Soil carbon sequestration in global working lands as a gateway for negative emission technologies.

The ongoing climate crisis merits an urgent need to devise management approaches and new technologies to reduce atmospheric greenhouse gas concentrations (GHG) in the near term. However, each year that GHG concentrations continue to rise, pressure mounts to develop and deploy atmospheric CO removal pathways as a complement to, and not replacement for, emissions reductions. Soil carbon sequestration (SCS) practices in working lands provide a low-tech and cost-effective means for removing CO from the atmosphere while also delivering co-benefits to people and ecosystems.

A review of carbon farming impacts on nitrogen cycling, retention, and loss.

Soil carbon (C) sequestration in agricultural working lands via soil amendments and management practices is considered a relatively well-tested and affordable approach for removing CO from the atmosphere. Carbon farming provides useful benefits for soil health, biomass production, and crop resilience, but the effects of different soil C sequestration approaches on the nitrogen (N) cycle remain controversial. While some C farming practices have been shown to reduce N fertilizer use in some cases, C farming could also impose an unwanted "N penalty" through which soil C gains can only be maintained with additional N inputs, thereby increasing N losses to the environment.