Net greenhouse gas emissions from manure management using anaerobic digestion technology in a beef cattle feedlot in Brazil

Autor(es)

Costa Junior, Ciniro ^[1] ; Cerri, Carlos E. P. ^[2] ; Pires, Alexandre V. ^[3] ; Cerri, Carlos C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ctr Nucl Energy Agr, Lab Biogeochem, BR-13416000 Piracicaba, SP - Brazil

^[2] Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Soil Sci, BR-13418900 Piracicaba, SP - Brazil

^[3] Univ Sao Paulo, Luiz De Queiroz Coll Agr, Dept Anim Sci, BR-13418900 Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Science of The Total Environment; v. 505, p. 1018-1025, FEB 1 2015.
• Citações Web of Science: 8

Resumo

As part of an agreement during the COP15, the Brazilian government is fostering several activities intended to mitigate greenhouse gas (GHG) emissions. One of them is the adoption of anaerobic digester (AD) for treating animal manure. Due to a lack of information, we developed a case study in order to evaluate the effect of such initiative for beef cattle feedlots. We considered the net GHG emissions (CH4 and N2O) from the manure generated from 140 beef heifers confined for 90 days in the scope ``housing to field application{''} by including field measurements, literature values, and the offset generated by the AD system through the replacement of conventional sources of nitrogen (N) fertilizer and electricity, respectively. Results showed that direct GHG emissions accounted for 0.14 +/- 0.06 kg of carbon dioxide equivalent (CO(2)eq) per kg of animal live weight gain (lwg), with similar to 80% originating from field application, suggesting that this emission does not differ from the conventional manure management (without AD) typically done in Brazil (0.19 +/- 0.07 kg of CO(2)eq per kg Iwg(-1)). However, 2.4 MWh and 658.0 kg of N-manure were estimated to be generated as a consequence of the AD utilization, potentially offsetting 0.13 +/- 0.01 kg of CO2eq kg lwg(-1) or 95% (45%) of total direct emissions from the manure management. Although, by replacing fossil fuel sources, i.e. diesel oil, this offset could be increased to 169% (+/- 47%). In summary, the AD has the potential to significantly mitigate GHG emissions from manure management in beef cattle feedlots, but the effect is indirect and highly dependent on the source to be replaced. In spite of the promising results, more and continuous field measurements for decreasing uncertainties and improving assumptions are required. Identifying shortcomings would be useful not only for the effectiveness of the Brazilian government but also for worldwide plans in mitigating GHG emissions from beef production systems. (C) 2014 Elsevier BM. All rights reserved. (AU)

• Processo FAPESP: 10/05111-7 - Emissões de metano e óxido nitroso pelo manejo dos dejetos de bovinos de corte confinados no Brasil: caracterização, medidas experimentais e modelagem matemática
• Beneficiário: Ciniro Costa Junior
• Linha de fomento: Bolsas no Brasil - Doutorado
• Processo FAPESP: 12/02642-7 - Simulação da emissão e mitigação de gases de efeito estufa pelo manejo de dejetos de bovinos de corte confinados no Brasil através da utilização do modelo matemático Manure-DNDC
• Beneficiário: Ciniro Costa Junior
• Linha de fomento: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 10/17837-2 - Balanço dos gases do efeito estufa na pecuária bovina de corte no Centro-Oeste do Brasil: bases técnicas para pecuária de baixo carbono
• Beneficiário: Carlos Clemente Cerri
• Linha de fomento: Auxílio à Pesquisa - Regular