Impact of agriculture on N2O emissions: A review

Increasing concentrations of GHGs (greenhouse gas concentrations) are accelerating climate change, threatening the continued existence of our civilization. Despite relatively lower concentrations than those of other GHGs, N2O has a warming capacity 265 times greater than CO2, and its lifetime in the atmosphere is 9 times longer than that of CH4. Global annual emissions of N2O increased by 270% between 1980 and the last decade, and emissions from anthropogenic sources amounted to 43%. The share of agricultural activity in total anthropogenic emissions is 53%. The main source of N2O emissions related to human activities is agriculture, contributing 53% thereof due to the widespread use of N fertilizers in farming. Modern agriculture tends to use fertilizers in excess. It is possible to reduce fertilizer consumption globally by 30% without reducing crop production. The level of available N and C in agricultural soils determines the amount of N2O emissions. Other soil characteristics: pH, salinity, structure and microbial activity, are also important, in addition to environmental factors, such as precipitation temperature and landform characteristics. Cultivation factors also have a significant impact on the level of N2O emissions. For example, the use of high-performance and slow-release nitrogen fertilizers can reduce N2O emissions and increase crop yields. Despite many benefits attributed to crop residues, they too contribute to the increase in emissions. Current knowledge does not allow us to clearly determine how zero and reduced tillage and agroforestry systems affect N2O emissions compared to conventional tillage.