Diffusion kinetics of multinutrient accumulation by mixed-bed ion- exchange resin

초록

Objectives of this research were to compare kinetic models to describe empirically multinutrient accumulation by the phytoavailability soil test (PST) method, and to test its sensitivity to conditions that influence diffusion kinetics. Existing kinetic models all described multinutrient accumulation, except for NO<inf>3</inf>-N. The parabolic diffusion law model consistently provided the best fit. Significant relationships were found between rate constants of K, P, S, and NH<inf>4</inf>-N, and respective ion activities in soil solution. Accumulation of all nutrients was directly related to temperature, except NO<inf>3</inf>-N, which was temperature and soil specific. These results suggest that the PST method has advantages over conventional methods for measuring nutrient dynamics. -from Authors