Proceedings

Emissions of the highly potent climate gas N2O account for ~1/3 of agriculture’s climate forcing, and no effective cure has been found until now: Ground-breaking biotechnological research by the NMBU Nitrogen Group, in collaboration with Veas WWTP, has demonstrated that digestate from biogas production can become an effective agent against N2O emissions [Jonassen et al 2021a and b] (Fig. 1). Our group has isolated bacteria which

1) are effective N2Osinks due to their genetic makeup,

2) grow fast to high cell densities in digestates, and

3) sustain their metabolic activity (N2O-reduction) in soil.

Enriching digestate with such bacteria and applying this as a fertilizer can effectively reduce N2O emissions from soil with up to 95 %, as shown by our field experiments (Fig. 5).