Greenhouse gas emissions and carbon sequestration by agroforestry systems in southeastern Brazil

Carlos Moreira Miquelino Eleto Torres,José Cola Zanuncio,Fernando de Castro Neto,Clyde William Fraisse,Carlos Pedro Boechat Soares,Laércio Antônio Gonçalves Jacovine,Sílvio Nolasco de Olivera Neto,Pedro Guilherme Lemes,Lino Roberto Ferreira

doi:10.1038/s41598-017-16821-4

Carlos Moreira Miquelino Eleto Torres, José Cola Zanuncio + Show 7 more

Open Access

https://doi.org/10.1038/s41598-017-16821-4

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Abstract

Agrosilvopastoral and silvopastoral systems can increase carbon sequestration, offset greenhouse gas (GHG) emissions and reduce the carbon footprint generated by animal production. The objective of this study was to estimate GHG emissions, the tree and grass aboveground biomass production and carbon storage in different agrosilvopastoral and silvopastoral systems in southeastern Brazil. The number of trees required to offset these emissions were also estimated. The GHG emissions were calculated based on pre-farm (e.g. agrochemical production, storage, and transportation), and on-farm activities (e.g. fertilization and machinery operation). Aboveground tree grass biomass and carbon storage in all systems was estimated with allometric equations. GHG emissions from the agroforestry systems ranged from 2.81 to 7.98 t CO2e ha−1. Carbon storage in the aboveground trees and grass biomass were 54.6, 11.4, 25.7 and 5.9 t C ha−1, and 3.3, 3.6, 3.8 and 3.3 t C ha−1 for systems 1, 2, 3 and 4, respectively. The number of trees necessary to offset the emissions ranged from 17 to 44 trees ha−1, which was lower than the total planted in the systems. Agroforestry systems sequester CO2 from the atmosphere and can help the GHG emission-reduction policy of the Brazilian government.

Highlights

Agrosilvopastoral and silvopastoral systems can increase carbon sequestration, offset greenhouse gas (GHG) emissions and reduce the carbon footprint generated by animal production
Agriculture is the main emission source with enteric fermentation being responsible for 90% of CH4 and animal manure on pasture for 33% of N2O emissions in Brazil in 20145
The Brazilian government established a “low-carbon agriculture plan” to promote sustainable practices in agriculture by reducing greenhouse gas (GHG) emissions while maintaining profitability[6]. This plan is based on practices such as restoration of degraded pastures, crop-livestock-forest integration, no-till farming, biological nitrogen fixation and forestry and agroforestry systems[6]

Summary

Introduction

Agrosilvopastoral and silvopastoral systems can increase carbon sequestration, offset greenhouse gas (GHG) emissions and reduce the carbon footprint generated by animal production. The Brazilian government established a “low-carbon agriculture plan” to promote sustainable practices in agriculture by reducing greenhouse gas (GHG) emissions while maintaining profitability[6] This plan is based on practices such as restoration of degraded pastures, crop-livestock-forest integration, no-till farming, biological nitrogen fixation and forestry and agroforestry systems[6]. Agrosilvopastoral and silvopastoral systems are agroforestry system types that can reduce and offset GHG emissions from the Brazilian agricultural sector, mainly using cattle and forest integration[12,13,14] These systems lower animal emission levels[12] by improving grass quality, which can reduce CH4 emissions from enteric fermentation[15] and digestion efficiency[16]. These systems may mitigate GHG emissions by enhancing carbon sequestration through increasing above and belowground biomass[17,18,19]

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