SLOW AND FAST RELEASE FERTILIZER COMPOSITION AND METHODS FOR MAKING SAME

摘要

A homogeneous fertilizer granule comprises slow-release (e.g. struvite) and fast release sources of phosphorus (P). The homogeneous fertilizer granule may further contain other essential nutrients and micronutrients required by plants. A number of methods may be used to make such granules. One method includes introducing a struvite slurry or fines and a liquid supply of water soluble P into a granulator. Alternatively, dry raw materials can be mixed with water/steam and/or another binder prior to being fed into a granulator. In another embodiment, pre-mixed dry raw materials are mechanically compacted and crushed to yield homogeneous fertilizer particles.

主权项

1. A granular fertilizer comprising:
granules having a size of at least SGN 100, the granules comprising particles of struvite having sizes of about SGN 10 or less and particles of a water-soluble phosphorus-containing material having sizes of about SGN 10 or less; wherein the struvite particles contain in the range of 6% to 18% of total phosphate in the granules; and the particles of struvite are uniformly distributed in the granules; and the granules consist essentially of struvite and monoammonium phosphate.