Coatings and compositions for delivery of phosphorous and nitrogen to plants and methods of preparing same

Abstract

The present disclosure provides compositions including a fertilizer and a carrier. The fertilizer includes phosphorus or nitrogen. The carrier includes starch and an element, or includes starch, an element, phosphorus and ammonium or potassium. The element is magnesium, iron, zinc, manganese, calcium or copper. The carrier is a coating over particles of the fertilizer, or the fertilizer and the carrier are granulated together to form particles. The compositions are added to soil for delivery of phosphorus or nitrogen to plants. Also provided are methods of preparing such compositions.

Description

COATINGS AND COMPOSITIONS FOR DELIVERY OF PHOSPHOROUS AND NITROGEN TO PLANTS AND METHODS OF PREPARING SAMEFIELD

[0001] This invention relates to coatings and compositions and methods for delivery of phosphorous and nitrogen to plants, and methods for preparing such coatings and compositions. In particular, the invention relates to compositions including a fertilizer comprising phosphorus or nitrogen and a carrier comprising starch and an element, wherein the element is covalently bonded to the starch.BACKGROUND

[0002] Many of the most highly used fertilizers in the agricultural industry are water soluble fertilizers which quickly release nutrients to plants when placed into soils. These fertilizers release all of their nutrients in a short period of time, mainly through dissolution of the fertilizers in water. The rate of release is partly modulated by vertical movement of water in the soil column. For example, if a high precipitation event or an intensive irrigation event follows application of these quick-release fertilizers, a significant amount of the fertilizer will become solubilized in water, and may move away from the roots of the crops, making them unavailable to the target plants.

[0003] Another problem with quick-release fertilizers is they are not available to plants at a variable rate. They release all nutrients in a short amount of time, which does not match the nutrient demands of plants which change during the stages of the plant growth cycle. For example, most plants have a smaller nutrient requirement in the early stages of growth, followed by a higher nutrient requirement in the middle stages of growth, and followed by a smaller nutrient requirement in the late stages of growth.

[0004] Phosphorus “tie up” is another problem exhibited by conventional fertilizers. Phosphorus can bond with other soil cations such as aluminum and / or iron ions before it is consumed by plants. If this happens, the fertilizer will not be available to plants, and will not contribute to plant growth.

[0005] Many growers will apply multiple fertilizer applications to accommodate plant nutrient demands throughout the growing season, however, over-application of fertilizer can expose plants to “burning” and nutrient loss through leaching or run-off which is a major source of agricultural pollution.

[0006] For example, nutrient pollution from fertilizers, mainly from nitrogen and phosphorus from agricultural run-off, may cause excessive growth of algae in bodies of water. This processis known as eutrophication and can lead to serious environmental issues such as low levels of oxygen dissolved in bodies of water. Severe algal growth blocks light that is needed for water borne plants such as seagrass, and mortality of seagrass consumes oxygen which in turn can increase mortality of aquatic animals.

[0007] A slow release fertilizer or a controlled release fertilizer can provide nutrients to plants over an extended period of time compared to conventional fertilizers, and reduces or inhibits leaching and / or run-off from fertilizers, however, some widely used controlled release fertilizers also cause other environmental problems.

[0008] Urea is intensively used in agriculture as a nitrogen fertilizer. When applied to soils, the high solubility of urea causes a large proportion of it to wash out of soils instead of being available to plant roots. In response, many suppliers have coated urea granules with polymers to slow the release rate of urea.

[0009] For example, a widely used class of controlled release fertilizers, known as polymer- coated fertilizers (PCFs), are composed of a soluble nutrient core surrounded by a thermoset polymer coating which is designed to release nutrients at a slower rate than convention fertilizers. Although PCFs reduce nutrient leaching and run-off loss, they contain persistent non- biodegradable polymers such as polyethylene and polyurethane which accumulate in soils and contribute to micro-plastic pollution. These micro-plastics may result in undesirable physiological and biochemical responses of plants. For example, micro-plastics in seed coatings can reduce seed germination viability, inhibit plant growth and impair food quality. The soil microbiome cannot degrade micro-plastics, but can only break them down into smaller sizes such as nanoplastics. These nano- and micro-plastics may contaminate soil, ground water sources, aquatic environments and food, leading to potential health and environmental disruptions.

[0010] Phthalic acid esters (PAEs) have been applied in polymers for controlled release fertilizers to make them more flexible, adhesive and soluble, however, PAEs can be released continuously and cause adverse effects on soil organisms.

[0011] Thus, there remains a need for compositions that control the release rate of fertilizers, yet do not include environmentally persistent polymers.SUMMARY

[0012] In one aspect, the present disclosure provides compositions for use in delivering a fertilizer comprising phosphorus or nitrogen to a plant, the compositions comprising a fertilizer comprising phosphorus or nitrogen, and a carrier comprising at least starch and an element, wherein the element is covalently bonded to the starch, and is magnesium, zinc, iron, manganese,calcium or copper. The fertilizer in the compositions as described herein have reduced solubility in water compared to other phosphorus- and nitrogen-containing compounds and compositions, while still providing the phosphorus or nitrogen to plants. Also provided are methods of making such compositions. Thus, the compositions as described herein are effective for controlling the release rate of phosphorous and nitrogen fertilizers, and are made primarily of plant-derived starch, which is a biodegradable and non-toxic material, and an element salt, such as magnesium sulfate, which is also a plant micronutrient that is used to correct element deficiency, such as magnesium deficiency, in soils and also improves nitrogen and phosphorus uptake by crops. The compositions as described herein may control leaching and run-off from fertilizers, thereby providing fertilizers with greater availability to plants, without leaving microplastics or synthetic compounds in soils.

[0013] Various aspects of the present disclosure provide a composition comprising: a fertilizer comprising phosphorus or nitrogen, and a carrier comprising: (a) starch and an element, wherein the element is covalently bonded to the starch, or (b) (i) starch, (ii) an element, (iii) phosphorus and (iv) ammonium or potassium, wherein the element is covalently bonded to the starch and forms an ammonium-element-phosphate complex and / or a potassium-element-phosphate complex, wherein the element is magnesium, iron, zinc, manganese, calcium or copper.

[0014] In various embodiments, the element is magnesium.

[0015] In various embodiments, the element is iron.

[0016] In various embodiments, the magnesium is covalently bonded to the hydroxyl groups of the starch.

[0017] In various embodiments, the composition comprises granules.

[0018] In various embodiments, the fertilizer and the carrier are granulated together. In such embodiments, the carrier may comprise (a) starch and the element. For example, the fertilizer may be triple super phosphate (TSP), diammonium phosphate (DAP) or monoammonium phosphate (MAP). For example, the element may be magnesium.

[0019] In various embodiments, the carrier is a coating over the fertilizer. In such embodiments, the carrier may comprise (a) starch and the element. For example, the element may be magnesium. The magnesium may form a potassium-magnesium-phosphate complex with the phosphorus of the fertilizer. For example, the fertilizer may be triple super phosphate (TSP) and the magnesium of the carrier forms a potassium-magnesium-phosphate complex with the phosphorus of the fertilizer. The magnesium of the carrier may form a potassium-magnesium- phosphate complex with the phosphorus of the fertilizer or an ammonium-magnesium-phosphate complex with the nitrogen of the fertilizer. In other embodiments, the carrier may comprise (b) (i)starch, (ii) the element, (iii) phosphorus and (iv) ammonium or potassium. For example, the carrier may comprise starch, magnesium, phosphorus and diammonium phosphate (DAP). The magnesium may be covalently bonded to the starch and forms an ammonium-magnesium- phosphate complex and / or a potassium-magnesium-phosphate complex. The fertilizer may comprise triple super phosphate (TSP) or monoammonium phosphate (MAP). The fertilizer may be urea and the element is iron. The fertilizer may also be triple super phosphate (TSP), monoammonium phosphate (MAP), or diammonium phosphate (DAP). In additional embodiments, the fertilizer is urea and the element is magnesium. In various embodiments, the fertilizer is urea.

[0020] In various embodiments, the composition further comprises potassium ions.

[0021] In various embodiments, a solubility of the fertilizer in the composition in water over 7 days is less than a solubility of the fertilizer in water over 7 days.

[0022] In various embodiments, a solubility of the fertilizer in the composition in water over 7 days is at least 10% less than a solubility of the fertilizer in water over 7 days.

[0023] In various embodiments, a solubility of the fertilizer in the composition in water over 7 days is at least 20% less than a solubility of the fertilizer in water over 7 days.

[0024] In various embodiments, a solubility of the fertilizer in the composition in water over 5 days is at least 40% less than a solubility of the fertilizer in water over 5 days.

[0025] In various embodiments, a solubility of the fertilizer in the composition in a soil column over 45 days is less than a solubility of the fertilizer in the soil column over 45 days.

[0026] In various embodiments, a solubility of the fertilizer in the composition in a soil column over 10 days is at least 20% less than a solubility of the fertilizer in the soil column over 10 days.

[0027] In various embodiments, a solubility of the fertilizer in the composition in a soil column over 20 days is at least 14% less than a solubility of the fertilizer in the soil column over 20 days.

[0028] In various embodiments, a solubility of the fertilizer in the composition in a soil column over 30 days is at least 8% less than a solubility of the fertilizer in the soil column over 30 days.

[0029] In various embodiments, the carrier further comprises cellulose.

[0030] In various embodiments, the carrier may comprise between about 1% and about 6% (wt / wt) potassium, based on the total weight of the carrier.

[0031] In various embodiments, the carrier comprises at least about 4% (wt / wt) element, based on the total weight of the carrier.

[0032] In various embodiments, the carrier comprises between about 1 % and about 5% (wt / wt) element, based on the total weight of the carrier.

[0033] In various embodiments, the carrier comprises between about 1 % and about 5% (wt / wt) element, phosphorus and potassium, based on the total weight of the carrier.

[0034] In various embodiments, the carrier comprises between about 1 % and about 5% (wt / wt) element, phosphorus and nitrogen, based on the total weight of the carrier.

[0035] In various embodiment, the carrier comprises pea starch, lentil starch, oat starch, potato starch, sweet potato starch, corn starch, bean starch, cassava starch, wheat starch, rice starch, sorghum starch, millet starch, taro starch, yam starch, arrow root starch, sago palm starch, plantains starch, banana starch, squash starch or a combination thereof.

[0036] In various embodiments, the composition is for delivery of the phosphorus or nitrogen to plants.

[0037] In various embodiments, the composition is for addition to soil.

[0038] Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In drawings which illustrate embodiments of the disclosure,

[0040] Figure 1 shows average phosphorus release of untreated TSP (“TSP”) compared to three different embodiments of the disclosure comprising TSP coated with a carrier after 24 hours in water (referred to as “E199”, “E208” and “E209” as described in Table 2).

[0041] Figure 2 shows average phosphorus release of untreated MAP (“MAP”) compared to three different embodiments of the disclosure comprising MAP coated with a carrier after 24 hours in water (referred to as “E125”, “E205” and “E206” as described in Table 2).

[0042] Figure 3 shows percent phosphorus leaching (or % phosphorus release) into water as a function of time for TSP particles or granules compared to an embodiment of TSP particles coated with a carrier as disclosed herein (referred to as “E208”).

[0043] Figure 4 shows a photograph of dry granules of TSP.

[0044] Figure 5 shows a photograph of untreated granules of TSP after 24 hours in water.

[0045] Figure 6 shows a photograph of a composition according to an embodiment of the disclosure comprising TSP coated with a carrier after 24 hours in water.

[0046] Figure 7 shows a photograph of dry granules of MAP.

[0047] Figure 8 shows a photograph of a composition according to an embodiment of the disclosure comprising MAP coated with a carrier after 24 hours in water.

[0048] Figure 9 shows a comparison of phosphorus release between untreated MAP fertilizer particles (“MAP”) and a composition according to an embodiment of the disclosure comprising MAP granulated with a carrier (“Agreos+MAP”).

[0049] Figure 10 shows a comparison of phosphorus release between untreated DAP fertilizer particles (“DAP”) and a composition according to an embodiment of the disclosure comprising DAP granulated with a carrier (“Agreos+DAP”).

[0050] Figure 11 shows a comparison of phosphorus release between untreated TSP fertilizer particles (“TSP”) and a composition according to an embodiment of the disclosure comprising TSP granulated with a carrier (“Agreos+TSP”).

[0051] Figure 12 show examples of compositions according to embodiments of the disclosure comprising TSP granulated with the carrier (left) and DAP granulated with the carrier (right).

[0052] Figure 13 shows a SEM image of a carrier prepared according to Example 1 and comprising starch and magnesium.

[0053] Figure 14 shows a SEM image of a carrier prepared according to Example 2 and comprising starch, magnesium, phosphorus and potassium.

[0054] Figure 15 shows the percent nitrogen in water after placement of compositions comprising various carriers coated over urea pellets according to embodiments as disclosed herein, as a function of time.

[0055] Figure 16 shows two photographs of soil columns following addition of urea (right-hand picture) and addition of urea coated with a carrier as disclosed herein (left-hand picture), and after rinsing of the column with 500 mL of water.

[0056] Figure 17 shows a scanning electron microscope (SEM) image of a carrier prepared according to Example 8 (AgreosVI).

[0057] Figure 18 shows a comparison of phosphorus leaching between untreated TSP and a composition according to an embodiment of the disclosure comprising TSP coated with a carrier according to Example 9 (AgreosP) after 24 hours in water.

[0058] Figure 19 shows a comparison of phosphorus leaching between untreated MAP and a composition according to an embodiment of the disclosure comprising MAP coated with a carrier according to Example 9 (AgreosP) after 24 hours in water.

[0059] Figure 20 shows cumulative percent-P leached over time (16 days) in sand columns for uncoated TSP and a composition according to an embodiment of the disclosure comprising TSP coated with a carrier according to Example 9 (AgreosP).

[0060] Figure 21 shows cumulative percent-P leached over time (16 days) in sand columns for uncoated MAP and a composition according to an embodiment of the disclosure comprising MAP coated with a carrier according to Example 9 (AgreosP).

[0061] Figure 22 shows a scanning electron microscope (SEM) image of a carrier prepared according to Example 10 (AgreosV2.1).

[0062] Figure 23 shows a scanning electron microscope (SEM) image of a carrier prepared according to Example 11 (AgreosV2.2).

[0063] Figure 24 shows nitrogen leaching dynamics of urea coated as AgreosNI (Example 13), AgreosN2.1 (Example 14), AgreosN2.2 (Example 15) and AgreosN3 (Example 16) compared to untreated urea in a 24 hour sand column study.

[0064] Figure 25 shows cumulative 24 hour nitrogen leaching of urea coated as AgreosNI (Example 13), AgreosN2.1 (Example 14), AgreosN2.2 (Example 15) and AgreosN3 (Example 16) compared to untreated urea in a 24 hour sand column study.

[0065] Figure 26 shows leaching of nitrogen from urea coated as AgreosN2.1 (Example 14) compared to untreated urea in a 45 day sand column study.

[0066] Figure 27 shows cumulative leaching of nitrate-nitrogen from urea coated as AgreosN2.1 (Example 14) compared to untreated urea in a 45 day sand column study.

[0067] Figure 28 shows a scanning electron microscope (SEM) image of urea granules coated with a carrier according to Example 15 (AgreosN2.2).

[0068] Figure 29 shows a scanning electron microscope (SEM) image of urea granules coated with a carrier according to Example 16 (AgreosN3).DETAILED DESCRIPTION

[0069] In the context of the present disclosure, various terms are used in accordance with what is understood to be the ordinary meaning of those terms.

[0070] In various embodiments, the disclosure provides compositions that include a biodegradable fertilizer coating or additive that degrades completely in soils without leaving undesirable residuals, yet also controls the solubility and hence the release rate of the fertilizer.

[0071] In various embodiments, the disclosure provides compositions for providing phosphorus and / or nitrogen to plants and / or which control the release rate of phosphorus- and nitrogen-containing fertilizers into soils. Phosphorus and nitrogen are important nutrients for plant growth, however, many phosphorus- and nitrogen-containing fertilizers are highly soluble in water. For example, urea is a nitrogen-containing fertilizer which is highly soluble in water. The fertilizers in the compositions as described herein have reduced solubility in water compared to otherphosphorus- and nitrogen-containing fertilizers, compounds and compositions. By having reduced solubility in water compared to other phosphorus- and nitrogen-containing compounds and compositions, less phosphorus and / or nitrogen leaches into the soil, thereby providing phosphorus, nitrogen and / or the phosphorus- or nitrogen-containing fertilizer to plants to improve crop growth without the negative effects associated with phosphorus and nitrogen leaching. Furthermore, the compositions as disclosed herein are easy to apply to soils due to this reduced solubility. For example, there may be less leaching of phosphorus and / or nitrogen into soils due to this reduced solubility.

[0072] The compositions disclosed herein comprise a fertilizer and a carrier. The fertilizer comprises phosphorus or nitrogen. The carrier comprises either: (a) starch and an element, wherein the element is covalently bonded to the starch, or (b) (i) starch, (ii) an element, (iii) phosphorus and (iv) ammonium or potassium, wherein the element is covalently bonded to the starch and forms an ammonium-element-phosphate complex and / or a potassium-element- phosphate complex, wherein the element is magnesium, iron, zinc, manganese, calcium or copper. In various embodiments, the element is covalently bonded to the hydroxyl groups of the starch. The compositions allow for the controlled release of phosphorus or nitrogen from the composition.

[0073] In various embodiments, the carrier is a coating over the fertilizer. For example, the carrier is a coating over a particle or granule of the fertilizer. A granule is a small compact particle of a particular substance. Such embodiments achieve a slower rate of dissolution of the fertilizer granule or particle in water and soil compared to the dissolution of particles of uncoated fertilizer in water. The coated particles may be prepared using a fluidized bed system or rotary drum. For example, a slurry of the carrier may be prepared by mixing the carrier with water, and with one or more of xanthan gum, glycerol and citric acid. Particles or granules of the fertilizer are then coated using a fluidized bed machine or rotary drum. In various embodiments, the coated particles may comprise an oil (such as, for example, canola oil or linseed oil), and / or a wax (such as, for example, carnuba wax).

[0074] In various embodiments, the fertilizer and the carrier are granulated together. Such embodiments also achieve a slower rate of dissolution of the fertilizer in water than the fertilizer particles or granules in the absence of the carrier. The granules may be prepared by mixing a powder of the fertilizer with the carrier. The resulting mixture may be granulated with the use of water as a binding agent and a mixer as a granulator. Following granulation, the mixture is dried.

[0075] The fertilizer includes any composition, compound or formulation comprising phosphorus and / or nitrogen and which may be used to promote plant growth and / or plant health.Examples of fertilizers comprising phosphorus are triple super phosphate (TSP), diammonium phosphate (DAP) and monoammonium phosphate (MAP). An example of a fertilizer comprising nitrogen is urea.

[0076] Starch is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. It consists of two types of molecules, the linear and helical amylose, and the branched amylopectin. Starch also comprises aliphatic hydroxyl groups and phenolic hydroxyl groups.

[0077] In various embodiments, the carrier comprises pea starch, lentil starch, oat starch, potato starch, sweet potato starch, corn starch, bean starch, cassava starch, wheat starch, rice starch, sorghum starch, millet starch, taro starch, yam starch, arrow root starch, sago palm starch, plantains starch, banana starch, squash starch or a combination thereof.

[0078] In embodiments where the carrier is a coating over the fertilizer, the components of the carrier may form various complexes, which act in combination with other features of the composition (such as, for example, the covalent bonding of the element to the starch) to slow down the dissolution of the fertilizer in water.

[0079] For example, when the carrier comprises starch and magnesium, the magnesium of the carrier may form a magnesium-phosphate complex with the phosphorus of the fertilizer. For example, such complexes may form when the fertilizer is triple super phosphate (TSP).

[0080] In alternative examples, when the carrier comprises (i) starch, (ii) magnesium, (iii) phosphorus and (iv) ammonium or potassium, an ammonium-magnesium-phosphate complex and / or a potassium-magnesium-phosphate complex may form. These complexes are similar to struvite. Struvite is a compound having the formula NF MgPC -eFW and / or MgKPO4'6H2O and readily forms in alkaline conditions when its constituent ions are present. In this embodiment, magnesium covalently bonded to the carrier forms such complexes uniformly on the surface of the carrier. As an additional example, for a fertilizer comprising phosphorus, potassium and ammonia, such as, for example, diammonium phosphate, the phosphorus and ammonia may form struvite with the magnesium of the carrier. In such embodiments, the potassium may form an ionic bond with the hydroxyl groups of the starch. For example, the carrier of the composition may be prepared from a Mg-source (such as, for example, magnesium sulphate), KOH, starch and diammonium phosphate (DAP). Such a carrier may be used to form a coating over a fertilizer particle, the carrier forming struvite-like complexes, such as ammonium-magnesium-phosphate complexes and / or a potassium-magnesium-phosphate complexes. Such fertilizer particle may be triple super phosphorus (TSP), diammonium phosphate (DAP) and monoammoniumphosphate (MAP). In various embodiments, the fertilizer is MAP. In various embodiments, the fertilizer is TSP. In various embodiments, the fertilizer is urea.

[0081] In various embodiments, a solubility of the fertilizer in the composition in water over 24 hours is less than a solubility of the fertilizer in water over 24 hours. For example, the solubility of the fertilizer in the composition in water over 24 hours is at least 10% less than the solubility of the fertilizer in water over 24 hours. For example, the solubility of the fertilizer in the composition in water over 24 hours is at least 15% less than the solubility of the fertilizer in water over 24 hours. For example, the solubility of the fertilizer in the composition in water over 24 hours is at least 20% less than the solubility of the fertilizer in water over 24 hours. For example, the solubility of the fertilizer in the composition in water over 24 hours is at least 25% less than the solubility of the fertilizer in water over 24 hours. For example, the solubility of the fertilizer in the composition in water over 24 hours is 10% to 25% less than the solubility of the fertilizer in water over 24 hours. For example, the solubility of the fertilizer in the composition in water over 24 hours is at least 30% less than the solubility of the fertilizer in water over 24 hours. For example, the solubility of the fertilizer in the composition in water over 24 hours is 20% to 46% less than the solubility of the fertilizer in water over 24 hours. Such reductions in solubility result in significantly less runoff of phosphorus or nitrogen from the soil and mean that less fertilizer can be used to achieve similar crop outcomes.

[0082] In various embodiments, a solubility of the fertilizer in the composition in water over 7 days is less than a solubility of the fertilizer in water over 7 days. For example, the solubility of the fertilizer in the composition in water over 7 days is at least 10% less than the solubility of the fertilizer in water over 7 days. For example, the solubility of the fertilizer in the composition in water over 7 days is at least 15% less than the solubility of the fertilizer in water over 7 days. For example, the solubility of the fertilizer in the composition in water over 5 days is at least 20% less than the solubility of the fertilizer in water over 5 days. For example, the solubility of the fertilizer in the composition in water over 5 days is at least 25% less than the solubility of the fertilizer in water over 5 days. For example, the solubility of the fertilizer in the composition in water over 7 days is 10% to 25% less than the solubility of the fertilizer in water over 7 days. For example, the solubility of the fertilizer in the composition in water over 5 days is at least 30% less than the solubility of the fertilizer in water over 5 days. For example, the solubility of the fertilizer in the composition in water over 5 days is 20% to 40% less than the solubility of the fertilizer in water over 5 days. Such reductions in solubility result in significantly less run-off of phosphorus or nitrogen from the soil and mean that less fertilizer can be used to achieve similar crop outcomes.

[0083] In various embodiments, a solubility of the fertilizer in the composition in a soil column over 45 days is less than a solubility of the fertilizer in the soil column over 45 days. For example,the solubility of the fertilizer in the composition in a soil column over 10 days is at least 20% less than the solubility of the fertilizer in the soil column over 10 days. For example, the solubility of the fertilizer in the composition in a soil column over 20 days is at least 15% less than the solubility of the fertilizer in the soil column over 20 days. For example, the solubility of the fertilizer in the composition in a soil column over 30 days is at least 8% less than the solubility of the fertilizer in the soil column over 30 days. For example, the solubility of the fertilizer in the composition in a soil column over 40 days is at least 2% less than the solubility of the fertilizer in the soil column over 40 days. For example, the solubility of the fertilizer in the composition in a soil column over 7 days is 24% less than the solubility of the fertilizer in the soil column over 7 days. For example, the solubility of the fertilizer in the composition in a soil column over 5 days is at least 30% less than the solubility of the fertilizer in the soil column over 5 days. For example, the solubility of the fertilizer in the composition in a soil column over 5 days is 20% to 40% less than the solubility of the fertilizer in the soil column over 5 days. Such reductions in solubility result in significantly less run-off of phosphorus or nitrogen from the soil and mean that less fertilizer can be used to achieve similar crop outcomes.

[0084] In various embodiments, the carrier comprises at least about 1% (wt / wt) of the element, based on the total weight of the carrier. In various embodiments, the carrier comprises at least about 2% (wt / wt) of the element, based on the total weight of the carrier. In various embodiments, the carrier comprises at least about 4% (wt / wt) of the element, based on the total weight of the carrier. In various embodiments, the carrier comprises at least about 5% (wt / wt) of the element, based on the total weight of the carrier. In various embodiments, the carrier comprises between about 1% (wt / wt) and about 5% (wt / wt) of the element, based on the total weight of the carrier, or any amount therebetween. In various embodiments, the carrier comprises between about 1% and about 5% (wt / wt) of the element, phosphorus and potassium, based on the total weight of the carrier, or any amount therebetween. In various embodiments, the carrier comprises between about 1% and about 5% (wt / wt) of the element, phosphorus and nitrogen, based on the total weight of the carrier, or any amount therebetween.

[0085] In various embodiments, the carrier may further comprise cellulose. Cellulose is a polysaccharide consisting of a linear chain of P(1 — >4) linked D-glucose units having the formula (C6HioOs)n and comprising aliphatic hydroxyl groups and phenolic hydroxyl groups. In various embodiments, the carrier comprises cellulose and starch. In various embodiments, the carrier comprises more starch than cellulose.

[0086] In various embodiments, the composition is resistant to or decreases phosphorus or nitrogen leaching in water. In various embodiments, the composition decreases phosphorus or nitrogen leaching into water sources.

[0087] In various embodiments, the composition may be non-toxic. For example, the composition does not cause nutrient toxicity when deployed in high concentrations. The compositions may be non-toxic to plants, humans and animals.

[0088] In various embodiments, the composition may be added to an environment of a plant in order to increase growth of the plant. The environment may be an agricultural field or soil. In various embodiments, the composition may be applied to soil.

[0089] In various embodiments, transport and application of the composition may result in the production of less dust than the fertilizer.EXAMPLES

[0090] These examples illustrate various aspects of the invention, evidencing a variety of conditions for preparing compositions comprising a fertilizer and a carrier comprising starch and an element, or starch, an element, phosphorus and ammonium or potassium. Selected examples are illustrative of advantages that may be obtained compared to alternative methods, and these advantages are accordingly illustrative of particular embodiments and not necessarily indicative of the characteristics of all aspects of the invention.

[0091] The TSP used was TSP 0-46-0 with available phosphate (P2O5) of 46%. The MAP used was MAP 11-52-0 with total nitrogen of 11%, available phosphoric acid (P2O5) of 52% and molybdenum (Mo) of 0.005%. The DAP used as DAP 21-53-0 with total nitrogen of 21% and available phosphate of 53%. The KOH used was liquid KOH with a concentration of 49.5%. The citric acid used was 99.5% citric acid and 0.5% water. The glycerol was 99.5% glycerol and 0.5% water, and the xanthan gum was food grade xanthan gum obtained from Westpoint Naturals.

[0092] As used herein, the term “about” refers to an approximately + / -10% variation from a given value. It is to be understood that such a variation is always included in any given value provided herein, whether or not it is specifically referred to.Example 1 : Preparation of a carrier comprising starch and magnesium (“AgreosMg”)

[0093] 14.5 grams of 90% pure potassium hydroxide (KOH) were added to 100 g of starch while stirring continuously. The mixture was stirred for 45 minutes at 20°C. In a separate container, 40 grams of magnesium sulfate heptahydrate (MgSO4'7H2O) was dissolved in 40 mL of distilled water and set aside. The MgSO4 solution was then added to the KOH / starch mixture during stirring. The resulting mixture was then stirred for 45 minutes, then heated to 55°C and stirred for an additional 30 minutes. The mixture was dried and used as a carrier for thecompositions described below. Figure 13 shows a SEM image of this carrier, with C, O, Mg, K and S detected in the product.Example 2: Preparation of a carrier comprising starch, magnesium, phosphorus and ammonium / potassium (“AgreosAMP”)

[0094] 29 grams of potassium hydroxide (KOH) was added to 24 mL of water at 20°C to form a potassium hydroxide solution (mixture A). Mixture A was mixed with 200g of starch and stirred for 60 minutes at 20°C (mixture B). In a separate container, 50 g of magnesium sulfate heptahydrate (MgSO4'7H2O) was dissolved in 50 mL of waer at 20°C (mixture C) and mixture C was added to mixture B while stirring, and stirring was continued for 30 minutes at 20°C (mixture D). In a separate container, 53 g of diammonium phosphate (DAP, (NH^HPO^s)) was dissolved in 50 mL of water at 20°C (mixture E). Mixture E was slowly added to mixture D while stirring, and the combined mixture was stirred for an additional 30 minutes at 20°C. The resulting mixture was then heated to 40°C and stirred for an additional 60 minutes. The resulting mixture (AgreosAMP) was dried overnight and used as a carrier for the compositions described below. Figure 14 shows a SEM image of this carrier, with Mg, P, K, C and O detected in the product.Example 3: Preparation of coated compositions of TSP and MAP

[0095] Granular MAP and TSP were obtained from commercial agricultural input distributors. All coating was done using a fluidized bed system. All coatings used the carriers prepared in Example 1 (referred to as “AgreosMg”) or Example 2 (referred to as “AgreosAMP”) mixed with water to form a slurry. In each case, the slurry was made at 20°C, used within 48 hours of preparation and stored at 4°C.

[0096] As described in further detail below, the slurries were prepared by mixing the dry materials, and then adding them gradually to the liquid ingredients after which they were mixed for 5 minutes and then placed in an 80°C water bath for 5 minutes. After this they were shaken for 30 seconds and then placed back into the water bath at 80°C for another 5 minutes. The slurries were then shaken for 40 seconds, left to return to 20°C, and then stored at 4°C until use.

[0097] For coatings over TSP, it was necessary to dilute the prepared slurry of carrier by 50% with distilled water before use to achieve successful coating and to prevent aggregation during the coating process.

[0098] Table 1 shows the composition of the slurries used to prepare the coated TSP and MAP. In each case, the carrier was mixed with xantham gum, glycerol and optionally citric acid to create a slurry.Table 1. Composition of slurries used to coat TSP and MAP

[0099] The slurries from Table 1 were prepared and used to coat TSP and MAP using the fluidized bed machine. Slurry A was used to coat TSP and Slurry B was used to coat MAP.

[0100] Table 2 provides examples of conditions used for preparing the compositions comprising coated TSP and MAP.Table 2. Composition of coatings applied to TSP and MAP*RPM refers to the speed of the peristaltic pump on the fluidized bed machine**lnlet refers to the inlet air pressure used on the fluidized machineArefers to the temperature of the inlet air pressure on the fluidized bed machineAArefers to the air pressure of the atomizer of the fluidized bed machineAAA% coating refers to the mass difference between uncoated and coated TSP and MAPExample 4: Determination of effects of coated compositions on phosphorus release into water

[0101] To determine the efficacy of the various coatings, uncoated TSP and MAP granules were compared with coated TSP and MAP granules.

[0102] Figure 1 shows the average phosphorus release of untreated TSP granules compared to three different coating treatments as defined in Table 2. The untreated TSP granules released approximately 80% of phosphorus within 24 hours in water. Treated TSP granules using formulation E199 had approximately 60% release of phosphorus within 24 hours in water, which represents a phosphorus release reduction of 25%. Treated TSP granules using formulation E208 had approximately 57% release of phosphorus within 24 hours, which represents a phosphorus release reduction of 29%. Treated TSP granules using formulation E209 had approximately 64% release of phosphorus within 24 hours, which represents a phosphorus release reduction of 20%. Treated TSP granules using formulation E281 had approximately 50% release of phosphorus within 24 hours, which represents a phosphorus release reduction of 38%.

[0103] Figure 2 shows the average phosphorus release of untreated MAP granules compared to three different coating treatments as defined in Table 2. The untreated MAP granules released approximately 80% of phosphorus within 24 hours in water. Treated MAP granules using formulation E185 had approximately 60% release of phosphorus within 24 hours in water, which represents a phosphorus release reduction of 25%. Treated MAP granules using formulation E205 had approximately 61% release of phosphorus within 24 hjours in water, which represents a phosphorus release reduction of 24%. Treated MAP granules using formulation E206 had approximately 69% release of phosphorus within 24 hours in water, which represents a phosphorus release reduction of 14%.

[0104] Figure 3 shows a release curve of phosphorus from uncoated TSP particles compared to phosphorus released from TSP particles coated with a composition as described herein, over 7 days in water. The entire content of water soluble phosphorus from the uncoated TSP particles, which is 80% of its phosphorus content, was dissolved in water within 24 hours. The TSP coated with sample ID E208 released 57% of total phosphorus after 24 hours soaking in water, which is a 29% release reduction.

[0105] Figure 4 shows untreated TSP dry granules. Figure 5 shows untreated TSP granules in water after a period of 24 hours. After 24 hours, the granules were in a state of dissolution, within a complete loss of the spherical structure of the granules. Figure 6 shows a photograph of treated TSP granules coated with a carrier as described herein, which shows a lesser state of dissolution in water compared to the untreated TSP granules. The treated TSP granules coated with the carrier remained stable and did not disintegrate in water.

[0106] Figure 7 shows a photograph of untreated MAP dry granules. Figure 8 shows a photograph of treated MAP granules coated with a carrier as described herein, which show a lesser state of dissolution in water. The coated MAP remained stable in water.Example 5: Preparation of granulated compositions by the inclusion method of synthesis

[0107] Another method of preparing the compositions as disclosed herein is to include the carrier during the granulation process. This inclusion method does not coat the fertilizer granules but instead the fertilizer materials are mixed with the carrier and subsequently granulated. An advantage of this method is that a coating process is not required to provide a reduction in solubility of the fertilizer in the composition. Rather, the carrier can be included in the existing manufacturing process prior to the granulation stage.

[0108] Monoammonium phosphate fertilizer (MAP), diammonium phosphate fertilizer (DAP) and triple superphosphate (TSP) were used in a 4:1 ratio of fertilizer carrier (weight / weight). The carrier was that prepared in Example 1 (AgreosMg).

[0109] MAP, DAP and TSP were each mixed with the carrier from Example 1 (AgreosMg) to prepare three different samples. The resulting mixture was subsequently granulated with the use of water as a binding agent. A mixer was used as a granulator. Water was added to the mixture during the granulation until the mixture granulated. The mixer was a conventional rotary drum. Following granulation, the mixture was dried. Once the granules were free-flowing, the granules were left to dry at 20°C for a period of approximately 12 hours. Figure 12 shows pictures of TSP granulated with the carrier (left-hand picture) and DAP granulated with the carrier (righthand picture).Example 6: Determination of effects of granulated compositions on phosphorus release into water

[0110] The granules from Example 5 were tested for phosphorus dissolution by soaking in water at approximately 20°C for a period of 24 hours.

[0111] Figure 9 shows the average phosphorus release in water over 24 hours from unmodified MAP compared to MAP combined with the carrier prior to granulation. The rate of dissolution was reduced from 100% for unmodified MAP to 88% for the composition comprising MAP and the carrier, resulting in a 12% reduction in dissolution of phosphorus in water over 24 hours.

[0112] Figure 10 shows the average phosphorus release in water over 24 hours from unmodified DAP compared to DAP combined with the carrier prior to granulation. Afer 24 hours,the unmodified DAP had a dissolution percentage of 100%, however, the DAP combined with the carrier prior to granulation had a dissolution percentage of 65% providing a 35% reduction in dissolution of phosphorus.

[0113] Figure 11 shows the average phosphorus release in water over 24 hours from unmodified TSP compared to TSP combined with the carrier prior to granulation. After 24 hours, the unmodified TSP had a dissolution percentage of 70%, however, the TSP combined with the carrier prior to granulation had a dissolution percentage of 41% providing a 41% reduction in dissolution of phosphorus.Example 7: Synthesis of carrier for compositions comprising urea

[0114] Different samples of coatings were prepared. Potassium hydroxide was mixed with water according to the amounts set out in Table 3, third column. The mixture was agitated until all of the potassium hydroxide was dissolved. The mixture was added to 200 g of pea starch and then mechanically agitated for a period of time as set out in Table 3, seventh column. This mixture was set aside. A separate solution of FeSO4'7H2O or MgSC rTFW and water was prepared according to column 4 of Table 3. The mixture containing pea starch was added to this mixture and mechanically agitated for a period of time according to column 8 of Table 3. The mixtures were then heated to a temperature according to Table 3, column 6 and mechanically agitated for a period of time according to column 9. This prepared the carrier sample labeled RZ145 in Table 3. This carrier was dried at 60°C and sieved with a 200 pm mesh sieve.Table 3. Parameters for preparation of carriers for compositions comprising urea

[0115] The coatings RZ145 and RY218 were analyzed for elemental presence using an XRF (X-ray fluorescence) device. The results are shown in Table 4.Table 4. Elemental analysis by XRX of carriers for urea

[0116] The next step was to coat urea pellets with the carriers. 4 grams of urea powder was placed into a pelleting die (HRC 60-62) and pressed into a pellet using a TMAXCN pellet press, yielding a disk-shaped pellet 4 mm thick and 32 mm diameter. The pellet was moistened with distilled water and placed into one of the carriers (referred to as “AgreosAMP”) until a coating of between about 5%-10% (m / m) was achieved. The pellet was then dipped into linseed oil for about 5-10 minutes and cured in an oven at 60°C for 48 hours. The pellet was dipped into molten microcrystalline or carnuba wax according to Table 5 and then allowed to harden at room temperature. This latter step was repeated until a mass of wax of about 15% to 20% (m / m) was achieved.

[0117] Table 5. Details of preparations of urea pellets coated with the carrier

[0118] The coated urea pellets were placed in a container of distilled water at room temperature (20°C) until all of the urea was dissolved. The concentration of nitrogen from urea in the ater was measured by ATR-FTIR spectroscopy and the results are shown in Figure 15. The uncoated urea dissolved in less than one day. The coated urea had its dissolution delayed between 1 day (for example, LIP14) and greater than 50 days (for example, LIP10). Thus, coating urea pellets with carriers as disclosed herein to form various compositions results in reduced solubility of urea in water, while still allowing for the urea to be available to plants. The compositions as disclosed herein may therefore control the release rate of urea fertilizers into soil.Example 8: Preparation of a carrier comprising starch and magnesium (“AgreosVT’)

[0119] 33.25 g of potassium carbonate was added to 100 g of starch, mixed thoroughly for 45 minutes at 20°C with water until the potassium carbonate was dissolved. 6.54 g of MgO was then added to the reaction mixture, and mixed for an extra 30 minutes. The whole reaction mixture was heated to 55°C and mixed at that temperature for 30 more minutes. Figure 17 shows a SEM image of AgreosVI .Example 9: Preparation of coated compositions with AgreosVI (“AgreosP”)

[0120] To make a coating formula in a 100 mL volume scale, 20 g of AgreosVI , 1 g of xanthan gum (“XG”), 2 mL of glycerin (“Gly”), 5 g of sorbitol, 2 g of citric acid (“GA”) and 6.63 mL of polyethylene glycol (PEG) were combined together and homogenized. The mixture was diluted by 50% with water. TSP and MAP fertilizers were then coated.

[0121] Figure 18 shows a comparison of phosphorus leaching or dissolution of TSP into water between uncoated TSP and coated TSP. Leaching of uncoated TSP was 60.46% and the leaching of coated TSP was reduced to 28% over a 24-hour period in water at 20°C. Figure 19 shows a comparison of phosphorus leaching or dissolution of MAP into water between uncoated MAP and coated MAP. Uncoated MAP leached 80.32% and coated MAP leached 56.2% over a 24-hour period in water at room temperature.

[0122] Cumulative percent-phosphorus leached over time in sand columns was also measured to compare leaching between untreated fertilizer and fertilizer coated with carriers as described herein. The sand column protocol was done as follows. Leaching results were determined using a 10cm sand column. A 10cm mini-column was packed with 68.0 g of clean sand and packed in by lightly tapping it on a table ~20 times. The sand was saturated with 14 mL of distilled water and left for 30 minutes, after which any water that leached from the column wasdiscarded. The top ~1 cm of sand was removed, and 1.17 g of sample was added to each column. The removed sand was added back to the column on top of the sample, followed by filter paper. After 1 hr, each column was irrigated with 10 mL of distilled water, and after 30 minutes, the leachate was collected, measuring the volume in the process. The irrigation was repeated 2 hours, 4 hours, and 24 hours after the sample was deposited in the column, with leachates collected 30 minutes after each irrigation. For the long-term leaching, leachate was collected every 24 hours. The ATR-FTIR spectrum of each leachate was collected to determine the P or N content in each of the leachates. Figure 20 shows a comparison of phosphorus leaching or dissolution of TSP over a 16 day study in a sand column. The coated TSP demonstrated a significatly slower rate of release of phosphorus than the uncoated TSP. Figure 21 shows a comparison of phosphorus leaching or dissolution of MAP over a 16 day period in a sand column. The coated MAP shows a significantly slower rate of release than the uncoated MAP.Example 10: Preparation of a carrier / coating for compositions comprising urea (“AgreosV2.1”)

[0123] 5.05 g of potassium hydroxide (49.5%) was added to 100 g of starch, mixed thoroughly for 60 minutes at 20°C with water until all of the potassium hydroxide was dissolved, and then 9.38 g of MgSCU was added to the reaction mixture, mixed for an extra 30 minutes, and 5.25 g of diammonium phosphate was added to the mixture and mixed for an additional 30 minutes. The mixture was then heated to 40°C and mixed at that temperature for 60 more minutes. Figure 22 shows a SEM image of the resulting AgreosV2.1 powder. The carrier comprised starch, element (as Mg), phosphorus and ammonium.Example 11 : Preparation of a carrier for compositions comprising urea (“AgreosV2.2”)

[0124] 3.37 g of potassium hydroxide (49.5%) was added to 100 g of starch, mixed thoroughly for 60 minutes at 20°C with water until all of the potassium hydroxide was dissolved, and then 6.54 g of MgSCU was added to the reaction mixture, mixed for an additional 30 minutes, and 3.5 g of diammonium phosphate was added to the mixture and mixed for an additional 30 minutes. The mixture was then heated to 40°C and mixed at that temeraturefor 60 more minutes. Figure 23 shows a SEM image of the resulting AgreosV2.2 powder. The carrier comprised starch, element (as Mg), phosphorus and ammonium.Example 12: Preparation of a carrier for compositions comprising urea (“AgreosV3”)

[0125] 1.54 g of MgO was added to 100 g of starch and mixed thoroughly for 60 minutes at 20°C with water until all of the MgO was dissolved. Then, 6.63 g of K2HPO4 was added to the reaction mixture, and mixed for an additional 90 minutes. The mixture was then heated to 40°Cand mixed at that temperature for 30 more minutes. The carrier comprised starch, element (as Mg), phosphorus and potassium.Example 13: Preparation of coated urea using AgreosVI (“AgreosNT’)

[0126] Per 100 grams of AgreosVI , 15 g of glycerin and 2.67 g of xanthan gum were mixed and homogenized to provide a coating formula. Urea granules were coated with AgreosVI using a rotary drum and demonstrated leaching of nitrogen of 55.37% after a 24 hour sand column study. Figure 24 shows the performance result of this coated formula compared to untreated urea.Example 14: Preparation of coated urea using AgreosV2.1 (“AgreosN2.1”)

[0127] Per 44.2 grams of AgreosV2.1 , 6.63 g of glycerin and 1.18 g of xanthan gum were mixed and homogenized to provide a coating formula. Urea granules were coated with AgreosV2.1 using a rotary drum and demonstrated leaching of nitrogen of 49% after a 24 hour sand column study. Figure 25 shows a comparison between the leaching results of AgreosNI , AgreosN2.1 , AgreosN2.2 and AgreosN3.

[0128] Figure 26 shows the leaching performance of Agreos N2.1 compared to untreated urea over a 45 day period. The data is from a soil column study. Soil columns were placed in a growth chamber at 20oC, 75% relative humidity, in triplicate. A homogeneous soil media mixture was prepared by combining 50% (w / w) washed sand with 50% air-dried soil. Soil columns were placed a 5 cm layer of gravel / stone (0.81 kg) at the bottom, followed by 20 cm of the soil-sand mixture (2.59 kg). Nitrogen fertilizer treatments were applied based on nitrogen (N) content to obtain a final concentration of 750 ppm, corresponding to approximately 5 g of fertilizer. The fertilizer was thoroughly mixed with 500 g of soil mixture and applied to the top of the column. Then a 3 cm layer of gravel / stone (0.5 kg) was added on top. The soil column was initially saturated with around 250 mL of DI water based on the water holding capacity. Subsequently, 250 mL of DI water was applied, and the leachate was collected and measured for volume. Columns were irrigated daily with 250 mL DI water for the first 5 days, then every 5 days thereafter. Leachates were analyzed for urea-N and nitrate-N using Fourier-transform infrared spectroscopy (FTIR). Ammonium-N (NH4+-N) concentrations were determined using the Nessler method. Figure 27 shows a 45 day soil column study of nitrate leaching of uncoated urea compared to coated urea.Example 15: Preparation of coated urea using AgreosV2.2 (“AgreosN2.2”)

[0129] Per 100 grams of AgreosV2.2, 15 g of glycerin and 2.67 g of xanthan gum were mixed and homogenized to provide a coating formula. Urea granules were coated with AgreosV2.2 using a rotary drum and demonstrated nitrogen leaching of 44% after a 24 hour sand column study. Figure 24 shows the performance results of this coating formula (AgreosN2.2) Figure 25 shows a comparison between the leaching results of AgreosNI , AgreosN2.1 , AgreosN2.2 and AgreosN3. Figure 28 shows SEM imagery of urea coated using the Agreos N2.2 formula.Example 16: Preparation of coated urea using AgreosV3 (“AgreosN3”)

[0130] Per 100 grams of AgreosV3, 15 g of glycerin and 2.67 g of xanthan gum were mixed and homogenized to provide a coating formula. Urea granules were coated with AgreosV3 using a rotary drum and demonstrated leaching of 47% after a 24 hour sand column study. Figure 24 shows the performance results of this coating formula (Agreos-N3) compared with other coating formulas and untreated urea. Figure 25 shows a comparison between the leaching results of Agreos-N1 , Agreos-N2.1 , Agreos-N2.2 and Agreos-N3. Figure 29 shows SEM imagery of urea coated using the AgreosN3 method.

[0131] Although various embodiments of the invention are disclosed herein, many adaptations and modifications may be made within the scope of the invention in accordance with the common general knowledge of those skilled in this art. Such modifications include the substitution of known equivalents for any aspect of the invention in order to achieve the same result in substantially the same way. Numeric ranges are inclusive of the numbers defining the range. The word "comprising" is used herein as an open-ended term, substantially equivalent to the phrase "including, but not limited to", and the word "comprises" has a corresponding meaning. As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a thing" includes more than one such thing. Citation of references herein is not an admission that such references are prior art to the present invention. Any priority document(s) and all publications, including but not limited to patents and patent applications, cited in this specification are incorporated herein by reference as if each individual publication were specifically and individually indicated to be incorporated by reference herein and as though fully set forth herein. The invention includes all embodiments and variations substantially as hereinbefore described and with reference to the examples and drawings.

Claims

CLAIMS1. A composition comprising: a fertilizer comprising phosphorus or nitrogen; and a carrier comprising: (a) starch and an element, wherein the element is covalently bonded to the starch, or (b) (i) starch, (ii) an element, (iii) phosphorus and (iv) ammonium or potassium, wherein the element is covalently bonded to the starch and forms an ammonium- element-phosphate complex and / or a potassium-element-phosphate complex, wherein the element is magnesium, iron, zinc, manganese, calcium or copper.

2. The composition of claim 1 , wherein the element is covalently bonded to the hydroxyl groups of the starch.

3. The composition of claim 1 or 2, wherein the fertilizer and the carrier are granulated together.

4. The composition of claim 3, wherein the carrier comprises (a) starch and the element.

5. The composition of claim 3 or 4, wherein the element is magnesium.

6. The composition of claim 3, 4 or 5, wherein the fertilizer is triple super phosphate (TSP), diammonium phosphate (DAP), monoammonium phosphate (MAP) or urea.

7. The composition of claim 1 or 2, wherein the carrier is a coating over the fertilizer.

8. The composition of claim 7, wherein the carrier comprises (a) starch and the element.

9. The composition of claim 7 or 8, wherein the element is magnesium.

10. The composition of claim 9, wherein the fertilizer is triple super phosphate (TSP) and the magnesium of the carrier forms a potassium-magnesium-phosphate complex with the phosphorus of the fertilizer.

11. The composition of claim 9, wherein the magnesium of the carrier forms a potassium- magnesium-phosphate complex with the phosphorus of the fertilizer or an ammonium- magnesium-phosphate complex with the nitrogen of the fertilizer.

12. The composition of claim 7, wherein the carrier comprises (b) (i) starch, (ii) the element, (iii) phosphorus and (iv) ammonium or potassium.

13. The composition of claim 12, wherein the carrier comprises starch, magnesium, phosphorus and diammonium phosphate (DAP).

14. The composition of claim 12, wherein the fertilizer is urea and the element is iron.

15. The composition of claim 12 or 13, wherein the fertilizer is triple super phosphate (TSP), monoammonium phosphate (MAP), diammonium phosphate (DAP) or urea.

16. The composition of any one of claims 1 to 15, wherein the composition further comprises potassium ions.

17. The composition of any one of claims 1 to 16, wherein the carrier further comprises cellulose.

18. The composition of any one of claims 1 to 17, wherein the carrier comprises between about 1% and about 5% (wt / wt) element, based on the total weight of the carrier.

19. The composition of any one of claims 1 to 17, wherein the carrier comprises between about 1% and about 5% (wt / wt) element, phosphorus and potassium, based on the total weight of the carrier.

20. The composition of any one of claims 1 to 17, wherein the carrier comprises between about 1% and about 5% (wt / wt) element, phosphorus and nitrogen, based on the total weight of the carrier.

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