Agro-climatic zoning and soybean yield potential in the SEALBA region
Agrometeorological model, SEALBA, sowing period, precipitation, reanalysis.ural zoning, agrometeorological model, cropgrop-soybean, water deficit, soy.
Since the early 2000s, Brazil has been one of the main grain producers worldwide, with agribusiness accounting for about 28% of Brazilian GDP by 2021. A new agricultural frontier emerges in Brazil, known as SEALBA and referring to three states located in the Northeast Brazil: Sergipe, Alagoas and Bahia. This is an extensive area with a favorable climate for the production of grains, including soybeans. Considering that the rainfall is the main climatic factor for farming, the lack of meteorological stations in the SEALBA region represents an impairment for an accurate assessment of its farming potential. Therefore, a performance evaluation of four different precipitation databases from alternative sources was carried out for observation: Two grade analysis, MERGE and CHIRPS, and two ECMWF reanalysis, ERA5 and ERA5Land. As all databases provide up-to-date data, they will serve as input for the agrometeorological model for water deficit to determine the planting periods for soybean cultivation, providing a sowing calendar aiming to minimize the possible losses caused by water deficiencies. As a result, the SEALBA region has ideal climatic conditions for grain production, especially for soybean, whose most favorable period for cultivation is from February to June, with emphasis on the month of April with estimated potential production above 90%. It is also concluded that the northern Alagoas subareas have a larger cultivation period, followed by the coastal subareas, which the beginning of the rainy season occurs in late December to early January, providing a wider period for grain cultivation.