Carbonate influences on the biogeochemical processes driving the stabilization of soil organic carbon in drylands

Increasing temperatures and worsening drought from climate change are exacerbating soil degradation and desertification in
drylands, presenting a major threat to food security. Soil organic carbon (SOC) loss is a strong driver of soil degradation and
desertification. Increasing SOC can mitigate soil degradation, but dryland SOC stocks can be minimal, and critically, most soil carbon
in drylands exists as carbonate (SIC). SIC likely moderates the physical stabilization of SOC in the soil mineral matrix via pedogenic
processes that form SIC-organo-mineral structures. Pedogenic processes may increase SOC stabilization by controlling physical access
of microorganisms to substrate, but it's unclear how they indirectly alter microbial processes and SOC decomposition/stabilization. To
this end, SIC-SOC-STABLE aims to 1) quantify the global influence of SIC on SOC stabilization in drylands using an established dataset,
and 2) validate global patterns along a local field gradient and to generate a detailed understanding of how physical stabilization
structures, driven by carbonate pedogenesis influence the microbial processes driving SOC stabilization. Further, considering the
impacts of soil management on SOC storage in drylands is fundamental given that soil tillage may accelerate carbonate pedogenesis.
It addresses the agricultural implications of IPCC recommended management practices like reduced tillage on SOC stabilization in
calcareous soils, by 3) experimentally quantifying the influence of soil disturbance on carbonate pedogenesis and the fate of
microbially-mediated SOC storage. Finally, because reduced tillage requires greater mechanical weeding, a role which predominantly
falls on women in rural drylands, the proposed MSCA considers gender disparity in labor when advocating best practices to increase
soil carbon. To achieve this, it 4) develops a scientifically robust training and support tool to empower and equip women for key roles
in agricultural management.