Impact assessment of climate change on N2O emissions in Brazilian sugarcane

• Ano de defesa: 2025
• Autor(a) principal: Leite, Emily Aquino
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Saccharum spp.; Climate change; DSSAT; Emissões de N2O; Modelagem; Modeling; Mudanças climáticas; N2O emissions
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/11/11152/tde-13082025-163918/

The escalating demand for food and energy necessitates innovative strategies to address global challenges while combating climate change. Sugarcane (Saccharum spp.) has emerged as a vital resource for reducing greenhouse gas (GHG) emissions and advancing energy sustainability. Crop modeling plays a pivotal role in devising adaptation strategies by capturing the intricate interactions among genetics, environment, and management that shape crop development and growth. Process-based crop models (PBMs) provide a mechanistic framework to simulate these dynamics, offering valuable insights for agricultural planning and decision-making. This study employed the DSSAT/SAMUCA model, calibrated for the RB867515 cultivar, to simulate sugarcane growth under the influence of a green cane trash blanket (GCTB). The SAMUCA model captures the role of GCTB in regulating soil temperature, moisture, and rhizosphere processes, critical for crop performance. Complementing this, the DSSAT/CENTURY model was used to assess soil organic matter and nutrient dynamics, focusing on carbon-nitrogen fluxes and the decomposition of organic matter. Together, these models, integrated into the DSSAT v4.8 platform, were applied to simulate sugarcane yield, water productivity (WP), and N2O emissions across nine agroclimatic zones in Brazil under three future climate scenarios-SSP1-2.6, SSP3-7.0, and SSP5-8.5-for the 2040-2070 period. Simulations incorporated variations in atmospheric CO2 concentrations and soil water content to evaluate the impacts of climate change. Results revealed that elevated CO2 levels and warmer climates have the potential to enhance sugarcane yields. However, these gains may be offset by a projected 5%-30% increase in N2O emissions relative to baseline levels. High-emission scenarios, such as SSP3-7.0 and SSP5-8.5, demonstrated amplified nitrogen emissions, driven by the decomposition of accumulated GCTB biomass and increased microbial activity. These findings highlight the urgent need for climate-resilient strategies to optimize WP and mitigate emissions, ensuring the long-term sustainability of sugarcane production and its pivotal role in the global energy transition.