Sensitivity analysis of the AquaCrop model for maize crop in Southern Brazil

Abstract

Crop growth models are abstract tools that represent a real system, being a simple and important technology to develop studies aiming to improve the yields of the most agricultural crops, like the maize in Brazil. The objective of this study was to analyze the sensitivity of the main AquaCrop model input parameters, as well as their responses in maize yield estimation, in Parana State, Southern Brazil. The analyses were performed with the genotype 30R50YH, 2014/15 harvest, planted on April 11, 2014. The parameters analyzed refer to crop, soil and soil management. The parameters were modified individually, maintaining the others fixed. With the results, the Sensitivity Index (SI) was calculated, which allowed the identification of the most sensitive AquaCrop parameters. The parameters related to the crop showed high sensitive, as they are associated with the main equations of the model. The parameters related to the harvest index, saturated hydraulic conductivity, soil water stress and air temperature stress did not present sensitivity in the model for the conditions evaluated. The crop coefficient with complete canopy expansion (Kc_TR,x) was the most sensitive parameter in the model, as it directly affects the maize biomass production and yield formation.