Estimativa de produtividade e Yield gap da Soja considerando as projeções de mudanças climáticas para a região de Gerais de Balsas-MA

Abstract

Agriculture, particularly soybean cultivation, is highly dependent on climatic conditions. This study aims to estimate soybean productivity and the Yield Gap by considering the impacts of water deficit and agricultural management in the Balsas-MA region under current and future climatic scenarios (RCP 4.5 and RCP 8.5). Climatic data, projections, and the Sarrazon Model were used to calculate the water balance, considering three planting periods (October, November, and December) and six soil available water classes (AWC). Productivity calculations were based on the FAO Agroecological Zone Model (FAO-AEZ). Results indicate that potential productivity (PP) varies according to planting date, with higher values observed in December. Attainable productivity (AP) increases with the soil's water retention capacity, peaking in December, but making the second crop planting unfeasible. In the current scenario, the climatic Yield Gap (YGc) reflects significant productivity losses due to water limitations, with Climatic Efficiency (CE) ranging from 47.1% to 83.4%. The management Yield Gap (YGm) is smaller, suggesting that efficient management practices can mitigate losses. For future scenarios, PP remains relatively unchanged, but AP decreases, particularly under RCP 8.5, due to increased water restrictions. YGc is higher in future scenarios, emphasizing the growing importance of agricultural management practices and adaptation to climate change. The study concludes that water availability is crucial for soybean productivity and that specific management strategies can alleviate the negative impacts of climate change. Moreover, future scenarios project increased water limitations and a reduction in AP, highlighting the need for climate change adaptation