Economic value of biological nitrogen fixation in soybean crops in Brazil

The global demand for a more sustainable in agriculture can be met in part by soil microorganisms that also play a key role in economic and ecosystem services. However, the value of ecosystem services provided by biological nitrogen fixation (BNF) process is still not clear. Thus, this study aimed to estimate the economic value of BNF in soybean crop in Brazil. We also provide methodological advances via mathematical models to verify the economic value of ecosystem services from BNF, inoculation with Bradyrhizobium spp. and coinoculation with Azospirillum brasilense of the soybean crop, and mitigation of greenhouse gases by BNF. Avoided cost methods were used to estimate the economic value of BNF and its carbon mitigation benefits in Brazil; economic outcomes generated by inoculation and coinoculation were estimated. The economic value resulting from replacement of N fertilizer (urea) by BNF in the 2019–2020 crop season was estimated at 15.2 billion USD. In this same crop season, the profit generated by inoculation and coinoculation was estimated at 914 million USD. In the 2019–2020 crop season, the technology of coinoculating soybean with Bradyrhizobium spp. and Azospirillum brasilense reached 25% of the whole soybean cropped area in Brazil. The replacement of N fertilizer by BNF corresponded to the mitigation of 183 million Mg CO2-e in the 2019–2020 season, equivalent to over €5 billion in carbon credits. Our results demonstrate that BNF provides multiple ecosystem services with a high level of economic value, contributing for a more sustainable agriculture. [Display omitted] •Biological nitrogen fixation (BNF) provides multiple ecosystem services with high economic value for soybean.•We determined the economic value of BNF for soybean in Brazil based on the crop area, yield and N demands.•BNF instead of N-urea saved 15.2 billion USD in the 2019–2020 season.•Replacing N-fertilizer by BNF avoided 183 million Mg of CO2-e of greenhouse gas emissions.•BNF provides ecosystem services with high economic value, contributing to more sustainable agriculture.