AU2002214880A1

AU2002214880A1 - Fertilizer

Info

Publication number: AU2002214880A1
Application number: AU2002214880A
Authority: AU
Inventors: Kerry Green
Original assignee: Koch Agronomic Services LLC
Current assignee: Koch Agronomic Services LLC
Priority date: 2000-11-08
Filing date: 2001-11-07
Publication date: 2002-07-25
Anticipated expiration: 2021-11-07

Description

FERTILIZER

FIELD OF THE INVENTION

The present invention relates generally to the field of chemical fertilizers.

PRIOR APPLICATIONS

This application claims priority under 35 USC § 119(e) to USSN 60/246,578, filed November 8, 2000, USSN 60/268,083, filed February 13, 2001 , USSN 60/293,209, filed June 25, 2001 and USSN 60/301 ,826, filed July 2, 2001.

BACKGROUND OF THE INVENTION

Carbon, hydrogen, oxygen, nitrogen, phosphorus and sulphur are the primary elements essential to all life. Soils contain all of these elements in addition to other macro and micronutrients which are needed for plant growth. Typically, such elements are not present in the soil in sufficient quantity or in forms that can support maximum plant growth and yield. In order to overcome these deficiencies, fertilizers having specific chemical constituents in specific amounts are often added to the soil, thereby enriching the growth medium. The fertilizers may be supplemented with certain trace elements such as copper, iron, manganese, zinc, cobalt, molybdenum, and boron, as oxides or salts containing the elements in the cationic form.

Agriculturally, metal ions are essentia^ nutrients for plant growth. Soil deficiency because of the unavailability or exhaustion of metal ions is very often the cause of poor plant growth. Both soil and foliar application of metal ions are routinely used to prevent, correct or minimize soil deficiencies.

The prior art teaches two basic types of fertilizers - fast uptake fertilizers and slow uptake fertilizers. The fast uptake fertilizers are typically liquid fertilizers which are easily assimilated by plants and can be easily and evenly applied either to the soil or directly onto the plants. The slow uptake fertilizers are typically dry fertilizers which are pellets or granules. The dry fertilizers are generally applied to the ground. The dry fertilizers are often coated in either clay or other biodegradable coatings. Over time, typically up to three weeks, the coating decays due to exposure to moisture and other elements, causing the fertilizer to be released into the soil where it is taken up by the plant. Liquid or fluid fertilizers are generally preferred due to the ease of handling, versatility of application and uniform application.

The prior art teaches several examples of liquid fertilizers. For example, US Patent 4,356,021 teaches a liquid fertilizer composed of ammonium thiosulfate and zinc oxide; US Patent 5,372,626 teaches a composition comprising metal ions and citric acid which is applied to plant roots; US Patent 5,997,600 teaches fertilizer additives including chelated metal ions, specifically, metal oxides; and US Patent 4,404,146 teaches a method of making metal oxyalkylates for use in supplying said metal to plants or animals, which involves reacting the metal with carboxylic acid and hydrogen peroxide in an aqueous reaction mixture.

Similarly, the prior art also teaches several examples of slow release fertilizers or coated fertilizers. For example, US Patent 5,435,821 teaches a vegetation enhancement agent comprising a mixture of at least one macronutrient, micronutrient, slow release fertilizer or nitrogen fertilizer and a pesticide, which is then coated with a sulfonated polymer which acts as a controlled release coating; US Patent 5,725,630 teaches a method for preparing a liquid fertilizer containing alkanoic acids which is subsequently mixed with a granular carrier, producing a dry granule fertilizer; US Patent 5,748,936 teaches a process for producing granular fertilizer using a slurry of clay in water, followed by screening to remove granules of undesired size; US Patent 5,002,601 teaches a method for preparing a suspension fertilizer wherein nutrient material and at least one crystal growth inhibitor are mixed with potassium chloride and clay is subsequently added as a suspending aid; and US Patent 6,039,781 teaches a controlled release fertilizer formed from nutrient granules coated in first an organic oil and second a polymeric encapsulating coating.

However, the prior art does not teach a fertilizer or supplement that combines both quick uptake and slow uptake. Furthermore, simply combining a liquid fertilizer and a dry fertilizer as known in the art does not produce a desirable product, due to obvious difficulties with mixing and subsequent application of the product.

The prior art teaches the use of oxide forms of nutrients as slow release liquid fertilizers arranged for foliar application. Typically, the oxides are in a highly basic form. Similarly, the use of sulfate forms of nutrients for quick release fertilizers is also known. However, the sulfates are typically very acidic, meaning that simply combining the oxide fertilizer and the sulfate fertilizer leads to precipitation of nutrients and a nonfunctional product.

This is a concern, as it is often necessary or desirable to apply fertilizers and/or supplements several times over the course of a growing season. As will be appreciated by one knowledgeable in the art, with each application, there is an inherent risk that damage will occur to the plants, thereby reducing crop value. This does not include the inherent cost involved in dedicating time and resources to the task of fertilizing. Furthermore, with multiple applications, there is significant risk that the required nutrients may not be available during an important stage in the plant's development.

Clearly, a single fertilizer having both short term, quick uptake nutrients and long term, slow uptake nutrients that can be applied in a single application is needed.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a nutrient fertilizer comprising a soluble form of the nutrient and an insoluble form of the nutrient.

The insoluble form of the nutrient may be coated and suspended.

The soluble form of the nutrient may be dissolved.

The nutrient may be selected from the group consisting of zinc, copper, manganese, boron, calcium, calcium sulfate (gypsum), magnesium, molybdenum, chloride, selenium, phosphate, nitrogen, potassium, sulfur and iron.

The fertilizer may be in a dry form.

The fertilizer may include at least one other micronutrient.

According to a second aspect of the invention, there is provided a method for improving crop yield comprising: providing a nutrient fertilizer comprising a soluble form of the nutrient and an insoluble form of the nutrient; and applying the fertilizer to soil and/or leaves of growing plants, wherein growth of the plant is promoted by providing the nutrient to the plant for an extended period of time.

The extended period of time may be1-28 days.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned hereunder are incorporated herein by reference.

DEFINITIONS

As used herein, "nutrient" refers to both micronutrients and macronutrients, for example, zinc, copper, manganese, boron, calcium, iron, calcium sulfate (gypsum), magnesium, molybdenum, chloride, selenium, phosphate, nitrogen, potassium and sulfur.

As used herein, "micronutrients" refers to elements ^' required in small or trace amounts for plant growth, for example, molybdenum, nickel, copper, zinc, manganese, boron, iron and chloride.

As used herein, "macronutrients" refers to elements typically required in large amounts for plant growth, for example, sulfur, phosphorus, phosphate, magnesium, calcium, potassium, nitrogen, oxygen, carbon and hydrogen.

As discussed above, existing nutrient inputs provide either an immediate short-term boost or a long-term slow release of the nutrient to the plant. Typically, a fast uptake fertilizer supplies the plant with nutrients from the time of application until approximately 14 days after application. On the other hand, slow uptake fertilizers supply micronutrients from 10-14 days after application until approximately 28 days after application. As will be apparent to one knowledgeable in the art, application at desired times may not be possible, as a result of weather conditions and/or the stage of plant development. As a consequence, required nutrients may not be available when needed most using these traditional fertilizers. This in turn would have a significant impact on yield.

Described herein is a nutrient fertilizer which provides both fast uptake and slow uptake nutrients. Specifically, the fertilizer comprises a combination of a soluble form of at least one nutrient and an insoluble form of the nutrient. That is, the fertilizer is a true solution mixed with a suspension. The fertilizer is arranged to be applied to the leaves of the plant, as foliar application of nutrients is more efficient than soil application for delivering adequate and uniform amounts of nutrients for plant uptake. Typically, soil applied nutrients are required at concentrations three to six times higher than foliar application. This is because the soil application requires the soil chemistry to move the nutrients to the plant root system whereas with the foliar application, the nutrients are applied right on the plant. It is of note however that in other applications the fertilizer described herein may be applied to the soil. The soluble form is highly water-soluble and is immediately absorbed by the plant, typically within 48 hours, thus giving the short-term boost in nutrients needed. The insoluble form is in a suspension and is absorbed by the plant over time, up to 3-4 weeks after application.

Specifically, prior to mixing, the insoluble form of the nutrient is coated and the soluble form of the nutrient may be acidified or otherwise modified if necessary, thereby allowing the two components to be mixed together. Thus, the fertilizer comprises a mixture of soluble nutrients and insoluble nutrients. While dry nutrients may be mixed together for soil application, the fertilizer described herein is applied as a liquid to the leaves of crops. As discussed above, when mixing these materials in solution, physical compatibility is an issue. The fertilizer described herein involves a saturation of soluble nutrients and then a suspension component which provides high analysis, ready availability (through soluble saturation) and continued availability through the suspension aspect. Thus, the fertilizer described herein is a mixture of soluble and insoluble elements, whereas the prior art focuses on making insoluble products completely soluble.

A distinct advantage of this arrangement is that the fertilizer can be co- applied at the fungicide/herbicide application stage, meaning that the farmer only goes over the field once.

It is of note that, in one embodiment, the fertilizer may be arranged such that approximately 67% of the nutrient in the fertilizer is in the insoluble form while 33% is in the soluble form. As will be appreciated by one knowledgeable in the art, other ranges, for example, 50-90% insoluble and 10-50% soluble, or 60-75% insoluble and 25-40% soluble, or 65-70% insoluble and 30-35% soluble, may also be used.

The nutrient may be, for example, zinc, copper, manganese, boron, calcium, iron, calcium sulfate (gypsum), magnesium, molybdenum, chloride, selenium, phosphate, nitrogen, potassium, sulfur or combinations thereof. By way of illustrative but in no way limiting examples, copper may be copper (cupric): hydroxide, chloride, sulfate, oxide, oxysulfate, nitrate, carbonate, ammonium carbonate, cupric chloride dihydrate, proteinate, acetate, citrate, chelate, complex, or sequestered; zinc may be zinc: acetate, amoniated zinc, ammonium chloride, sulfate, oxide, oxysulfate, nitrate.chloride, citrate, chelate, or complex sequestered; manganese (manganous) may be manganese: nitrate, chloride, sulfate, oxide, oxysulfate, acetate anhydrous, carbonate, potassium mangagnese sulfate, acetate tetrahydrate, nitrate hexahydrate, citrate, chelate, or complex sequestered. Boron may be: boric acid, sodium borate, potassium tetraborate tetrhydrate, calcium borate.calcium- sodium borate, US Borax Products tradenames - solubor™ (disodium octoborate tetrahydrate), Optibor™ (orthoboric acid), granubor™, borax™, or fertibor™; Calcium may be calcium: carbonate, chloride, sulfate, gypsum, calcium borate, lime, nitrate, phosphate, citrate, chelate, or complex sequestered; and Iron may be iron: sulfate, sulfate anhydrous, chloride, tetrahydrate, hexahydrate, nitrate, nitrate nonahydrate, chloride hexahydrate, ammonium citrate, ammonium sulfate, chelate, sequestered, or complex.

As will be apparent to one knowledgeable in the art, the fertilizer may have any suitable or desirable nutrient concentration, whether a single nutrient or a combination thereof. That is, the concentration of the nutrient(s) may vary from 1-99%, depending upon intended use and application conditions. In some embodiments, the fertilizer may have a nutrient concentration of, for example: 5-45% zinc; 5-45% copper; 5-45% manganese or a mixture of 7% copper, 7% zinc and 6% magnesium. As will be apparent to one knowledgeable in the art, the concentrations of the nutrients may be varied according to customer preference, soil conditions and/or need, depending on the circumstances. Other embodiments are shown in the examples.

As discussed above, in some embodiments, the fertilizer may be applied directly to the soil rather than to the leaves of the plants.

The fertilizer may comprise soluble and insoluble forms of more than one nutrient.

The fertilizer may include thickeners and other chemicals known in the art for use with foliar fertilizers, for example, pesticides and the like.

In some embodiments, the fertilizer is converted to a dry fertilizer, for example, a dry dispersible granule, using means known in the art and as described herein in the examples. In this arrangement, the fertilizer is "dried" by removing the majority of the water, which makes the fertilizer easier to store and transport. It is of note that the dry granule is rehydrated prior to application.

In some embodiments, the fertilizer is an aqueous flowable concentrate consisting of a water soluble nutrient salt and a water insoluble nutrient salt as active ingredients. The fertilizer also includes a dispersing agent, a wetting agent, a thickening agent and water. The thickening agent may be made up of several components and may include a preservative to prevent microbial growth in the formulation.

The soluble form may be a sulfate form of the nutrient, for example, copper sulfate produced, for example, by dissolution of metallic copper in sulfuric acid, zinc sulfate produced, for example, by dissolution of metallic zinc in sulfuric acid, manganese sulfate or the like or the soluble form may be manganese chloride, potassium borate, potassium tetraborate tetrahydrate or the like. As will be appreciated by one knowledgeable in the art, other nutrients may be similarly prepared using means known in the art. The insoluble form may be an oxide form of the nutrient, for example, copper oxide, produced, for example, by pyrolysis of copper nitrate, zinc oxide, produced, for example, by pyrolysis of zinc nitrate or carbonate, manganese oxide or the like or the insoluble form may be boric acid, manganese sulfate or the like. As will be appreciated by one knowledgeable in the art, other nutrients may be similarly prepared using means known in the art.

As discussed above, the insoluble form of the nutrient is coated to allowing mixing with other components of the fertilizer such that the insoluble form of the nutrient is suspended within the fertilizer. As described below, in some embodiments, the insoluble form of the nutrient is coated with the wetting and/or dispersing agents. For example, copper oxide and zinc oxide may be coated with Morwet D425 and Aerosol OT-B or other suitable agents known in the art. Manganese oxide may, for example, be coated with Soprophor S/40-P in combination with 45% KOH or other suitable agents known in the art.

In these embodiments, the fertilizer is prepared by adding the soluble form of the nutrient prepared as described above to the water and the mixing agent. The mixture is stirred and a dispersing agent is added. The insoluble form of the nutrient is then added, along with the thickening agent.

The invention will now be illustrated by examples, which do not, however, restrict the invention in any way.

In the Examples, the wetting agent comprises Aerosol OT-B, a synthetic wetting agent of the class sodium dioctyl sulfusuccinate. As will be apparent to one knowledgeable in the art, other suitable wetting agents may also be used.

In the Examples, the dispersing agent is Morwet D425, a synthetic dispersing agent of the class sodium alkylnaphthylene sulfonate. As will be apparent to one knowledgeable in the art, other suitable dispersing agents may also be used.

In the Examples, the thickening agent comprises a mixture of propylene glycol (antifreeze), Rhodopol 23 (xanthan gum), Vangel B (thickening agent of the type magnesium aluminum silicate) and Legend MK (antimicrobial agent of class isothiazolinone). As will be apparent to one knowledgeable in the art, other suitable components may be substituted or used in the thickening agent.

In the Examples, starch is used as a component of the formulas. As will be appreciated by one knowledgeable in the art, other suitable materials, for example, clays, for example, kaolin, may be substituted. EXAMPLE I - COPPER FERTILIZER

In one embodiment, a fertilizer according to the above described invention is prepared wherein the metal is copper, having a general formula as described below:

21.33 % CuO

15.87% CuSO₄

0.10% Aerosol OT-B

1.50% Morwet D425

1.25% Propylene glycol

0.50% Rhodopol 23

1.25% Vangel B

0.375% Legend MK water q.s. to 100%

An example is herein provided wherein 10000 liters of fertilizer is prepared. As will be appreciated by one knowledgeable in the art, the order of addition of the ingredients is important in making this formulation, as is the type of mixer used, although other suitable mixers may also be used. Three mixing vessels are required to produce the product. The product is a blend of an aqueous suspension concentrate with a thickening agent made from of two components. The process involves producing two gums mixture concentrates, which are then blended into the copper fertilizer slurry to produce the finished product.

In this example, Vessel #1 is a 200-litre drum with lightning mixer clamped onto the side.

In this example, Vessel #2 is a vessel of 3,000 - 5,000 liter capacity incorporating a paddle stirrer with 2, 3-blade paddles on the shaft, one close to the bottom of the tank and the other about half way up. The tank may be baffled but should be capable of giving good, efficient mixing.

In this example, Vessel#3 is a vessel of approximately 10,000 liter capacity incorporating a paddle stirrer with 2, 3-blade paddles on the shaft, one close to the bottom of the tank and the other about half way up. Rhodopol 23 suspension

Propylene glycol 125 Kg

Rhodopol 23 50 Kg

Vangel B suspension Water 2162.5 L

Legend MK 37.5 Kg

Vangel B 125 Kg

Into mixing vessel #1 (approx. 200 liter capacity), weigh the batch quantity (125 Kg) of propylene glycol add the batch quantity (50 Kg) of Rhodopol 23 with stirring using a Lightning mixer. High-shear mixing is not required at this stage.

Into mixing vessel #2 (approx. 3,000 liter capacity), add 2162.5 L of water and 37.5 Kg of Legend MK followed by 125 Kg of Vangel B and mix for 30 minutes using a high speed paddle stirrer. If high-shear mixing is available it should be used for 15 minutes at this stage, if not, vigorous paddle stirring for 30 minutes should be adequate.

Fertilizer formulation composition for 10,000 L

Water 3,620 L

Aerosol OT-B 10 Kg

Morwet D425 150 Kg

Copper sulfate 1 ,587 Kg

Copper oxide 2, 133 Kg

Vangel B suspension from (A) above 2325 Kg

Rhodopol 23 suspension from (A) above 175 Kg

Into mixing vessel #3 (approx. 10,000 litre capacity) charge 3,620 L of water and add the batch quantity, (10 Kg) of Aerosol OT-B and stir gently with a paddle stirrer. Add the batch quantities of Morwet D425 (150 Kg), Copper sulfate (1,587 Kg) and copper oxide (2,113 Kg) in that order with constant stirring. Allow the mixture to stir for 30 minutes and then add the Vangel B solution by pumping from vessel #2. Allow the mixture to stir for 30 minutes to facilitate swelling of the gum. Add the Rhodopol 23 solution by pumping from vessel #1 , at this stage the product will thicken slightly. Continue paddle stirring for 30 minutes. Discharge and pack as required.

It is of note that the dilution of this formulation in water was found to give a good, spontaneous bloom in both hard and soft water with good after dilution suspensibility.

In another embodiment, there is provided a formula and a method for preparing 1000 I batches:

Ingredient Amount (Kg)

CuO grade 07-7750 (75% Cu) 213.3 16.0% Cu

CuSO₄.5H₂O grade 07-7300 (25.2%Cu) 158.7 4.0% Cu

Aerosol OT-B 1.0

Morwet D425 15.0

Propylene glycol 12.5

Rhodopol 23 2.5

Vangel B 12.5

Legend MK 3.75

Water 578.25

The order of addition of the ingredients is important in making this formulation, as is the type of mixer used. Two mixing vessels are required to produce the product. The product is made by blending an aqueous suspension concentrate with a thickening agent. The procedure for product preparation is outlined below.

Mixing equipment: To produce a 1 ,000 Kg batch of finished product

Vessel #1 : This vessel can be a small pail of approximately 30 litre capacity. Vessel #2: This should be a vessel of 1 ,500 - 2,000 litre capacity incorporating a paddle stirrer with 2, 3-blade paddles on the shaft, one close to the bottom of the tank and the other about half way up. The tank may be baffled but should be capable of giving good, efficient mixing.

Mixing procedure for preparation of 1 ,000 kilograms of formulation:- A) Preparation of gums solution.

Rhodopol 23 suspension Propylene glycol 12.5 Kg

Rhodopol 23 2.5 Kg

Into mixing vessel #1 (approx. 30 litre capacity), weigh the batch quantity (12.5 Kg) of propylene glycol add the batch quantity (2.5 Kg) of Rhodopol 23 and stir with a paddle stirrer. High-shear mixing is not required at this stage.

B) Preparation of 1 ,000 Kg of fertilizer suspension.

Fertilizer formulation composition for 1 ,000 Kg

Water 578.25 Kg

Vangel B 12.5 Kg Aerosol OT-B 1.0 Kg

Morwet D425 15.0 Kg

Copper sulfate 158.7 Kg

Copper oxide 213.3 Kg

Rhodopol 23 suspension from (A) above 15.0 Kg

Legend MK 3.75 Kg

Into mixing vessel #2 (approx. 1 ,500 litre capacity) charge 578.25 Kg of water and add the batch quantity, (12.5 Kg) of Vangel B and stir vigorously with a paddle stirrer for 30 minutes to facilitate swelling of the gum. Add the batch quantities of Aerosol OT-B (1.0 Kg), Morwet D425 (15.0 Kg), copper sulfate (158.7 Kg) and copper oxide (213.3 Kg) in that order with constant stirring. Allow the mixture to stir for 30 minutes and then add the Rhodopol 23 solution by pouring from vessel #1, at this stage the product will thicken slightly. Continue paddle stirring for 30 minutes. Add the batch quantity of Legend MK (3.75 Kg) and stir for another 30 minutes. Discharge and pack as required.

The desired viscosity for the finished formulation is 2,500 ± 500 cps. If the product is below this value add more Rhodopol 23 + propylene glycol solution to increase the viscosity as necessary.

The dilution of this formulation in water was found to give a good, spontaneous bloom in both hard and soft water with good after dilution suspensibility.

EXAMPLE II - ZINC FERTILIZER

In one embodiment, a fertilizer according to the above described invention is prepared wherein the metal is copper, having a general formula as described below

ZnO 27.78%

ZnSO₄.H₂O 5.63%

Aerosol OT-B 0.10% Morwet D425 1.50%

Propylene glycol 1.25%

Rhodopol 23 0.25%

Vangel B 1.25%

Legend MK 0.375%

Water 61.87%

The order of addition of the ingredients is important in making this formulation, as is the type of mixer used, although other suitable mixers may also be used. Three mixing vessels are required to produce the product. The product is a blend of an aqueous suspension concentrate with a thickening agent made from of two components. The process involves producing two gums mixture concentrates, which are then blended into the zinc fertilizer slurry to produce the finished product. The actual procedure for product preparation is outlined below. The zinc oxide can sometimes contain some larger clumps and should be sieved through 60 mesh prior to use.

In the illustrative example herein, a 10000 litre batch of fertilizer is prepared.

Vessel #1 may be a 200 litre drum with lightning mixer clamped onto the side.

Vessel#2 may be a vessel of 3,000 - 5,000 litre capacity incorporating a paddle stirrer with 2, 3-blade paddles on the shaft, one close to the bottom of the tank and the other about half way up. The tank may be baffled but should be capable of giving good, efficient mixing.

Vessel#3 may be a vessel of approximately 10,000 litre capacity incorporating a paddle stirrer with 2, 3-blade paddles on the shaft, one close to the bottom of the tank and the other about half way up.

Rhodopol 23 suspension

Propylene glycol 125 Kg

Rhodopol 23 25 Kg

Vangel B suspension

Water 2187.5 Kg

Legend MK 37.5 Kg Vangel B 125 Kg

Into mixing vessel #1 (approx. 200 litre capacity), weigh the batch quantity (125 Kg) of propylene glycol add the batch quantity (25 Kg) of Rhodopol 23 with gentle stirring using a paddle stirrer. High-shear mixing is not required at this stage. Into mixing vessel #2 (approx. 3,000 litre capacity), add 2187.5 Kg of water and 37.5 Kg of Legend MK followed by 125 Kg of Vangel B and mix for 30 minutes using a high speed paddle stirrer. If high-shear mixing is available it should be used for 15 minutes at this stage, if not, vigorous paddle stirring for 30 minutes should be adequate.

Fertilizer formulation composition for 10,000 Kg

Water 3999 Kg

Aerosol OT-B 10 Kg

Morwet D425 150 Kg

Zinc sulfate 563 Kg

Zinc Oxide 2778 Kg

Vangel B suspension from (A) above 2350 Kg

Rhodopol 23 suspension from (A) above 150 Kg

Into mixing vessel #3 (approx. 10,000 litre capacity) charge 3999 Kg of water and add the batch quantity, (10 Kg) of Aerosol OT-B and stir gently with a paddle stirrer. Add the batch quantities of Morwet D425 (150 Kg), zinc sulfate (563 Kg) and zinc oxide (2778 Kg) in that order with constant stirring. Allow the mixture to stir for 30 minutes and then add the Vangel B solution by pumping from vessel #2. Allow the mixture to stir for 30 minutes to facilitate swelling of the gum. Add the Rhodopol 23 solution by pumping from vessel #1 , at this stage the product will thicken slightly. Continue paddle stirring for 30 minutes. Discharge and pack as required.

In another embodiment, there is provided a formulation composition for 1 ,000 kilograms of formulation:

Ingredient Amount (Kg) Active level

ZnO grade 07-8000 (72% Zn) 277.8 20.0% Zn ZnSO₄.H₂O grade 07-8361 (35.5%Zn) 56.3 2.0% Zn

Aerosol OT-B 1.0

Morwet D425 15.0

Propylene glycol 12.5

Rhodopol 23 2.5

Vangel B 12.5

Legend MK 3.75

Water 618.65

The order of addition of the ingredients is important in making this formulation, as is the type of mixer used. Two mixing vessels are required to produce the product: The product is made by blending an aqueous suspension concentrate with a thickening agent. The procedure for product preparation is outlined below. The zinc oxide can sometimes contain some larger clumps and should be sieved through 60 mesh prior to use.

Mixing equipment: To produce a 1 ,000 Kg batch of finished product Vessel #1 : This vessel can be a small pail of approximately 30 litre capacity. Vessel #2: This should be a vessel of 1 ,500 - 2,000 litre capacity incorporating a paddle stirrer with 2, 3-blade paddles on the shaft, one close to the bottom of the tank and the other about half way up. The tank may be baffled but should be capable of giving good, efficient mixing.

Mixing procedure for preparation of 1 ,000 kilograms of formulation:-

A) Preparation of gums solution.

Rhodopol 23 suspension Propylene glycol 12.5 Kg

Rhodopol 23 2.5 Kg

B) Preparation of ,000 Kg of fertilizer suspension. Fertilizer formulation composition for 1 ,000 Kg

Water 618.65 Kg

Vangel B 12.5 Kg

Aerosol OT-B 1.0 Kg

Morwet D425 15.0 Kg

Zinc sulfate 56.3 Kg

Zinc Oxide 277.8 Kg

Rhodopol 23 suspension from (A) above 15.0 Kg

Legend MK 3.75 Kg

Into mixing vessel #2 (approx. 1 ,500 litre capacity) charge 618.65 Kg of water and add the batch quantity, (12.5 Kg) of Vangel B and stir vigorously with a paddle stirrer for 30 minutes to facilitate swelling of the gum. Add the batch quantities of Aerosol OT-B (1.0 Kg), Morwet D425 (15.0 Kg), zinc sulfate (56.3 Kg) and zinc oxide (277.8 Kg) in that order with constant stirring. Allow the mixture to stir for 30 minutes and then add the Rhodopol 23 solution by pouring from vessel #1 , at this stage the product will thicken slightly. Continue paddle stirring for 30 minutes. Add the batch quantity of Legend MK (3.75 Kg) and stir for another 30 minutes. Discharge and pack as required.

EXAMPLE III - MANGANESE FERTILIZER Formulation Composition for 10,000 litres of formulation:

Ingredient Amount (Kg)

MnO grade 07-6000 (60% Mn) 1875

MnSO₄ grade 07-5228 (29.5% Mn) 1271

Aerosol OT-B 10

Morwet D425 150

Propylene glycol 125

Rhodopol 23 50 Vangel B 125

Legend MK 37.5

Water (to 10,000 litres) 7619.1

The order of addition of the ingredients is important in making this formulation, as is the type of mixer used. Three mixing vessels are required to produce the product. The product is a blend of an aqueous suspension concentrate with a thickening agent made from of two components. The process involves producing two gums mixture concentrates which are then blended into the Manganese fertilizer slurry to produce the finished product. The actual procedure for product preparation is outlined below.

Mixing eguipment: To produce a 10.000 L batch of finished product

Vessel #1 : This vessel can be a 200 litre drum with lightning mixer clamped onto the side.

Vessel#2: This should be a vessel of 3,000 - 5,000 litre capacity incorporating a paddle stirrer with 2, 3-blade paddles on the shaft, one close to the bottom of the tank and the other about half way up. The tank may be baffled but should be capable of giving good, efficient mixing.

Vessel#3: This should be a vessel of approximately 10,000 litre capacity incorporating a paddle stirrer with 2, 3-blade paddles on the shaft, one close to the bottom of the tank and the other about half way up.

Mixing procedure for preparation of 10,000 litres of formulation:-

A) Preparation of gums solutions.

Rhodopol 23 suspension

Propylene glycol 125 Kg

Rhodopol 23 50 Kg

Vangel B suspension

Water 2162.5 L

Legend MK 37.5 Kg

Vangel B 125 Kg Into mixing vessel #1 (approx. 200 litre capacity), weigh the batch quantity (125 Kg) of propylene glycol add the batch quantity (50 Kg) of Rhodopol 23 with stirring using a Lightning mixer. High-shear mixing is not required at this stage. Into mixing vessel #2 (approx. 3,000 litre capacity), add 2162.5 L of water and 37.5 Kg of Legend MK followed by 125 Kg of Vangel B and mix for 30 minutes using a high speed paddle stirrer. If high-shear mixing is available it should be used for 15 minutes at this stage, if not, vigorous paddle stirring for 30 minutes should be adequate.

B) Preparation of 10,000 L of fertilizer suspension.

Fertilizer formulation composition for 10,000 L

Water 5456.6 L Aerosol OT-B 10 Kg

Morwet D425 150 Kg

Manganese sulfate 1271 Kg

Manganous oxide 1875 Kg

Vangel B suspension from (A) above 2325 Kg Rhodopol 23 suspension from (A) above 175 Kg

Into mixing vessel #3 (approx. 10,000 litre capacity) charge 5456.6 L of water and add the batch quantity, (10 Kg) of Aerosol OT-B and stir gently with a paddle stirrer. Add the batch quantities of Morwet D425 (150 Kg), Manganese sulfate (1875 Kg) and manganous oxide (1271 Kg) in that order with constant stirring. Allow the mixture to stir for 30 minutes and then add the Vangel B solution by pumping from vessel #2. Allow the mixture to stir for 30 minutes to facilitate swelling of the gum. Add the Rhodopol 23 solution by pumping from vessel #1 , at this stage the product will thicken slightly. Continue paddle stirring for 30 minutes. Discharge and pack as required.

In another embodiment, the following formula is used:

Ingredient %w/w

Manganous oxide 8.33

Manganese chloride 35.71 ' Soprophor S40-P 1.0

Natrosol 250HR 0.4

Water 54.56

In yet other embodiments, the fertilizer may be a mixture of 2% MnO and 18% MnCI₂ or a mixture of 2% MnO and 16% MnCI₂. As will be apparent to one knowledgeable in the art, other combinations are also possible, depending on consumer preference and soil conditions.

EXAMPLE IV - Production of Boron Micronutrient Fertilizer Formulation containing 20% Boron salts.

Formulation Composition for 1 ,000 kilograms of formulation:-

Ingredient Amount (Kg.

Boric acid 100.0

Potassium tetraborate tetrahydrate 100.0

Urea 20.0

Soprophor S/40-P 10.0

Propylene glycol 50.0

Rhodopol 23 2.5

Vangel B 12.5

Water to 1000.0 Kg

Final product contains 20.0% boron salts.

The order of addition of the ingredients is important in making this formulation, as is the type of mixer used. Two mixing vessels are required to produce the product. The process involves pre-dispersing the Vangel B in water followed by addition of the actives, stabilizer and wetting agent in one vessel. The antifreeze and Rhodopol 23 (thickener solution) are blended together in a separate vessel. The thickener solution is then blended into the boron fertilizer suspension to produce the finished product. The actual procedure for product preparation is outlined below. High-shear mixing is required to adequately swell the Vangel B and to help reduce the particle size of the boric acid. Mixing eguipment: To produce a 1,000 Kg batch of finished product

Vessel #1 : This vessel can be a small pail of approximately 100 litre capacity.

Vessel #2: This should be a vessel of approximately 1 ,500 litre capacity incorporating a high-shear mixer.

Mixing procedure for preparation of 1 ,000 kilograms of formulation:-

A) Preparation of gums solution.

Rhodopol 23 suspension Propylene glycol 50.0 Kg

Rhodopol 23 2.5 Kg

Into mixing vessel #1 (approx. 100 litre capacity), weigh the batch quantity (50 Kg) of propylene glycol add the batch quantity (2.5 Kg) of Rhodopol 23 and stir with a paddle stirrer. High-shear mixing is not required at this stage.

B) Preparation of 1 ,000 Kg of fertilizer suspension.

Fertilizer formulation composition for 1 ,000 Kg

Water 705.0 Kg

Vangel B 12.5 Kg

Potassium tetraborate tetrahydrate 100.0 Kg

Boric acid 100.0 Kg

Urea 20.0 Kg

Soprophor S40-P 10.0 Kg

Rhodopol 23 suspension from (A) above 52.5 Kg

Into mixing vessel #2 (approx. 1 ,500 litre capacity) charge 705Kg of water and add the batch quantity, (12.5 Kg) of Vangel B and stir vigorously with a high-shear mixer for 30 minutes to facilitate swelling of the gum. Add the batch quantity of potassium tetraborate tetrahydrate (100Kg) and agitate for 15 minutes. Add the batch quantity of boric acid (100Kg) and agitate for 15 minutes. Replace the high-shear mixer with a paddle stirrer or remove the shear head from the mixer. Add the batch quantities of urea (20Kg) and Soprophor S40-P (10Kg) with constant agitation. Allow the mixture to stir for 30 minutes and then add the Rhodopol 23 solution by pouring from vessel #1 , at this stage the product will thicken slightly. Continue paddle stirring for 30 minutes. Discharge and pack as required.

The desired viscosity for the finished formulation is 800 ± 300 cps by Brookfield spindle #2 at 30 rpm. If the product is below this value add more Rhodopol 23 + propylene glycol solution to increase the viscosity as necessary.

EXAMPLE V Production of Manganese Micronutrient Fertilizer Formulation containing 55.06%) Manganese salts (20% elemental Manganese)

Formulation Composition for 1 ,000 kilograms of formulation:-

Ingredient Amount (Kg) Active level

MnCI₂ prills (42% Mn) 238.1 10% Mn

MnSO₄ 312.5 10% Mn

Soprophor S/40-P 10.0

Urea 20.0

Rhodopol 23 2.0

Propylene glycol 50.0

Antifoam FG-10 0.5

Water to 1000.0 Kg

The order of addition of the ingredients is important in making this formulation, as is the type of mixer used. Two mixing vessels are required to produce the product but high-shear mixing is not required. Mixing vessel #1 should be approximately 100 litre capacity with a paddle stirrer capable of 100 - 300 rpm. Mixing vessel #2 should be approximately 1 ,200 litre capacity with baffled sides and a paddle stirrer capable of 60 - 100 rpm. The process involves pre-dispersing the Rhodopol 23 in the propylene glycol in one vessel whilst mixing the other components in a separate vessel. The Rhodopol thickener solution is then blended into the manganese fertilizer slurry to produce the finished product. The actual procedure for product preparation is outlined below. During dissolution of the manganese chloride the solution will become hot. Care should be take to ensure that all of the manganese chloride has dissolved before continuing with addition of other ingredients.

Mixing procedure for preparation of 1.000 kilograms of formulation:-

A) Preparation of 52 Kg of thickener solution.

Gums mixture composition for 250 Kg Rhodopol 23 2.0 Kg

Propylene glycol 50.0 Kg

Into mixing vessel #1 add 50 Kg of propylene glycol and start the agitation. With constant agitation carefully add 2 Kg of Rhodopol 23 into the vortex and continue stirring until ready to add to the main batch. The gum will not swell in the propylene glycol but will settle to the bottom when the agitation is stopped.

B) Preparation of 1 ,000 Kg of fertilizer suspension.

Fertilizer formulation composition for 1 ,000 Kg

Water 348.9 Kg

Manganese chloride 238.1 Kg

Soprophor S/40-P 10.0 Kg

Urea 20.0 Kg

Manganese sulfate 312.5 Kg

Antifoa FG-10 0.5 Kg

Gums mixture from (A) above 52.0 Kg

Into mixing vessel #2 charge 368.9 Kg of water and start the agitation. Slowly add the batch quantity, (238.1 Kg) of Manganese chloride prills with constant agitation over a period of 30 minutes to avoid causing the temperature to rise too high. Continue stirring for 30 minutes after completion of addition to allow all of the manganese chloride to dissolve prior to continuing with addition of the other ingredients. Add the batch quantity of Soprophor S/40-P (10 Kg) and stir gently for 30 minutes to allow dissolution. Add the batch quantity of urea (20 Kg) and mix for 10 minutes. Add the batch quantity of Manganese sulfate (312.5 Kg) slowly taking care to keep air entainment to a minimum and continue stirring for 30 minutes to allow complete mixing. Add the batch quantity of Antifoam FG-10 (0.5 Kg) and mix for 5 minutes to help the surface foam break. Add the whole 52 Kg of the Rhodopol thickener solution from (A) above. Continue paddle stirring for 30 minutes. Discharge and pack as required.

EXAMPLE VI - Production of Manganese Micronutrien Fertilizer Formulation containing 55.06% Manganese salts (20% elemental Manganese). Formulation Composition for 1 ,000 kilograms of formulation:-

Ingredient Amount (Kg)

MnCI₂ prills (42% Mn) 238.1 10% Mn

MnSO₄ Super Man-Gro (32% Mn) 312.5 10% Mn

Soprophor S/40-P 10.0

Urea 20.0

Rhodopol 23 3.0

Propylene glycol 50.0

Antifoam FG-10 0.5

Water to 1000.0 Kg

The order of addition of the ingredients is important in making this formulation, as is the type of mixer used. Two mixing vessels are required to produce the product but high- shear mixing is not required. Mixing vessel #1 should be approximately 100 litre capacity with a paddle stirrer capable of 100 - 300 rpm. Mixing vessel #2 should be approximately 1 ,200 litre capacity with baffled sides and a paddle stirrer capable of 60 - 100 rpm. The process involves pre-dispersing the Rhodopol 23 in the propylene glycol in one vessel whilst mixing the other components in a separate vessel. The Rhodopol thickener solution is then blended into the manganese fertilizer slurry to produce the finished product. The actual procedure for product preparation is outlined below. During dissolution of the manganese chloride the solution will become hot. Care should be take to ensure that all of the manganese chloride has dissolved before continuing with addition of other ingredients.

Mixing procedure for preparation of 1 ,000 kilograms of formulation:-

A) Preparation of 53 Kg of thickener solution.

Gums mixture composition for 250 Kg Rhodopol 23 3.0 Kg

Propylene glycol 50.0 Kg

1. Into mixing vessel #1 add 50 Kg of propylene glycol and start the agitation. With constant agitation carefully add 3 Kg of Rhodopol 23 into the vortex and continue stirring until ready to add to the main batch. The gum will not swell in the propylene glycol but will settle to the bottom when the agitation is stopped.

B) Preparation of 1 ,000 Kg of fertilizer suspension.

Fertilizer formulation composition for 1 ,000 Kg

Water 365.9 Kg

Manganese chloride 238.1 Kg

Soprophor S/40-P 10.0 Kg

Urea 20.0 Kg

Manganese sulfate 312.5 Kg

Antifoam FG-10 0.5 Kg

Gums mixture from (A) above 53.0 Kg

1. Into mixing vessel #2 charge 365.9 Kg of water and start the agitation. 2. Slowly add the batch quantity, (238.1 Kg) of Manganese chloride prills with constant agitation over a period of 30 minutes to avoid causing the temperature to rise too high. Continue stirring for 30 minutes after completion of addition to allow all of the manganese chloride to dissolve prior to continuing with addition of the other ingredients.

3. Add the batch quantity of Soprophor S/40-P (10 Kg) and stir gently for 30 minutes to allow dissolution.

4. Add the batch quantity of urea (20 Kg) and mix for 10 minutes.

5. Add the batch quantity of Manganese sulfate (312.5 Kg) slowly taking care to keep air entainment to a minimum and continue stirring for 30 minutes to allow complete mixing.

6. Add the batch quantity of Antifoam FG-10 (0.5 Kg) and mix for 5 minutes to help the surface foam break.

7. Add the whole 52 Kg of the Rhodopol thickener solution from (A) above.

8. Continue paddle stirring for 30 minutes. Discharge and pack as required.

EXAMPLE VII - DRY DISPERSIBLE GRANULE

In this embodiment, the liquid fertilizer is prepared as discussed above and is converted to a dry fertilizer, in this example example, a dry dispersible granule. In this arrangement, the fertilizer is "dried" by removing the majority of the water, which makes the fertilizer easier to store and transport. It is of note that the dry granule is rehydrated prior to application.

Nutrient : % soluble + % insoluble = Total % Active (A) Guaranteed Minimum Analysis (B)

% B\A Morwet D424 5

Morwet EFW 2

Kaolinn Clay Q5 0.1-30 Total 100%

In other embodiments, as discussed below, starch is used in place of clay. As will be appreciated by one knowledgeable in the art, other suitable compounds may also be used in place of clay or starch.

Formulation and Spray Drying of Zinc Oxide and Sulfate

Zinc Oxide Powder 49.2 kg

Zinc Sulfate Powder 10.8 kg

Morwent D425 Powder 2 kg

EFW Powder 2 kg

Anticaking agent (SiO₂) 0.80 kg

Maltodextrin 15.2 kg

240 kg of soft water is placed in a tank under agitation and the chemicals listed above are added thereto. The mixture is mixed for approximately 30 minutes, that is, until a uniform slurry is obtained. The slurry is pumped to a spray dryer, a pilot plant in-line mixer and a strainer, in order to remove large foreign particles. The spray drying is then conducted using means known in art, under an inlet temperature of approximately 185- 188°C, an outlet temperature of approximately 84-88°C and a feed temperature of 30- 60°C.

Formulation and Spray Drying of Copper Solution

Copper Oxide Powder 45 kg

Copper Sulfate Powder 15 kg

Morwent D425 Powder 2 kg

EFW Powder 2 kg

Anticaking agent (SiO₂) 0.80 kg

Maltodextrin 15.2 kg

240 kg of soft water is placed in a tank under agitation and the chemicals listed above are added thereto. The mixture is mixed for approximately 30 minutes, that is, until a uniform slurry is obtained. The slurry is pumped to a spray dryer, a pilot plant in-line mixer and a strainer, in order to remove large foreign particles. The spray drying is then conducted using means known in art, under an inlet temperature of approximately 185- 188°C, an outlet temperature of approximately 84-88°C and a feed temperature of 30- 60°C. EXAMPLE VIII Formulation and Spray Drying of Manganese

Material: 1. Formulation of Manganese Chloride and Sulfate

20 kg of Manganese chloride powder 32.43%

26.25 kg of Manganese sulfate powder 42.57%

1.54 kg of Morwet D425 powder 2.5%

1.54 of EFW powder 2.5% 1.23 kg Urea 2%

0.62 kg of anticaking agent (SiO₂) 1 %

10.48 kg of maltodextrin (star dry 5) 17% Total: 61.66 kg 100%

1. Directives

1.1 Add about 185 kg of soft water to a tank and have a good agitation.

1.2 Add the following ingredients to the tank under good agitation:

20 kg of Manganese chloride powder 32.43%

26.25 kg of Manganese sulfate powder 42.57%

1.54 kg of Morwet D425 powder 2.5%

1.54 of EFW powder 2.5%

1.23 kg Urea 2%

0.62 kg of anticaking agent (SiO₂) 1 %

10.48 kg of maltodextrin (star dry 5) 17%

Total: 61.66 kg 100%

1.3 Mix for 30 minutes until uniform slurry is obtained under good agitation.

1.4 Pump the slurry to the spray dryer (SD1) through a strainer in order to remove large foreign particles. 1.5 Conduct the spray drying under the following conditions:

Inlet Temperature: 185-188C°

Outlet Temperature: 84-88°C Feed Temperature: 25-60°C EXAMPLE IX - Formulation of Boron

1. Control Formulation #1

Potassium Tetraborate, Disodium Octoborate Tetrahydrate, and Boric Acid: 85 %

42.42% potassium tetraborate (K₂B₄0₇.4H₂0) 28.64% disodium octaborate tetrahydrate (Na₂B₈0₁₃.4H₂θ) 28.94% boric acid (H₃B0₃)

Dispersing Agent 5 %

50% Morwet D425 and 50% EFW

Kaolin Clay: 10 %

Total: 100% (w/w)

2. Test Formulation #1

Potassium Tetraborate, Disodium Octoborate

Tetrahydrate, and Boric Acid: 85 %

42.42% potassium tetraborate (K₂B₄0₇.4H₂0)

28.64% disodium octaborate tetrahydrate (Na₂B₈0₁₃.4H₂0)

28.94% boric acid (H₃B0₃)

Dispersing Agent 5% 50% Morwet D424 and 50% EFW

Modified Starch: 9%

Anti-caking Agent (SiO₂): 1 %

Total: 100% (w/w)

Note:

The targeted moisture level is in the range of 2-4% for the control and test formulations. In the above formulation, approximately 35.18% actual boron from potassium tetraborate, 35.17% actual boron from disodium octaborate tetrahydrate, and 29.64% actual boron from boric acid.

EXAMPLE X - Formulation of Boron

3. Control Formulation #1

Potassium Tetraborate, Disodium Octoborate

Tetrahydrate, and Boric Acid: 75 %

48.08% potassium tetraborate (K₂B₄0₇.4H₂0)

32.46% disodium octaborate tetrahydrate (Na₂B₈0₁₃.4H₂0)

19.46% boric acid (H₃B0₃)

Dispersing Agent 5 %

50% Morwet D425 and 50% EFW

Kaolin Clay: 20 %

Total: 100% (w/w)

4. Test Formulation #1 Potassium Tetraborate, Disodium Octoborate

Tetrahydrate, and Boric Acid: 75 %

48.08% potassium tetraborate (K₂B₄0₇.4H₂0)

32.46% disodium octaborate tetrahydrate (Na₂B₈0₁₃.4H₂0)

19.46% boric acid (H3BO3)

Dispersing Agent 5%

50% Morwet D424 and 50% EFW

Modified Starch: 19%

Anti-caking Agent (SiO₂): 1%

Total: 100% (w/w)

Note:

The targeted moisture level is in the range of 2-4% for the control and test formulations. In the above formulation, approximately 40% actual boron from potassium tetraborate, 40% actual boron from disodium octaborate tetrahydrate, and 20% actual boron from boric acid.

EXAMPLE XI - Calcium Formula

Calcium Nitrate 7.5%

Calcium Chloride 7.5%

Calcium Carbonate 60%

Soprophor S/40-P 3%

Water 22%

Prepared as described above in the other examples.

While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made therein, and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.

Claims

1. A nutrient fertilizer comprising a soluble form of a nutrient and an insoluble form of the nutrient.

2. The fertilizer according to claim 1 wherein the insoluble form of the nutrient is coated and suspended.

3. The fertilizer according to claim 1 wherein the soluble form of the nutrient is dissolved.

4. The fertilizer according to claim 1 wherein the nutrient is selected from the group consisting of zinc, copper, manganese, boron, calcium, iron, calcium sulfate (gypsum), magnesium, molybdenum, chloride, selenium, phosphate, nitrogen, potassium and sulfur.

5. The fertilizer according to claim 1 in a dry form.

6. The fertilizer according to claim 1 wherein the nutrient comprises 50-90% insoluble form and 10-50% soluble form.

7. The fertilizer according to claim 1 wherein the nutrient comprises 60-80% insoluble form and 20-40% soluble form.

8. The fertilizer according to claim 1 wherein the nutrient comprises

65-70% insoluble form and 30-35% soluble form.

9. The fertilizer according to claim 1 wherein the nutrient is a mixture of two or more of the following: zinc, copper, manganese, boron, calcium, iron, calcium sulfate (gypsum), magnesium, molybdenum, chloride, selenium, phosphate, nitrogen, potassium, sulfur.

10. A method for improving crop yield comprising: providing a nutrient fertilizer comprising a soluble form of the nutrient and an insoluble form of the nutrient; and applying the fertilizer to soil and/or leaves of growing plants, wherein growth of the plant is promoted by providing the nutrient to the plant for an extended period of time.

11. The method according to claim 10 wherein the extended period of time is 1-28 days.

12. The method according to claim 10 wherein the insoluble form of the nutrient is dissolved, formulated and coated.

13. The method according to claim 10 wherein the soluble form of the nutrient is acidified.

14. The method according to claim 10 wherein the nutrient is selected from the group consisting of zinc, copper, manganese, boron, calcium, iron, calcium sulfate (gypsum), magnesium, molybdenum, chloride, selenium, phosphate, nitrogen, potassium, sulfur.

15. A method of preparing a dry dispersible granule fertilizer comprising: providing a nutrient fertilizer comprising a soluble form of a nutrient and an insoluble form of the nutrient; and removing water from the fertilizer.

16. The method according to claim 15 wherein the insoluble form of the nutrient is coated and suspended.

17. The method according to claim 15 wherein the soluble form of the nutrient is dissolved.

18. The method according to claim 15 wherein the nutrient is selected from the group consisting of zinc, copper, manganese, boron, calcium, iron, calcium sulfate (gypsum), magnesium, molybdenum, chloride, selenium, phosphate, nitrogen, potassium and sulfur.

19. The method according to claim 15 wherein the water is removed by mixing the fertilizer with starch.

20. The method according to claim 15 wherein the water is removed by mixing the fertilizer with clay.

21. The method according to claim 15 wherein the nutrient comprises 50-90% insoluble form and 10-50% soluble form.

22. The method according to claim 15 wherein the nutrient comprises 60-80% insoluble form and 20-40% soluble form.

23. The method according to claim 15 wherein the nutrient comprises 65-70% insoluble form and 30-35% soluble form.

24. The method according to claim 15 wherein the nutrient is a mixture of two or more of the following: zinc, copper, manganese, boron, calcium, iron, calcium sulfate (gypsum), magnesium, molybdenum, chloride, selenium, phosphate, nitrogen, potassium, sulfur.