Emerging options for mitigating N2O emissions from food production by manipulating the soil microbiota

mproved understanding of the microbes producing andreducing N2O spurs the invention of direct and manipulativemethods to reduce N2O emissions, beyond that achieved by 'good agronomic practice’. A core issue is the kinetics of N2O-reductase by denitrifying organisms during anoxic/hypoxicspells; the ‘hot moments’ of N2O emission. Soil pH has apervasive effect on the expression of the enzyme, and limingsoils will reduce the N2O emission. In this review we presentsome novel options for mitigation of N2O emissions, besideliming. During recent years, an increasing number of stronglyN2O reducing organisms have been identified, and ways toenhance their numbers and activity in soil are emerging. Onesuggestion is to develop inoculants for legumes that are strongN2O reducers. Another is to grow N2O reducing organisms indigestates from biogas production. These promising optionsneed further elaboration and validation.