Speaker
Description
Arbuscular mycorrhizal fungi (AMF) are highly abundant microbes in agricultural fields. They form an obligatory symbiotic relationship with crops, providing essential nutrients such as phosphorous while receiving carbohydrates and lipids from their host plants. Moreover, AMF play a crucial role in improving soil structure, and influencing the formation and stabilization of soil organic matter. In addition, AMF also affect weathering of soil minerals either directly by e.g. serving as a sink for ions released during weathering, by increasing reactive surface area and by secreting exudates, or indirectly by e.g. increasing the total belowground carbon flux as a result of improved plant growth. Given the promising role of agricultural fields for enhanced silicate weathering (ESW), it is essential to understand the influence of AMF on the carbon dioxide removal (CDR) potential of this negative emission technology. However, this has not been studied yet.
To investigate the interaction between basalt application and AMF, a full-factorial basalt x AMF mesocosm experiment was set up. During the growing season of the crops, soil CO2 fluxes were measured, soil pore water was analyzed for weathering products, and plant growth was monitored. After the growing season, plants were harvested, soil samples were taken and carbon sequestration rates were calculated. AMF hyphal length was analyzed to investigate whether basalt application influenced AMF growth. Our preliminary results show that near the end of the growing season, dissolved inorganic carbon in the pore water increased with basalt application, which was reinforced by AMF presence. With basalt, the CO2 flux increased in presence of AMF whereas AMF did not influence the CO2 flux in the control treatment where no basalt was applied. AMF hyphal length was not affected by basalt application. Given the abundance of AMF in agriculture, and the clear influence on DIC concentrations found in this study, further investigation of its effect on the CDR potential of ESW is encouraged.
