Is the expansion of sugarcane over pasturelands a sustainable strategy for Brazil's bioenergy industry?

Abstract

Biofuels are fundamental for meeting societal energy needs within the next few decades, but the sustainability of large-scale land use conversions to supply feedstock crops remains unclear. Quantitative data documenting how biofuel crop expansion will affect ecosystem services (ES) is needed to develop sustainable energy policies. Using pairwise comparisons of published and novel environmental, social and economic indicators, we quantitatively assessed the provision of critical ES related to key aspects of the sustainability of pasture-to-sugarcane transitions in Brazil. We found that with the exception of maintaining biodiversity, conversion of pasturelands to sugarcane fields enhanced many ES. Based on the Sustainability index, aimed to capture changes on key sustainability aspects by considering multiple ES and properly integrating them, we concluded that pasture to sugarcane transitions would increase the sustainability by 78% in south-central Brazil. Our results provide science-based empirical evidence that the expansion of sugarcane into degraded pasturelands is a suitable strategy to enhance Brazil's biomass feedstock supplies for producing bioenergy. Moreover, facing the complex and multidimensional concept of sustainability, our study also illustrates the importance of considering holistically land use change effects rather than individual ESs when establishing sustainable land management practices and bioenergy policies.

Linking Soil Water Changes to Soil Physical Quality in Sugarcane Expansion Areas in Brazil

“…Our findings showing soil physical degradation and its consequent negative implications on water dynamics in extensive PA soils confirm what previous studies with a broader scope have reported, namely that those areas are characterized by poor overall soil quality [42] and provision of soil-related ecosystem services [13], low productivity and stocking rate [5], and low economic developments to farmers, workers, and the surrounding urban centers [13]. Due to all these environmental and socio-economic aspects, the prevalent scenario of sugarcane and other annual crops expansion has been, and will continue to be, over areas previously occupied with extensive pasture [4,13]. The full monitoring of PA soil conditions is fundamental to evaluate if sugarcane cultivation is degrading, sustaining, or even enhancing soil quality compared to the pasture baseline.…”

Revealing soil legacy phosphorus to promote sustainable agriculture in Brazil

“…Brazil, one of the world's leading producers and suppliers of food, fibres and bioenergy 3 , is an emerging nation whose agriculture has rapidly expanded in recent decades, notably in the Cerrado region (over 204 million hectares (Mha)), and whose land base and deep soils provide large opportunity for conversion of extensive pasturelands into intensive croplands 4 . This land use transition is a promising scenario to allow agricultural expansion in Brazil with minimum environmental impacts 5 – 7 . However, one major economic and environmental issue associated with expansion and intensification of Brazilian agriculture is the substantial increase in fertiliser demand to sustain crop yields in these new areas (mainly in Cerrado region) characterized by highly-weathered, acid and P-fixing soils 8 .…”

What Has Been the Focus of Sugarcane Research? A Bibliometric Overview

“…Other authors argue that ethanol has significantly grown in popularity due to government regulations and economic incentives [56], but that this kind of feedstock is essentially food, and other sources for bio-ethanol production exist that could substitute sugarcane [57]. At the same time, the demand for sugarcane used as biofuel in countries such as Brazil [58] has led to an increase in the sugarcane production area, in some cases, converting pasturelands to sugarcane fields [59]. This has been an important debate among researchers, generating many publications oriented towards the demonstration of its technical and economic viability for promising new raw materials, e.g., microalgae [60] or alternative energy sources, as well as the way to process them and the technology developed to that end, representing a threat for sugarcane based energy production.…”