The kinetic study of the nutrient release was also evaluated in soil (Fig. ). The temporal profile for the precursor KH2PO4 indicates a P increase from 0 mg/kg to 107 mg/kg after 3 days of release keeping constant after 30 days, representing 40% of total P from precursor (KH2PO4). Differently, for sample 2 h/600 rpm, the phosphorus release is more progressive (from 0 mg/kg to 25 mg/kg at 3 days and 45 mg/kg at 30 days) corresponding to 15% of total P content recovered from the milled sample. These results indicate that sample 2 h/600 rpm presented a longer delay in phosphorus release compared to the precursor (KH2PO4), corroborating with the results observed in citric acid solution.