Calcite　is　a　promising　material　choice　for　adsorbing　phosphates　because　of　its　abundance　and　environmentally　benign　nature.　However,　the　slow　adsorption　kinetics　and　hence　low　adsorption　capacity　within　a　short　time　frame　hinders　its　practical　application.　In　this　work,　we　solve　these　problems　by　presenting　a　low　Mg2+-doped　calcite　adsorbent,　Mg-10.　With　a　3.75　wt%　of　Mg2+　doping,　Mg-10　exhibits　a　remarkable　adsorption　capacity　of　157.7　mg　P/g.　It　also　demonstrates　a　substantial　boost　in　the　adsorption　kinetics,　achieving　a　sixfold　increase　in　adsorption　capacity　within　24　h　compared　to　the　undoped　calcite.　Meanwhile,　Mg-10　not　only　offers　improved　adsorption　selectivity　but　also　maintains　a　stable　effluent　pH,　underscoring　its　environmental　compatibility.　By　conducting　soil　column　experiments,　we　find　that　Mg-10　quickly　captures　the　excess　phosphates　during　the　mimicking　fertilization　process,　and　slowly　releases　the　nutrient　afterwards,　which　can　increase　the　feralization　efficiency.　These　results　provide　alternative　strategies　for　managing　phosphate　pollution　originated　from　fertilization,　and　underscores　the　potential　of　Mg-10　in　sustainable　agriculture　and　environmental　remediation.