Land use change, management, and CO2 balance of second-crop corn in Brazil

Abstract Corn is Brazil's second most cultivated crop (21 Mha in 2023, 80% as a second crop), vital for food, feed, and biofuels. This study provides the first country-level mapping of second-crop corn for Brazil, with results for 2023 and the previous land use/cover 20 and 10 years before. Based on these, we estimated CO₂ balance from direct land use change (dLUC) and agricultural management practices (MP). Our results show that the share of corn area that was natural vegetation was 12.9% in 2003–2023 and reduced to 3.6% in 2013–2023 period. 20-year dLUC emissions ranged from 0.6 to 0.9 tCO₂⋅ha⁻ ¹⋅year⁻ ¹, depending on the allocation method, but consistently lower than in the literature. Carbon removals from MP ranged from 0.15 to 0.2 tCO₂.ha⁻ ¹.yr⁻ ¹, mitigating 20% of dLUC. dLUC + MP balance for second-crop corn ethanol ranged from 2.3–5.3 gCO₂⋅MJ⁻ ¹ in 2003–2023, reducing to 0.32–1.5 in the more recent 2013–2023 period.