Modelling nutrient uptake considering sorption kinetics: Phosphorus uptake from a one dimensional rhizosphere

Abstract

A mathematical model was developed which accounts for sorption kinetics of nutrients having limited availability in soil material. Model trials in which predictions of P uptake and concentration profiles in a one dimensional simulated rhizosphere were performed. Data and parameters for the kinetic sorption of P in soil were taken from two mechanistic‐kinetic models (4,8). In addition, an apparent buffer power was defined on the basis of the mechanistic‐kinetic models (9) and was used in the uptake model as well. Predictions obtained from the uptake model based on the buffer power concept were compared to those obtained for the same soils with the kinetic sorption model. The results indicate a reduction in both the predicted uptake and concentration profiles, when sorption kinetics is accounted for.