Fertiliser containing potassium magnesium - and nitrogen

摘要

K-Mg-N fertiliser composition, particularly suitable for acid solis, and capable of gradually and continuously releasing Mg, is available as granules of KNO3 containing 1-25 wt.% of finely dispersed MgO (or Mg(OH)2). Pref. fertiliser contains additional trace elements and N2-sources with higher N-content than KNO3, such as urea, and is prepared by (1) preparing dry mixture of KNO3 and MgO and optional additives, heating to fuse KNO3, where mixture is sufficiently fluid at 350-400 degrees C to be worked into granules; or (2) by first preparing melt of KNO3 and additives which fuse at KNO3 melting temp., adding MgO and other infusible additives and working into granules.