Mitigation of Greenhouse Gas Emissions From Soils by Enhancing the N2O to N2 Reduction Pathway

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 continue to rise rapidly since industrialisation. Agricultural soils represent a major source of N2O, a potent greenhouse gas with a significant global warming potential. Over time, we explore the evolution and application of biotechnical strategies aimed at mitigating N2O emissions in soils. Here, we present two key mitigation approaches, which are: (1) climatic liming which involves the addition of lime to attain a soil pH of 6.8, and (2) inoculation of legumes with rhizobial strains harbouring nosZ genes, known to encode for N2O reductase. These approaches were based on prior research conducted to demonstrate their respective efficacy in stimulating N2O conversion to N2 in soil and thus in reducing soil N2O emissions, with reduction reaching up to 50 % in certain field conditions. Additionally, our findings from climatic liming suggested its potential to mitigate soil CO2 emissions. Nevertheless, further research is required to understand the underlying mechanisms, environmental determinants, and broader applicability of this approach to mitigate soil CO2 emissions.