Microbe Management: Optimizing soil carbon sequestration and fertility for sustainable agriculture

Microorganisms break down soil organic matter (SOM), thus releasing carbon (C) to the atmosphere and nitrogen (N) and phosphorus (P) for plant uptake. A core assumption of ecosystem models is that C and nutrient mineralization rates are "coupled".

However, recent studies have shown that the release of C and nutrients from SOM can become "decoupled" if microorganisms "mine" nutrient-rich components to avoid resource limitation.

Selective microbial nutrient mining may therefore be harnessed to increase the C sequestration capacity of soils, whilst maintainng the release of nutrients to fuel plant growth.

However, the potential for selective nutrient mining in agricultural systems remains unexplored, hidering opportunities for effective land-management.

In this project, we will combine a survey of soils from across Sweden with controlled manipulation experiments, and assessments of soils from long-term field-experiments.

Specifically, we will: Evaluate the potential for plant-derived C inputs to induce microbial nutrient mining in agricultural soils; Identify how management practices affect the balance between C, N and P release from SOM; Determine how microbial mining varies over seasonal cycles, and is modulated by soil nutrient availability; Synthesize and integrate insights from 1-3 into CoupModel to assess the implications of microbial mining for ecosystem-scale pools and fluxes of C, N and P, and how microbes may be "managed" to optimize soil C storage and fertility.