[M-GI29] [EJ] Data-driven analysis, modeling and prediction in geosciences

[MGI29-16] Managing soil organic carbon sequestration in China’s croplands

*Guocheng Wang¹ (1.Institute of Atmospheric Physics, Chinese Academy of Sciences)

Increasing the soil organic carbon (SOC) pool in croplands can not only promote crop production but also mitigate climate change; however, the amounts of organic C that are input to balance the soil C loss and for targeted soil C sequestration in China’s croplands are unclear. By using a biogeophysical model (Agro-C), we performed simulations with a high spatial resolution (10 km×10 km) across China’s croplands to quantify the rate of C input under given scenarios. The model simulations showed that an average C input of 2.1 Mg C ha^-1 yr^-1 is required to stop soil C loss and that SOC density could approach the global mean of 55 Mg C ha^-1 by 2050 when 5.1 Mg C ha^-1 per year is incorporated into the soils of China’s croplands. The quantified C inputs showed a large spatial disparity, depending on the existing SOC level, mean annual temperature and precipitation. The existing SOC level in Heilongjiang Province, where the cropland area accounts for 9.2% of the national total, is much higher but the current C input is much lower than it is in other regions in China. Increasing the organic C input should be given priority in this province; otherwise, the risk of SOC loss may increase.