Arwenyo, BeatriceNavarathna, ChanakaKrishna, Naba DasHitt, AddieMlsna, Todd2023-12-162023-12-162023-01-19Arwenyo, B.; Navarathna, C.; Das, N.K.; Hitt, A.; Mlsna, T. Sorption of Phosphate on Douglas Fir Biochar Treated with Magnesium Chloride and Potassium Hydroxide for Soil Amendments. Processes 2023, 11, 331. https://doi.org/10.3390/pr11020331https://doi.org/10.3390/pr11020331https://hdl.handle.net/20.500.14270/427This research received no external fundingWith increasing climate variability, a sustainable crop production approach remains an indispensable concern across the globe. In this study, P retention/availability of MgCl2.6H2O/KOH modified Douglas fir biochar was assessed. The MgCl2·6H2O/KOH treated Douglas fir biochar was prepared by sequentially treating Douglas fir biochar with magnesium chloride and potassium hy droxide solutions. The biochar’s surface area, pore volume, morphology, and elemental composi tions were determined using BET, SEM, SEM/EDS, and powder X-ray analyzes. Both surface area and pore volume were reduced by more than 97% following modification. Similarly, the morphol ogy and elemental compositions changed after modification. The maximum P adsorbed correspond ing to Langmuir–Freundlich model was 41.18 mg g−1 . P sorption on biochar soil mixture was pH dependent. More studies are required to establish the field applicability of P-laden MgCl2 ·6H2O/KOH-modified Douglas fir biochar as a soil additive.enAttribution-NonCommercial-NoDerivs 3.0 United StatesModified biocharsoil pHP retentionP availabilityArticle