Cascade Effect of Nitrogen on Brazilian Soybean Production Chain

Abstract

Soybean is one of the most traded products. Naturally, soy fixes nitrogen through biological symbiosis. Its cultivation transforms natural inert atomic nitrogen into its reactive forms. The advancement of soybean can have environmental impacts, both locally and globally. This study estimated nitrogen flows and their use efficiency in the Brazilian soybean production chain applying material flow analysis. We innovate proposing a new indicator to estimate the “cascade effect of nitrogen” in a framework of 12 years (2007 to 2019). We hypothesized that it is capable to show accumulated nitrogen emissions through the chain. Besides, the method can show the main sources of nitrogen to the environment. The biological fixation was the largest entry. The efficiency in the use of nitrogen was 81% for grain production, and the nitrogen cascade indicator, which represents the ratio of the nitrogen emission in the environment to the total nitrogen available in the product, was only 5.2% in the soybean meal production chain for the year of 2019, with a clear trend of increasing during the period. Thus, Brazil contributes significantly to global nitrogen emissions in the environment since the country is an important producer and player in the world market.

Brazilian soybeans as feed for livestock in Europe: an insight into the nitrogen flows

“…The NCI calculations for the production chain of Brazilian soybean to the European livestock revealed: (i) a soybean production of 0.524% in 2007 to 0.522% in 2019 (Rezende et al 2021 ), (ii) the agro-industrial production of Brazilian soybean meal of 4.145% in 2007 to 5.216% in 2019 (Rezende et al 2021 ) and similarly (iii) the European livestock was 42.84% over the entire period. The resultant increase suggests nitrogen accumulation in the environment, corresponding to 42.84% of the total nitrogen available in livestock products (meat, milk and eggs).…”

“…Complete details regarding nitrogen flows are given in online resource 1 . For Brazilian soybean products, the system boundaries and nitrogen flows followed Rezende et al ( 2021 ). This study considered the data (Eurostat and FAOSTAT) from swine, cattle and chicken herds from 28 countries in the European Union (European Commission 2021 ; FAO 2021 ).…”

“…To estimate the nitrogen cascade effect on European livestock, NCI was calculated following Rezende et al ( 2021 ) according to Eq. ( 4 ): …”

“…The main consequence of distancing is the degraded recycling of nutrients (Galloway et al 2008) that have, in turn, increased demand for extra N r at each phase of the production chain. As stated, the use of additional N r can increase nitrogen emission to the ecosystem, and this is termed the "nitrogen cascade effect" (Galloway et al 2008;Lassaletta et al 2014;Rezende et al 2021). The cascade effect permits nitrogen mobility, which then transforms and accumulates it locally, regionally and globally; this can potentially damage the biosphere (Galloway 1998;Erisman 2021).…”

Addressing nitrogenous gases from croplands toward low-emission agriculture

“…In the case of sugarcane yields, the emission factor of NH 3 volatilization exhibited a wide range of 1-25% (corresponding to 80 to 100 kg-N ha −1 fertilization rate) during the warm and wet Brazilian summer 51 . Brazil is also the largest producer of soybeans in the world 52 ; therefore, biological fixation represents a large source of reactive nitrogen in the Brazilian nitrogen cycle as leguminous crops (e.g., soybean) can fix inert N into reactive nitrogen through biological symbiosis. Our literature search identified no recent studies on the NO x emission from agricultural fertilization in Brazil.…”