Vinasse application and cessation of burning in sugarcane management can have positive impact on soil carbon stocks

PeerJ

article

Caio F. Zani¹  Arlete S. Barneze²  Andy D. Robertson²  Aidan M. Keith²  Carlos E.P. Cerri⁵  Niall P. McNamara²  Carlos C. Cerri¹ 

[1] Centro de Energia Nuclear na Agricultura, Universidade de São Paulo;Lancaster Environment Centre, Centre for Ecology & Hydrology;Soil and Ecosystem Ecology Laboratory, Lancaster Environment Centre, Lancaster University;Institute of Biological and Environmental Sciences, University of Aberdeen;Departamento de Ciência do Solo, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo

关键词: Physical fractionation;    Soil carbon profile;    Payback time;    CENTURY model;    Bioenergy crop;    Management practice changes;   

DOI  :  10.7717/peerj.5398

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Bioenergy crops, such as sugarcane, have the potential to mitigate greenhouse gas emissions through fossil fuel substitution. However, increased sugarcane propagation and recent management changes have raised concerns that these practices may deplete soil carbon (C) stocks, thereby limiting the net greenhouse gas benefit. In this study, we use both a measured and modelled approach to evaluate the impacts of two common sugarcane management practices on soil C sequestration potential in Brazil. We explore how transitions from conventional (mineral fertiliser/burning) to improved (vinasse application/unburned) practices influence soil C stocks in total and in physically fractionated soil down to one metre. Results suggest that vinasse application leads to an accumulation of soil C of 0.55 Mg ha−1yr−1 at 0–30 cm depth and applying unburned management led to gains of ∼0.7 Mg ha−1yr−1 at 30–60 cm depth. Soil C concentration in the Silt+Clay fraction of topsoil (0–20 cm) showed higher C content in unburned management but it did not differ under vinasse application. The CENTURY model was used to simulate the consequences of management changes beyond the temporal extent of the measurements. Simulations indicated that vinasse was not the key factor driving increases in soil C stocks but its application may be the most readily available practice to prevent the soil C losses under burned management. Furthermore, cessation of burning may increase topsoil C by 40% after ∼50 years. These are the first data comparing different sugarcane management transitions within a single area. Our findings indicate that both vinasse application and the cessation of burning can play an important role in reducing the time required for sugarcane ethanol production to reach a net C benefit (payback time).

【 授权许可】

CC BY