Stabilized porous growing medium

Abstract

A growing medium comprising a stabilized, porous body of homogenized components including a natural material, and an isocyanate-based binder, its derivatives, or both, the growing medium being hydrophilic, rewettable, and having a field capacity of about 79-84.5 m / m% and a porosity of about 55-80 wt. %, based on the total weight of the growing medium.

Description

[0001]STABILIZED POROUS GROWING MEDIUM CROSS-REFERENCE This application claims the benefit of U.S. provisional application Serial No.63 / 625,603, filed January 26, 2024, and U.S. provisional application Serial No.63 / 625,593, filed January 26, 2024, the disclosures of which are hereby incorporated in their entirety by reference herein. TECHNICAL FIELD The present disclosure relates to a hydroponic growing medium, specifically a stabilized propagation growing medium including natural fiber and a binder and methods of making and using the same. BACKGROUND Hydroponics is a subset of horticulture relating to a method of growing plants without soil, using mineral nutrient solutions in a water solvent. The plants may be grown without a substrate altogether such that only the plant roots are exposed to the mineral solution. Alternatively, the roots may be supported by a medium or substrate which is generally free of soil. SUMMARY In one embodiment, a growing medium is disclosed. The growing medium may include a stabilized, porous body of components including: a natural material and an isocyanate-based binder, its derivatives, or both. The growing medium may be hydrophilic, rewettable, and have a density of about 0.2-0.7 kg / L and porosity of about 55-80 %. In another embodiment, a method of forming a stabilized growing medium is disclosed. The method may include forming a slurry by reacting a natural material with an aqueous blend including a first surfactant and a binder; shaping the slurry into a three-dimensional shape; and curing the three-dimensional shape to obtain the stabilized growing medium having density of about 0.2-0.7 kg / L and porosity of about 55-80 %. In one or more embodiments, a hydroponic plug is disclosed. The plug may include a body having a foamed, porous structure, the body being rewettable and having a water reuptake rate of about 90% saturation in 25-240 s and compressibility to 50% of the body’s original height by force of about 5000-6000 g, as measured by a universal texture analyzer, the hydroponic plug being hydrophilic. The hydroponic plug may have a field capacity of about 79-84.5 m / m%. The porous structure may be an open-cell porous structure. The hydroponic plug may have a water reuptake rate of about 90% saturation in 50-90 s. The hydroponic plug may be biobased, according to ASTM D6866 or EN 16640 norm. The hydroponic plug may have a biogenic content of more than about 80 wt. %. The body may be cylindrical and include coir, peat, wood fiber, or a combination thereof. In yet another embodiment, a stabilized growing medium is disclosed. The medium may include a three-dimensional foamed body including a natural material, the body having a density of about 0.2-0.7 kg / L and field capacity of about 79-84.5 m / m%, the growing medium being rewettable and hydrophilic. The field capacity may be about 80-82 m / m%. The natural material may be coir. The growing medium may be biobased, according to ASTM D6866 or EN 16640 norm. The medium may have water reuptake rate of at least about 90% saturation in 25-240s. In another embodiment, a growing medium is disclosed. The growing medium may include a stabilized, porous body of homogenized components including a natural material and an isocyanate-based binder, its derivatives, or both. The growing medium may be hydrophilic, rewettable, and having a field capacity of about 79-84.5 m / m% and a porosity of about 55-80 wt. %, based on the total weight of the growing medium. The growing medium may be biobased, according to ASTM D6866 or EN 16640 norm. The isocyanate-based binder may be biobased, according to ASTM D6866. The binder may be methylene diphenyl diisocyanate (MDI). The body may be an open-cell body. The body may be compressible to 50% of the body’s original height by force of about 5000-6000 g, as measured by a universal texture analyzer. The natural material may be peat-free. The body may include a network of first cavities and a separate network of second cavities, the second cavities having a greater diameter than the first cavities. The growing medium may be structured as a frustoconical or cylindrical grow plug. In another embodiment, a method of forming a stabilized growing medium is disclosed. The method may include forming a slurry by reacting a natural material with an aqueous blend including a first surfactant and a binder, shaping the slurry into a three-dimensional shape, and curing the three-dimensional shape to obtain the stabilized growing medium being compressible to 50% of the body’s original height by force of about 5000-6000 g, as measured by a universal texture analyzer. The curing may include producing a foam resulting in the growing medium being porous and having porosity of about 55-80 wt. %, based on the total weight of growing medium. The curing may include forming a hydrophilic matrix from the slurry and trapping CO2 in the formed matrix. The hydrophilic matrix may have a field capacity of about 79-84.5 m / m%. The first surfactant may be an amphoteric surfactant. The aqueous blend may include a second surfactant different from the first surfactant in at least one physical property. The binder may be a non-TDI-based binder. The shaping the slurry may include forming a cylindrical plug. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 shows a non-limiting example of a growing medium configured as a grow plug according to one or more embodiments disclosed herein; FIGURE 2 is a plot of a water reuptake rate for Examples 50-54; FIGURE 3 is a plot of a water reuptake rate for Examples 54-57 and 63; FIGURE 4 is a plot of a water reuptake rate for Examples 54 and 58-62; FIGURE 5 is a graph of field capacity of Examples 50-63; FIGURE 6 is a graph of compression force required to compress Examples 50-63 to 50% of their original heights; FIGURE 7 is a plot of a water reuptake rate for Examples 64-68; FIGURE 8 is a plot of a water reuptake rate for Examples 69-73; FIGURE 9 is a graph of field capacity of Examples 64-73; FIGURE 10 is a graph of compression force required to compress Examples 64-73 to 50% of their original heights; and FIGURE 11 is a photograph of a texture analyzer TA10 / 490L – TA.XTplus ExpressC during compression testing of a non-limiting example plug, according to one or more embodiments disclosed herein. DETAILED DESCRIPTION Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations. Except in the examples, or where otherwise expressly indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and / or use are to be understood as modified by the word “about” in describing the broadest scope of the disclosure. Practice within the numerical limits stated is generally preferred. Also, unless expressly stated to the contrary: percent, “parts of,” and ratio values are by weight; the description of a group or class of materials as suitable or preferred for a given purpose in connection with the disclosure implies that mixtures of any two or more of the members of the group or class are equally suitable or preferred; description of constituents in chemical terms refers to the constituents at the time of addition to any combination specified in the description, and does not necessarily preclude chemical interactions among the constituents of a mixture once mixed. Unless stated otherwise, the wt.% is based on the total weight of the substrate and the vol.% is based on the total volume of the substrate. The first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation. Unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property. It must also be noted that, as used in the specification and the appended claims, the singular form “a,” “an,” and “the” comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components. As used herein, the term “substantially,” “generally,” or “about” means that the amount or value in question may be the specific value designated or some other value in its neighborhood. Generally, the term “about” denoting a certain value is intended to denote a range within + / - 5% of the value. As one example, the phrase “about 100” denotes a range of 100+ / - 5, i.e. the range from 95 to 105. Generally, when the term “about” is used, it can be expected that similar results or effects according to the disclosure can be obtained within a range of + / - 5% of the indicated value. The term “substantially” may modify a value or relative characteristic disclosed or claimed in the present disclosure. In such instances, “substantially” may signify that the value or relative characteristic it modifies is within ± 0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or 10% of the value or relative characteristic. It should also be appreciated that integer ranges explicitly include all intervening integers. For example, the integer range 1-10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Similarly, the range 1 to 100 includes 1, 2, 3, 4, ..., 97, 98, 99, 100. Similarly, when any range is called for, intervening numbers that are increments of the difference between the upper limit and the lower limit divided by 10 can be taken as alternative upper or lower limits. For example, if the range is 1.1. to 2.1 the following numbers 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 can be selected as lower or upper limits. Similarly, whenever listing integers are provided herein, it should also be appreciated that the listing of integers explicitly includes ranges of any two integers within the listing. In the examples set forth herein, concentrations, temperature, and reaction conditions (e.g., pressure, pH, flow rates, etc.) can be practiced with plus or minus 50 percent of the values indicated rounded to or truncated to two significant figures of the value provided in the examples. In a refinement, concentrations, temperature, and reaction conditions (e.g., pressure, pH, flow rates, etc.) can be practiced with plus or minus 30 percent of the values indicated rounded to or truncated to two significant figures of the value provided in the examples. In another refinement, concentrations, temperature, and reaction conditions (e.g., pressure, pH, flow rates, etc.) can be practiced with plus or minus 10 percent of the values indicated rounded to or truncated to two significant figures of the value provided in the examples. As used herein, the term “and / or” means that either all or only one of the elements of said group may be present. For example, “A and / or B” means “only A, or only B, or both A and B”. In the case of “only A,” the term also covers the possibility that B is absent, i.e. “only A, but not B”. It is also to be understood that this disclosure is not limited to the specific embodiments and methods described below, as specific components and / or conditions may, of course, vary. Furthermore, the terminology used herein is used only for the purpose of describing particular embodiments of the present disclosure and is not intended to be limiting in any way. The term “comprising” is synonymous with “including,” “having,” “containing,” or “characterized by.” These terms are inclusive and open-ended and do not exclude additional, unrecited elements or method steps. The term “including” or “includes” may encompass the phrases “comprise,” “consist of,” or “essentially consist of.” The phrase “consisting of” excludes any element, step, or ingredient not specified in the claim. The phrase “consisting essentially of” limits the scope of a claim to the specified materials or steps, plus those that do not materially affect the basic and novel characteristic(s) of the claimed subject matter. When the phrase “consisting of” or “consisting essentially of” appear in a clause of the body of a claim relative to an element, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole. With respect to the terms “comprising,” “consisting of,” and “consisting essentially of,” where one of these three terms is used herein, the presently disclosed subject matter can include the use of either of the other two terms. The term “one or more” means “at least one” and the term “at least one” means “one or more.” The terms “one or more” and “at least one” include “plurality” as a subset. The description of a group or class of materials as suitable for a given purpose in connection with one or more embodiments implies that mixtures of any two or more of the members of the group or class are suitable. Also, the description of a group or class of materials as suitable for a given purpose in connection with one or more embodiments implies that the group or class of materials can “comprise,” “consist of,” and / or “consist essentially of” any member or the entirety of that group or class of materials. First definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation. Unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property. As the agricultural and horticultural production around the world focuses on efficiency, economy, and sustainability, new growing media are being developed and improved to meet the demand. In many parts of the world, soil, which has been overused and damaged by machinery and insensitive environmental practices in the past centuries, is generally depleted of minerals and nutrients and is not the best material for commercial plant growth. Additionally, growing in soil is typically limited by climate conditions, weather patterns, temperatures, and other factors. Hence, modern agricultural and horticultural efforts have been transferred to soil-free or hydroponic growing. While hydroponics gained its name due to plant growth in water, the term also encompasses cultivation of terrestrial plants in substrates different from water as long as the substrate is generally free from soil. Nonlimiting example substrates include an expanded clay aggregate, growstones, coir or coco peat, rice husks, perlite, vermiculite, pumice, sheep wool, rock or mineral wool, brick shards, polystyrene packing peanuts, among other types. Hydroponic growing presents several advantages in comparison to traditional growing in soil. The roots of the grown plants may have better access to the beneficial amount of oxygen, nutrients, and water than plants grown in soil. Additionally, hydroponic growing, which provides nutrients to the roots in a more accessible way than soil growing, may have increased capability to produce more nutritious foods, stronger, healthier plants, plants with increased longevity or abundance of blossoms, or a combination thereof. Further still, hydroponic growing may enable increased plant and / or food production locally, which plays a vital role in attaining sustainable practices. Typically, each stage of hydroponic growing utilizes a different hydroponic product. For example, the seedling may be started and developed to a certain stage in a grow plug. Grow plugs are stabilized generally soilless propagation media. Typically, grow plugs include a blend of natural materials held together with a binder. The grow plugs are shaped to fit within a cell of a tray such that they can be inserted before growing and removed with the plant once a seedling is established and a root structure develops to a predetermined degree. The grow plugs can be used with automated transplant machinery, allow for production control, increase uniformity within a greenhouse, etc. Different grow plugs have been developed. Traditionally, a grow plug includes a blend of natural material(s) such as peat with a foam binder to generate a foam plug. The foam is typically created by reacting a prepolymer binder (polyol reacting with isocyanate) with water. A non- limiting example isocyanate binder may include toluene diisocyanate-based binders (TDI). But TDI itself, a clear, colorless liquid, while providing good foaming qualities, is rather volatile and its vapors need to be removed during production. Using TDI-based isocyanate binders, and inclusion of TDI in production, thus requires strict measures which may add costs and challenges to management of production lines. Additionally, as the best practices have become directed towards sustainability and ecological principles, mitigation of carbon footprint keeps gaining traction. Utilization of foam binders such as TDI-based prepolymers is thus a limiting obstacle in achieving a lower carbon footprint. Therefore, it would be desirable to identify a different binder than TDI-based binders for production of grow plugs and other hydroponic grow media. Further still, plants typically benefit from the aeration which the traditional growing medium, soil, has. Yet, soil is not practical for growth for many reasons – lack of nutrients and lack of ability to transplant soil by a machine, just to name a few. Therefore, it would be desirable to develop a growing medium which is transportable and provides ideal growing properties for variety of plants. In one or more embodiments, a hydroponic growing medium is disclosed. The growing medium may be a plug, growing medium plug, grow plug, horticultural plug, or a starter plug. A plug is a compact mass of a growing medium, typically used for seed germination and rooting cuttings. While the term plug is used throughout the disclosure, the growing medium may be shaped into larger units such as grow cubes or slabs, which may be used to house grow plugs and serve during advanced stages of plant growth. Furthermore, the growing medium disclosed herein may be used for any and / or all stages of plant growing and have any configuration and size needed for that purpose. The growing medium may be self-supporting, three-dimensional, structurally stable, or a combination thereof. The growing medium may be stabilized in relation to its structure, chemistry, physical properties, or a combination thereof. After curing, the growing medium may have, retain, carry its shape, chemical composition, physical properties for a predetermined length of time, at least for a growing season for the specific crop or plant the growing medium is configured for. The growing medium may have any shape, size, or configuration. A non-limiting example shape may include a full or partial cylinder, frustocone, cube, prism, cone, hemisphere, bullet, sphere. The growing medium may have a body having a uniform or non-uniform shape. The plug may have a cylindrical, cuboid, cone-shaped, or otherwise-shaped body. The body may have one or more slots, openings, apertures, openable ends, rims, overhangs, or their combination. The growing medium may have one or more sides. The growing medium may have a top side and a bottom side. The top and bottom sides may have the same or different size, shape, configuration, or a combination thereof. A non-limiting example of a grow plug is shown in Fig. 1. The growing medium may have at least one dibble, indentation, recess in the top side of the plug. The growing medium may be free of a dibble, indentation, or recess. The growing medium may be enclosed on all sides or have one or more openings, apertures, cavities, discontinuities, slots, cuts, the like, or a combination thereof. The growing medium is suitable for germination and growth of different plants, horticultural, floricultural, and agricultural purposes. For example, the growing medium may be suitable for growth of annuals, perennials, woody ornamentals including trees, shrubs, groundcover, vines, agricultural crops, vertical farming, aquaponics, aeroponics, tropicals, berries, citrus plants, specialty crops, orchids, etc. The growing medium may be hydrophilic, structured to wet and keep moisture, thus providing water and nutrients to the plant throughout its surface area while at the same time preventing pooling of water. The growing medium may be rewettable, relating to a process in which the growing medium is formed as a moist medium, which may be subsequently dried, and will rewet and remain hydrophilic throughout the plant germination process after rewetting. This is in contrast to other media which may not be able to retain moisture after they become dry, for example after their moisture content drops below about 15, 10, or 5 wt.%. The growing medium may include a porous structure. The structure may include a body which may be molded, extruded, or otherwise made into a predetermined shape, as was discussed above. The body may be rigid enough to attain, keep, preserve a specific shape. At the same time, the body may be pliable, soft, and / or flexible enough to enable penetration of plant parts such as plant roots throughout the body. Upon penetration, the body of the growing medium effectively does not fall apart but retains its shape. The body of the growing medium also generally retains its shape while being manipulated by a machine such as during replanting or transplanting. The body may be porous. The body may include a material mass / volume and a plurality of cavities, openings, apertures, semi-apertures, dents, depressions, holes, pockets, or voids within the material mass. The body may be an open-cell body. The term open-cell refers to open spaces between the cell walls such that the cells are not completely sealed, enabling fluid flow throughout the material. The cavities may be about 10 to 10000, 50 to 5000, or 100 to 1000 µm wide. The cavities may be about 10, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4100, 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900, 5000, 5100, 5200, 5300, 5400, 5500, 5600, 5700, 5800, 5900, 6000, 6100, 6200, 6300, 6400, 6500, 6600, 6700, 6800, 6900, 7000, 7100, 7200, 7300, 7400, 7500, 7600, 7700, 7800, 7900, 8000, 8100, 8200, 8300, 8400, 8500, 8600, 8700, 8800, 8900, 9000, 9100, 9200, 9300, 9400, 9500, 9600, 9700, 9800, 9900, or 10000 µm wide. The cavities may be roughly spherical, circular, globular, spheroidal in nature. The cavities may have a diameter of about 20 to 5000, 50 to 2500, or 100 to 1000 µm. The cavity diameter may be about 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4100, 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900, or 5000 µm. The cavities may have uniform or nonuniform diameter. The cavities may form a system or network of cavities. At least some of the cavities may be interconnected or intertwined, forming pathways within the body. The cavities may include first cavities of a first diameter range d1 and second cavities of a second diameter range d2. The first diameter d1 may be smaller than the second diameter d2. The first cavities may include capillary transportation cavities structured to transport and hold water within the body. The second cavities may be air cavities structured to promote aeration throughout the body. Within the system, the first and second cavities cooperate to enable balanced air holding capacity and water holding capacity of the growing medium. The herein-disclosed growing medium thus features a system for optimal rooting and plant germination. The body has a porosity of about 55-80, 60-75, or 62-70 %. The total porosity may be about, at least about, or at most about 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80 %. The body has a density in the range of about 0.2 – 0.7, 0.25 – 0.6, or 0.3 – 0.55 kg / L. The density may be about, at least about, or at most about 0.2, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, or 0.70 kg / L. Unlike the traditional foam plugs created by a reaction of the binder with water, the herein-disclosed growing medium utilizes at least one or more different components, production methods, or both. Some of the components remain in the final product while other components are consumed in one or more reactions of the production process. The components are homogenized such that the growing medium has a uniform, even, well-balanced distribution of the components within the body of the growing medium. The body is thus homogenized. The growing medium may include one or more of (A) natural materials, (B) binders, (C) liquids, (D) additional materials, and (E) air. One or more of the components may be sterile. The amounts of at least some of the components (A)-(E) differ in the beginning of the production process and in the final product because some of the components react and / or are consumed by reactions. For example, the final product or the final growing medium such as a plug, slab, or grow cube may include about 0.5-10, 2-8, or 3-5 wt.% binder and its derivatives and about 90-99.5, 92-98, or 95-97 wt.% natural material(s). In other examples, the final product may include about 0.5-10, 2-8, or 3-5 wt.% binder and its derivatives, about 80-99.4, 83-97.5, or 86-96 wt.% natural material(s), and about 0.1-10, 0.5-9, or 1-8 wt.% additional materials. In another example, the final product may include about 0.5-10, 2-8, or 3-5 wt.% binder and its derivatives, about 75- 98, 78.5-95.4, or 82.7-93.3 wt.% natural material(s), about 1-10, 2-9, or 3-8 wt.% additional materials, and about 0.5-5, 0.6-4.5, or 0.7-4.3 wt.% air. The one or more natural material(s) (A) may include one or more non-synthetic, non- man-made, non-artificial materials. The natural materials (A) may include raw or processed natural materials. For example, the natural materials may include fiber and / or particles from wood, bark, coco coir, peat, moss, jute, sisal, cotton, leaf fiber, mineral fiber, straw, rice hulls, grass such as bamboo, hemp, bagasse, alfalfa, flax, the like, or a combination thereof. The fibrous or particulate material may be shredded, cut, milled, hammermilled, extruded, refined, crushed, pressed, heated, conditioned to alter pH or one or more properties, the like, or a combination thereof. The fibrous or particulate material may be processed in a retruder, extruder, refiner, pressure vessel, heater, the like, or a combination thereof. The natural materials (A) may be free of one or more materials such as wood, bark, coco coir, peat, jute, sisal, cotton, leaf fiber, mineral fiber, straw, rice hulls, grass such as bamboo, hemp, alfalfa, flax. The growing medium may be peat-free. The wood and / or bark fiber and / or particles may be derived from one or more types of trees such as yellow poplar, cedar such as Western red cedar, fir such as Douglas fir, California redwood, pine such as Ponderosa, Sugar, White, Red, Jack, Longleaf, Turkish, Virginia, Lodgepole, Pitch, Maritime, Sand, Slash, Loblolly, Bristlecone, Austrian, Japanese Black, Japanese White, Lacebark, Mediterranean, Monterey, Caribbean, Queensland, Bunya, Norfolk Island, and Yellow varieties of pine fiber, oak, walnut, mahogany (Swietenia macrophylla, Swietenia mahagoni, Swietenia humilis), hemlock, Douglas fir, alder, elm, birch, Sitka spruce, European spruce, sycamore, and the like, and combinations thereof. The wood and / or bark fiber and / or particles may have the same or different particle distribution such that a first type of wood / bark fiber and second type of wood / bark fiber may be used, each having a different particle distribution or sieve size averages. The growing medium may include about 100 wt. or vol. % of a single type of fiber such as peat, wood fiber, or coco coir, based on the total weight of the natural material. Alternatively, the substrate may include about 1-99, 10-80, or 30-50 wt. or vol. % of a first type of fiber and about 1-99, 10-80, or 30-50 wt. or vol. % of a second type of fiber, based on the total weight of the natural material. Potentially, the substrate may also include about 1-99, 10-80, or 30-50 wt. or vol. % of a third type of fiber, based on the total weight of the natural material. More types of fiber are contemplated. The substrate may include even or uneven wt. or vol. % of each type of fiber. The wt.% or vol. % is based on the total weight or volume of the substrate, prior to adding liquids or binders and additional materials. In a non-limiting example, the substrate may include at least about 50 vol / wt.% peat or coco coir, the remainder being at least one other type of fiber or another material named herein. In another example, the substrate may include about, at least about, or at most about 10, 20, 30, 40, 50, 60, 70, 80, or 90 vol / wt.% wood fiber and the remainder being at least one other type of fiber or material named herein. For example, the substrate may include about 80 vol / wt.% peat or coir and 20 vol / wt.% wood and / or bark fiber, and / or another fiber / material. The substrate may include about 70 wt.% peat and / or coir and about 30 vol / wt.% another fiber / material. The wt.% or vol. % is based on the total weight or volume of the substrate, prior to adding liquids or binders and additional materials. A non-limiting example of component (A) may include about 100:0 to 0:100 coir / peat mixture. The ratio of coir : peat may be about, at least about, or at most about 0:100, 1:99, 5:95, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, 99:1, or 100:0. The weight or volume % of the component (A) during the process and in the final product may be the same or substantially the same. The one or more binder(s) (B) may include a single type of binder or a mixture of binders. The one or more binder(s) (B) may include an isocyanate and a polyol. The binder may include an isocyanate prepolymer, a polyurethane prepolymer in which all of the polyol hydroxyl end groups have reacted with isocyanate groups, a compound with isocyanate functionality at the termini. The binder may include TDI, MDI (methylene diphenyl diisocyanate), IPDI (isophorone diisocyanate), HDI (hexamethylene diisocyanate), HMDI (4,4’-methylene-bis(cyclohexyl isocyanate)), the like, or a mixture thereof. TDI-based binders have been utilized as a grow plug binder in the past. But due to TDI’s acute toxicity, sensitizing risks and volatility, its use in manufacturing is relatively complicated and costly. Additionally, with the desire to move to more sustainable plugs, and bio-based materials, there is a desire to replace TDI-based binders with a different binder. The use of TDI in the structured grow plugs was based on TDI’s use for soft polyurethane foams, allowing formation of a relatively soft grow plug. A simple replacement of TDI for MDI in the same amount would not result in a functional grow plug since MDI has a different structure, performance, and forms much more rigid foam than TDI. Because MDI is typically used for the production of rigid polyurethane foams, in the past, it was not considered a suitable candidate for grow plugs which have to be soft enough for the plant roots to penetrate. Additionally, MDI-based prepolymers are more costly than TDI-based analogues, and TDI has a higher isocyanate content and its foaming volume per unit mass is larger. Yet, it was unexpectedly discovered that MDI-based prepolymers may be used instead of TDI-based analogues as a binder in the herein-disclosed growing medium. Without limiting this disclosure to a single theory, it is believed that the inclusion of the component (C) enables prolonged foaming such that the released CO2 remains trapped in the formed matrix. Prolonged foaming may be due to increased nucleation of the forming bubbles. Consequently, the formed CO2is trapped instead of being off-gassed, as is typical for grow plug production. The increased amount of CO2within the matrix results in the foamed product with a desirable density. As a result, less binder is needed to generate CO2 upon reaction with water, which renders the production more economical. Additionally, since MDI has a longer chain and a more rigid structure, providing a more rigid foam than TDI, a relatively small amount of MDI is needed to form a well-foamed plug of desirable softness and porosity provided that the CO2 is secured within the matrix during production. At the same time, the herein-disclosed growing medium material has satisfactory properties such as good rewettability, field capacity, and softness / compressibility. The herein-disclosed MDI-based growing medium has several advantages. For example, MDI is less toxic than TDI but has a lower curing speed than TDI. Additionally, because MDI is less volatile (200 times lower vapor pressure than TDI), the manufacturing process utilizing MDI is safer and may be less economical due to lower requirements for ventilation. The weight or volume % of the component (B) during the process and in the final product is different. The binder is typically reacted in the production process. Specifically, the binder reacts with the component (C) to generate CO2 which expands a solid mixture including components (A) and, optionally, (D). The final product may include one or more polymerized derivatives of component (B). The component (C) may include one or more liquids in a mixture or blend. The mixture or blend may be aqueous. The component (C) may include water. The water may be tap water, deionized water, brackish water, salt water, the like, or a combination thereof. The component (C) may be an aqueous solution. The component (C) may include one or more surfactants. Surfactants, or surface-active agents, are compounds that lower the surface tension between two liquids or between a liquid and a solid. Surfactant(s) may be added to increase foaming, hydrophilicity, void formation, bubble formation and stability, structural stability of the final product, the like, or a combination thereof. A non-limiting example surfactants may include anionic surfactants, cationic surfactants, zwitterionic surfactants, non-ionic surfactants, amphoteric surfactants, neutral surfactants, or their combination. The surfactant blend may include a combination of a first, second, and / or third surfactant. The surfactants are compatible with one another. The first, second, third surfactant may each be the same or different regarding the type (anionic, cationic, zwitterionic, non-ionic, amphoteric, neutral), chemical composition, physical properties, or a combination thereof. For example, the first surfactant may be an amphoteric surfactant, the second surfactant may be a non-ionic surfactant. In another non-limiting example, the first surfactant may be a cationic surfactant and the second surfactant may be a non-ionic surfactant. In yet another example, the first surfactant may be an anionic surfactant and the second surfactant may be a neutral surfactant. In yet another example, the first surfactant may be a neutral surfactant and the second may be amphoteric surfactant. The first : second : third surfactant weight ratio may be about, at least about, or at most about 1:1:0, 1:1:1, 1:2:0, 1:3:0, 1:4:0, 2:1:0, 2:1:1, 3:1:0, 3:1:1, 4:1:0, 4:1:1, 5:1:0, 5:1:1, 5:2:0, 5:2:1, 5:3:0, 5:3:1, 5:4:0, 5:4:1, 5:6:0, 5:7:0, or 5:8:0. The surfactants may include one or more polyethers, inner salts, alkanoates such as sodium alkanoate, polysorbates, glycosides, sulphates such as lauryl sulphate, a morpholines, olefin sulfonates, lauric acid groups, citric acid, stearate, stearic acid, esters, amines, oxides, linear, branched, unsaturated or saturated fatty acids with C6-C24, glycerol, sugar alcohols, betaines, isethionates, ethoxylates, carboxylates, mixed alcohols, grafted copolymers with a polydimethylsiloxane backbone and polyethylene oxide-co-propylene oxide pendant groups, azo- , hydrazine and other nitrogen-based materials, the like, or a combination thereof. Non-limiting example surfactants may include one or more of the following: C6-C24 fatty acids and their diesters, block copolymers of ethylene oxide / propylene with 8 to 40 EO / PO units, alkyl polyglycol ethers, alkylphenols, glycerol monoesters and diesters, monoglycerides, alkylpropionic acids, alkyltaurines, benzethonium chloride, acylaminopropyl-N,N- dimethylammonium glycinates, cocoalkylaminopropionate, cocoacylaminoethylaminopropionate, methyl-quaternized difatty acid triethanolamine ester salts, poly aryl ether phosphate, cetyl oleyl ethoxy phosphate, dodecyldimethylamine oxide, cetrimonium bromide dioctadecyldimethyl ammonium bromide, sorbitan ester, phenol + 4EO phosphate ester - potassium salt, cetylpyridinium chloride, 5-Bromo-5-nitro-1,3-dioxane, sulfosuccinates, lauryl amineoxide, behenamidopropyl betaine, coco betaine, babassuamidopropyl betaine, cocamidopropyl betaine, disodium lauroampho diacetate, sodium cocoamphoacetate, cocamidopropyl hydroxysultaine, phospholipids, polyoxirane polyol, sodium dodecyl sulfate, acrylates / steareth-20 methacrylate copolymer, PEG-60 hydrogenated castor oil, glycerin, PEG- 200 hydrogenated glyceryl palmate, butylene glycol, sodium lauroyl sarcosinate, quaternised cocoamine ethoxylate, tall oil fatty acid imidazoline, dodecylbenzene sulphonic acid, dodecylbenzene sulphonic acid, sodium laureth-3 sulphate, alkyl ether sulphate ammonium salt, sodium dioctylsulphosuccinate in ethanol / water, tridecanol + 5EO phosphate ester acid form, coconut diethanolamide, ethoxylated sorbitan mono-oleate, ethoxylated sorbitan tri-oleate, tallowamine + 15EO, oleic acid + 7-14EO the like, or a combination thereof. The one or more surfactants may be synthetic and / or derived from natural sources such as sugar beets, castor oil, coconut oil, palm oil, corn glucose, lecithin, lanolin, saponins, or the like. The surfactant may be used pure or as a solution. In a non-limiting example, the solution may be about 10-60, 20-50, or 30-40% surfactant solution. The one or more surfactants may have glycolic acid content of about 0.1-1.7, 0.2-1.6, or 0.3-1.5 wt. or vol. %. The glycolic acid content may be about, at least about, or at most about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, or 1.7 wt. or vol. %. The one or more surfactants may have free amino amine content of about 0.1-0.5, 0.15-0.45, or 0.2-0.4 wt. or vol. %. The free amino amine content may be about, at least about, or at most about 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, or 0.5 wt. or vol. %. The one or more surfactants may have a flash point of about 200-272, 210-270, or 215- 168⁰C. The flash point may be about, at least about, or at most about 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 271, or 272⁰C. The one or more surfactants may be foaming, food-safe, odorless, have salt content of about 0-8, 1-6, 2-3.5 wt. %. The salt content may be about, at least about, or at most about 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4,4.5, 5, 5.5, 6, 6.5, 7, 7.5, or 8 wt. %. The one or more surfactants may have a critical micelle concentration of about 0.01-3.2, 0.1-3, or 1-2.5 mM. The critical micelle concentration may be about, at least about, or at most about 0.01, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, or 3.5 mM. The values or the critical micelle concentration may be assessed at pH of 7.4. Without limiting this disclosure to a single theory, it is believed that micelle formation influences softness of the plug, which is herein measured using compression force required to compress the medium to 50% of its original height, using a texture analyzer. Formation of micelles may influence formation and retention of the foam in the setting slurry. The one or more surfactants may have density of about 5-10, 5.5-9.5, or 6-9 lb / gal or 599- 1198, 659-1138, or 718-1078 kg / m3. The density may be about, at least about, or at most about 5, 5.5, 5.7, 6, 6.5, 6.7, 7, 7.5, 7.7, 8, 8.5, 8.7,9, 9.5, 9.7, or 10 lb / gal or 599, 659, 683, 718, 778, 802, 838, 898, 922, 958, 1018, 1042, 1078, 1138, or 1198 kg / m3. The one or more surfactants may have specific gravity of about 0.9-1.1, 0.91-1.08, or 0.95-1.02. The specific gravity may be about 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.0, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, or 1.1. The one or more surfactants may have molar mass of about 200-10,000, 250-5,000, or 300-2,500 g / mol. The molar mass may be about, at least about, or at most about 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 315, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1650, 1700, 1750, 1800, 1850, 1900, 2000, 2050, 2100, 2150, 2200, 2250, 2300, 2350, 2400, 2450, 2500, 2600, 2700, 2800, 2900, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, or 10000 g / mol. In a non-limiting example, component (C) may include two surfactants, each having a density in the range of about 7.5-9 lb / gal. In a non-limiting example, component (C) may include two surfactants, the first having a molar mass greater than 2000 g / mol, the second having a molar mass smaller than 2000 g / mol. In a non-limiting example, component (C) may include two surfactants, the first having a molar mass of about 6, 8, or 10 times smaller than the second surfactant. In a non-limiting example, component (C) may include two surfactants, both surfactants having a salt content of about 0%. In a non-limiting example, component (C) may include two surfactants, the first having a critical micelle concentration of about 0.01-0.1 mM, and the second surfactant having a critical micelle concentration of about 2-3 mM. The component (C) may have neutral or slightly acidic pH of about 6-8.5, 6.5-8, or 7-7.5. The pH may be about 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4, or 8.5. The one or more surfactants may form a mixture of about, at least about, or at most about 0.05 - 0.8, 0.1 - 0.7, or 0.2 - 0.6 wt. or vol. %, based on the total wt. or vol. of the component (C) or slurry (components A, B, C, D, or their combination) or v / v% aqueous solution. The amount may be about, at least about, or at most about 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, or 0.8 wt. or vol. %, based on the total wt. or vol. of the component (C) or slurry (components A, B, C, D, or their combination) or v / v% aqueous solution. The one or more surfactants may be dissolved in the water. In a non-limiting example, the amount of the surfactants may be about 0.2-0.6 v / v% aqueous solution. In another non-limiting example, the amount of the first surfactant may be about 0.2-0.4 v / v% aqueous solution and the amount of the second surfactant may be about 0.2-0.4 v / v% aqueous solution. In another non-limiting example, the amount of the first surfactant may be about 0.1-0.3 v / v% aqueous solution and the amount of the second surfactant may be about 0.1-0.3 v / v% aqueous solution. The one or more additional material(s) (D) are optional materials of natural or synthetic origin. The materials (D) may be treated, pre-processed, or untreated. The material(s) (D) may be biobased. The additional materials may include inorganic materials, inert aluminosilicates containing alkali and alkaline-earth metals, perlite, vermiculite, clay, calcined clay, seashells, limestone, perovskites, sand, zeolites, biochar, compost, animal manure, fish meal, plant waste, paper fiber, textile fiber, fertilizers such as fertilizer starters (NPK), nutrients, natural gum(s), biostimulant(s), man-made fiber, the like, or a combination thereof. The fertilizers may be nitrogen fertilizers, phosphate fertilizers, potassium fertilizers, compound fertilizers, or the like. For example, melamine / formaldehyde, urea / formaldehyde, urea / melamine / formaldehyde and like components may serve as a slow-release or control-release fertilizer. Fertilizers having lesser nutritional value, but providing other advantages such as improving aeration, water absorption, or being environmental-friendly may be also used. Control- release fertilizers with polyolefin, polyurethane, polymeric, and / or biodegradable coating may be used. The control-release fertilizers may be tailored for a specific growing goal such as yield, length of a growing season, and / or plant species. Nutrients are well-known and may include, for example, macronutrient, micronutrients, and minerals. Examples of macronutrients include calcium, chloride, magnesium, phosphorus, potassium, and sodium. Examples of micronutrients are also well-known and include, for example, boron, cobalt, chromium, copper, fluoride, iodine, iron, magnesium, manganese, molybdenum, selenium, zinc, vitamins, organic acids, and phytochemicals. Other macro- and micronutrients may be used. Biostimulants may include any substance or microorganism that, when applied to seeds or plants, stimulates natural processes to enhance or benefit nutrient uptake, nutrient use efficiency, and / or crop quality and yield, mitigate stress, or their combination. Biostimulants may include many different types. Non-limiting example biostimulants include enzymes, proteins, peptides, amino acids, protein hydrolysates and / or other N-containing compounds, micronutrients such as Al, Co, Na, Se and Si, phenols, salicylic acid, monosilicic acid, polysilicic acids, humic acid, fulvic acid, seaweed extract, botanicals, biopolymers such as chitosan, inorganic compounds such as amorphous silica (SiO2.nH2O), silicates such as potassium silicate, calcium silicate, microbial biostimulants including mycorrhizal and non-mycorrhizal fungi, fungal spores, bacterial endosymbionts (like Rhizobium) and Plant Growth-Promoting Rhizobacteria, biologicals, etc. The biostimulants may be included as part of various components such as rice hulls, fish meal, byproducts of dairy production, etc. The calcined particles may be based on clay. The calcined clay particles may include one or more types of clay. The clay may include, for example, smectite clay(s) including the following minerals: montmorrilonite, beidellite, nantronite, saponice, hectorite. The clay may be gray, red, or both. The clay particles may be processed in the following manner for the purposes of the disclosed application. The clay may be calcined at a temperature of about 1000 to 1400, 1100 to 1350, or 1200 to 1300°F or 537-760, 593-732, or 648-704°C. The clay may be subsequently sized or micronized, for example, by grinding. The clay may be provided in various sizes. The heat- treated mineral particles may be added to the hydroponic substrate pre- or post-compression. The additional materials (D) may be added for a variety of reasons. For example, the limestone may added as a pH buffering agent to adjust pH of the growing medium. Depending on the type of component (A), pH may have to be raised or lowered. For example, humic acids from peat may warrant use of limestone to increase pH. Alternatively or additionally, component (D) may be added to adjust water uptake, air uptake, color, incorporate nutrients, the like, or a combination thereof. The weight or volume % of the component (D) during the process and in the final product may be the same or different. Some of the component (D) may be incorporated as a lasting component such as clay. Alternatively, some of the component (D) may succumb to a reaction, and potentially be released in time or during a lifetime of the growing medium. For example, limestone may be included in the production and the final product in the same vol. or wt. %, but over time, limestone may be consumed to suppress oxidatively formed acids in situ during a plant’s lifetime once the plant is growing in the herein-disclosed growing medium. The component (E), air, may be optionally added to the product during the production process, for example by injection into the slurry before the slurry is molded into a desirable shape of the growing medium. For example, air may be added to increase porosity, support foaming, the like, or a combination thereof. The air may be heated, cooled prior to the insertion into the slurry. The air may be also provided into a mixture of components (B) and (C) prior to their mixing with components (A), (D), or their combination. The air may be a mixture of gases (oxygen, nitrogen, carbon dioxide, methane, hydrogen, water vapor, argon, helium, neon, etc.) and solids such as dust particles. The amount of component (E) during the production and in the final product may be the same or different. In one or more embodiments, the growing medium may be compostable, bio-based, or both. The term bio-based relates to a material intentionally made from substances derived from living organisms. Biobased certifications differ around the world and can be based on the biogenic carbon content. Biogenic or biobased carbon content is often used as the metric indicative of the “naturalness” of a chemical compound or product. Biogenic carbon, having originated from living organisms is often contrasted with fossil carbon. While in fact, all fossil carbon was once living as well, the distinction is made mostly on the basis of age. Fossil feedstock is being depleted and does not replenish to any useful extent within the foreseeable future. Fossil carbon is generally derived from oil or leans heavily on petrochemical products or intermediates. In contrast, examples of replenishable carbon include plant material, biomass, grasses and weeds, coco coir, wood, or the like. Different bio-based certifications require different amount of biogenic content, from about 20 to 80 wt. %. For example, DIN Geprüft Certification and TÜV AUSTRIA Belgium certification are both derived from the EN 16640 norm. TÜV AUSTRIA Belgium’s OK Biobased certification is available as a class approach metric with class ranking of 20-40, 40-60, 60-80, and more than 80 wt. % biobased products. DIN CERTCO also has multiple classes of biobased certification. The ASTM standard D6866 serves as the testing method for Biobased Content, a certification that includes federal purchasing preference. The required biobased content is dependent on the product category (137 categories as of January 2024). Of these, the stabilized growing media disclosed herein may fall either under Gardening supplies and accessories with minimum biobased content of 43 wt. % or Soil amendments with a minimum biobased content of 72 wt. %. TÜV Belgium, highest certification grade requires all certified biobased materials to have >80 wt. % biogenic carbon. Biobased carbon may be determined by14C :12C ratio in the material, where14C is created from atmospheric nitrogen by solar irradiation. The14C (in the form of14CO2) is incorporated in biological tissues through photosynthesis, and as such is an accurate way to estimate the amount of carbon in a material that is derived from biological sources. The growing medium disclosed herein may be bio-based according to ASTM D6866, EN 16640 norm, DIN CERTCO, DIN Geprüft Certification, TÜV AUSTRIA, the like, or a combination thereof. The growing medium may be free or substantially free of fossil resources or materials. The herein-disclosed growing medium may have a biogenic content of more than about 60, 65, 70, 75, 80, or 85 wt. %. For purposes of bio-based growing media, the largest portion of non-biogenic carbon may come from component (A), followed by component (B). With respect to component (A), non- biogenic carbon may be reduced by eliminating materials which are fossil-based or which are not easily replenishable such as peat. Peat does not qualify as “natural” under some certifications while under other certifications, its age determines its qualification as natural. In bio-based plugs, peat amounts may be reduced, minimized, or peat may be replaced altogether with alternative materials of component (A) named above such as coco coir, wood fiber, etc. Additionally, the bio-based growing medium may include a biobased component (B). Reduction of the amount of component (B) may also add to a greater biogenic content of the final product. The herein-disclosed component (C) causes a significant foaming activity and retention of CO2 within the matrix (component A-D matrices), resulting in a low-density slurry during production, which carries less carbon content than the traditional grow plugs. Additionally, if MDI is to be used, since MDI forms a more rigid foam, by nature, a lower amount can be used in combination with the component (C) to generate a growing medium with desirable properties. The lower amount translates into lower carbon content (for biogenic carbon purposes, a binder content may be determined as a volumetric percentage of slurry). Component (D) may be a bio-based material from a renewable, replenishable source. A method of producing the herein-disclosed growing medium is disclosed herein. The method may include blending the one or more material(s) of component (A), optionally adding one or more additional component(s) (D) to form a solids mixture. The method may include heating water, premixing the water with one or more surfactant(s) to form a blend, or both as component (C). The method may then include a step of mixing the water, surfactant(s) (C), and binder(s) (B) with the solid mixture (components (A), (D), or a combination thereof) to form a slurry. The method may include providing the blend of component (C) and the component (B) into the solids mixture. The component (C) and (B) may be provided simultaneously or at different times. The providing may be via injection under pressure or otherwise. The method may further include providing the slurry onto a processing line to form the growing medium into desirable shapes such as plugs within trays, molds, loose plugs, another unit, or a combination thereof. The trays and / or molds may include a release agent to facilitate extraction of the final product. The method may further include removing the final product from the trays, molds, conveyor belt. Before the growing medium is fully set, the growing medium may be further adjusted in its shape, size, configuration, for example by adding a dibble, indentation, cut, the like, or a combination. The method may also include air, component (E), injection into the slurry to aerate the slurry. The air injection may be provided through or into the slurry. The air injection may be conducted prior to the deposition of the slurry onto the processing line. The method may include premixing or mixing of one or more components. The method may include heating, preheating, or cooling of one or more components such as water, water and surfactant mixture, binder, the like, or a combination thereof. The hydroponic medium disclosed herein may have beneficial properties with respect to plant cultivation. For example, the medium may have moisture content or field capacity of about 79-84.5, 79.5-83, 80-82 m / m%, based on the weight of a saturated medium over the weight of the dry medium. The field capacity may be about, or at most about 79, 79.1, 79.2, 79.3, 79.4, 79.5, 79.6, 79.7, 79.8, 79.9, 80.0, 80.1, 80.2, 80.3, 80.4, 80.5, 80.6, 80.7, 80.8, 80.9, 81.0, 81.1, 81.2, 81.3, 81.4, 81.5, 81.6, 81.7, 81.8, 81.9, 82.0, 82.1, 82.2, 82.3, 82.4, 82.5, 82.6, 82.7, 82.8, 82.9, 83.0, 83.1, 83.2, 83.3, 83.4, 83.5, 83.6, 83.7, 83.8, 83.9, 84.0, 84.1, 84.2, 84.3, 84.4, or 84.5 m / m%. The field capacity should not be lower than about 79 m / m% as such values may lead to decreased water retention in the medium and as a result require excessive water. Additionally, higher values than 84.5 m / m% may lead to excessive moisture, which may increase development of algae. Some application may require or benefit from a plug with a field capacity of about 80-82 m / m%. The field capacity may be measured as the weight of a saturated medium over the weight of the dry medium. The herein-disclosed media are structured to retain water, and field capacity thus indicates how much free water is carried by the medium or how much water is saturated into the medium. The herein-disclosed medium does not require as frequent watering as traditional media such as the rockwool. In comparison, media such as rockwool absorb water poorly, and thus need to be watered 10 to 20 times a day. No water is stored internally in the rockwool. Another benefit of the herein-disclosed medium is a fast rewetting. The fast rewetting may be illustrated via a rewetting rate, rate of rewetting or saturating the medium with a liquid, or a water reuptake rate. The terms used are rewetting and reuptake as the values are true for repeated saturation with a liquid, not just an initial introduction of moisture. The water reuptake rate may be about, at least about, or at most about 90% saturation in 25 – 240, 40 – 200, or 50 – 150 s. The water reuptake rate may be about 90% saturation in 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, or 240250 s. In a non-limiting example, the water reuptake rate of the medium, having the first surfactant, may be about 90% in about 50 s or more. In another non-limiting example, the water reuptake rate of the medium, having the first and second surfactant, may be about 90% in about 25 s or more. The rewetting rate or water reuptake rate and field capacity disclosed herein, and in the Examples below, were assessed using the following methodology. The materials needed included an accurate scale, flat basin on a level table, a stopwatch, and dried plugs. The dried plugs included plugs with 3.0 g < dry mass < 12.0 g, which can be removed from their respective tray for accurate results. Plugs with 3.0 > dry mass should be measured in batches and kept in their tray during measurements. The method included the following steps. A large, flat-bottomed basin was filled water forming a layer of about 2 mm in height. The basin was clean and devoid of any surfactants such as soaps or detergents, which affect water absorption. Water was clean and measured about 20⁰C. The samples were prepared. The samples can be measured with or without a tray. Data from plugs measured with a tray should not be compared to data from plugs measured without a tray. The dry mass of each sample was between 3 and 12 g, for accuracy. For accuracy, it is also advisable to have at least 6 different entries. Weigh of all dry samples was logged. A time interval was selected and logged. All sample plugs were deposited simultaneously in the basin with the layer of water. At the selected interval time, a plug entry was removed from the basin, weighed, and the weight logged. After weighing, the sample plug was returned to the basin, and remained in the basin for 30-60 minutes to saturate. Once saturation time passed, the sample plugs were removed from the basin, set to drain on a non-wicking surface for 5 minutes and weighed for final mass. The weight and final time were logged. Maximum uptake was the saturation mass of the water. The rewetting rate or the water reuptake rate and the field capacity were calculated using the following formulas (1)-(4). The field capacity, expressed as mass fraction, was calculated with only the dry and saturated mass of the plugs. ^^^^^^ ^^^^^^^^^^^^ = ^^^^^^^^^^^^ − ^^^^^^^^ (1),^^^^^^^^^^^^ ^^^^ ^^ = ^^^^^^^^^^^^ − ^^^^ (2),%^^^^^^^^^^^^^^^^ =(^^^^^^^^^^^^−^^^^)∙100% ^^^^^^^^^^^^−^^^^^^^^(3), . An additional advantage of the herein-disclosed medium is its relative softness. As was mentioned above, it is desirable that the medium has sufficient pliability for the plant’s roots to penetrate the material. Thus, rather than being constrained by the physical form of the medium, the plant is allowed to expand its growth through the medium while using the medium as a support. The relative softness of the medium may be assessed using measured compression force which is required to compress the medium to 50% of its original height. The medium may be compressible with a compression force of about 3000 – 10000, 4000 – 9000, or 4100 – 8500 grams (g) as measured by a universal texture analyzer TA.XT. The compression force may be about, at least about, or at most about 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, 9000, 9500, or 10000 g. In a non-limiting example, the compression force may be about 5000- 6000 g. Additionally, a growing medium such as a plug compressible with the force disclosed herein may also be suitable for manual handling. For example, certain types of plugs include sides to be stretched manually to allow for ingress of a seedling or a young plant to the plug’s internal volume. The plug needs to be pliable enough to allow for the manipulation, frequently done by a grower’s fingers, flexible enough to enable efficient handling, sturdy enough to provide support for the roots, and at the same time, soft enough to enable root penetration throughout the plug body during the growing season. The relatively soft medium disclosed herein has sufficient integrity to be handled and transported by a machine, robot, automation. The medium is suitable for automation and machine transport. The compression force disclosed herein and in the Examples below was assessed using the following methodology. The equipment used was a texture analyzer TA10 / 490L – TA.XTplus ExpressC (10 kg load cell), equipped with 75 mm compression plates. The assessment was conducted with plugs at field capacity. The texture analyzer TA10 / 490L, with a non-limiting example plug according to one or more embodiments disclosed herein, during compression force assessment is shown in Fig.11. A plug sample at field capacity was placed on the texture analyzer, under the compression plate. The texture analyzer had the following settings: Mode: compression Pretest speed: 2 mm / s Test speed: 1 mm / s Post-test speed: 10 mm / s Target mode: Strain (50%) Trigger force 25 g The texture analyzer compressed the sample plug to 50% of its original height, which was determined automatically. The force required to do so was logged. The measurement was taken in 6-fold to account for plug variability. The resulting average force (in g) with the standard deviation were reported. EXPERIMENTAL SECTION Example 1 A grow plug structure for orchid propagation was formed via the process described above. For a continuous process, 1 m3coco coir was premixed with about 0.5 kg limestone, and 1.2 kg fertilizer. The dry mixture was moved by augered horizontal pipeline. A mixture of 400 L water with 1.4 L surfactants was injected into the pipeline and kept at about 38-40°C. Before the mixture entered the auger, the binder (isocyanate prepolymer) was injected into the aqueous mix to form a mixture. The resulting slurry was injected with 1400 L pressurized air / m3coir, and the aerated slurry was augered onto a mold. The mold was skimmed and set aside for 4 minutes for the plugs to set and cool. The resulting plug had a foamed porous structure, was soft and flexible, rewettable, and suitable for orchid germination. Examples 2-8 An estimation was made for a peat-free plug that included about 70 wt. or vol% water. The peat-free plug included 100 wt.% coco coir, based on the total weight of the component (A). The coco coir solids were assumed to be fully biogenic. In the calculations, limestone charge was neglected for practical purposes. The carbon content of dry coir was estimated to be about 45%, and the carbon content of the binder was about 61%. Binder use was estimated at 6% of slurry mass, corresponding to the binder levels of the sturdiest orchid plugs. The total biobased carbon percentage was calculated to be about 78.7%. For results, see Table 1. Table 1 – Bio-based content of Examples 2-8 Example No. Binder charge [v / v% Peat-free bio-based + 10% peat bio- f l rr ] nt nt b d nt nt Examples 9-18 Table 2 below summarizes biogenic content of various examples of the grow plugs disclosed herein. Table 2 lists details of components A-D as well as amount of each component (v / v% of slurry). Based on the carbon isotope ratio (14C carbon dating), biobased content of the final product was determined by linking the average age of carbon in components to a biobased percentage. The term “component” was abbreviated to “Comp.” Table 2 – Biobased content of Examples 9-18 Example Comp. A Comp. A Comp. B Comp. B Comp. C Comp. D Biobased No. [wt.%] [v / v% of [v / v% [%] Examples 19-30 Examples 19-30 were prepared according to the method described above. Each Example was prepared as a grow plug to assess desirable properties listed below in Table 3. Component A included coir or peat / coir mix. Component B included MDI. Component C included a mixture of water and a blend of surfactants disclosed herein. In Table 3, absorption relates to time it took to fully absorb water through capillary action when a plug was left in 1 cm layer of water. All plugs were deemed rewettable upon testing. Comp. C ratio indicates volume ratio of first : second surfactant used. Firmness and softness were determined organoleptically on a scale of 1-9 (1 indicating not firm / not soft, 9 indicating very firm / very soft). A generally desirable result for firmness / softness is about 7-9. Overall assessment included assessment of firmness, softness, bonding, friability, density, and rewettability for each plug and was also determined organoleptically (7-9 are desirable values). Germination, and growth in 7 days following germination, were tested as the ability to germinate / grow cress seeds with a desirable result above 6. Table 3 – Properties of Examples 19-30 Example Comp. Comp. Comp. Absorption Firmness Overall Germination / Growth 25 50 4 1:0 300 8 / 7 7 8 / 6 Examples 31 - 45 Examples 31 – 45 were prepared as plugs by the process described above. The formed Examples were weighed (as produced) and set aside in trays to set fully. After 3 days, the combined weight of 3 plugs for each Example was recorded and divided by the assumed volume of the plugs (3696 mL / 66 * 3). An average weight of a plug was 16-17 g. Component A includes coir, either alone or in a combination with wood fiber. The wood fiber is characterized as wood fiber 1 and wood fiber 2 because their particle distribution differed. The wood fiber may be wood or wood and bark fiber. Table 4 – Properties and compositions of Examples 31-45 Example Comp. A (material, %) Comp. Comp. B Comp. C Density 33 Coir: wood fiber 1 (80:20) TDI 2.1 0.2 0.43 Examples 46-49 Examples 46-49 were prepared as plugs according to the method described above. The plugs had uniform shape and weight of about 16-17 g each. Total porosity, water holding capacity (WHC), and air space were measured and are noted in Table 5 below. Table 5 – Properties and compositions of Examples 46-49 Example Comp. A Comp. B Comp. C Total WHC Air No. (material, [v / v% porosity [%] [%] Space Example 50 - 63 A plurality of growing media shaped as plugs were formulated according to procedures disclosed above. Trays having 66 cells each and volume of 3697 mL were used. Each Example included 50 mL of TDI binder per entry (Component B). The final binder concentration was 1.5 vol.% and was calculated based on the number of plugs made by 3L of dry substrate. Component A included 100 wt.% coir in each Example 50 – 63. Comp. C 1 indicates a first surfactant, Comp. C 2 indicates a second surfactant. Table 6 – Properties and compositions of Examples 50-63 Exam Comp. A Comp. Comp. C Comp. Comp. C Comp. # Binder ] aqueous aqueous based on solution] solution] # cells Property information about the surfactants used in Examples 50-63 is shown in Table 7. Table 7 also shows surfactants used in Examples 64-73 discussed below. Table 7 – Surfactants of Examples 50-73 Surfactant Surfactant Surfactant Molar mass Critical micelle name type composition type [g / mol] concentration [mM] As can be observed from Table 6 above, the addition of the second surfactant resulted in a lower density of the plugs (compared with a single surfactant), which is illustrated by the # of cells which were filled with the respective volume of the slurry. The addition of the second surfactant thus generated a foamier, airier, less dense slurry which was used to fill a greater number of cells than Examples lacking the second surfactant. Water absorption rates were measured for Examples 50-63. The water reuptake speed to saturation or rewetting speed was recorded and normalized. Results are shown in Figs. 2-4. Specifically, Fig.2 shows a water reuptake rate for Examples 50-54, in which the concentration of the first surfactant was varied, the fastest reuptake rate being recorded for Example 54. Fig. 3 shows results for Examples 55-57 and 63 in comparison to Example 54. Fig.4 shows results for Examples 58-62 in comparison to Example 54. In was observed that concentration of the first surfactant in Example 54 generated a desirable water uptake rate. Lower concentration or lack of any surfactant resulted in slow saturations rates. Presence of the first and second surfactant was also observed with desirable results. The first surfactant’s influence on the water reuptake rate was preserved even in the presence of the second surfactant, as can be seen in Figs.3 and 4. Field capacity or moisture content was also studied for Examples 50-63. The field capacity corresponds to a saturation point or a point at which the plug becomes saturated with a liquid. The field capacity was measured as the weight of the saturated plug over the weight of the dry plug. For example, the moisture content or field capacity of Example 54 was approximately 82.5%. Presence of the first and second surfactant, in general, increased the field capacity or moisture content. In general, moisture content or field capacity should not be below about 80% according to grower standards. A compression force needed to compress the Examples 50-63 to 50% of their respective original heights was measured using a TA.XT texture analyser for universal applications using the methodology described herein. The pressure required to compress each Example was recorded and results are shown in Fig.6 (n = 6). The compression required provided an accurate indication of how soft a respective Example plug was. As can be seen in the Fig.6 and Table 8 below, Example 54 was a relatively soft plug. The compressibility increased with a greater concentration of the first surfactant. A combination of the first and second surfactants resulted in a greater compressibility and thus greater softness. Examples 58 and 61-63 demonstrated the greatest compressibility. Table 8 – Compression force required to compress Examples 50-63 to 50% of their original heights Example No. Force [g] Std. deviation Examples 64 – 73 A plurality of hydroponic plugs was formulated according to procedures disclosed above. Trays having 66 cells each and volume of 3697 mL were used. Each Example included 75 mL of TDI binder per entry (Component B). The final binder concentration (binder concentration in Table 9) was 2.5 vol.% and was calculated based on the number of plugs made by 3L of dry substrate. Component A included 100 wt.% coir in each of the Examples 64-73. The surfactant quantity was 0.2 v / v% aqueous solution in each Example 64-72, and no surfactant was present in Example 73. Table 9 – Properties and compositions of Examples 64-73 Example Comp. A Comp. Comp. C [v / v% Comp. C1 # cells Binder conc. d The water reuptake rate or rewetting rate was measured for Examples 64-73 as in Examples 50-63 discussed above. The results are shown in Fig.7 for Examples 64-68 and in Fig. 8 for Examples 69-73. The field capacity or moisture content was assessed as for Examples 50-63 discussed above. The field capacity results are shown in Fig.9. The field capacity fluctuated between about 80 to 85 m / m%. The compression force required to compress each Example by 50% of their respective original height was assessed using a TA.XT texture analyzer as for Examples 50-63 discussed above. The compression data for Examples 64-73 is provided in Table 10 and Fig.10. Table 10 – Compression force required to compress Examples 64-73 to 50% of their original heights Example No. Force [g] Std. deviation 73 10638 76 While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.

Claims

WHAT IS CLAIMED IS:

1. A hydroponic plug comprising: a body having a foamed, porous structure, the body being rewettable and having a water reuptake rate of about 90% saturation in 25-240 s and compressibility to 50% of the body’s original height by force of about 5000-6000 g, as measured by a universal texture analyzer, the hydroponic plug being hydrophilic.

2. The hydroponic plug of claim 1, wherein the hydroponic plug has a field capacity of about 79-84.5 m / m%.

3. The hydroponic plug of claim 1, wherein the porous structure is an open-cell porous structure.

4. The hydroponic plug of claim 1, wherein the hydroponic plug has a water reuptake rate of about 90% saturation in 50-90 s.

5. The hydroponic plug of claim 1, wherein the hydroponic plug is biobased, according to ASTM D6866 or EN 16640 norm.

6. The hydroponic plug of claim 1, wherein the hydroponic plug has a biogenic content of more than about 80 wt. %.

7. The hydroponic plug of claim 1, wherein the body is cylindrical and includes coir, peat, wood fiber, or a combination thereof.

8. A stabilized growing medium comprising: a three-dimensional foamed body including a natural material, the body having a density of about 0.2-0.7 kg / L and field capacity of about 79-84.5 m / m%, the growing medium being rewettable and hydrophilic.

9. The medium of claim 8, wherein the field capacity is about 80-82 m / m%.

10. The medium of claim 8, wherein the natural material is coir.

11. The medium of claim 8, wherein the growing medium is biobased, according to ASTM D6866 or EN 16640 norm.

12. The medium of claim 8, wherein the medium has water reuptake rate of at least about 90% saturation in 25-240s.

13. A growing medium comprising: a stabilized, porous body of homogenized components including: a natural material; and an isocyanate-based binder, its derivatives, or both, the growing medium being hydrophilic, rewettable, and having a field capacity of about 79-84.5 m / m% and a porosity of about 55-80 wt. %, based on the total weight of the growing medium.

14. The growing medium of claim 13, wherein the growing medium is biobased according to ASTM D6866.

15. The growing medium of claim 13, wherein the isocyanate-based binder is biobased, according to ASTM D6866 or EN 16640 norm.

16. The growing medium of claim 13, wherein the binder is methylene diphenyl diisocyanate (MDI).

17. The growing medium of claim 13, wherein the body is an open-cell body.

18. The growing medium of claim 13, where in the body is compressible to 50% of the body’s original height by force of about 5000-6000 g, as measured by a universal texture analyzer.

19. The growing medium of claim 13, wherein the natural material is peat-free.

20. The growing medium of claim 13, wherein the body includes a network of first cavities and a separate network of second cavities, the second cavities having a greater diameter than the first cavities.

21. The growing medium of claim 13, wherein the growing medium is structured as a frustoconical or cylindrical grow plug.

22. A method of forming a stabilized growing medium, the method comprising: forming a slurry by reacting a natural material with an aqueous blend including a first surfactant and a binder; (a) shaping the slurry into a three-dimensional shape; and (b) curing the three-dimensional shape to obtain the stabilized growing medium being compressible to 50% of the body’s original height by force of about 5000-6000 g, as measured by a universal texture analyzer.

23. The method of claim 22, wherein the curing includes producing a foam resulting in the growing medium being porous and having porosity of about 55-80 wt. %, based on the total weight of growing medium.

24. The method of claim 22, wherein the curing includes forming a hydrophilic matrix from the slurry and trapping CO2 in the formed matrix.

25. The method of claim 24, wherein the hydrophilic matrix has a field capacity of about 79-84.5 m / m%.

26. The method of claim 22, wherein the first surfactant is an amphoteric surfactant.

27. The method of claim 26, wherein the aqueous blend includes a second surfactant different from the first surfactant in at least one physical property.

28. The method of claim 22, wherein the binder is a non-TDI-based binder.

29. The method of claim 22, wherein the shaping the slurry includes forming a cylindrical plug.