Abstract: A process for making controlled release fertilizer product containing an increased amount of sustained-release nitrogen includes the step of mixing a partly water soluble thermoplastic binder, and urea-formaldehyde condensate and a pH modifier. The amount of pH modifier should be sufficient to bring the pH of the shaped fertilizer product to the range from about 6 to about 12. The mixture is subjected to such conditions including temperature and pressure so as to produce a shaped fertilizer product. The resulting shaped fertilizer product includes approximately the same amount of sustained-release nitrogen as the urea-formaldehyde condensate in the mixture.

Abstract: A composite granular mixture of source materials, providing an NPK Fertilizer content of desired value, say 16-8-8, and a plastic binder composed of granular uncured urea-formaldehyde resin are compressed into a briquette of good "green strength" and then resinously bonded into a drivable spike by curing the resin either at room temperature or at a suitably elevated temperature. The resulting plant food spike, when driven into the ground, functions to fertilize the immediately surrounding area at a slow even rate.

Abstract: Extrusion apparatus for extruding pliable materials wherein the material is introduced into an extrusion chamber and through a plurality of extrusion orifices located in an extrusion plate closing off one end of the extrusion chamber. The extrusion orifices are circumferentially spaced about the center of the die plate. Air injection means are provided for injecting air radially outwardly from the center of the die toward the ribbons of material being extruded, and also separate air streams are directed radially inwardly at the material as it is being extruded through the orifices.

Abstract: A substantially dry fertilizer tablet which is adapted to absorb water and disintegrate comprises particles of fertilizer source materials and particles of a water insoluble, water swellable, hydrophilic polymeric gel pressed together into a dense tablet bonded together by a cured water insoluble thermoset resinous binder such as urea formaldehyde.