MODELING YIELD, SOIL WATER BALANCE, AND ECONOMIC RETURN OF SOYBEAN UNDER DIFFERENT WATER DEFICIT LEVELS

• Autor(a) principal: Petry,Mirta T.
• Data de Publicação: 2020
• Outros Autores: Basso,Laudenir J., Carlesso,Reimar, Armoa,Maria S., Henkes,Jonas R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Engenharia Agrícola
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000400526
• topic: Glycine max; soil water balance; SIMDualKc model; economic return

ABSTRACT Evaluating the impacts of water stress on crop yield allows comparing irrigation management alternatives, aiming to ensure an economic return for the irrigated farms. Thus, the main objectives of this study were to model the soil water balance, deriving the crop coefficients, grain yield prediction, and economic return of soybean grown at different levels of water deficit and price quotations. The experiment was carried out under a rainout shelter, using four irrigation water managements. Irrigations were applied when the soil available water in the root zone reached 75%, 64%, 60%, and 50% of the total available water (TAW). Crop and soil parameters were monitored throughout the crop season. The SIMDualKc model was used to simulate the soil water balance. Statistics indicators demonstrated the goodness of the simulation, with regression coefficients (b0) ranging from 0.96 and 0.99 and root mean square errors (RMSE) ≤8.4 mm. Crop coefficients for initial, intermediate, and final stages were calibrated and validated at 0.15, 1.00, and 0.10, respectively. Crop yield and economic return were higher for the treatment kept at 75% of TAW, results that should be considered in irrigation management programs.