Nitrous Oxide Emissions from the Nitrogen Cycle in Arable Agriculture: Estimation and Mitigation

Human activities are probably the major cause of the increase in the atmospheric N₂O concentration of 0.7ppb per year and of the increased release of NO into the atmosphere. Nitrous oxide is a greenhouse gas, which constitutes 6 per cent of the anthropogenic greenhouse effect (Forster et al, 2007), and also contributes to the depletion of stratospheric ozone (IPCC, 2001). Although the contributions of N₂O from the different sources remain less well known than for all other greenhouse gases, it is generally accepted that the use of mineral N fertilizers and animal manure management are the major anthropogenic sources of N₂O (Mosier et al, 1998; IPCC, 2001).