Abstract: Improved release profiles which can, for the first time, be customized to match requirements of systems including crop nutrient uptake are realized by providing a plurality of heterogeneous particles comprised of water-soluble constituents set in a matrix of water-insoluble materials, and further providing a continuous homogeneous barrier of same, or a different water-insoluble material, juxtaposed the peripheral surface of each such heterogeneous particle. A first alternate embodiment includes forming in situ reaction products to reduce the specific gravity of such heterogeneous particles. In a second alternate embodiment, there is substituted for all, or a portion of such water-soluble material, organic media comprised primarily of composted poultry litter wherein soluble iron values remain available for substantial periods of time without incorporating or utilizing expensive conventional synthetic chelating agents.

Abstract: An improved batch process for the production, in equipment readily available at the fertilizer dealer level, of high-analysis stable ammonium orthophosphate suspension fertilizers effected by the ammoniation of solid intermediates derived from wet-process orthophosphoric acids or combinations of the solid intermediates with such wet-process type acid or other impure phosphoric acids. Fluorosilicic acid, a by-product of the phosphate industry which is readily available and relatively inexpensive, is utilized as a source of fluoride. The fluorosilicic acid is added to the batch formulation prior to the ammoniation step thereby allowing the fluorosilicic acid to be converted to ammonium fluoride. Subsequently, the metallic impurities are allowed to precipitate as fluoride compounds instead of the usual troublesome impurity-phosphate-water gels which have been identified as causing complete destruction of suspension fluidity during storage.

Abstract: In the production of suspension fertilizers the addition of an additive comprising lignosulfonate to the wet-process acid prior to the ammoniation step prevents severe thickening of the suspension during its formation, which severe thickening is normally associated with in situ mass crystallization of monoammonium phosphate and which mass crystallization results in (1) the total prevention of further ammoniation of said acid or, at the very least, extremely slow further ammoniation thereof, and/or (2) excessive ammonia losses. Also, addition of said lignosulfonate to the acid prevents the formation of metallic impurity gel-like compounds which cause extremely high viscosities, nonpourability, and complete destruction of fluidity.

Abstract: Crystalline urea phosphate mixed with sufficient quantities of previously produced urea-ammonium polyphosphate liquid to provide fluidity is pyrolyzed batchwise in one stage to give molten urea ammonium polyphosphate containing up to 50 percent of the phosphate as polyphosphate. Water or aqua ammonia can be substituted for the polyphosphate liquid if certain prescribed steps in proper sequence are followed. Heat from ammoniation of the urea phosphate provides all of the heat for pyroloysis. The molten urea-ammonium polyphosphate is then processed into high-analysis liquid fertilizer.

Abstract: A batch process is disclosed for the production of relatively pure urea ammonium polyphosphate liquid fertilizers from crystalline urea phosphate made from wet-process acid and urea. Initially, crystalline urea phosphate is fed to a tank where it is combined with previously produced liquid product; the latter is added to provide fluidity for agitation. The mixture is then ammoniated batchwise in one stage to pyrolyze the urea phosphate to condense orthophosphate to polyphosphate and form molten urea-ammonium polyphosphates. Pyrolysis takes place at relatively low temperatures of 220.degree. F. to 300.degree. F. and heat from ammoniation of the urea phosphate crystals provides all the heat to effect the condensation. The molten pyrolyzate which contains mixtures of urea, ammonium orthophosphate, and ammonium polyphosphate is dissolved in an ammonia-water mixture to yield high-analysis liquid fertilizer that contains 10 to 15 percent nitrogen and 16 to 30 percent P.sub.2 O.sub.