OA20907A - Agglomerated dispersible granules, methods for amending soil, and activated alumina suspensions. - Google Patents

Abstract

Agglomerated dispersible granules are disclosed including activated alumina particles and phosphate particles. The activated alumina particles have a porous structure and a plurality of electrically-charged binding sites disposed within the porous structure. The activated alumina particles and the phosphate particles are present in the agglomerated dispersible granules as distinct phases agglomerated together. A method for amending soil with buffered phosphorus is disclosed including physically blending and then agglomerating activated alumina particles with phosphate particles to form the agglomerated dispersible granules. The agglomerated dispersible granules are applied to soil with the activated alumina particles and the phosphate particles being present as distinct phases and the activated alumina particles being free of phosphate disposed within the porous structure. An activated alumina suspension is disclosed including activated alumina particles suspended as a dispersed phase in a continuous phase, the activated alumina particles having a particle size less than 200 µm.

Description

AGGLOMERATED DISPERSIBLE GRANULES, METHODS FOR AMENDING SO1L, AND ACTIVATED ALU MINA SUSPENSIONS

RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Prov. App. No. 62/987,461, filed March 10, 2020, entitled “Improved Methods for Making and Applying Buffered Phosphorus,” which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

[0002] This application is directed to agglomerated dîspersible granules, methods for 5 amending soil, and activated alumina suspensions. In particular, this application is directed to agglomerated dîspersible granules having alumina particles and phosphate partîcles présent as distinct phases, methods for amending soil with buffered phosphorus in the form of the agglomerated dîspersible granules, and activated alumina suspensions wherein the activated alumina particles constitute a dispersed phase suspended in a continuous phase.

BACKGROUND OF THE INVENTION ₁₀ |0003] Phosphorus is a key nutrient for plant growth. Métal oxides, including activated alumina, kaolin, bauxite, iron oxide, calcium oxide, and magnésium oxide, hâve been used as a buffer to apply phosphorus as a fertîlîzer. Activated alumina, in particular, has been used in buffered-release activated alumina and phosphorus soil amendments (“BRAAPSA”). Traditionally, BRAAPSA has been madeby loading liquid phosphorus (e.g., phosphoric acid) onto 15 activated alumina to create a BRAAPSA which may be physically put into the soil as a soil amendment for plants. Lynch et al. in U.S. Patent No. 6,287,357 describe a method for forming BRAAPSA, which method is dépendent on a phosphorous source being reversibly bound to acidactîvated alumina prior to soil application. BRAAPSA has sîgnificantly reduced unwanted phosphorus loss due to leaching which is unwanted because phosphorus leaching may cause ground water contamination as well as increasing the amount of phosphorus that needs to be 20 applied to the soil. Additionally, BRAAPSA may positively împrove plant growth for various plant species (e.g., by improving root growth, etc ). This is because the buffered-release mechanism of BRAAPSA releases nutrients based on a Chemical gradient whereas existing coated fertîlîzer technologies rely upon environmental conditions and lead to more phosphorus being leached (i.e., lost) into the ground water.

[0004] Activating a métal oxide may be done in a variety of ways. Actîvated alumina adsorbents are often produced by agglomérat! ng and heat processing (i.e., cal ci ni ng) alumînum trihydrate powder. Spherical alumina is formed, then crushed (e.g., mechanical fracturing), then followed by a screening process to produce granular actîvated alumina of various sizes (often referred to as mesh sizes due to the size of the mesh sîeves used to separate particles based on size). The adsorptive capacity of an actîvated métal oxide such as actîvated alumina is determined in large part by the surface area. Because of the porous nature of actîvated alumina, a majority of the surface area exists in the pore spaces which are produced by the calcination process (i.e., a more porous compound has more surface area than a similarly-sized particle with less porous surface). The capacity for chemi-adsorbing orthophosphate is high compared to other plant nutrients such as nitrogen and potassium due to the high anionic exchange capacity of the material, makîng actîvated alumina a préférable substrate for buffering the release of phosphate fertilîzers. However, a variety of métal oxides may be actîvated and used in a similar manner.

[0005] Although applying to the soil a BRAAPSA soil amendment is somewhat more efficient than conventional methods of applying phosphorus-containing fertilizer directly to the soil (i.e., either directly or via a coated fertilizer), BRAAJPSA may be difficult, expensive, and timeconsuming to make. The process of loading a granular actîvated alumina with a liquid source of phosphorus (e.g., phosphoric acid) does hâve problems. By way of example, liquid phosphorus compounds (e.g., phosphoric acid, orthophosphoric acid, phosphoric (V) acid) are acids which requîre careful handling and use of personal protective equipment because acids such as phosphoric acid may cause severe irritation of the skin and eyes. Additionally, liquid phosphorus (e.g., phosphoric acid) requires spécifie equipment to handle because equipment may be degraded from contact with acid. Additionally, actîvated alumina has insoluble characteristics which can give it limited application opportun!ties. For example, actîvated alumina must be physically and/or mechanically incorporated into the soil (e.g., applied to small holes of a certain depth). Physical and/or mechanical application to the soil may prove to be a time-consuming and laborious process for farmers. Additionally, physical and/or mechanical application is not idéal for a variety of fertilizer application opportunities (e.g,, hydroponics and no-tîll plants such as fruit trees and turf).

The application process is typically limited to granular activated alumina sized to pass through 8x14, 14x28, or 14x48 mesh. The particle size may provide structural benefits to soil application (e.g., parti clés that are too smail can resuit in dust which results in loss of product and also can be harmful to humans when înhaled, parti clés that are too large may hâve iess surface area and may bave reduced buffering capacîty as well as being more expensive).

[0006] In most agriculture uses (e.g., turf, omamental, and crop) production Systems, fertilizer is applied to the surface of the growing medium (e.g., soil) and then watered into the soil profile (e.g., a solid particulate fertilizer is applied to the surface of the soil and when water is applied, the soluble fertilizer goes into the soil). The limitation of applying activated alumina alone or BRAAPSA directly to the surface of the growing medium (e.g.. soil) is that it is not efficiently watered in (e.g., because of the solubility and/or particle size). For example, the traditional particle sizes that are able to be pre-loaded with a liquid fertilizer source are too big to be watered into the soil effectively, and activated alumina, without phosphorus, has limited solubility which makes watering in a challenge.

[0007] A soil amendment including activated alumina not suffering from the above-described limitations would be désirable.

BRIEF DESCRIPTION OF THE INVENTION

[0008] In one exemplary embodiment, agglomerated dispersible granules include activated alumina particles and phosphate particles. The activated alumina parti cl es hâve a porous structure and a plurality of electricaliy-charged binding sites disposed within the porous structure. The activated alumina particles and the phosphate particles are présent in the agglomerated dispersible granules as distinct phases agglomerated together.

[0009] In another exemplary embodiment, a method for amending soil with buffered phosphorus includes physically blending activated alumina particles with phosphate particles and then agglomerating the alumina particles with the phosphate particles to form agglomerated dispersible granules and applying the agglomerated dispersible granules to soil. The activated alumina particles hâve a porous structure and a plurality of electricaliy-charged binding sites disposed within the porous structure. The activated alumina particles and the phosphate particles are présent in the agglomerated dispersible granules as distinct phases agglomerated together and the activated alumina particles are free of phosphate disposed within the porous structure when applied to the soil.

[0010] In another exemplary embodiment, an activated alumina suspension includes activated alumina particles and a continuous phase. The activated alumina particles hâve a porous structure, 5 a plurality of electrically-charged binding sites disposed within the porous structure, and a partiele size measured by largest particle dimension less than 1 pm. The activated alumina particles constitute a dispersed phase suspended in the continuous phase.

DETAILED DESCRIPTION OF THE INVENTION

[0011] Disclosed herein are agglomerated dispersible granules having alumina particles and phosphate particles présent as distinct phases, methods for amending soil with buffered phosphorus in the form of the agglomerated dispersible granules, and activated alumina suspensions wherein ¹⁰ the activated alumina particles constitute a dispersed phase suspended in a continuous phase. In particular, by applying agglomerated dispersible granules having alumina particles and phosphate particles présent as distinct phases into soil, and then by applying water to the agglomerated dispersible granules on or in the soil (either by irrigation or by natural précipitation) BRAAPSA may be formed ifi situ in the soil. The compositions and methods disclosed herein, in comparison 15 to compositions and methods not including one or more of the features disclosed herein, may be applied directly to soil surface of most agricultural uses, such as turf, ornamental, and crop production Systems, decrease costs of manufacturing and application, increase BRAAPSA pénétration into the soil, decrease runoff and waste, or combinations thereof It is particularly noteworthy that while previous work, such as disclosed by Lynch et al. in U.S. Patent No, 20 6,287,357, describes methods for forming BRAAPSA which require a phosphorous source to be reversibly bound to acid-activated alumina prior to soil application, in the présent invention it has been unexpectedly discovered that applying phosphate and activated alumina without binding prior to application yields équivalent or even superior results, and is suitable for buffering additional nutrients beyond phosphorous as well. This method and use of material is much simpler than pre- ²⁵ loading activated alumina prior to soil application. Also, with this method, the amount of activated alumina needed on an area basis (per hectare) is at least 50% less, up to 90% less, or even up to

A

95% less that the amount of activaied alumina needed when pre-loaded with phosphorus with binding.

[0012] As used herein, “about” indicates a variance of up to 10% from the value being so modified. Ail values modified with “about” are also intended to convey the unmodified value as an alternative, so that “about 10 gm,” by way of examples, discloses both a range of 9-11 gm as well as specifically 10 gm.

[0013] In one embodiment, agglomerated dispersible granules include activated alumina particles and phosphate particles. The activated alumina partîcles hâve a porous structure and a plurality of electrically-charged binding sites disposed within the porous structure. The activated alumina particles and the phosphate particles are présent in the agglomerated dispersible granules as distinct phases agglomerated together.

[0014] The activated alumina particles may be calcined alumina particles or calcined alumina 10 particles which hâve additionally been acid washed, either prior to or following calcination.

Activated alumina particles may be produced from spherîcal alumina being crushed and screened based on particle distribution ranges. The pore space in the activated alumina particles encompasses a majority of the adsorptive capacity because a large amount of the surface area of an activated alumina particle may be in the pores. The activated alumina particles may hâve any 15 suitable size. In one embodiment, to maintain adsorptive capacity for phosphate and optimizing the activated alumina particle size for penetrating the soil profile through a surface application, a preferred particle size for activated alumina particles is smaller than about 300 gm, altematively smaller than about 150 gm, or smaller. Activated alumina particle size alteration includes, but is not limited to, taking a fraction of about 2,400 gm to about 1,200 gm, about 1,200 gm to about 20 600 gm, about 1,200 gm to about 300 gm, or other common grading sizes, and physically breaking the particles (e.g., milling the product to about 300 gm to about 150 gm, about 150 gm to about 75 gm, or <75 gm through grinding processes). This créâtes smaller-sized activated alumina particles.

[0015] In another embodiment, suitably, by way of example, for a suspension, the activated alumina particles hâve a particle size less than about 200 gm, altematively less than about 150 gm, 25 altematively less than about 100 gm, altematively less than about 75 gm, altematively less than about 1 pm, altematively less than about 1 pm, altematively less than about 50 pm, altematively less than about 25 pm, altematively less than about 10 pm, altematively less than about 5 pm, altematively less than about 2 μιη, altematively less than about 1 μηι, altematively less than about 0.75 μηι, altematively less than about 0.5 μιη, altematively less than about 0.25 μιη, altematively ⁵ less than about 0.1 μηι, altematively less than about 0.05 μηι, altematively less than about 0.01 μιη, as measured by largest parti cl e dimension. Applying smaller-sized activated aluni ina partiel es directly to the surface of the soi! may be challenging because activated alumina has limited solubîlity and small parti cle sizes may be dusty. It is noted with respect to suspension of parti clés, that agitation may be employed to form a temporary suspension with parti clés which might 10 otherwise be too large to form a stable suspension, and that viscosity of a continuous phase may be increased to further stabilize a suspension and compensate for particle size.

[0016] Suitable phosphate particles include, but are not limited to, particles of monoammonium phosphate, diammonium phosphate, monopotassium phosphate, dipotassium phosphate, triple super phosphate, pol y phosphate, any other similar dry phosphate, or 15 combinations thereof. In one embodiment, a dry granular phosphate source may be physically broken (i.e., milled or ground) to a size similar to the size/mesh/density of the smaller-sized activated alumina particles to promote homogenous blending.

[0017J In one embodiment, the activated alumina particles are essentially free, altematively free, of phosphate disposed within the porous structure. As used herein, “essentially free” indicates that less than 5% of available pores in the activated alumina particles include phosphate.

|0018} The activated alumina particles and the phosphate particles may be homogenously distributed or heterogeneously distributed in the agglomerated dispersible granules.

[0019] The agglomerated dispersible granules may hâve any suitable weight ratio of alumina to phosphate, including but not limited to a weight ratio of 10:1 to 1:10, altematively 8:1 to 1:8, altematively 7:1 to 1:7, altematively 6:1 to 1:6, altematively 5:1 to 1:5, altematively 4:1 to 1:4, 25 altematively 3:1 to 1:3, altematively 2:1 to 1:2, altematively 3:1 to 1:1, altematively 1:1 to 1:3, alternative about 2:1, altematively about 1:1, altematively about 1:2, or any sub-range or combination of ranges thereof.

[0020] The agglomerated dispersible granules may further include addîtional nutrient content. The addîtional nutrient content may be in the form of particles présent as distinct phases and agglomerated with the activated alumina particles and the phosphate particles, or as an addîtional nutrient layer coated onto the agglomerated dispersible granules, or as addîtional free particles of nutrient intermixed with the agglomerated dispersible granules.

[0021] Suitable addîtional nutrient content includes, but is not limited to, bioavaîlable species of molybdenum, sélénium, zinc, copper, cobalt, iron, nickel, manganèse, vanadium, calcium, potassium, sulfur, chlorine, Silicon, magnésium, sodium, nitrogen, boron, or combinations thereof. Bioavaîlable species of the foregoing nutrients include, but are not limited to, MoOr, SeCh”, Zn²\ ZnCl CuCOs, Co²f Fe²⁺, Fe³⁺, Ni²⁺, NiCf, Mn^I+, MnCl⁺, HVO?’, Ca^a+, K+, SO4², Cl SiOH4, Mg²⁺, Na⁺, NH⁴⁺, ΝΟΓ, H3BO3, and B₄O7²T

[0022] In one embodiment, the activated alumina particles are essentîally free, altematively free, of the at least one nutrient within the porous structure. As used herein, “essentîally free” indicates that less than 5% of availabié pores in the alumina particles include the at least one nutrient.

[0023] The agglomerated dispersible granules may further include pesticide content, The pesticide content may be in the form of particles présent as distinct phases and agglomerated with the activated alumina particles and the phosphate particles, or as a pesticide layer coated onto the agglomerated dispersible granules, or as addîtional free particles of pesticide intermixed with the agglomerated dispersible granules. Suitable pesticides include, but are not limited to, herbicides, insecticides, fungicides, nematicides, or combinations thereof. Suitable herbicides include, but are not limited to, suifonylureas, HPPD-inhîbitors, chloroacetamides, PPO-inhibitors, phenylurea, triazines, or combinations thereof. Suitable insecticides include, but are not limited to, organophosphates, carbamîdes, pyrethrins, neonicotinoids, spinosins, indoxacarb, diamîdes, or combinations thereof,. Suitable fungicides include, but are not limited to, strobîlurines, pyrimidines, triazoles, dicarboximides, or combinations thereof. Suitable nematicides include, but are not limited to, avennectin, carbamates, organophosphates, or combinations thereof

[0024] The agglomerated dispersible granules may further include biological additive content, The biological additive content may be in the form of particles présent as distinct phases and agglomerated with the activated alumina particles and the phosphate particles, or as a biological additive layer coated onto the agglomerated dispersible granules, or as additional free particles of biological additive intermixed with the agglomerated dispersible granules. Suitable biological additive content incudes, but is not limited to, humics, fulvics, living microbes, microbial métabolites, plant extracts, exogenous plant hormones, or combinations thereof. There are numerous suitable variations of humic or fulvic acid-containing formulations, any materials of which are organic matter derived and contain numerous humic and/or fulvic acid species. Microbes may include, but are not limited to, Rhodopseudomonas spp., Bacillus spp., Pseudomonas spp., Saccharomyces spp., Aspergillus spp., Candida spp., Streptococcus spp., Lactobacillus spp., or combinations thereof. Plant extracts may include, but are not limited to, phytohormones, quînols, plastoquinones, flavonoids, plant-growth-promoting métabolites, or combinations thereof. Exogenous plant hormones may include, but are not limited to, IDAA, gîbberellin, abscisic acid, auxins, jasmonates, brassinosteroîds, cytokinins, salicylic acid, or combinations thereof.

[0025] The agglomerated dispersible granules may further include minerai particles. The minerai particles may be agglomerated with the activated alumina particles and the phosphate particles or may be additional free particles intermixed with the agglomerated dispersible granules.

[00261 The agglomerated dispersible granules may include any suitable additive, such as, but not limited to, water-soluble binders, suspension agents, emulsifyîng agents, or combinations thereof. In one embodiment, the agglomerated dispersible granules include, by weight, 1-40% water-soluble binder, altematively 5-35%, altematively 5-15%, altematively 10-20%, altematively 15-25%, altematively 20-30%, altematively 25-35%, or any sub-range or combination thereof. Suitable water-soluble binders include, but are not limited to, calcium lignosulfonate, ammonium lignosulfonate, or combinations thereof. Suitable suspension agents include, but are not limited to, polysaccharides, inorganîc salts, carbomers, or combinations thereof. Suitable emulsifyîng agents include, but are not limited to, vegetable dérivatives such as acacia, tragacanth, agar, pectin, carrageenan, or lecithin, animal dérivatives such as gelatin, lanolin, or cholestérol, semi-synthetic agents such as methylcellulose, or carboxymethylcellulose, synthetics such as benzalkonium chloride, benzéthonium chloride, alkali soaps (including sodium or potassium oleate), amine soaps (including triethanolamine stéarate), détergents (including sodium lauryl sulfate, sodium dioctyl sulfosuccinate, or sodium docusate), sorbitan esters, polyoxyethylene dérivatives of sorbitan esters, glyceryl esters, or combinations thereof.

[0027] In one embodiment, the agglomerated dispersible granules include by weight, 10-80% activated alumina parti cl es, 10-80% phosphate parti clés, and 10-50% water-soluble binder, altematively 30^40% activated alumina particles, 30^10% phosphate particles, and 20^40% water-soluble binder, altematively 35% activated alumina particles, 35% phosphate particles, and 30% water-solublebinder. In afurther embodiment, the agglomerated dispersiblegranules include by weight, 10-70% activated alumina particles, 10-70% phosphate particles, and 10-50% watersoluble binder, and up to 20% surfactants and emulsifiers combined, altematively consist of, by weight, 10-50% activated alumina particles, 10-50% phosphate particles, and 10-50% watersoluble binder, and up to 5% surfactants and emulsifiers combined.

[0028] The agglomerated dispersible granules may hâve any suitable size (as measured by diameter based upon the médian within the sample). Suitable sizing for the agglomerated dispersible granules may include, but is not limited to, about 0.4 mm to about 4.0 mm, altematively about 0.4 mm to about 1.2 mm, altematively about 0.9 mm to about 1.5 mm, altematively about 1.2 mm to about 1.8 mm, altematively about 1.5 mm to about 2.1 mm, altematively about 1.8 mm to about 2.4 mm, altematively about 2.1 mm to about 2.7 mm, altematively about 2.4 mm to about 3.0 mm, altematively about 2.7 mm to about 3.3 mm, altematively about 3.0 mm to about 3.6 mm, altematively about 3.3 mm to about 4.0 mm, altematively about 0.4 mm, altematively about 0.5 mm, altematively about 0.6 mm, altematively about 0.7 mm, altematively about 0.8 mm, altematively about 0.9 mm, altematively about 1.0 mm, altematively about 1.1 mm, altematively about 1.2 mm, altematively about 1.3 mm, altematively about 14 mm, altematively about l .5 mm, altematively about 1.6 mm, altematively about 1.7 mm, altematively about 1.8 mm, altematively about 1.9 mm, altematively about 2.0 mm, altematively about 2.1 mm, altematively about 2.2 mm, altematively about 2.3 mm, altematively about 2.4 mm, altematively about 2.5 mm, altematively about 2.6 mm, altematively about 2.7 mm, altematively about 2.8 mm, altematively about 2.9 mm, altematively about 3.0 mm, altematively about 3.1 mm, altematively about 3.2 mm, altematively about 3.3 mm, altematively about 3.4 mm, altematively about 3.5 mm, altematively about 3.6 mm, altematively about 3.7 mm, altematively about 3.8 mm, altematively about 3.9 mm, altematively about 4.0 mm, altematively more than about 4.0 mm, or any sub-range or combination thereof. In ¹⁰ one non-limiting example, golf greens may use agglomerated dispersible granules of about 0.5 mm to about 0.8 mm. In another non-limitingexample, corn may use agglomerated dispersiblegranules via a broadcast application of about 2.4 mm. In a third non-limiting example, any crop with a striptill machine application may use agglomerated dispersible granules of about 1.5 mm. In one ⁵ embodiment, suitable, for example, for application as a suspension, the agglomerated dispersible granules are micronized, and hâve a particle size less than about 200 pm, altematively less than about 150 pm, altematively less than about 100 pm, altematively less than about 75 pm, altematively less than about 1 pm, altematively less than about 1 pm, altematively less than about 50 pm, altematively less than about 25 pm, altematively less than about 10 pm, altematively less 10 than about 5 pm, altematively less than about 2 pm, altematively less than about 1 pm, altematively less than about 0.75 pm, altematively less than about 0.5 pm, altematively less than about 0.25 pm, altematively less than about 0.1 pm, altematively less than about 0.05 pm, altematively less than about 0.01 pm, as measured by largest particle dimension.

[0029] A method for amending soil with buffered phosphorus includes physically blending 15 activated alumina particles (as described above) with phosphate particles, agglomerating the alumina particles with the phosphate particles to form agglomerated dispersible granules, and applying the agglomerated dispersible granules to soil. The activated alumina particles and the phosphate particles are présent in the agglomerated dispersible granules as distinct phases agglomerated together. The activated alumina particles may be free or essentially free of phosphate 20 disposed within the porous structure when applied to the soil. As used herein, “essentially free” indicates that less than 5% of available pores in the activated alumina particles include phosphate.

[0030] Agglomerating the aluminaparticles with the phosphate particles to form agglomerated dispersible granules may include any suitable agglomération method, such as, but not limited to, heat agglomération, agglomération using Chemical additîves (such as pan granulation), compaction agglomération, or combinations thereof.

[0031] The agglomerated dispersible granules may include an increased pénétration ability relative to BRAAPSA having the same ratio of activated alumina to phosphate such that a greater amount of the agglomerated dispersible granules would reach the root zone following contact with water than would BRAAPSA being applied in the same manner. Due tothis increased pénétration.

and the ability of the agglomerated dispersible granules to form BRAAPSA in situ upon contact with water, the agglomerated dispersible granules provide a more efficient pathway for buffering phosphate in the root zone than does direct application of BRAAPSA. The ability of the agglomerated dispersible granules to form BRAAPSA in situ may be due to the highly charged parti cl es of activated alumina in the agglomerated dispersible granules successfully competing with the soil to attract the phosphate ions from the agglomerated dispersible granules following contact with water. Additionally, agglomerated dispersible granules may be applied with fertilizers, pesticides, or both, makîng application more efficient for farmers who may add agglomerated dispersible granules to their traditional fertilizer or pesticide application methods. In this way, agglomerated dispersible granules may penetrate the soil profile where the activated alumina parti clés remain in the solid-phase State and the phosphate fertilizer source is solubilîzed and provides buffered phosphorus nutrients to plant roots, which may both improve plant growth and also reduce leaching of phosphorus.

[0032] Applying the agglomerated dispersible granules to the soil may include surface scattering the agglomerated dispersible granules on the soil, aerating the soil and disposing the agglomerated dispersible granules into the resulting aération holes, or tilling the soil with the agglomerated dispersible granules. In one embodiment, the agglomerated dispersible granules are applied to the soil without tilling the soil. Application of the agglomerated dispersible granules without tilling the soil may be particularly suitable for use with turf, fruit trees, vines, perennials, and other plants for which tilling the soil is undesirable.

[0033] In one embodiment, wherein the agglomerated dispersible granules are micronized, having a partîcle size less than about 200 gm, altemativeiy less than about 150 gm, altemativeiy less than about 100 gm, altemativeiy less than about 75 gm, altemativeiy less than about 1 gm, altemativeiy less than about 1 gm, altemativeiy less than about 50 gm, altemativeiy less than about 25 gm, altemativeiy less than about 10 gm, altemativeiy less than about 5 gm, altemativeiy less than about 2 gm, altemativeiy less than about 1 gm, altemativeiy less than about 0.75 gm, altemativeiy less than about 0.5 gm, altemativeiy less than about 0.25 gm, altemativeiy less than about 0.1 gm, altemativeiy less than about 0.05 gm, altemativeiy less than about 0.01 gm, as measured by largest particle dimension, the agglomerated dispersible granules may be suspended as a dispersed phase in a continuous phase. The continuous phase may be any suitable phase, încluding, but not limited to, water, a pesticide solution, a fertilizer solution, or combinations thereof. Tn a further embodiment, wherein the largest particle dimension precludes a stable suspension, the suspension may be agitated prior to or during application of the agglomerated dispersible granules. Application may include spraying the suspension or distributing the suspension through an irrigation System to the soil.

[0034] In one embodiment, an activated alumina suspension includes activated alumina particles (as otherwise described above), having a particle size less than about 200 gm, altematively less than about 150 gm, ahematively less than about 100 gm, altematively less than about 75 gm, altematively less than about 1 gm, altematively less than about 1 gm, altematively less than about 50 gm, altematively less than about 25 gm, altematively less than about 10 gm, altematively less than about 5 gm, altematively less than about 2 gm, altematively less than about 1 gm, altematively less than about 0.75 gm, altematively less than about 0.5 gm, altematively less than about 0.25 gm, altematively less than about 0.1 gm, altematively less than about 0.05 gm, altematively less than about 0.01 gm, as measured by largest particle dimension, distributed as a dispersed phase suspended in a continuous phase. The continuous phase may be any suitable phase, încluding, but not limited to, water, a pesticide solution, a fertilizer solution, or combinations thereof. The pesticide solution and the fertilizer solution may be aqueous solutions. The continuous phase may include solubilized phosphate or non-solubilized phosphate as a second dispersed phase suspended in the continuous phase. In a further embodiment, wherein the largest particle dimension precludes a stable suspension, the suspension may be agitated prior to or during application of the agglomerated dispersible granules. Application may include spraying the suspension or distributing the suspension through an irrigation system to the soil.

EXAMPLES

[0035] Comparative and inventive compositions were tested to study the effects of soil amendment on plant growth (perennial ryegrass). Testing conditions included graded fine 100% sand as the soil (reduced water, low nitrogen, reduced phosphorous) disposed in four inch round pots having 650 g medium per pot with 100 cm² surface area. 8 réplications per treatment were performed. The light source was 200-250 gmol/m²/s with a 16 hour light and 8 hour dark cycle at 28 °C under light and 22° C under dark. Fertilizer was applied (10-0-32 at rate of 0.1 g per pot;

0.01 g N per pot; TSP 0-45-0 at 0.1 g P2O5 per pot).

[0036] Example 1 (comparative): 0.045 g P2O5 / pot (triple super phosphate used as full phosphores control).

[0037] Example 2 (comparative): 0.023 g P₂Os / pot (triple super phosphate used as 50% load (rate) phosphores control).

[0038] Example 3 (comparative): Phosphorus-bound alumina (amount applied to provide 100% phosphores, equal amount of to 100% phosphores load (rate) control of Example 1). This comparative embodiment is not suitable for agricultural use due to înconsistent sizing, extremely dusty material, and limitations of agricultural application equipment.

[0039] Example 4 (comparative): Phosphorus-bound alumina (amount applied to provide 50% phosphores, equal amount of to 50% phosphores load (rate) control of Example 2). This comparative embodiment is not suitable for agricultural use due to înconsistent sizing, extremely dusty material, and limitations of agricultural application equipment.

[0040] Example 5 (inventive): Agglomerated dispersible granules (amount of alumina applied with added phosphores to equal 50% phosphores load (rate) of Example 2).

[0041] Example 6 (inventive): Agglomerated dispersible granules (amount of alumina applied with added phosphores to equal 50% phosphores load (rate) of Example 2).

[0042] Example 7 (comparative): Base material (non-agglomerated alumina with amount of alumina applied with added phosphores to equal 50% phosphores load (rate) of Example 2). While effective for testing purposes, this comparative embodiment is not suitable for agricultural use due to înconsistent sizing, extremely dusty material, and limitations of agricultural application equipment.

[0043] Example 8 (comparative): Base material (non-agglomerated alumina with amount of alumina applied with added phosphores to equal 50% phosphores load (rate) of Example 2). While effective for testing purposes, this comparative embodiment is not suitable for agricultural use due to înconsistent sizing, extremely dusty material, and limitations of agricultural application equipment.

[0044] Example 9 (inventive): Base material (about 1,200 pm to about 300 pm with amount of alumina applied with added phosphorus to equal 50% phosphorus load (rate) of Example 2).

[0045] Example 10 (inventive): Base material (about 700 pm to about 175 pm with amount of alumina applied with added phosphorus to equal 50% phosphorus load (rate) of Example 2).

[0046] Example 11 (inventive): Base material (about 150 pm with amount of alumina applied with added phosphorus to equal 50% phosphorus load (rate) of Example 2).

[0047] Table 1. Composition Effects

Example	Activated Alumina1	Emerge Day I02	Root Mass (fi)	Root Mass SE	Root Mass % Increase	Root PUE3	Root PUE%3	Product efficacy4
1 (comparative)	0	39.1	0.93	0.07		20.6
2 (comparative)	0	39.0	0.96	0.06		42.6
3 (comparative)	476	39.6	1.12	0.08	16.3	32.8	-23.0	2.6
4 (comparative)	476	41.9	1.33	0.05	38.5	39.0	-8.4	3.1
5 (inventive)	56	41.2	1.04	0.06	8.6	46.3	8.60	20.8
6 (inventive)	112	42.1	1.14	0.07	18.7	50.6	18.73	11.4
7 (comparative)	56	39.4	1.13	0.08	17.3	50.0	17.34	22.5
8 (comparative)	112	38.8	1.26	0.07	31.1	55.9	31.10	12.6

¹ (kg/ha) Applied.

² Number of Plants ³ Phosphorus Use Efficiency ⁴ Material Applied

[0048] There is little variation between Examples 1-8 in number of plants emerging at day 10, or the resulting root mass using phosphorus-bound alumina (Examples 3 and 4), activated (calcined) alumina (Examples 7 and 8) and the inventive examples (Examples 5 and 6). There is, however, a différence in root phosphorus use efficiency and product efficacy per amount applied.

For root phosphorus efficiency, while phosphorus-bound alumina increases overail root mass, the root phosphorus use efficiency is lower than for unmodified activated alumina or agglomerated dispersible granules of phosphate and activated alumina. Because alumina is a strong adsorber of phosphorus once activated, either by acid rinsing or by calcination, it was expected that either would increase root mass. ït was surprising, however, that using activated alumina without phosphorous would give a better phosphorus use efficiency for the same amount of phosphorus as is delivered through phosphorus-bound alumina.

[0049] To achieve the same level of root mass growth by supplying plant phosphorous needs through phosphorus-bound alumina, much more material is needed than using activated alumina alone. 56-112 kg/ha of activated alumina (without being bound to phosphorus) achieves the same results as adding 476 kg/ha of phosphorus-bound alumina.

[0050] Table 2. Size Effects: Root Mass % Increase is Relative to Control of 50% Phosphorus Level in Example 2

Example	Sizes from Larger to Smaller	Root Mass % Increase
9	~ 1,200 pm —300 pm	5.2
10	- 700 pm —175 pm	23.9
11	- 150 pm	24.5

[0051] Unexpectedly, Examples 9-11 demonstrate agglomerated dispersible granules having same composition, but different activated alumina parti cle sizes increase the adsorption and ultimate release to plants, as indicated by root mass % increase, of phosphorus. Agglomerated dispersible granules having a maximum about 150 pm activated alumina particle size demonstrated the highest root mass % increase, whereas agglomerated dispersible granules having a size between about 1,200 pm to about 300 pm demonstrated the lowest root mass % increase.

[0052] While the foregoing spécification illustrâtes and describes exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and équivalents may be substituted for éléments thereof without départing from the scope of the invention. In addition, many modifications may be made to adapt a parti cul ar situation or material to the teachîngs of the invention without départing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include ali embodiments falling within the scope of the appended daims.

Claims (10)

1. ]. Agglomerated dîspersible granules, comprising: activated alumina particles having: a porous structure; and a plurality of electrically-charged binding sites disposed within the porous structure; and phosphate particles, wherein the activated alumina particles and the phosphate particles are présent in the agglomerated dîspersible granules as distinct phases agglomerated together.
2. 2. The agglomerated dîspersible granules of claîm 1, wherein the activated alumina particles are free of phosphate disposed within the porous structure.

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3. 3. The agglomerated dîspersible granules of claim 1, wherein the activated alumina particles and the phosphate particles are homogenously dîstributed in the agglomerated dîspersible granules.
4. 4. The agglomerated dîspersible granules of claim 1, having a weight ratio of alumina to phosphate of 10:1 to 1:10.
5. 5 a plurality of electrically-charged binding sites disposed within the porous structure; and a particle size measured by largest particle dimension less than 200 pm; and a continuous phase, wherein the activated alumina particles constitute a dispersed phase suspended in the continuous phase.

   19. The activated alumina suspension of claim 18, where in the continuous phase is selected from the group consisting of water, a pesticide solution, a fertilizer solution, or combinations thereof,

   5. The agglomerated dîspersible granules of claîm 1, further including additional nutrient particles présent as distinct phases and agglomerated with the activated alumina particles and the phosphate particles.

   ¹θ
6. 6. The agglomerated dîspersible granules of claim 5, wherein the additional nutrient particles includes at least one nutrient selected from the group consisting of bioavaîlable species of molybdenum, sélénium, zinc, copper, cobalt, iron, nickel, manganèse, vanadium, calcium, potassium, sulfur, chlorine, Silicon, magnésium, sodium, nitrogen, boron, and combinations thereof.
7. 7. The agglomerated dîspersible granules of claim 1, wherein the activated alumina particles are free of the at least one nutrient within the porous structure.

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8. 8. The agglomerated dîspersible granules of claim 1, wherein the agglomerated dîspersible granules are coated with an additional nutrient layer, the additional nutrient layer including at least one nutrient selected from the group consisting of bioavaîlable species of molybdenum, sélénium, zinc, copper, cobalt, iron, nickel, manganèse, vanadium, calcium, potassium, sulfur, chlorine, Silicon, magnésium, sodium, nitrogen, boron, and combinations thereof.
9. 9. The agglomerated dispersible granules of claim 1, further including pesticide particles présent as distinct phases and agglomerated with the activated alumina particles and the phosphate particles.

   5

   10. The agglomerated dispersible granules of claim 1, wherein the agglomerated dispersible granules are coated with a pesticide layer.

   11. The agglomerated dispersible granules of claim 1, further including biological additive particles présent as distinct phases and agglomerated with the activated alumina particles and the phosphate particles.

   12. The agglomerated dispersible granules of claim 11, wherein the biological additive particles include at least one additive selected from the group consisting of humics, fui vies, living 10 microbes, microbial métabolites, plant extracts, exogenous plant hormones, and combinations thereof.

   13. The agglomerated dispersible granules of claim 1, wherein the agglomerated dispersible granules are coated with a biological additive layer, the biological additive layer including at least one additive selected from the group consisting of humics, fulvics, living microbes, microbial métabolites, plant extracts, exogenous plant hormones, and combinations thereof.

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   14. The agglomerated dispersible granules of claim 1, further including at least one of a water- soluble binder, a suspension agent, or an emulsifying agent.

   15. The agglomerated dispersible granules of claim 1, wherein the activated alumina particles are less than 200 pm in size as measured by largest particle dimension.

   16. A method foramending soil with buffered phosphorus, comprising: physîcally blending activated alumina particles with phosphate particles, the activated alumina particles having:

   a porous structure; and a plurality of electrically-charged binding sites disposed within the porous structure, and then

   20 agglomerating the alumina particles with the phosphate particles to form agglomerated dispersible granules; and applyîng the agglomerated dispersible granules to soil, wherein the activated alumina partîcles and the phosphate particles are présent in the agglomerated dispersible granules as distinct phases agglomerated together and the activated alumina particles are free of phosphate dîsposed wîthîn the porous structure when applied to the soil,

   17. The method of claim 16, wherein the agglomerated dispersible granules are applied to the soi! without tilling the soil.

   18. An activated alumina suspension, comprising:

   activated alumina particles having:

   a porous structure;
10. 10 20. The activated alumina suspension of claim 18, where in the continuous phase includes solubilized phosphate or non-solubilized phosphate as a second dispersed phase suspended in the continuous phase.