Exploring the fate of carbon in saline soils after CO2 uptake

A large number of studies have now concluded that CO2, CH4 and N2O are the major greenhouse gases, with CO2 having the greatest impact on global warming. However, the problem of lost carbon sinks has not been solved so far, and finding the destination of the missing carbon can help improve our understanding of the lost carbon sinks. Saline soils are mainly divided into arid and semi-arid regions, and most of the research in recent years has focused on (1) the phenomenon of CO2 uptake by saline soils, which is considered a new carbon sink. (2) Studying the influence of salinity, alkalinity, temperature, moisture, and microorganisms on CO2 uptake in saline soils is also the focus. There are three possible destinations of carbon in saline soils after CO2 uptake: the soil is sequestered as carbonate after CO2 uptake, microorganisms in the soil convert DIC to CH4, and it enters groundwater with precipitation or irrigation water in the form of DIC. Studying the fate of carbon is the key to solving the problem of lost carbon sink, but it is not fully verified at present. Future research in this field should focus on the migration and transformation process of saline soils after CO2 uptake and the significance of inorganic carbon in the terrestrial carbon cycle process and its role in carbon sequestration in the Earth's surface system to be further studied and demonstrated, which will provide some new directions to solve the problem of global carbon loss sinks.