Evaluating basalt weathering for organic-inorganic ‘double carbon’ stabilization of the soil priming effect

Abstract

AbstractAimsBasalt weathering has the potential to absorb soil CO2emission and stabilize the organic carbon by its weathering products, e.g. montmorillonite and kaolinite. However, the feasibility of basalt weathering on organic-inorganic ‘double carbon’ stabilization of soil priming effect (PE) remains unclear.MethodsWe conducted a 28-d incubation experiment by adding13C-glucose with or without basalt, montmorillonite or kaolinite to a farmland soil planted with peach (Prunus persica(L.) Batsch) for more than 20 years. CO2emission and its13C value were continuously measured to calculate the PE and soil net carbon balance.ResultsAfter 28-d incubation, the basalt treatment resulted in an increase in soil pH from 5.32 to 7.17. Additionally, compared to the control, the basalt treatment showed a 143.7% and 168.6% increase in dissolved organic carbon (DOC) and soil inorganic carbon (SIC), respectively. Subsequently, the basalt treatment induced the highest cumulative PE among all treatments, with the activities of β-glucosidase (S-β-GC), soil leucine amino peptidase (S-LAP), and soil catalase (S-CAT) being the highest. Furthermore, the kaolinite treatment showed significantly lower emissions of CO2-C, glucose mineralization, and cumulative PE (P< 0.05). It is worth noting that all treatments significantly enhanced the net soil net carbon balance, with the most significant improvement observed in the kaolinite treatment.ConclusionsBasalt and its weathering products can promote the organic-inorganic ‘double carbon’ stabilization in the PE. Basalt, in particular, has the most significant effect on SIC stabilization, while kaolinite has the highest potential for improving the soil net carbon balance.