@misc{GypserSchuetzeFreese, author = {Gypser, Stella and Sch{\"u}tze, Elisabeth and Freese, Dirk}, title = {Single and binary Fe- and Al-hydroxides affect potential phosphorus mobilization and transfer from pools of different availability}, series = {Soil Systems}, volume = {5}, journal = {Soil Systems}, number = {2}, doi = {10.3390/soilsystems5020033}, pages = {1 -- 21}, abstract = {Phosphorus (P) fixation is a global problem for soil fertility and negatively impacts agricultural productivity. This study characterizes P desorption of already fixed P by using KCl, KNO3, histidine, and malic acid as inorganic and organic compounds, which are quite common in soil. Goethite, gibbsite, and ferrihydrite, as well as hydroxide mixtures with varying Fe- and Al-ratio were selected as model substances of crystalline and amorphous Fe- and Al-hydroxides. Especially twoand multi-component hydroxide systems are common in soils, but they have barely been included in desorption studies. Goethite showed the highest desorption in the range from 70.4 to 81.0\%, followed by gibbsite with values in the range from 50.7 to 42.6\%. Ferrihydrite had distinctive lower desorption in the range from 11.8 to 1.9\%. Within the group of the amorphous Fe-Al-hydroxide mixtures, P desorption was lowest at the balanced mixture ratio for 1 Fe: 1 Al, increased either with increasing Fe or Al amount. Precipitation and steric effects were concluded to be important influencing factors. More P was released by crystalline Fe-hydroxides, and Al-hydroxides of varying crystallinity, but desorption using histidine and malic acid did not substantially influence P desorption compared to inorganic constituents.}, language = {en} }