Fertilizer interactions with micronutrients in tropical volcanic soils

This project evaluated the how the addition of high concentrations of fertilizer to volcanic soil systems could affect the availability and transport of micronutrients. First, in Chapter 1, we studied the phosphate-boric acid interactions by the development of boron batch adsorption experiments (with and without the presence of phosphate), and interpreting the results by the implementation of a state-of-the-art multi-surface adsorption model. Then, in Chapter 2, we evaluated the effect of high additions of potassium chloride on zinc sorption processes and its transport. For this chapter we developed zinc batch adsorption experiments at different pH and different ionic strength. In addition, we conducted potassium transport experiments in undisturbed and unsaturated volcanic soil columns, evaluating its effect on zinc leaching from the system. Finally, for Chapter 3, we assessed the effect of the addition of high concentrations on parameter values of the most commonly applied solute transport models (e.g., Convection-Dispersion Equation).