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Titel |
Simulated soil C changes over sugarcane expansion in Brazil |
VerfasserIn |
Dener Oliveira, Stephen Williams, Carlos Cerri, Keith Paustian |
Konferenz |
EGU General Assembly 2017
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Medientyp |
Artikel
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Sprache |
en
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 19 (2017) |
Datensatznummer |
250146350
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Publikation (Nr.) |
EGU/EGU2017-10373.pdf |
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Zusammenfassung |
In recent years, the increase in Brazilian ethanol production has been based on expansion of
sugarcane cropped area, mainly by the land use change (LUC) pasture-sugarcane. However,
second generation (2G) cellulosic-derived ethanol supplies are likely to increase dramatically
in the next years in Brazil. Both these management changes potentially affect soil C (SOC)
changes and may have a significant impact on the greenhouse gases balance of Brazilian
ethanol. To evaluate these impacts, we used the Daycent model to predict the influence of the
LUC native vegetation (NV) - pasture (PA) - sugarcane (SG), as well as to evaluate the effect
of different management practices (straw removal, no-tillage and application of organic
amendments) on long-term SOC changes in sugarcane areas in Brazil. The DayCent
model estimated that the conversion of NV-PA caused SOC losses of 0.34±0.03 Mg
ha−1 yr−1, whilst the conversion PA-SG resulted in SOC gains of 0.16±0.04 Mg
ha−1 yr−1. Moreover, simulations showed SOC losses of 0.19±0.04 Mg ha−1yr−1
in SG areas in Brazil with straw removal. However, our analysis suggested that
adoption of some best management practices can mitigate these losses, highlighting the
application of organic amendments (+0.14±0.03 Mg C ha−1 yr−1). Based on the
commitments made by Brazilian government in the UNFCCC, we estimated the
ethanol production needed to meet the domestic demand by 2030. If the increase
in ethanol production was based on the expansion of sugarcane area on degraded
pasture land, the model predicted a SOC accretion of 144 Tg from 2020-2050,
whilst increased ethanol production based on straw removal as a cellulosic feedstock
was predicted to decrease SOC by 50 Tg over the same 30 year period in Brazil. |
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