Reducing greenhouse gas emissions from soils by reducing N2O to N2

The mitigation of greenhouse gas (GHG) emissions, particularly nitrous oxide (N2O) from agricultural soils, is crucial given the unprecedented atmospheric concentrations of GHGs such as carbon dioxide (CO2), methane (CH4), and N2O, which have continued to rise rapidly since industrialization. Agricultural soils represent a major source of N2O, a potent greenhouse gas with significant global warming potential. We explore the evolution and application over time of biotechnical strategies aimed at mitigating N2O emissions in soils. Here, we present two key mitigation approaches: (1) climatic liming which involves liming addition to attain a soil pH of 6.8, and (2) the inoculation of legumes with rhizobial strains harbouring nosZ genes, known to encode for N2O reductase. These approaches are based on prior research conducted to demonstrate their respective efficacy in stimulating N2O conversion to N2 in soil. Additionally, our findings from climatic liming point towards its potential to mitigate soil CO2 emissions although further research is required to understand the underlying mechanisms, environmental determinants, and broader applicability of this approach.