Slow release fertilizer composition
OwnerMichael A. Michaudinventor
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Abstract
A slow release fertilizer composition providing to a plant a controlled amount of plant primary nutrients and micronutrients over a prolonged period of time is described. The solubility and concentration of each of the plant nutrients is determined by the addition to the fertilizer composition of specified fertilizer constituents or components which on going into solution coact to control at an optimum concentration each of the plant nutrients. The slow release fertilizer composition comprises the plant primary nutrients nitrogen, phosphorous, calcium, sulfur, magnesium, and potassium and the plant micronutrients iron, manganese, zinc, copper and boron. A single application of the fertilizer composition of the present invention provides sufficient plant nutrients for a full growing season or one or more growing seasons.
Claims20
A slow release fertilizer composition consisting essentially of
- ______________________________________ % by Weight ______________________________________ (a) Primary Nutrients NH.sub.4 CaPO.sub.4 . 7H.sub.2 O 20-80 CaHPO.sub.4 0-60 CaCO.sub.3 . MgCO.sub.3 7-16 K.sub.2 SiO.sub.3 5-30 CaSO.sub.4 up to 25 (b) Micro-Nutrients Fe.sub.2 O.sub.3 0.02-0.5 MnO 0.006-0.2 ZnO 0.006-0.04 CuO 0.0025-0.02 BPO.sub.4 0.03-0.2 ______________________________________
A process for preparing a slow release fertilizer composition which comprises:
- (a) adding a concentrated aqueous solution of FeSO.sub.4, MnSO.sub.4, ZnSO.sub.4 and CuSO.sub.4 to a relatively large amount of CaCO.sub.3.MgCO.sub.3 and thoroughly mixing the aqueous solution with the CaCO.sub.3.MgCO.sub.3 ;
- (b) heating the mixture at a temperature of 80.degree. to 100.degree. C. for 0.5 to 3 hours to convert the FeSO.sub.4, MnSO.sub.4, ZnSO.sub.4 and CuSO.sub.4 to the corresponding FeCO.sub.3, MnCO.sub.3, ZnCO.sub.3 and CuCO.sub.3 and a small portion of the CaCO.sub.3 of the CaCO.sub.3.MgCO.sub.3 to CaSO.sub.4 and to dry the mixture;
- (c) further heating the dry mixture at a temperature of 350.degree. to 450.degree. C., for 0.5 to 3 hours to decompose the FeCO.sub.3, MnCO.sub.3, ZnCO.sub.3 and CuCO.sub.3 to the corresponding Fe.sub.2 O.sub.3, Mn.sub.2 O.sub.3, ZnO and CuO to obtain an intermediate product I;
- (d) adding concentrated aqueous solution of H.sub.3 BO.sub.3 to a relatively large amount by weight of a phosphate mixture of CaHPO.sub.4 and Ca(H.sub.2 PO.sub.4).sub.2 and heating to dryness;
- (e) further heating the dried H.sub.3 BO.sub.3 and phosphate mixture at a temperature of 350.degree. to 450.degree. C. for 1 to 4 hours to obtain BPO.sub.4 and Ca.sub.3 (PO.sub.4).sub.2 and unreacted phosphate, as intermediate product II;
- (f) the intermediate product I is mixed with intermediate product II and CaCO.sub.3.MgCO.sub.3 and potassium silicate and thoroughly mixed together to obtain mixture III;
- (g) the mixture III is then mixed with NH.sub.4 CaPO.sub.4.7H.sub.2 O;
- (h) optionally washing the mixture to remove readily soluble compounds;
- and
- (i) drying the mixture to obtain the slow release fertilizer composition.
A slow release fertilizer composition consisting essentially of:
- ______________________________________ % by Weight ______________________________________ (a) Primary Nutrients NH.sub.4 CaPO.sub.4 . 7H.sub.2 O 65-80 CaCO.sub.3 . MgCO.sub.3 12-13 K.sub.2 SiO.sub.3 7-9 CaSO.sub.4 6-8 (b) Micro-Nutrients Fe.sub.2 O.sub.3 0.02-0.5 MnO 0.006-0.2 ZnO 0.006-0.04 CuO 0.0025-0.02 BPO.sub.4 0.03-0.2 ______________________________________
A slow release fertilizer composition including K.sub.2 SiO.sub.3 and consisting essentially of the following elements:
- ______________________________________ % by Weight ______________________________________ (a) Primary Nutrients N 1-4 Ca 12-17 P 7-11 Mg 1-2 K 3-15 S 0.1-5 (b) Micro-Nutrients Fe 0.01-0.3 Mn 0.005-0.15 Zn 0.005-0.03 Cu 0.003-0.015 B 0.003-0.015 ______________________________________
An aqueous mixture containing undissolved slow release fertilizer composition, including K.sub.2 SiO.sub.3, and containing in solution the following concentrations of essential active nutrient ingredients:
- ______________________________________ PPM ______________________________________ (a) Primary Nutrients NH.sub.4 12-50 Ca 150-500 PO.sub.4 13-185 Mg 15-60 K 100-500 SO.sub.4 150-1200 (b) Micro-Nutrients Fe 0.1-5 Mn 0.2-0.7 Zn 0.02-0.2 Cu 0.02-0.08 B 0.2-3.0 (c) Other CO.sub.3 10-200 ______________________________________
Dependencies are inferred from the claim text.