Single and Binary Fe- and Al-hydroxides Affect Potential Phosphorus Mobilization and Transfer from Pools of Different Availability

Phosphorus (P) fixation is a global problem for soil fertility and negatively impacts agricultural productivity. This study characterizes P desorption of already fixed by using KCl, KNO3, histidine, malic acid as inorganic organic compounds, which are quite common in soil. Goethite, gibbsite, ferrihydrite, well hydroxide mixtures with varying Fe- Al-ratio were selected model substances crystalline amorphous Al-hydroxides. Especially two- multi-component systems soils, but they have barely been included studies. Goethite showed the highest range from 70.4 to 81.0%, followed gibbsite values 50.7 42.6%. Ferrihydrite had distinctive lower 11.8 1.9%. Within group Fe-Al-hydroxide mixtures, was lowest at balanced mixture ratio 1 Fe: Al, increased either increasing Fe or Al amount. Precipitation steric effects concluded be important influencing factors. More released Fe-hydroxides, Al-hydroxides crystallinity, histidine did not substantially influence compared constituents.