Contribution of Legume-Derived Biological Nitrogen Fixation in Reducing Greenhouse Gas Emissions Originating from Agriculture in Türkiye

Abstract

Nitrogen fertilizer production and use contribute to the increase in greenhouse gas (GHG) emissions. GHGs due to nitrogen (N) fertilizer use can be reduced to a certain extent with legume agriculture. This study was conducted to estimate the amount of N produced by biological N fixation (BNF) in legumes grown in Türkiye, the amount of synthetic N fertilizer corresponding to this amount of N, and the global GHG emission equivalent of the production, transport, and use of this fertilizer in the field. Firstly, the amount of N fixed by BNF in a year in legume cultivation areas in Türkiye was calculated. Then, the GHG equivalents emitted during the production, transport, and application in the field of synthetic N fertilizers, which is the equivalent of N fixed by BNF, were calculated. The total amount of N fixed with BNF in 2022 in Türkiye is 363,354 tons. The total GHGs emissions during the production, transport, and use of N fertilizer equivalent to 363354 t of N fixed by BNF is 2,631,043 tons CO 2 -eq. In other words, in one year in Türkiye, 2,631,043 tons of CO 2 -eq GHGs will be reduced thanks to legume agriculture. GHG emissions of the Turkish agricultural sector (total 72.1 Mt CO 2 -eq) have been reduced by about 3.65% (2.63 Mt CO 2 -eq). For an economically and environmentally sustainable agriculture, we need to give more importance to the cultivation of pulses.