Emily Aquino Leite a , Evandro H. Figueiredo Moura da Silva b , Izael Martins Fattori Júnior a , Fábio R. Marin a c
- aDepartment of Biosystems Engineering, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, SP, Brazil
- bDepartment of Soil Science, Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, SP, Brazil
- cCenter for Carbon Research in Tropical Agriculture (CCARBON), Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, SP, Brazil
Highlights
- CSM-SAMUCA-Sugarcane simulated sugarcane yield, water productivity, and N2O emissions.
- Future climate scenarios increased sugarcane yield in several agroclimatic zones.
- N2O emissions from sugarcane are projected to increase between 5 % and 15 % by 2050.
- Crop water productivity showed diverse responses across Brazil’s sugarcane zones.
Abstract
Context
Sugarcane-based bioenergy systems are critical in Brazil’s renewable energy sector, contributing significantly to global efforts to reduce fossil fuel dependence. However, climate change introduces uncertainties related to sugarcane yield, water use efficiency, and greenhouse gas emissions. Rising atmospheric carbon dioxide (CO2) levels, increasing temperatures, and shifts in precipitation patterns are expected to impact Brazil’s bioenergy cultivated areas, necessitating a comprehensive evaluation of their effects on sugarcane production and environmental sustainability.
Objective
This study assessed the effects of rising CO2, temperature increases, and altered precipitation on sugarcane yield, crop water productivity (WP), and nitrous oxide (N2O) emissions across Brazil’s bioenergy cultivation areas under future climate scenarios.
Methods
We integrated the CSM-SAMUCA-Sugarcane model with the DSSAT-GHG module to simulate sugarcane systems across nine agroclimatic zones. Future projections (2040–2070) were based on 20 CMIP6 Global Climate Models (GCMs) under three Shared Socioeconomic Pathways (SSP1–2.6, SSP3–7.0, SSP5–8.5).
Results and conclusions
SSP1–2.6 (low-emission scenario) showed minor yield changes, with some CO₂ fertilization gains. SSP3–7.0 (intermediate/high-emission scenario) may increase yield by up to 10 % due to warming and CO₂ effects. However, SSP5–8.5 (most extreme warming) and rainfall reductions increased yield variability. N₂O emissions may rise by 5–30 %, with intensities up to 40 % higher, driven by warmer soils and faster residue decomposition. WP responses varied: some regions gained from CO₂-induced efficiency, others declined due to soil moisture limits.
Significance
Balancing yield improvements with N2O mitigation under climate change remains a challenge. Climate-resilient nitrogen and residue management strategies are essential to ensure sustainable bioenergy production in Brazil.
Keywords
Greenhouse gas emissions; Process-based crop model; Soil nitrogen dynamics; Water use efficiency; Agroclimatic zones
