Co-Pyrolysis of Poultry Litter and Phosphate and Magnesium Generates Alternative Slow-Release Fertilizer Suitable for Tropical Soils
2017
Lustosa Filho, José F. | Penido, Evanise S. | Castro, Patrícia P. | Silva, Carlos A. | Melo, Leônidas C. A.
Monoammonium phosphate (MAP), triple superphosphate (TSP), and phosphoric acid (H₃PO₄), with and without the addition of magnesium oxide (MgO), were mixed with poultry litter (PL) to produce biochar-based fertilizers (BBFs). This is a novel approach aiming to add value to PL residue and to increase P use efficiency in acidic tropical soils. Samples of BBFs were assessed by P-release kinetics in water, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and a bioassay with maize in a greenhouse using a clayey Oxisol. Addition of MgO reduced the kinetics of P released from BBFs impregnated with all P sources. XRD analysis showed the formation of low-solubility Ca₂P₂O₇ and Mg₂P₂0₇ compounds, which is supported by P—O—P or P═O stretching observed in the FTIR spectra. The MgO-treated BBFs increased shoot dry matter production compared to the control, but were inferior when compared to TSP in the short term. The slow release of P and the alkaline reaction of the BBFs show great potential for these materials to be used as enhanced P fertilizers in tropical soils.
显示更多 [+] 显示较少 [-]