An empirical model to estimate nutrients concentration in controlled release fertilizers aqueous solutions

Abstract

Controlled release fertilizers (CRFs) insure controlled release of nutrients due to their coating. The aim of this study was to investigate the effect of nutrient solution parameters as well as time on the evolution of NO3, NH4, PO4 and K concentrations. For this reason, 0.5 g of Multicote fertilizers 14-14-14 and 15-7-15 dissolved in 100 mL and 300 mL of deionized water respectively. The solutions remained at 24oC and their pH was adjusted once during their preparation at 5.5, 6.0 and 6.5 or adjusted every three days for a 24 days period. A linear empirical mathematical model was developed for the prediction of the above mentioned nutrients concentrations (CX) in relation to the remaining (Vs) and the removed (dVs) volume of the nutrient solution, its pH and time (t) from its preparation. The model output compares favorably with data for the prediction of the concentration of these nutrients. Copyright © 2017 for this paper by its author