Potassium uptake by sweet corn predicted by a simulation model

Abstract

Eleven soil and plant of sweet corn (Zea mays L.) parameters affecting K uptake were analyzed with a mathematical model, combining two soil substrates and two N forms. This model describes K uptake in terms of root growth and morphology, kinetics of nutrient uptake and supply of nutrients to the root by diffusion and mass-flow. Sensitivity analysis indicated that root surface area is one of the most sensitive parameters due to K uptake increase with the simulated variation of root mean radius, relative growth rate and maximum influx. Values of effective-diffusion coefficient for K in the soil, buffer power of K on the solid phase for K in solution and initial concentration of K in the soil solution were affected by K application. Predicted K uptake was greater than observed K uptake, for treatments involving a Red-Yellow Latosol, and was lower for treatments with Red-Yellow Latosol with sand.