Method and system for preparing a nutrient solution for plants

Abstract

Disclosed is a method for preparing a nutrient solution for plants. The disclosure further relates to a system for utilizing the fertilizers for preparing the nutrient solution for plants in hydroponics cultivation. The nutrient solution disclosed herein comprises nutrients in the ionic forms that are most desired and readily adsorbed by the plants.

Description

[0001] DESCRIPTION

[0002] METHOD AND SYSTEM FOR PREPARING A NUTRIENT SOLUTION FOR PLANTS

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of Indian Application No. 202441102823, filed December 24, 2024, the contents of which are incorporated into the present application by reference in its entirety.

[0004] FIELD OF THE DISCLOSURE

[0005] The present disclosure relates to a method for preparing a nutrient solution for plants. The disclosure further relates to a system for utilizing the fertilizers for preparing the nutrient solution for plants in hydroponics cultivation.

[0006] BACKGROUND

[0007] Urea is the most common, preferred, and economic source of Nitrogen (N) for plant growth and enhanced yields. This fertilizer has been used primarily to increase soil-based food production. Plants absorb nitrogen from the soil as both ammonium (NHT) and nitrate (NOs") ions. Under soil conditions, urea is transformed into ammonium and nitrate ions, readily converted to ammonium via urease enzyme and then to nitrate (nitrification, mediated by nitrifying bacteria such as nitrobacter). The urease enzyme and nitrifying bacteria occur naturally and thrive in most soils / plant environments.

[0008] To enhance crop yield and satisfy the growing needs of an increasing population, more of urea based fertilizers are being used in agriculture. However, excessive use of urea fertilizer, due to its rapid hydrolysis and nitrification in the soil by soil-bacteria, can lead to nutrient imbalance and loss of soil fertility. It has been reported that a significant amount of nitrogen in urea is lost by volatilization and leaching. Additionally, urea is associated with the release of CO2 and N2O in the air, leading to greenhouse gas (GHG) emissions. Therefore, it is found that most of the nutrients from these fertilizers get wasted leading to an increased carbon footprint.

[0009] To address the above problems, soilless and hydroponic systems were introduced. However, the efforts to use urea or urea based fertilizers in soilless and hydroponic systems are limitedmainly because of two reasons- 1) in hydroponics, fertilizers must dissolve completely in water or the nutrient solution to ensure plants can absorb the necessary nutrients; 2) the unavailability of urea transforming microorganisms and methods to apply them in aquatic conditions. Thus, there is an increased interest in developing a method and a system for preparing a nutrient solution for plants in hydroponics cultivation that uses urea based fertilizers and makes maximum use of the nitrogen contained in the fertilizers. Further, there is a need to develop a sustainable and efficient method & a system to produce a nutrient solution for plants that involves reduction or elimination of greenhouse gas emissions. Such methods and systems related thereto are disclosed herein.

[0010] SUMMARY OF THE INVENTION

[0011] Accordingly, an object of the present invention is to provide a solution to the above problems. In accordance with the present invention, disclosed herein is a method and a system for preparing a nutrient solution for plants. Preferably, disclosed herein is a method and a system for preparing a nutrient solution for plants in hydroponic cultivation.

[0012] Accordingly, the method and system as disclosed herein use the fertilizers, preferably urea based fertilizers, to prepare a nutrient solution that comprises nutrients in the ionic forms. These ionic forms are most desired and readily adsorbed by the plants thus ensuring that the nitrogen contained in the fertilizers does not go waste and gets completely taken up by the plants for higher yields, thereby enabling the high efficiency of the method and the system.

[0013] In some embodiments, the present invention disclosed herein relates to a method for preparing a nutrient solution for plants comprising the steps of:

[0014] decomposing one or more fertilizers in a first reactor to produce a first reactor solution;

[0015] transferring at least a part of the first reactor solution from the first reactor to a second reactor;

[0016] oxidizing at least the part of the first reactor solution transferred in the second reactor to produce a second reactor solution;

[0017] combining at least a part of a remaining first reactor solution from the first reactor and at least a part of the second reactor solution from the second reactor in a reservoir to produce the nutrient solution; and

[0018] dispensing the nutrient solution in the reservoir to a plant carrying unit.In some embodiments, the subject matter of the present invention disclosed herein is directed to a system for preparing a nutrient solution for plants comprising:

[0019] a first reactor comprising a first inlet and a first outlet;

[0020] a second reactor comprising a second inlet and a second outlet;

[0021] a conduit between the first reactor and the second reactor; and

[0022] a reservoir comprising a third inlet, a fourth inlet and a third outlet, wherein the first inlet is configured to receive one or more fertilizers;

[0023] wherein the first reactor is configured for decomposing one or more fertilizers to produce a first reactor solution;

[0024] wherein the conduit is configured to transfer at least a part of the first reactor solution from the first reactor to the second reactor;

[0025] wherein the second reactor is configured for oxidizing at least a part of the first reactor solution transferred to produce a second reactor solution;

[0026] wherein the third inlet of the reservoir is configured to receive the first reactor solution from the first outlet;

[0027] wherein the fourth inlet of the reservoir is configured to receive the second reactor solution from the second outlet; and

[0028] wherein the third outlet is connected to a plant carrying unit.

[0029] In some embodiments, the subject matter of the present invention disclosed herein is directed to the use of the method and system for preparing the nutrient solution for enhancing the growth of plants in water and / or soil.

[0030] The present inventors have found that use of such method and system involve the maximum utilization of nitrogen contained in the fertilizers by significantly reducing or eliminating the undesirable loss of nitrogen and emission of greenhouse gases i.e., nitrous oxide (N2O) & carbon dioxide (CO2). Without willing to be bound by it, the method disclosed herein makes the most efficient use of all the products (NH3 and CO2) resulting from the decomposition of urea based fertilizers. This method converts urea from its organic form to its gaseous products, which are not released into the air but remain captured for in- situ conversion into ionic forms that are more suitable to be taken up by plants. The method thereby eliminates the unwanted loss of nitrogen contained in the urea based fertilizers and also significantly reduces or even eliminates the emission of CO2 into the atmosphere. Therefore, the method disclosed herein is more environmental, sustainable, efficient, and economic, and most importantly helps inachieving United Nations sustainable development goals (UN SDGs) by significantly reducing the emission of greenhouse gases from the use of urea based fertilizers in soil.

[0031] It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method or composition of the invention, and vice versa. Furthermore, the compositions of the invention can be used to achieve methods of the invention.

[0032] Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.

[0035] FIG. 1 is a schematic depiction of a system for preparing a nutrient solution according to a non-limiting example of a system and method disclosed herein.

[0036] FIG. 2 is a schematic depiction of a system for preparing a nutrient solution including a phosphorous source tank according to a non-limiting example of a system and method disclosed herein.

[0037] FIG. 3 is a schematic depiction of a system for preparing a nutrient solution including a recycling unit and a phosphorous source tank according to a non-limiting example of a system and method disclosed herein.

[0038] FIG. 4 is a schematic depiction of a system for preparing a nutrient solution including a micronutrients tank and a phosphorous source tank according to a non-limiting example of a system and method disclosed herein.

[0039] FIG. 5 is a schematic depiction of a system for preparing a nutrient solution including a micronutrients tank, a phosphorous source tank and a recycling unit according to a non-limiting example of a system and method disclosed herein.DETAILED DESCRIPTION

[0040] The presently disclosed subject matter will now be described more fully hereinafter. However, many modifications and other aspects of the presently disclosed subject matter set forth herein will come to mind to one skilled in the art to which the presently disclosed subject matter pertains having the benefit of the teachings presented in the foregoing descriptions. Therefore, it is to be understood that the presently disclosed subject matter is not to be limited to the specific aspects disclosed and that modifications and other aspects are intended to be included within the scope of the appended claims. In other words, the subject matter described herein covers all alternatives, modifications, and equivalents. If one or more of the incorporated literature, patents, and similar materials differ from or contradict this application, including but not limited to defined terms, term usage, described techniques, or the like, this application controls. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in this field.

[0041] Certain embodiments of the present invention are characterized through the following aspects.

[0042] In some aspects, the method for preparing a nutrient solution involves conversion of fertilizers into the ionic forms more suitable for absorption by the plants. Preferably, the method for preparing a nutrient solution involves conversion of urea based fertilizers into their ionic forms more suitable for absorption by the plants. In some aspects, the method involves the use of urease and nitrifying enzymes to produce ammonium (NH4+) and nitrate (NO3 ) ions, respectively, in adequate ratios to attain ideal nitrogen nutrient levels for highest plant growth and yield.

[0043] One of the aspects relates to a method for preparing a nutrient solution for plants comprising the steps of:

[0044] - decomposing the one or more fertilizers in a first reactor to produce a first reactor solution;

[0045] transferring at least a part of the first reactor solution from the first reactor to a second reactor;

[0046] oxidizing at least a part of the first reactor solution transferred in the second reactor to produce a second reactor solution;

[0047] combining at least a part of a remaining first reactor solution from the first reactor and at least a part of the second reactor solution from the second reactor in a reservoir to produce the nutrient solution; and- dispensing the nutrient solution in the reservoir to a plant carrying unit.

[0048] In some aspects, the part of the first reactor solution transferred to the second reactor comprises at least 30% ammonium ions. Further, the part of the first reactor solution transferred to the second reactor comprises 30% to 90% ammonium ions. In some aspects, the part of the first reactor solution transferred to the second reactor comprises 30% to 90%, preferably 40% to 90%, preferably 50% to 90%, preferably 60% to 90%, preferably 70% to 90%, preferably 30% to 80%, preferably 40% to 80%, preferably 50% to 80%, preferably 60% to 80%, and / or preferably 70% to 80% ammonium ions.

[0049] In some aspects, the part of the first reactor solution transferred to the second reactor is in the amount of 30 vol.% to 90 vol.% of the first reactor solution, preferably 40 vol.% to 90 vol.%, preferably 50 vol.% to 90 vol.%, preferably 60 vol.% to 90 vol.%, preferably 70 vol.% to 90 vol.%, preferably 30 vol.% to 80 vol.%, preferably 40 vol.% to 80 vol.%, preferably 50 vol.% to 80 vol.%, preferably 60 vol.% to 80 vol.%, and / or preferably 70 vol.% to 80 vol.% of the first reactor solution.

[0050] In some aspects, the part of a remaining first reactor solution from the first reactor to be combined with at least a part of the second reactor solution from the second reactor in a reservoir to produce the nutrient solution is in the amount of 30 vol.% to 100 vol.% of the remaining first reactor solution, preferably 40 vol.% to 100 vol.%, 50 vol.% to 100 vol.%, preferably 60 vol.% to 100 vol.%, preferably 70 vol.% to 100 vol.%, preferably 80 vol.% to 100 vol.%, and / or preferably 90 vol.% to 100 vol.% of the remaining first reactor solution. In some aspects, the part of the second reactor solution from the second reactor to be combined with at least a part of a remaining first reactor solution from the first reactor in a reservoir to produce the nutrient solution is in the amount of 30 vol.% to 100 vol.% of the second reactor solution, preferably 40 vol.% to 100 vol.%, 50 vol.% to 100 vol.%, preferably 60 vol.% to 100 vol.%, preferably 70 vol.% to 100 vol.%, preferably 80 vol.% to 100 vol.%, and / or preferably 90 vol.% to 100 vol.% of the second reactor solution.

[0051] In some aspects, the first reactor is a hydrolysis reactor and / or the second reactor is a nitrification reactor. In certain aspects, the first reactor is a hydrolysis reactor. In other aspects, the second reactor is a nitrification reactor. In some aspects, the first reactor is a hydrolysis reactor and the second reactor is a nitrification reactor. In some aspects, the first reactor and / or the second reactor is a continuous stir tank reactor. In some aspects, the first reactor and the second reactor are continuous stir tank reactors. In some aspects, the first reactor or the secondreactor is a continuous stir tank reactor. Further, the first reactor may be a continuous stir tank reactor for hydrolysis, and the second reactor may be a continuous stir tank reactor for nitrification. Further, the reservoir may or may not be a continuous stir tank reactor. The reservoir may require stirring at intervals. Also, the plant carrying unit carries plant in water, soil, or a combination thereof.

[0052] In some aspects, the one or more fertilizers are urea based fertilizers. The urea based fertilizers are selected from one or more of urea, urea phosphate, urea calcium sulfate, urea calcium phosphate, urea ammonium nitrate, urea ammonium sulfate, urea potassium sulfate, or urea adduct.

[0053] In some aspects, the method is a bio-mediated method for use in a hydroponics system. The method uses urease enzyme for decomposing the urea based fertilizers. The urea based fertilizers are decomposed in the first reactor by the urease enzyme to produce the first reactor solution. Non-limiting example reactions can include the following:

[0054] CO(NH2)2+ H2O 2NH3+ CO2

[0055] 2NH3+ CO2+ H2O (NH4)2CO3

[0056] (NH4)2CO32NH4++ CO32’

[0057] H2O + CO32’ HCO3+ OH

[0058] Further, the method uses an oxidizing bacteria for oxidizing the part of the first reactor solution transferred into the second reactor. The method wherein the oxidizing bacteria is selected from one or more of Nitrobacter, Nitrosomonas, or Nitrosococcus. In some aspects, the part of the first reactor solution transferred from the first reactor to the second reactor comprises ammonium (NH4+) ions. In some aspects, the method uses oxidizing bacteria for oxidizing the part of the first reactor solution in the second reactor to produce the second reactor solution. Non-limiting example reactions can include the following:

[0059] NH4++ oxidizing bacteria —> NO3

[0060] In some aspects, the first reactor solution comprises at least ammonium ions and / or the second reactor solution comprises at least nitrate ions. In some aspects, the first reactor solution comprises at least ammonium ions. The first reactor solution may further comprise one or more of nitrate ions, carbonate ions, bicarbonate ions, sulfate ions, phosphate ions, potassium ions, chloride ions, and / or calcium ions. In some aspects, the second reactor solution comprises at least nitrate ions. The second reactor solution may further comprise one or more of ammoniumions, carbonate ions, bicarbonate ions, sulfate ions, phosphate ions, potassium ions, chloride ions, and / or calcium ions.

[0061] Some aspects relate to a system for preparing nutrient solution for plants, comprising:

[0062] a first reactor comprising a first inlet and a first outlet;

[0063] a second reactor comprising a second inlet and a second outlet;

[0064] a conduit between the first reactor and the second reactor; and

[0065] a reservoir comprising a third inlet, a fourth inlet and a third outlet, wherein the first inlet is configured to receive one or more fertilizers;

[0066] wherein the first reactor is configured for decomposing a nitrogen component to produce first reactor solution;

[0067] wherein the conduit is configured to transfer at least a part of the first reactor solution from the first reactor to the second reactor;

[0068] wherein the second reactor is configured for oxidizing at least a part of the second reactor solution transferred to produce a second reactor solution;

[0069] wherein the third inlet of the reservoir is configured to receive at least a part of a remaining first reactor solution from the first outlet;

[0070] wherein the fourth inlet of the reservoir is configured to receive at least a part of the second reactor solution from the second outlet; and

[0071] wherein the third outlet is connected to a plant carrying unit.

[0072] In some aspects, the first inlet is configured to receive one or more fertilizers and / or the second inlet is configured to receive the oxidizing bacteria.

[0073] In some aspects, the reservoir is further configured to receive a solution comprising a phosphorus source from a phosphorous source tank before dispensing the nutrient solution from the reservoir into a plant carrying unit. The solution comprising a phosphorus source may be a solution comprising phosphoric acid. Accordingly, in some aspects, the reservoir is further configured to receive a solution comprising phosphoric acid from a phosphorous source tank before dispensing the nutrient solution from the reservoir into a plant carrying unit. The phosphoric acid solution not only provides phosphorus nutrient to the nutrient solution but also acts as a pH regulator to maintain the nutrient solution within a desired pH range of 5.5 to 7. Furthermore, the reservoir is further configured to receive a solution comprising one or more micronutrients selected from one or more of inorganic or organometallic compounds of boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo), nickel (Ni) or zinc (Zn) from a micronutrient tank before dispensing the nutrient solution from the reservoirinto a plant carrying unit. In some aspects, the nutrient solution dispensed into the plant carrying unit is not completely used, leading to some unused nutrient solution. In some aspects, the reservoir is further connected with a recycling unit configured to recycle the unused nutrient solution from the plant carrying unit. In some aspects, the phosphorous source tank is further configured to receive and recycle the unused nutrient solution from the plant carrying unit. In some aspects, methods of dispensing the nutrient solution for plants are described. The method can include dispensing the nutrient solution to a plant carrying unit. The plant carrying unit comprises plants in water and / or soil. In some aspects, the nutrient solution is allowed to run through the plant carrying unit at the rate of 12-8 L / hr every 2-3 hours with a scheduled break of 1 hour, repeated 4 times. Overall, the method and system disclosed herein may be applied to enhance the growth of plants or crops in water and / or soil.

[0074] The above and other non-limiting aspects of the present invention are discussed in further detail in the following sections. The following also includes definitions of various terms and phrases used throughout this specification.

[0075] The terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art. In one non-limiting embodiment, the terms are defined to be within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%. The terms “%” and “vol.%” refer to a percentage or a volume percentage of a component, respectively, based on the total percentage or the total volume of material that includes the component. In a non-limiting example, 10 mL of a solution out of 100 mL of the solution is 10 vol% of the solution.

[0076] The terms “eliminating” or “reducing” ” or “avoiding” or any variation of these terms, when used in the claims and / or the specification, includes any measurable decrease or complete elimination to achieve a desired result.

[0077] The use of the words “a” or “an” when used in conjunction with any of the terms “comprising,” “including,” “containing,” or “having” in the claims, or the specification, may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”

[0078] The words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”), or “containing” (and any form of containing, suchas “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0079] The term “remaining”, as that term is used in the specification and / or claims, means not transferred, still existing after transferring some part / portion of a component, reactant, product, solvent or solution to accomplish a desired, expected, or intended result.

[0080] The term “unused”, as that term is used in the specification and / or claims, means not used or not used fully or partially to accomplish a desired, expected, or intended result.

[0081] The method for preparing a nutrient solution for plants and a system for preparing a nutrient solution for plants of the present invention can “comprise,” “consist essentially of,” or “consist of’ particular steps, ingredients, components, solutions, compositions, etc. disclosed throughout the specification.

[0082] The term “nutrient solution” is defined as a solution comprising one or more nutrients in the form of one or more ions that is supplied to a plant carrying unit in water and / or soil to provide plants with (a) nutrients essential or beneficial for the growth of plants and / or (b) stimulants or enhancers to increase or enhance plant growth. Non-limiting examples of the composition of a nutrient solution include one or more nutrients in the form of ammonium ions, nitrate ions, carbonate ions, bicarbonate ions, sulfate ions, phosphate ions, potassium ions, chloride ions, calcium ions, and / or magnesium ions. In some aspects of the disclosure, the nutrient solution comprises at least ammonium and nitrate ions. The nutrient solution may comprise nitrogen (N) as ammonium and nitrate ions. Further, the nutrient solution may comprise ammonium and nitrate ions in the ratio of 10:90, preferably 20:80, preferably 30:70, preferably 40:60, preferably 50:50, preferably 60:40, preferably 70:30. The nutrient solution may further comprise one or more of carbonate ions, bicarbonate ions, sulfate ions, phosphate ions, potassium ions, chloride ions, and / or calcium ions. In some aspects, the nutrient solution includes micronutrients selected from one or more of iron, manganese, zinc, copper, boron, molybdenum, and / or chlorine. The nutrient solution may include agents that enhance plant growth and / or enhance the ability for a plant to receive the benefit of the nutrients in a nutrient solution, such as, but not limited to organic matter, bio-stimulants and / or pH buffers. In some instances, the pH buffer comprises phosphoric acid. In some aspects, the pH buffer may include MgO, KH2PO4, NaHCOs, chalk powder, aluminum, magnesium hydroxide, aluminum hydroxide / magnesium hydroxide co-precipitate, aluminum hydroxide / sodium bicarbonate coprecipitate, calcium acetate, calcium bicarbonate, calcium borate, calcium carbonate, calciumbicarbonate, calcium citrate, calcium gluconate, calcium hydroxide, dibasic sodium phosphate, dipotassium hydrogen phosphate, dipotassium phosphate, disodium hydrogen phosphate, magnesium acetate, magnesium borate, magnesium bicarbonate, magnesium carbonate, magnesium hydroxide, magnesium lactate, magnesium oxide, magnesium phosphate, magnesium silicate, magnesium succinate, magnesium tartrate, potassium acetate, potassium carbonate, potassium bicarbonate, potassium borate, potassium citrate, potassium metaphosphate, potassium phthalate, potassium phosphate, potassium polyphosphate, potassium pyrophosphate, potassium succinate, potassium tartrate, sodium acetate, sodium bicarbonate, sodium borate, sodium carbonate, sodium citrate, sodium gluconate, sodium hydrogen phosphate, sodium hydroxide, sodium lactate, sodium phthalate, sodium phosphate, sodium polyphosphate, sodium pyrophosphate, sodium tartrate, sodium tripolyphosphate, synthetic hydrotalcite, tetrapotassium pyrophosphate, tetrasodium pyrophosphate, tripotassium phosphate, trisodium phosphate, and trometamol, and combinations thereof.

[0083] The term “macronutrient” is defined as a chemical element or substance used in relatively large to moderate amounts for plant growth and are less likely to limit crop growth. Non-limiting examples of macro nutrients include N, P, K, Ca, Mg, and S.

[0084] The term “micronutrient” is defined as a chemical element or substance used in trace amounts for the normal growth and development of a plant. Non-limiting examples of micronutrients include B, Cu, Fe, Mn, Mo, Zn, Se, and Si or compounds thereof.

[0085] The invention relates to a method for preparing a nutrient solution for plants in hydroponics cultivation. The invention further relates to a system for preparing a nutrient solution for plants in hydroponics cultivation. In some aspects, hydroponics cultivation means the cultivation of plants without soil, and can include an aggregate substrate, or growing media, such as vermiculite, coconut coir, perlite, gravel, or other substrates. Plants are cultivated using a liquid solution of water and nutrients. In some aspects, the nutrients used in hydroponics cultivation system can come from many different organic or inorganic sources, including fish excrement, duck manure, chemical fertilizers, converted chemical fertilizers, artificial standard or hybrid nutrient solutions.

[0086] The fertilizer can comprise one or more nutrients to provide plants with one or more plant nutrients essential or beneficial for the growth of plants and / or stimulants or enhancers to increase or enhance plant growth. These nutrients can be used as is or can be converted into a more acceptable form for plants. The fertilizer can comprise one or more macronutrients and / ormicronutrients and can be applied directly in the soil and / or water, or can be converted into other forms suitable to be taken up by plants. The subject matter disclosed herein refers urea based fertilizers. Non-limiting examples of urea based fertilizers include urea, urea phosphate, urea calcium sulfate, urea calcium phosphate, urea ammonium nitrate, urea ammonium sulfate, urea potassium sulfate, urea adduct, or a combination thereof.

[0087] The fertilizer can be of any suitable shape or may be a liquid, powder, or slurry. Non-limiting shapes include spherical, cuboidal, cylindrical, puck shape, oval, and oblong shapes. In some aspects, the fertilizer can be of prismatic or cylindrical shape with a circular, elliptical, ovular, triangular, square, rectangular, pentagonal, or hexagonal cross section, although a prismiatic or cylindrical shaped core having a cross section of other shapes can also be made. In some aspects, the fertilizer at its widest dimension can be 0.5 mm to 6 mm, or 0.5 mm to 5 mm, preferably 1 mm to 4 mm, or at least any one of, at most any one of, equal to any one of, or between any two of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, and 6 mm. In some particular aspects, the fertilizer can have a substantially spherical shape with an average diameter of 0.5 mm to 6 mm, or 0.5 mm to 5 mm, preferably 1 mm to 4 mm, or at least any one of, at most any one of, equal to any one of, or between any two of 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, and 6 mm.

[0088] The fertilizer can or cannot be water soluble. In some aspects, a fertilizer, such as a fertilizer granule having a size of 2 mm to 4 mm prior to adding to water, can disintegrate into particles having sizes less than 1 mm, less than 0.9 mm, less than 0.8 mm, less than 0.7 mm, less than 0.6 mm, less than 0.5 mm, less than 0.4 mm, or less than 0.3 mm, within 1 minute of adding the fertilizer to water at a pH 7, under stirring at a rate 90 rpm to 110 rpm, at an ambient temperature.

[0089] Method of preparing the nutrient solution:

[0090] Certain aspects herein use one or more fertilizers to prepare a nutrient solution for plants. In certain aspects, the urea based fertilizers are decomposed into ammonia and carbon dioxide to ultimately produce a nutrient solution comprising the nutrients in ionic forms. These ionic forms are more readily absorbed by the plants. In certain aspects, the method comprises prefilling a first reactor with water and adding one or more fertilizers in the first reactor; decomposing the one or more fertilizers in the first reactor to produce a first reactor solution; transferring at least a part of the first reactor solution from the first reactor to a second reactor;oxidizing at least a part of the first reactor solution transferred to the second reactor to produce a second reactor solution; combining at least a part of the remaining first reactor solution from the first reactor and at least a part of the second reactor solution from the second reactor in a reservoir to produce the nutrient solution; and; dispensing the nutrient solution in the reservoir to a plant carrying unit.

[0091] In the method of preparing the nutrient solution, decomposing the one or more fertilizers to produce a first reactor solution may also be referred to as hydrolysis of one or more fertilizers, and oxidizing the part of the first reactor solution may also be referred to as nitrification of a part of the first reactor solution.

[0092] Referring to FIG. 1, a schematic depiction of a system and method for preparing a nutrient solution according to one example of the present invention is depicted. The system 100 can include a first reactor 102 and a second reactor 104. A feed mixture 106 comprising one or more fertilizers can be fed into the first reactor 102 via a first inlet. The first reactor 102 can be capable of having conditions suitable for the reactions described herein to produce a first reactor solution. A part of the first reactor solution 108 can be transferred to the second reactor 104 via a conduit between the first reactor 102 and the second reactor 104. The second reactor can further receive oxidizing bacteria 112 from a second inlet. The second reactor can be capable of having conditions suitable for the reactions described herein to produce a second reactor solution. The system further comprises a reservoir 114 comprising a third inlet to receive at least a part of a remaining first reactor solution 134 from a first outlet of the first reactor 102 and a fourth inlet to receive at least a part of the second reactor solution 110 from a second outlet of the second reactor 104. The part of the remaining first reactor solution 134 and the part of the second reactor solution 110 from the first and second outlets, respectively, can be combined in the reservoir 114 to produce a nutrient solution 116 in the reservoir. The nutrient solution 116 from the reservoir 114 can then be dispersed into a plant carrying unit 118 via a third outlet.

[0093] Referring to FIG. 2, a schematic depiction of a system and method for preparing a nutrient solution according to one example of the present invention is depicted. The system 200 can include a first reactor 202 and a second reactor 204. A feed mixture 206 comprising one or more fertilizers can be fed into the first reactor 202 via a first inlet. The first reactor 202 can be capable of having conditions suitable for the reactions described herein to produce a first reactor solution. A part of the first reactor solution 208 can be transferred to the second reactor204 via a conduit between the first reactor 202 and the second reactor 204. The second reactor can further receive oxidizing bacteria 212 from a second inlet. The second reactor can be capable of having conditions suitable for the reactions described herein to produce a second reactor solution. The system further comprises a reservoir 214 comprising a third inlet to receive at least a part of a remaining first reactor solution 234 from a first outlet of the first reactor 202 and a fourth inlet to receive at least a part of the second reactor solution 210 from a second outlet of the second reactor 204. The part of the remaining first reactor solution 234 and the part of the second reactor solution 210 from the first and second outlets, respectively, can be combined in the reservoir 214 which can be further configured to receive a solution 222 comprising phosphoric acid from a phosphorous source tank 220 to produce a nutrient solution 216 in the reservoir. The nutrient solution 216 from the reservoir 214 can then be dispersed into a plant carrying unit 218 via a third outlet. In some instances, the unused nutrient solution 224 from the plant carrying unit can be recycled back into the phosphorous source tank 220.

[0094] Referring to FIG. 3, a schematic depiction of a system and method for preparing a nutrient solution according to one example of the present invention is depicted. The system 300 can include a first reactor 302 and a second reactor 304. A feed mixture 306 comprising one or more fertilizers can be fed into the first reactor 302 via a first inlet. The first reactor 302 can be capable of having conditions suitable for the reactions described herein to produce first reactor solution. A part of the first reactor solution 308 can be transferred to the second reactor 304 via a conduit between the first reactor 302 and a second reactor 304. The second reactor can further receive oxidizing bacteria 312 from a second inlet. The second reactor can be capable of having conditions suitable for the reactions described herein to produce a second reactor solution. The system further comprises a reservoir 314 comprising a third inlet to receive at least a part of a remaining first reactor solution 334 from a first outlet of the first reactor 302 and a fourth inlet to receive at least a part of the second reactor solution 310 from a second outlet of the second reactor 304. The part of the remaining first reactor solution 334 and the part of the second reactor solution 310 from the first and second outlets, respectively, can be combined in the reservoir 314 which can be further configured to receive a solution 322 comprising phosphoric acid from a phosphorous source tank 320 to produce a nutrient solution 316 in the reservoir. The nutrient solution 316 from the reservoir 314 can then be dispersed into a plant carrying unit 318 via a third outlet. In some instances, the reservoir 314 is further connected with a recycling unit 330 configured to recycle the unused nutrient solution 324 from the plantcarrying unit 318. The recycled solution 332 from the recycling unit 330 is fed back into the reservoir 314.

[0095] Referring to FIG. 4, a schematic depiction of a system and method for preparing a nutrient solution according to one example of the present invention is depicted. The system 400 can include a first reactor 402 and a second reactor 404. A feed mixture 406 comprising one or more fertilizers can be fed into the first reactor 402 via a first inlet. The first reactor 402 can be capable of having conditions suitable for the reactions described herein to produce a first reactor solution. A part of the first reactor solution 408 can be transferred to the second reactor 404 via a conduit between the first reactor 402 and the second reactor 404. The second reactor can further receive oxidizing bacteria 412 from a second inlet. The second reactor can be capable of having conditions suitable for the reactions described herein to produce a second reactor solution. The system further comprises a reservoir 414 comprising a third inlet to receive at least a part of a remaining first reactor solution 434 from a first outlet of the first reactor 402 and a fourth inlet to receive at least a part of the second reactor solution 410 from a second outlet of the second reactor 404. The part of the remaining first reactor solution 434 and the part of the second reactor solution 410 from the first and second outlet, respectively, can be combined in the reservoir 414 which can be further configured to receive a solution 422 comprising phosphoric acid from a phosphorous source tank 420 to produce a nutrient solution 416 in the reservoir. The reservoir 414 can be further configured to receive a solution 428 comprising one or more micronutrients from the micronutrients tank 426 before dispensing the nutrient solution 416 from the reservoir 414 to a plant carrying unit 418. The nutrient solution 416 from the reservoir 414 can then be dispersed into the plant carrying unit 418 via a third outlet. In some instances, the unused nutrient solution 424 from the plant carrying unit 418 can be recycled back into the phosphorous source tank 420.

[0096] Referring to FIG. 5, a schematic depiction of a system and method for preparing a nutrient solution according to one example of the present invention is depicted. The system 500 can include a first reactor 502 and a second reactor 504. A feed mixture 506 comprising one or more fertilizers can be fed into the first reactor 502 via a first inlet. The first reactor 502 can be capable of having conditions suitable for the reactions described herein to produce first reactor solution. A part of the first reactor solution 508 can be transferred to the second reactor 504 via a conduit between the first reactor 502 and the second reactor 504. The second reactor can further receive oxidizing bacteria 512 from a second inlet. The second reactor can be capable of having conditions suitable for the reactions described herein to produce a second reactorsolution. The system further comprises a reservoir 514 comprising a third inlet to receive at least a part of a remaining first reactor solution 534 from a first outlet of the first reactor 502 and a fourth inlet to receive at least a part of the second reactor solution 510 from a second outlet of the second reactor 504. The part of the remaining first reactor solution 534 and the part of the second reactor solution 510 from the first and second outlets, respectively, can be combined in the reservoir 514 which can be further configured to receive a solution 522 comprising phosphoric acid from a phosphorous source tank 520 to produce a nutrient solution 516 in the reservoir. The reservoir 514 can be further configured to receive a solution 528 comprising one or more micronutrients from the micronutrients tank 526 before dispensing the nutrient solution from the reservoir 514 to a plant carrying unit 518. The nutrient solution 516 from the reservoir 514 can then be dispersed into the plant carrying unit 518 via a third outlet. In some instances, the reservoir 514 is further connected with a recycling unit 530 configured to recycle the unused nutrient solution 524 from the plant carrying unit 518. The recycled solution 532 from the recycling unit 530 is fed back into the reservoir 514.

[0097] Methods of dispensing the nutrient solution for plants are described. A method can include dispensing the nutrient solution to a plant carrying unit. The plant carrying unit comprises plants in water and / or soil. In some aspects, the nutrient solution is allowed to run through the plant carrying unit at the rate of 12-8 L / hr such as 12 L / hr, 11 L / hr, 10 L / hr, 9 L / hr, or 8 L / hr. In some aspects, the nutrient solution is dispensed every 2-3 hours with a scheduled break of 1 hour, repeated 4 times. In some aspects, the nutrient solution is not dispensed at night for 8-12 hours. In some aspects, the plants are harvested after 2-4 weeks.

[0098] EXAMPLES

[0099] The present invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes only, and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of noncritical parameters which can be changed or modified to yield essentially the same results.

[0100] Example 1

[0101] Preparation of a nutrient solution

[0102] A first reactor was filled with 30 L of water and 150 g urea was added and mixed thoroughly. To this solution of urea, 50 mg of crystalline urease enzyme was added. The mixture was stirred for 30 minutes at 25°C to prepare a first reactor solution. After 30 mins of gentle mixing, 20 L(66.7 vol%) of the first reactor solution in the first reactor was transferred from the first reactor to a second reactor via a conduit. To this part of the first reactor solution in the second reactor, 30 mg of a nitrifying bacteria Nitrobacter was added and the stirring was continued gently for 30 minutes at 25°C to produce a second reactor solution in the second reactor. The first reactor solution from the first reactor and the second reactor solution from the second reactor were then combined in a reservoir to produce the nutrient solution. The nutrient solution was then dispensed to a plant carrying unit at the rate of 10 L / hour.

[0103] Example 2

[0104] Preparation of a nutrient solution with phosphoric acid

[0105] The first reactor solution from the first reactor and the second reactor solution from the second reactor as produced in Example 1 were combined in a reservoir. A phosphoric acid solution in the range 54-68% P2O5 was then fed into the reservoir was to produce the nutrient solution. The nutrient solution was then dispensed to a plant carrying unit at the rate of 10 L / hour. Example 3

[0106] Preparation of a nutrient solution with micronutrients & phosphoric acid

[0107] The first reactor solution from the first reactor and the second reactor solution from the second reactor as produced in Example 1 were combined in a reservoir. A solution containing micronutrients with concentrations of 4.6M H3BO3, 0.5M MnChAfLO, 0.2M ZnSCU-VtLO, 0.1M NH4(6MO7O24-4H2O), 0.2M CuSCL-SthO, and 45M FeCh was then fed into the reservoir followed by feeding a phosphoric acid solution in the range 54-68% P2O5 into the reservoir to produce the nutrient solution. The nutrient solution was then dispensed to a plant carrying unit at the rate of 10 L / hour.

[0108] Analysis of nutrient solution

[0109] Samples from the continuous stirring tank reactor for hydrolysis and continuous stirring tank reactor for nitrification were analyzed and found that the solution from the continuous stirring tank reactor for hydrolysis contained nitrogen as ammonium (NH4+) ions, and the solution from the continuous stirring tank reactor for nitrification contained nitrogen as nitrate (NO3 ) ions. Further, the resultant nutrient solution from the reservoir was analyzed and found that it contained NH4+, HCO3’, CO32’, NO3’ ions. It was found that in the nutrient solution, the nitrogen was present as ammonium (NH4+) and nitrate (NO3’) with the ratio of NH4+: (NO3 as 30:70.All of the methods and system disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the methods and systems of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.

Claims

CLAIMS1. A method for preparing a nutrient solution for plants comprising the steps of:decomposing one or more fertilizers in a first reactor to produce a first reactor solution;transferring at least a part of the first reactor solution from the first reactor to a second reactor;oxidizing at least a part of the first reactor solution transferred in the second reactor to produce a second reactor solution;combining at least a part of a remaining first reactor solution from the first reactor and at least a part of the second reactor solution from the second reactor in a reservoir to produce the nutrient solution; anddispensing the nutrient solution in the reservoir to a plant carrying unit.

2. The method of claim 1, wherein the one or more fertilizers are urea based fertilizers.

3. The method of claim 2, wherein the urea based fertilizers are selected from urea, urea adduct, urea phosphate, urea calcium sulfate, urea ammonium nitrate, urea ammonium sulfate, or a combination thereof.

4. The method of any of claims 1 to 3, wherein the part of the first reactor solution transferred to the second reactor comprises at least 30% ammonium ions.

5. The method of any of claims 1 to 4, wherein the first reactor and / or the second reactor is a continuous stir tank reactor.

6. The method of any of claims 1 to 5, wherein the first reactor is a hydrolysis reactor and / or the second reactor is a nitrification reactor.

7. The method of any of claims 1 to 6, wherein the method uses urease enzyme for decomposing the one or more fertilizers.

8. The method of any of claims 1 to 7, wherein the method uses an oxidizing bacteria for oxidizing the part of the first reactor solution transferred in the second reactor, andwherein the oxidizing bacteria is selected from one or more of nitrobacter, nitrosomonas, or nitrosococcus.

9. The method of any of claims 1 to 8, wherein the first reactor solution comprises at least ammonium ions and / or the second reactor solution comprises at least nitrate ions.

10. The method of any of claims 1 to 9, wherein the nutrient solution comprises at least ammonium and nitrate ions.

11. A system for preparing a nutrient solution for plants comprising:a first reactor comprising a first inlet and a first outlet;a second reactor comprising a second inlet and a second outlet;a conduit between the first reactor and the second reactor; anda reservoir comprising a third inlet, a fourth inlet and a third outlet, wherein the first inlet is configured to receive one or more fertilizers;wherein the first reactor is configured for decomposing one or more fertilizers to produce a first reactor solution;wherein the conduit is configured to transfer at least a part of the first reactor solution from the first reactor to the second reactor;wherein the second reactor is configured for oxidizing at least a part of the first reactor solution transferred to produce a second reactor solution;wherein the third inlet of the reservoir is configured to receive a part of a remaining first reactor solution from the first outlet;wherein the fourth inlet of the reservoir is configured to receive a part of the second reactor solution from the second outlet; andwherein the third outlet is connected to a plant carrying unit.

12. The system of claim 11 , wherein the reservoir is further configured to receive a solution comprising phosphoric acid from a phosphorous source tank before dispensing the nutrient solution from the reservoir into a plant carrying unit.

13. The system of any of claims 11 and 12, wherein the reservoir is further connected with a recycling unit configured to recycle the unused nutrient solution from the plant carrying unit.

14. The system of any of claims 11 to 13, wherein the reservoir is further configured to receive a solution comprising one or more micronutrients selected from one or more of inorganic or organometallic compounds of boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo), nickel (Ni) or zinc (Zn) from a micronutrient tank before dispensing the nutrient solution from the reservoir into a plant carrying unit.

15. Use of the method of any of claims 1 to 10 and the system of any of claims 11 to 14 for enhancing the growth of plants or crops in water and / or soil.

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