. Studying the impact of agricultural practices on soil organic carbon (SOC) within oases can provide valuable insights into the dynamics of carbon input and sequestration in oasis agriculture. It can contribute to the development of well-reasoned agricultural policies. This study focuses on the farmland in the typical inland river basin of the Shiyang River. We established an observation system and collected soil samples from different areas within the basin: upstream (mountainous farmland), midstream (oasis farmland), and downstream (farmland at the edge of the oasis). We analyzed the SOC content and compared the effects of various agricultural activities (abandoned land, forest land, grassland, and farmland abandoned for two years) on SOC levels. The findings suggest that: (1) In the same inland river basin, the organic carbon of farmland in the upper and middle reaches is significantly higher than that in the lower reaches, and the farmland in the core area of the oasis is higher than that in the marginal area; (2) Farmland in the inland river basin exhibits a higher SOC content compared to woodland and grassland areas. the process of agricultural leads to an increase in SOC content within the inland river basin; (3) The abandonment of cultivated land leads to a decrease in SOC, and plastic film mulching has no obvious effect on the content of SOC. The research clarifies the impact of agricultural activities on SOC in arid oasis areas, and quantified the impact of different agricultural activities on SOC. The research can provide new references for understanding the impact of agriculture in arid regions on carbon cycling.