The fate of phosphorus from bone char-based fertilizers in soil pools in a 5-year crop rotation

Abstract Bone char (BC) is a promising P-recycling fertilizer but with rather low P-solubility, which can be increased by modifying the BC surface elemental sulfur (BC plus ), effects on soil P status have not been tested under field conditions yet. Hence, long-time experiment was started 2013 to track fate of and into different pools compared control triple superphosphate (TSP) treatment for severely deficient (iSPTC-A) vs . sufficiently fertilized (iSPTC-C) soil. The fingerprint recent land-use history (six years grassland prior arable land) reflected elevated labile-P o NaOH-P concentrations at beginning experiment. However, after 3 years, labile converged stabilized in both soils similar level. formation this new equilibrium suggests that rate mineralization was, some extent, controlled amount available legacy P. After first crop rotation, effect fertilization soil-P budgets fractions were small mostly insignificant. Only TSP available-P other affected treatments except stable-P significantly application iSPTC-A. former laboratory results higher solubility over could confirmed within duration trial. prove are capable maintaining adequate long-term supply, continuation unique trial highly recommended.