Straw preservation reduced total N2O emissions from a sugarcane field

Autor(es)

Pitombo, L. M. ^{[1, 2]} ; Cantarella, H. ^[1] ; Packer, A. P. C. ^[3] ; Ramos, N. P. ^[3] ; do Carmo, J. B. ^[2]

Afiliação do(s) autor(es)

^[1] Agron Inst Campinas IAC, Soils & Environm Resources Ctr, Av Barao Itapura 1481, BR-13020902 Campinas, SP - Brazil

^[2] Fed Univ Sao Carlos UFSCar, Dept Environm Sci, Rod Joao Leme Santos Km 110, BR-18052780 Sorocaba, SP - Brazil

^[3] Embrapa Environm, Rod SP 340 Km 127-5, BR-13820000 Jaguariuna, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SOIL USE AND MANAGEMENT; v. 33, n. 4, p. 583-594, DEC 2017.
• Citações Web of Science: 11

Resumo

Post-harvest biomass can be used as feedstock for energy production and alter N2O emissions from the soil, which is among the main issues determining bioethanol sustainability. To assess the effects of sugarcane straw return on gas emissions, we established a field experiment in which 0, 50, 75 or 100% (0, 5.65, 8.47 and 11.30 Mg/ha dry biomass, respectively) of the crop residues (straw) was left in the field during the first two ratoon crops. As fertilizer is applied in bands to sugarcane, we also investigated the contribution of different positions to the N2O emissions within the field. There was an interactive effect between straw and inorganic fertilizer, leading to a nonlinear effect of crop residues on the fertilizer emission factor (EF). However, straw consistently reduced N2O emissions from the field, acting mainly in the unfertilized areas in the field (P<0.05). We observed that considering the typical EF used in the literature, the N2O-N emissions attributed to fertilizer ranged from 0.19 to 0.79kg/ha, while the total emissions ranged from 3.3 to 5.2kg/ha, from the highest amount of straw to the lowest. We conclude that overall, the fertilizer EF is not as relevant as the total emissions, based on this and other studies. Consequently, management practices might be more effective in improving the GHG balance than changing inorganic fertilizer use. We conclude that keeping up to 11 Mg/ha of straw with a large C:N ratio (>100:1) on site might increase sugarcane production sustainability by reducing the greenhouse gas emissions from the field. (AU)

• Processo FAPESP: 12/50694-6 - Emissão de gases do efeito estufa durante o manejo da vinhaça e da palha em áreas cultivadas com cana de açúcar: ampliação da infraestrutura analítica
• Beneficiário: Janaina Braga do Carmo
• Modalidade de apoio: Auxílio à Pesquisa - Regular