Agglomerated dispersible granules, method of improving soil and active alumina suspension

Abstract

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

Description

[0001] Related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application No. 62 / 987,461, filed March 10, 2020, entitled “Improved Methods for Making and Applying Buffered Phosphorus,” which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to agglomerated dispersible particles, methods for soil improvement, and activated alumina suspensions. In particular, this application relates to agglomerated dispersible particles having alumina particles and phosphate particles existing as different phases, methods for improving soil with buffered phosphorus in the form of agglomerated dispersible particles, and activated alumina suspensions, wherein activated alumina particles constitute a dispersed phase suspended in a continuous phase. Background Technology

[0004] Phosphorus is a critical nutrient for plant growth. Metal oxides, including activated alumina, kaolin, bauxite, iron oxide, calcium oxide, and magnesium oxide, have been used as buffers for phosphorus application as fertilizer. In particular, activated alumina has been used as a buffer-release alumina and phosphorus soil conditioner (“BRAAPSA”). Traditionally, BRAAPSA is prepared by loading liquid phosphorus (e.g., phosphate) onto activated alumina to produce BRAAPSA, which can be physically introduced into the soil as a soil conditioner for plants. Lynch et al. describe a method for forming BRAAPSA in U.S. Patent No. 6,287,357, which relies on the reversible binding of a phosphorus source to acid-activated alumina prior to soil application. BRAAPSA significantly reduces unwanted phosphorus loss due to leaching, which is unwanted because phosphorus leaching can lead to groundwater contamination and increase the amount of phosphorus that needs to be applied to the soil. Furthermore, BRAAPSA can positively improve plant growth in various plant species (e.g., by improving root growth, etc.). This is because BRAAPSA's buffer release mechanism is based on chemical gradient nutrient release, while existing coated fertilizer technologies rely on environmental conditions and result in more phosphorus leaching (i.e. loss) into groundwater.

[0005] Activation of metal oxides can be carried out in various ways. Activated alumina adsorbents are typically produced by agglomeration and thermal treatment (i.e., calcination) of alumina trihydrate powder. Spherical alumina is formed, then pulverized (e.g., mechanically crushed), and then sieved to produce granular activated alumina of various sizes (often referred to as sieve aperture due to the size of the mesh used for separating particles based on size). The adsorption capacity of activated metal oxides such as activated alumina depends largely on surface area. Due to the porous nature of activated alumina, most of its surface area exists in the pores created by the calcination process (i.e., more porous compounds have a larger surface area than particles of similar size with fewer pores). Compared to other plant nutrients such as nitrogen and potassium, its ability to chemisorb orthophosphate is higher due to the material's high anion exchange capacity, making activated alumina a preferred matrix for buffering phosphate fertilizer release. However, many other metal oxides can be activated and used in similar ways.

[0006] While applying BRAAPSA soil conditioner to the soil is more effective than conventional methods of directly applying phosphorus-containing fertilizers to the soil (i.e., directly or via coated fertilizers), the preparation of BRAAPSA can be difficult, expensive, and time-consuming. The method of loading granular activated alumina with a liquid phosphorus source (e.g., phosphoric acid) presents significant problems. For example, liquid phosphorus compounds (e.g., phosphoric acid, orthophosphoric acid, phosphoric(V) acid) are acids that require careful handling and the use of personal protective equipment, as acids such as phosphoric acid can cause severe irritation to the skin and eyes. Furthermore, liquid phosphorus (e.g., phosphoric acid) requires specialized equipment for handling, as contact with the acid can degrade the equipment. Additionally, the insolubility of activated alumina limits its application opportunities. For example, activated alumina must be physically and / or mechanically bound to the soil (e.g., applied to small holes at a certain depth). For farmers, physical and / or mechanical application to the soil can prove to be a time-consuming and laborious process. Moreover, physical and / or mechanical application is not ideal for various fertilizer application opportunities (e.g., hydroponics and no-till plants, fruit trees, and turf). Application processes are typically limited to granular activated alumina with a size of 8×14, 14×28, or 14×48 mesh. Particle size can provide structural benefits for soil application (e.g., particles that are too small can generate dust, leading to product loss and being harmful to humans when inhaled; particles that are too large can have a smaller surface area and can have reduced buffering capacity and be more expensive).

[0007] In most agricultural production systems (e.g., lawns, ornamental plants, and crops), fertilizers are applied to the surface of the growing medium (e.g., soil) and then irrigated into the soil profile (e.g., solid granular fertilizers are applied to the soil surface, and soluble fertilizers enter the soil when water is applied). The limitation of applying activated alumina alone or directly to the surface of the growing medium (e.g., soil) is that it cannot be effectively irrigated (e.g., due to solubility and / or particle size). For example, conventional granules that can be pre-loaded with liquid fertilizer sources are too large to be effectively irrigated into the soil, and phosphorus-free activated alumina has limited solubility, making irrigation a challenge.

[0008] Soil conditioners containing active alumina that are not subject to the above restrictions would be ideal. Summary of the Invention

[0009] In one exemplary embodiment, the agglomerated dispersible particles include activated alumina particles and phosphate particles. The activated alumina particles have a porous structure and multiple charged binding sites disposed within the porous structure. The activated alumina particles and phosphate particles exist as different phases agglomerated together in the agglomerated dispersible particles.

[0010] In another exemplary embodiment, a method for improving soil with buffered phosphorus includes physically mixing activated alumina particles with phosphate particles, then agglomerating the alumina particles and phosphate particles to form agglomerated dispersible particles, and applying the agglomerated dispersible particles to the soil. The activated alumina particles have a porous structure and multiple charged binding sites disposed within the porous structure. The activated alumina particles and phosphate particles exist as different phases agglomerated together in the agglomerated dispersible particles, and when applied to the soil, the activated alumina particles do not contain phosphate disposed within the porous structure.

[0011] In another exemplary embodiment, the activated alumina suspension comprises activated alumina particles and a continuous phase. The activated alumina particles have a porous structure and multiple charged binding sites disposed within the porous structure, and the particle size, measured by the largest particle size, is less than 1 μm. The activated alumina particles constitute a dispersed phase suspended in the continuous phase. Detailed Implementation

[0012] This document discloses a method for improving soil with buffered phosphorus in the form of agglomerated dispersible particles having alumina particles and phosphate particles existing as different phases, and an activated alumina suspension, wherein the activated alumina particles constitute a dispersed phase suspended in a continuous phase. Specifically, BRAAPSA can be formed in situ in soil by applying agglomerated dispersible particles having alumina particles and phosphate particles existing as different phases to the soil, followed by applying water to the soil or the agglomerated dispersible particles in the soil (by irrigation or by natural precipitation). Compared to compositions and methods that do not include one or more of the features disclosed herein, the compositions and methods disclosed herein can be directly applied to the soil surface of most agricultural production systems (e.g., turf, ornamental plants, and crops), reducing manufacturing and application costs, increasing the infiltration of BRAAPSA into the soil, reducing runoff and waste, or combinations thereof. Of particular note is that while previous work, such as that disclosed by Lynch et al. in U.S. Patent No. 6,287,357, describes a method for forming BRAAPSA that requires the phosphorus source to be reversibly bound to acid-activated alumina prior to soil application, it has been unexpectedly discovered in this invention that applying phosphate and activated alumina without binding prior to application yields equivalent or even better results, and is also applicable to buffering nutrients other than phosphorus. This method and the use of the materials are significantly simpler than preloading activated alumina prior to soil application. Furthermore, using this method, the amount of activated alumina required per hectare is at least 50%, at most 90%, or even at most 95% less than that required when preloading bound phosphorus.

[0013] As used herein, “about” indicates a deviation of up to 10% from the value so modified. All values ​​modified with “about” are also intended to express the unmodified value as an alternative; thus, for example, “about 10 μm” discloses a range of 9–11 μm and a specific 10 μm.

[0014] In one embodiment, the agglomerated dispersible particles include activated alumina particles and phosphate particles. The activated alumina particles have a porous structure and multiple charged binding sites disposed within the porous structure. The activated alumina particles and phosphate particles exist as different phases agglomerated together in the agglomerated dispersible particles.

[0015] Activated alumina particles can be calcined alumina particles or calcined alumina particles that have undergone additional acid washing before or after calcination. Activated alumina particles can be produced from spherical alumina that has been crushed and sieved based on particle size distribution. The pores in activated alumina particles contain most of the adsorption capacity because a large portion of the surface area of ​​the activated alumina particles is likely within the pores. Activated alumina particles can have any suitable size. In one embodiment, to maintain phosphate adsorption capacity and optimize the activated alumina particle size for surface application to infiltrate soil profiles, the preferred particle size of the activated alumina particles is less than about 300 μm, or less than about 150 μm or smaller. Variations in activated alumina particle size include, but are not limited to, portions ranging from about 2400 μm to about 1200 μm, from about 1200 μm to about 600 μm, from about 1200 μm to about 300 μm, or other common size grades, as well as physically broken particles (e.g., the product is ground to about 300 μm to about 150 μm, about 150 μm to about 75 μm, or less than 75 μm by a grinding process). This results in smaller-sized activated alumina particles.

[0016] In another implementation, suitably, for example for suspensions, the particle size of the activated alumina particles, measured by maximum particle size, is less than about 200 μm, or less than about 150 μm, or less than about 100 μm, or less than about 75 μm, or less than about 1 μm, or less than about 1 μm, or less than about 50 μm, or less than about 25 μm, or less than about 10 μm, or less than about 5 μm, or less than about 2 μm, or less than about 1 μm, or less than about 0.75 μm, or less than about 0.5 μm, or less than about 0.25 μm, or less than about 0.1 μm, or less than about 0.05 μm, or less than about 0.01 μm. Applying smaller-sized activated alumina particles directly to the soil surface can be challenging because activated alumina has limited solubility, and small particle sizes can be dusty. Note that for particle suspensions, stirring can be used to form a temporary suspension of particles, otherwise the particles may be too large to form a stable suspension. The viscosity of the continuous phase can be increased to further stabilize the suspension and compensate for particle size.

[0017] Suitable phosphate particles include, but are not limited to, monoammonium phosphate, diammonium phosphate, monopotassium phosphate, dipotassium phosphate, superphosphate, polyphosphates, any other similar dry phosphates, or combinations thereof. In one embodiment, the dry granular phosphate source may be physically crushed (i.e., ground or pulverized) to a size similar to that of smaller activated alumina particles in terms of size / mesh / density to promote uniform mixing.

[0018] In one embodiment, the activated alumina particles are substantially free of, or contain no, phosphates situated within the porous structure. As used herein, “substantially free of” means that less than 5% of the available pores in the activated alumina particles contain phosphates.

[0019] Activated alumina particles and phosphate particles can be uniformly or unevenly distributed in agglomerated dispersible particles.

[0020] The agglomerated dispersible particles may have any suitable alumina to phosphate weight ratio, including but not limited to weight ratios of 10:1 to 1:10, or 8:1 to 1:8, or 7:1 to 1:7, or 6:1 to 1:6, or 5:1 to 1:5, or 4:1 to 1:4, or 3:1 to 1:3, or 2:1 to 1:2, or 3:1 to 1:1, or 1:1 to 1:3, or about 2:1, or about 1:1, or about 1:2, or any subrange or combination thereof.

[0021] The agglomerated dispersible particles may further include additional nutrient components. These additional nutrient components may be in the form of particles existing in a different phase and agglomerated with the activated alumina particles and phosphate particles, or as additional nutrient layers coated on the agglomerated dispersible particles, or as additional free nutrient particles mixed with the agglomerated dispersible particles.

[0022] Suitable additional nutrients include, but are not limited to, bioavailable substances of molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, or combinations thereof. Bioavailable substances of the above nutrients include, but are not limited to, MoO2. – SeO2 – Zn 2+ ZnCl – CuCO3, Co 2+ Fe 2+ Fe 3+ Ni 2+ NiCl + Mn 2+ MnCl + HVO4 2– Ca 2+ K+, SO4 2– Cl – SiOH4, Mg 2+ Na + NH 4+ NO3 – H3BO3 and B4O7 2– .

[0023] In one embodiment, the activated alumina particles are substantially free of, or contain no, at least one nutrient in their porous structure. As used herein, “substantially free of” means that less than 5% of the available pores in the activated alumina particles contain at least one nutrient.

[0024] The agglomerated dispersible particles may further comprise pesticide components. The pesticide components may be in the form of particles existing in a different phase and agglomerated with activated alumina particles and phosphate particles, or as a pesticide layer coated on the agglomerated dispersible particles, or as additional free pesticide particles mixed with the agglomerated dispersible particles. Suitable pesticides include, but are not limited to, herbicides, insecticides, fungicides, nematicides, or combinations thereof. Suitable herbicides include, but are not limited to, sulfonylureas, HPPD inhibitors, chloroacetamides, PPO inhibitors, phenylurea, triazines, or combinations thereof. Suitable insecticides include, but are not limited to, organophosphates, urea, pyrethroids, neonicotinoids, spinosin, indoxacarb, diamides, or combinations thereof. Suitable fungicides include, but are not limited to, strobilurines, pyrimidines, triazoles, dicarboximides, or combinations thereof. Suitable nematicides include, but are not limited to, abamectin, carbamates, organophosphates, or combinations thereof.

[0025] The agglomerated dispersible particles may further include bio-additive components. These bio-additive components may exist in a different phase and agglomerated with activated alumina and phosphate particles, or as a bio-additive layer coated on the agglomerated dispersible particles, or as additional free bio-additive particles mixed with the agglomerated dispersible particles. Suitable bio-additive components include, but are not limited to, humic substances, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, or combinations thereof. Formulations containing humic or fulvic acid have various suitable variations, any of which are derived from organic matter and contain multiple types of humic and / or fulvic acids. Microorganisms may include, but are not limited to, *Rhodopseudomonas*, *Bacillus*, *Pseudomonas*, *Saccharomyces*, *Aspergillus*, *Candida*, *Streptococcus*, *Lactobacillus*, or combinations thereof. Plant extracts may include, but are not limited to, plant hormones, quinone alcohols, plastoquinones, flavonoids, plant growth-promoting metabolites, or combinations thereof. Exogenous plant hormones may include, but are not limited to, IDAA, gibberellin, abscisic acid, auxin, jasmonic acid, rapeseed steroids, cytokinins, salicylic acid, or combinations thereof.

[0026] The agglomerated dispersible particles may further include mineral particles. The mineral particles may agglomerate with activated alumina particles and phosphate particles, or may be additional free particles mixed with the agglomerated dispersible particles.

[0027] The agglomerated dispersible particles may include any suitable additives, such as, but not limited to, water-soluble binders, suspending agents, emulsifiers, or combinations thereof. In one embodiment, the agglomerated dispersible particles comprise 1-40% by weight, or 5-35% by weight, or 5-15% by weight, or 10-20% by weight, or 15-25% by weight, or 20-30% by weight, or 25-35% by weight, or any subrange or combination thereof of a water-soluble binder. Suitable water-soluble binders include, but are not limited to, calcium lignosulfonate, ammonium lignosulfonate, or combinations thereof. Suitable suspending agents include, but are not limited to, polysaccharides, inorganic salts, carbomer, or combinations thereof. Suitable emulsifiers include, but are not limited to, plant derivatives such as gum arabic, tragacanth, agar, pectin, carrageenan, or lecithin; animal derivatives such as gelatin, lanolin, or cholesterol; semi-synthetic agents such as methylcellulose or carboxymethylcellulose; synthetic agents such as benzalkonium chloride, benzyl chloride, alkaline soaps (including sodium oleate or potassium oleate), amine soaps (including triethanolamine stearate), detergents (including sodium dodecyl sulfate, sodium dioctyl sulfosuccinate, or sodium docusate), sorbitol esters, polyethylene oxide derivatives of sorbitol esters, glycerides, or combinations thereof.

[0028] In one embodiment, the agglomerated dispersible particles comprise 10-80 wt% activated alumina particles, 10-80 wt% phosphate particles, and 10-50 wt% water-soluble binder; or 30-40 wt% activated alumina particles, 30-40 wt% phosphate particles, and 20-40 wt% water-soluble binder; or 35 wt% activated alumina particles, 35 wt% phosphate particles, and 30 wt% water-soluble binder. In another embodiment, the agglomerated dispersible particles comprise 10-70 wt% activated alumina particles, 10-70 wt% phosphate particles, and 10-50 wt% water-soluble binder, and up to 20 wt% a combination of surfactant and emulsifier; or consist of 10-50 wt% activated alumina particles, 10-50 wt% phosphate particles, and 10-50 wt% water-soluble binder, and up to 5 wt% a combination of surfactant and emulsifier.

[0029] The agglomerated dispersible particles can have any suitable size (based on diameter measurements of the median within the sample). Suitable sizes of the agglomerated dispersible particles may include, but are not limited to, about 0.4 mm to about 4.0 mm, or about 0.4 mm to about 1.2 mm, or about 0.9 mm to about 1.5 mm, or about 1.2 mm to about 1.8 mm, or about 1.5 mm to about 2.1 mm, or about 1.8 mm to about 2.4 mm, or about 2.1 mm to about 2.7 mm, or about 2.4 mm to about 3.0 mm, or about 2.7 mm to about 3.3 mm, or about 3.0 mm to about 3.6 mm, or about 3.3 mm to about 4 mm, or about 0.4 mm, or about 0.5 mm, or about 0.6 mm, or about 0.7 mm, or about 0.8 mm, or about 0.9 mm, or about 1.0 mm, or about 1 mm. The particle size may be approximately 0.1 mm, or about 1.2 mm, or about 1.3 mm, or about 1.4 mm, or about 1.5 mm, or about 1.6 mm, or about 1.7 mm, or about 1.8 mm, or about 1.9 mm, or about 2.0 mm, or about 2.1 mm, or about 2.4 mm, or about 2.5 mm, or about 2.6 mm, or about 2.7 mm, or about 2.8 mm, or about 2.9 mm, or about 3.0 mm, or about 3.1 mm, or about 3.2 mm, or about 3.3 mm, or about 3.4 mm, or about 3.5 mm, or about 3.6 mm, or about 3.7 mm, or about 3.8 mm, or about 4.0 mm, or greater than about 4.0 mm, or any subrange or combination thereof. In a non-limiting example, agglomerated dispersible particles of about 0.5 mm to about 0.8 mm may be used on a golf green. In another non-limiting example, maize can be applied by broadcasting using agglomerated dispersible particles of about 2.4 mm. In a third non-limiting example, any crop applied using a strip tiller can use agglomerated dispersible particles of about 1.5 mm. In one embodiment, suitably, for example for application as a suspension, the agglomerated dispersible particles are micronized and have a particle size less than about 200 μm, or less than about 150 μm, or less than about 100 μm, or less than about 75 μm, or less than about 1 μm, or less than about 1 μm, or less than about 50 μm, or less than about 25 μm, or less than about 10 μm, or less than about 5 μm, or less than about 2 μm, or less than about 1 μm, or less than about 0.75 μm, or less than about 0.5 μm, or less than about 0.25 μm, or less than about 0.1 μm, or less than about 0.05 μm, or less than about 0.01 μm, as measured by the maximum particle size.

[0030] A method for improving soil with buffered phosphorus includes physically mixing activated alumina particles (as described above) with phosphate particles, agglomerating the alumina and phosphate particles to form agglomerated dispersible particles, and applying the agglomerated dispersible particles to the soil. The activated alumina particles and phosphate particles exist as different phases agglomerated together within the agglomerated dispersible particles. When applied to the soil, the activated alumina particles may contain no or substantially no phosphate contained in the porous structure. As used herein, "substantially no" means that less than 5% of the usable pores in the activated alumina particles contain phosphate.

[0031] Agglomerating alumina particles with phosphate particles to form agglomerated dispersible particles can include any suitable agglomeration method, such as, but not limited to, thermal agglomeration, agglomeration using chemical additives (e.g., disc granulation), compaction agglomeration, or a combination thereof.

[0032] Compared to BRAAPSA with the same active alumina to phosphate ratio, agglomerated dispersible particles (ADMPs) can have increased permeability, allowing a greater amount of ADMPs to reach the root zone after contact with water compared to BRAAPSA applied in the same manner. Due to this increased permeability, and the ability of ADMPs to form BRAAPSA in situ upon contact with water, ADMPs provide a more efficient pathway for buffering phosphates in the root zone than direct application of BRAAPSA. The ability of ADMPs to form BRAAPSA in situ is likely due to the highly charged active alumina particles within the ADMPs successfully competing with the soil to attract phosphate ions from the ADMPs upon contact with water. Furthermore, ADMPs can be applied with fertilizers, pesticides, or both, making application more efficient for farmers who can add ADMPs to their traditional fertilizer or pesticide application methods. In this way, the aggregated dispersible particles can penetrate into the soil profile, where the active alumina particles remain in a solid state, the phosphate fertilizer source is dissolved and provides buffered phosphorus nutrients to the plant roots, which can both improve plant growth and reduce phosphorus leaching.

[0033] Applying agglomerated dispersible particles to soil may include dispersing the agglomerated dispersible particles on the surface of the soil, aerating the soil, placing the agglomerated dispersible particles in the resulting aeration pores, or tilling the soil with the agglomerated dispersible particles. In one embodiment, the agglomerated dispersible particles are applied to the soil without tilling. Applying agglomerated dispersible particles without tilling the soil may be particularly suitable for turf, fruit trees, vines, perennials, and other plants for which tilling is not desired.

[0034] In one embodiment, the agglomerated dispersible particles are micronized to have a particle size less than about 200 μm, or less than about 150 μm, or less than about 100 μm, or less than about 75 μm, or less than about 1 μm, or less than about 1 μm, or less than about 50 μm, or less than about 25 μm, or less than about 10 μm, or less than about 5 μm, or less than about 2 μm, or less than about 1 μm, or less than about 0.75 μm, or less than about 0.5 μm, or less than about 0.25 μm, or less than about 0.1 μm, or less than about 0.05 μm, or less than about 0.01 μm, as a dispersed phase, and the agglomerated dispersible particles can be suspended as a dispersed phase in a continuous phase. The continuous phase can be any suitable phase, including but not limited to water, pesticide solutions, fertilizer solutions, or combinations thereof. In another embodiment, where the maximum particle size precludes a stable suspension, the suspension can be agitated before or during the application of the agglomerated dispersible particles. Application may include spraying the suspension or distributing the suspension to the soil via an irrigation system.

[0035] In one embodiment, the activated alumina suspension comprises activated alumina particles (as described above) having a particle size less than about 200 μm, or less than about 150 μm, or less than about 100 μm, or less than about 75 μm, or less than about 1 μm, or less than about 1 μm, or less than about 50 μm, or less than about 25 μm, or less than about 10 μm, or less than about 5 μm, or less than about 2 μm, or less than about 1 μm, or less than about 0.75 μm, or less than about 0.5 μm, or less than about 0.25 μm, or less than about 0.1 μm, or less than about 0.05 μm, or less than about 0.01 μm, as measured by maximum particle size. The agglomerated dispersible particles may be suspended as a dispersed phase in a continuous phase. The continuous phase may be any suitable phase, including but not limited to water, pesticide solutions, fertilizer solutions, or combinations thereof. Pesticide solutions and fertilizer solutions may be aqueous solutions. The continuous phase may include dissolved phosphate or insoluble phosphate suspended in the continuous phase as a second dispersed phase. In another embodiment, where the largest particle size precludes a stable suspension, the suspension may be agitated before or during application of the agglomerated dispersible particles. Application may include spraying the suspension or distributing it to the soil via an irrigation system.

[0036] Example

[0037] The comparative composition and the composition of this invention were tested to study the effects of soil conditioners on plant growth (perennial ryegrass). Test conditions included placing graded 100% fine sand (reduced water, low nitrogen, reduced phosphorus) in four-inch round pots, each containing 650g of medium and a surface area of ​​100cm². 2Each treatment was repeated 8 times. The light source was 200-250 μmol / m³. 2 / s, with a 16-hour light and 8-hour dark cycle, maintained at 28°C under light and 22°C under dark. Fertilizer applied (10-0-32 at a rate of 0.1g per pot; 0.01g N per pot; TSP 0-45-0 at a rate of 0.1g P2O5 per pot).

[0038] Example 1 (Comparative): 0.045g P2O5 / pot (triple superphosphate was used as a total phosphorus control)

[0039] Example 2 (Comparative): 0.023 g P2O5 / pot (superphosphate was used as a 50% phosphorus loading (ratio) control)

[0040] Example 3 (Comparative): Phosphorus-bonded alumina (applied in an amount equal to the amount of 100% phosphorus load (ratio) control of Example 1). This comparative example is not suitable for agricultural use due to inconsistent dimensions, the dusty material, and limitations of agricultural application equipment.

[0041] Example 4 (Comparative): Phosphorus-bonded alumina (applied in an amount equal to 50% phosphorus as the control of 50% phosphorus loading (ratio) in Example 2). This comparative example is not suitable for agricultural use due to inconsistent dimensions, the dusty material, and limitations of agricultural application equipment.

[0042] Example 5 (of the present invention): Agglomerated dispersible particles (the amount of phosphorus-added alumina applied is equal to 50% of the phosphorus loading (ratio) of Example 2)

[0043] Example 6 (of the present invention): Agglomerated dispersible particles (the amount of phosphorus-added alumina applied is equal to 50% of the phosphorus loading (ratio) of Example 2)

[0044] Example 7 (Comparative): Base material (non-agglomerated alumina, with an applied amount of phosphorus-added alumina equal to 50% of the phosphorus loading (ratio) of Example 2). Although effective for testing purposes, this comparative example is not suitable for agricultural use due to inconsistent dimensions, the abundance of dust in the material, and limitations of agricultural application equipment.

[0045] Example 8 (Comparative): Base material (non-agglomerated alumina, with an applied amount of phosphorus-added alumina equal to 50% of the phosphorus loading (ratio) of Example 2). Although effective for testing purposes, this comparative example is not suitable for agricultural use due to inconsistent dimensions, the abundance of dust in the material, and limitations of agricultural application equipment.

[0046] Example 9 (the present invention): base material (about 1200 μm to about 300 μm, the amount of phosphorus-added alumina applied is equal to 50% phosphorus loading (ratio) of Example 2).

[0047] Example 10 (the present invention): base material (about 700 μm to about 175 μm, the amount of phosphorus-added alumina applied is equal to 50% phosphorus loading (ratio) of Example 2).

[0048] Example 11 (the present invention): base material (approximately 150 μm, the amount of phosphorus-added alumina applied is equal to 50% phosphorus loading (ratio) of Example 2).

[0049] Table 1 Compositional Effects

[0050]

[0051]

[0052] 1 Application rate (kg / ha).

[0053] 2 Number of plants

[0054] 3 Phosphorus utilization efficiency

[0055] 4 Application materials

[0056] The number of plants appearing on day 10 in Examples 1-8, or the root mass obtained using phosphorus-bound alumina (Examples 3 and 4), activated (calcined) alumina (Examples 7 and 8), and the examples of the present invention (Examples 5 and 6), showed almost no change. However, root phosphorus utilization efficiency and product efficacy per application amount differed. For root phosphorus efficiency, although phosphorus-bound alumina increased the total root mass, its root phosphorus utilization efficiency was lower than that of unmodified activated alumina or agglomerated dispersible particles of phosphate and activated alumina. Because alumina, once activated, is a strong adsorbent for phosphorus, whether by acid washing or calcination, an increase in root mass is expected in either case. Surprisingly, however, for the same amount of phosphorus delivered via phosphorus-bound alumina, using phosphorus-free activated alumina yielded better phosphorus utilization efficiency.

[0057] To achieve the same level of root quality growth by supplying the plant's phosphorus requirements with phosphorus-bound alumina, significantly more material is needed than using activated alumina alone. 56-112 kg / ha of activated alumina (without phosphorus binding) achieved the same effect as adding 476 kg / ha of phosphorus-bound alumina.

[0058] Table 2 Size effect: % increase in root mass relative to 50% phosphorus level in Example 2.

[0059] Example Size from largest to smallest Root mass percentage increase 9 ~1,200μm–~300μm 5.2 10 ~700μm–~175μm 23.9 11 ~150μm 24.5

[0060] Unexpectedly, Examples 9-11 demonstrated that agglomerated dispersible particles with the same composition but different activated alumina particle sizes increased the adsorption and eventual release of phosphorus by plants, as indicated by the increase in root mass % (%). Agglomerated dispersible particles with an activated alumina particle size of up to approximately 150 μm exhibited the highest increase in root mass % (%), while agglomerated dispersible particles with a particle size of approximately 1,200 μm to approximately 300 μm exhibited the lowest increase in root mass % (%).

[0061] While the foregoing specification illustrates and describes exemplary embodiments, those skilled in the art will understand that various changes can be made without departing from the scope of the invention, and that equivalents can be substituted for its elements. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of the invention without departing from the basic scope of the invention. Therefore, the invention is not limited to the specific embodiments disclosed as the best mode for carrying out the invention, but rather includes all embodiments falling within the scope of the appended claims.

Claims

1. Agglomerated dispersible particles, comprising: Activated alumina particles, wherein the activated alumina particles have: Porous structure; and Multiple charged binding sites placed within the porous structure; and Phosphate granules, The activated alumina particles and phosphate particles exist as different phases aggregated together in the aggregated dispersible particles. The size of the agglomerated dispersible particles is measured in median diameter as 0.4 mm to 4.0 mm.

2. The agglomerated dispersible particles according to claim 1, wherein the activated alumina particles do not contain phosphates disposed within the porous structure.

3. The agglomerated dispersible particles according to claim 1, wherein the activated alumina particles and phosphate particles are uniformly distributed in the agglomerated dispersible particles.

4. The agglomerated dispersible particles according to claim 1, having a weight ratio of alumina to phosphate of 10:1 to 1:

10.

5. The agglomerated dispersible particles according to claim 1, further comprising additional nutrient particles existing in a different phase and agglomerated with the activated alumina particles and phosphate particles.

6. The agglomerated dispersible particles according to claim 5, wherein the additional nutrient particles comprise at least one nutrient selected from the group consisting of bioavailable substances selected from molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, and combinations thereof.

7. The agglomerated dispersible particles according to claim 1, wherein the activated alumina particles do not contain at least one nutrient within the porous structure.

8. The agglomerated dispersible particles according to claim 1, wherein the agglomerated dispersible particles are coated with a further nutrient layer, the further nutrient layer comprising at least one nutrient selected from the group consisting of bioavailable substances selected from molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, and combinations thereof.

9. The agglomerated dispersible particles according to claim 1, further comprising pesticide particles existing in different phases and agglomerated with activated alumina particles and phosphate particles.

10. The agglomerated dispersible particles according to claim 1, wherein the agglomerated dispersible particles are coated with a pesticide layer.

11. The agglomerated dispersible particles according to claim 1, further comprising bio-additive particles existing in different phases and agglomerated with activated alumina particles and phosphate particles.

12. The agglomerated dispersible particles according to claim 11, wherein the bio-additive particles comprise at least one additive selected from the group consisting of humic substances, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, and combinations thereof.

13. The agglomerated dispersible particles according to claim 1, wherein the agglomerated dispersible particles are coated with a biological additive layer, the biological additive layer comprising at least one additive selected from the group consisting of humic substances, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, and combinations thereof.

14. The agglomerated dispersible particles according to claim 1, further comprising at least one of a water-soluble binder, a suspending agent, or an emulsifier.

15. The agglomerated dispersible particles according to claim 1, wherein the size of the activated alumina particles, measured by the maximum particle size, is less than 200 μm.

16. A method for improving soil with buffered phosphorus, comprising: Activated alumina particles are physically mixed with phosphate particles, wherein the activated alumina particles have the following characteristics: Porous structure; and Multiple charged binding sites are placed within the porous structure; Then Alumina particles are agglomerated with phosphate particles to form agglomerated dispersible particles, wherein the size of the agglomerated dispersible particles is measured to be 0.4 mm to 4.0 mm in median diameter; and Apply aggregated dispersible particles to the soil. The activated alumina particles and phosphate particles exist as different phases aggregated together in the aggregated dispersible particles, and when applied to soil, the activated alumina particles do not contain phosphate placed in a porous structure.

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

18. Agglomerated dispersible particles comprising: 10–80% by weight of activated alumina particles, said activated alumina particles having: Porous structure; and Multiple charged binding sites are placed within the porous structure; 10–80% by weight of phosphate particles; and 10–50% by weight of water-soluble adhesives, The activated alumina particles and phosphate particles exist as different phases aggregated together in the aggregated dispersible particles.

19. The agglomerated dispersible particles of claim 18, wherein the activated alumina particles do not contain phosphates disposed within a porous structure.

20. The agglomerated dispersible particles according to claim 18, wherein the activated alumina particles and phosphate particles are uniformly distributed in the agglomerated dispersible particles.

21. The agglomerated dispersible particles according to claim 18, having a weight ratio of alumina to phosphate of 10:1 to 1:

10.

22. The agglomerated dispersible particles of claim 18, further comprising additional nutrient particles existing in a different phase and agglomerated with the activated alumina particles and phosphate particles.

23. The agglomerated dispersible particles of claim 22, wherein the additional nutrient particles comprise at least one nutrient selected from the group consisting of bioavailable substances selected from molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, and combinations thereof.

24. The agglomerated dispersible particles of claim 18, wherein the activated alumina particles do not contain at least one nutrient within the porous structure.

25. The agglomerated dispersible particles of claim 18, wherein the agglomerated dispersible particles are coated with a further nutrient layer, the further nutrient layer comprising at least one nutrient selected from the group consisting of bioavailable substances selected from molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, and combinations thereof.

26. The agglomerated dispersible particles according to claim 18, further comprising pesticide particles existing in different phases and agglomerated with activated alumina particles and phosphate particles.

27. The agglomerated dispersible particles of claim 18, wherein the agglomerated dispersible particles are coated with a pesticide layer.

28. The agglomerated dispersible particles of claim 18, further comprising bio-additive particles existing in different phases and agglomerated with activated alumina particles and phosphate particles.

29. The agglomerated dispersible particles according to claim 28, wherein the bio-additive particles comprise at least one additive selected from the group consisting of humic substances, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, and combinations thereof.

30. The agglomerated dispersible particles of claim 18, wherein the agglomerated dispersible particles are coated with a biological additive layer, the biological additive layer comprising at least one additive selected from the group consisting of humic substances, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, and combinations thereof.

31. The agglomerated dispersible particles according to claim 18, further comprising at least one of a water-soluble binder, a suspending agent, or an emulsifier.

32. The agglomerated dispersible particles of claim 18, wherein the size of the activated alumina particles, measured by maximum particle size, is less than 200 μm.

33. A method for improving soil with buffered phosphorus, comprising: Activated alumina particles are physically mixed with phosphate particles, wherein the activated alumina particles have the following characteristics: Porous structure; and Multiple charged binding sites are placed within the porous structure; Then Alumina particles are agglomerated with phosphate particles to form agglomerated dispersible particles; and Apply aggregated dispersible particles to the soil. The activated alumina particles and phosphate particles exist as different phases aggregated together in the aggregated dispersible particles, and when applied to soil, the activated alumina particles do not contain phosphate placed in a porous structure.

34. The method of claim 33, wherein the agglomerated dispersible particles are applied to the soil without tilling the soil.

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