Magnetic Treatment of Fertigation Solutions Can Change the Phosphorus Adsorption Dynamics on a Typic Hapludox Soil

The aim of this study was to evaluate the influence of preparation procedure of magnetically treated phosphate solutions and the evaluation time after the magnetic treatment, in the phosphorus adsorption on a Typic Hapludox soil, for different initial concentrations. The experimental treatments were defined by the combination of three evaluation times after magnetization (5 min, 60 min, and 24 hours), three forms of phosphate solution preparation (control, solution preparation with magnetic water, and phosphate solution magnetically treated), and five initial concentrations of phosphorus (50, 100, 150, 200 and 300 mg L−1) obtained from solutions of purified NH4H2PO4. The phosphorus adsorption evaluation was made by the decantation sorption method. To evaluate the adsorption behavior, the data were fitted to the Linear, Freündlich, Langmuir and Redlich-Peterson adsorption isotherm models. It was observed that magnetically treated phosphate solutions determined different phosphorus adsorption behavior and magnitudes than the untreated solution, with potential to decrease the amount of adsorbed phosphorus up to 60 minutes after treatment, for solutions prepared with previously magnetized water, and for up to 24 hours for magnetized phosphate solutions.