WO2022208097A1

WO2022208097A1 - Compressed growing medium

Info

Publication number: WO2022208097A1
Application number: PCT/GB2022/050815
Authority: WO
Inventors: Bomirige Sudesh Sanjeeva FERNANDO; Thomas William OGDEN
Original assignee: Cocogreen (UK) Ltd
Priority date: 2021-04-01
Filing date: 2022-03-31
Publication date: 2022-10-06
Also published as: GB202104716D0; GB2605582A; GB2605582B

Abstract

The present invention relates to a compressed growing medium dosed with a controlled release fertilisers and/or slow release fertiliser and a method of manufacturing the same. The present invention also relates to a modular unit comprising a compressed growing medium and the use of a compressed growing medium for horticulture or agriculture as described herein.

Description

Compressed Growing Medium

Field of the Invention

The present invention relates to a compressed growing medium dosed with a controlled release fertilisers and/or slow release fertiliser and a method of manufacturing the same.

Background of the Invention

Controlled release fertilisers (CRFs) and slow release fertilisers (SRFs) are widely applied to growing mediums to aid the plant growing process. CRFs and SRFs typically contain plant nutrients (e.g. nitrogen, phosphorus, potassium) in a form which delays the availability of the nutrients in the growing medium for plant uptake, or that releases the nutrients into the growing medium for an extended period of time.

It is well established that plant growers apply CRFs and SRFs to saturated growing mediums on-site using suitable dosing methods. The saturated growing mediums are usually purchased from commercial suppliers, transported and then used by plant growers for horticultural or agricultural purposes. Challenges associated with the bulk handling and transport of heavy saturated growing mediums have led to the advent of lighter, and less bulky, dehydrated growing medium materials which are typically easier to manage for manufacturers, commercial suppliers and plant growers.

When using dehydrated growing medium materials, plant growers will normally purchase the mediums from commercial suppliers, rehydrate the mediums on-site and then dose the rehydrated material with liquid fertilisers, typically via drip feed irrigation methods, ready for plant growing. This can however lead to significant run-off waste during the dosing process resulting in a large proportion of the supplied fertiliser nutrients not being absorbed by plants.

In view of the drawbacks associated with known growing mediums and the wastage involved with on-site CRF and SRF dosing methods currently adopted by plant growers, the present inventors have pioneered the development of a pre-dosed compressed dehydrated growing medium material. These compressed growing mediums can be successfully used as modular units (e.g. grow bags or the like) which can be sold and distributed on a global scale whilst ensuring that the pre-dosed CRFs and SRFs remain intact throughout the process.

It is a further object of the invention to obviate or mitigate at one or more of the disadvantages of the prior art whether described herein or elsewhere.

Summary of the Invention

The present invention relates to a compressed growing medium that is easy to handle and also provides plant growers with a more efficient alternative to the on-site CRFs and SRFs dosing methods currently adopted when working with dehydrated growing medium materials. The present invention also relates to a method of manufacturing a compressed growing medium as described herein.

In a first aspect of the present invention there is provided a method of manufacturing a compressed growing medium, comprising: providing a dehydrated growing medium material; adding a controlled release fertiliser and/or slow release fertiliser to the dehydrated growing medium material to form a dosed growing medium material; and compressing the dosed growing medium material to form the compressed growing medium.

In a second aspect of the present invention there is provided a compressed growing medium, comprising: a dehydrated growing medium material; and a controlled release fertiliser and/or slow release fertiliser dosed within the dehydrated growing medium material.

In a third aspect of the present invention there is provided a compressed growing medium obtained according to a method of the first aspect of the present invention or any embodiment thereof.

In a fourth aspect of the present invention there is provided a modular unit comprising a compressed growing medium according to the second aspect, third aspect of the present invention or any embodiment thereof optionally wherein the modular unit is a growing container.

In a fifth aspect of the present invention there is provided a use of a compressed growing medium according to the second aspect or third aspect of the present invention or any embodiment thereof or a modular unit according to the fourth aspect of the present invention or any embodiment thereof for horticulture or agriculture.

As used herein, a “growing medium” encompasses a substrate (i.e. a “growth substrate” or the like) for supporting the growth of plants.

It will be understood that a compressed growing medium according to the first aspect and second aspect of the present invention or embodiments thereof is dosed with a controlled release fertiliser and/or slow release fertiliser. The compressed growing medium as described herein may also be referred to a compressed dosed growing medium.

It will be appreciated that a dehydrated growing medium material according to the first aspect and second aspect of the present invention may be any growing medium that has been conditioned to have a reduced moisture content level as compared to its unconditioned form. For example, where the dehydrated growing medium material is coconut coir based, the raw coconut coir starting material may have undergone a step of drying to reduce its moisture content to provide the dehydrated growing medium material. It will also be appreciated that the dehydrated growing medium material according to the first aspect and second aspect of the present invention may be any growing medium that can undergo compression to reduce its overall volume and increase its density. In embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material is selected from the group consisting of peat, perlite, wheat straw, coconut coir, bark, stonewool, vermiculite, wood fibre, expanded clay balls, sphagnum, green waste, sand, pumice stone, wood shaving, sawdust, rice hulls, nut hulls or any combination thereof.

In some embodiments the first aspect and second aspect of the present invention, the dehydrated growing medium material is coconut coir. It will be understood that coconut coir refers to the materials forming the mesocarp, or outer husk, of a coconut. Coconut coir (sometimes simplified and referred to herein as “coir”) is composed of two principal components, namely, coir pith and coir fibres. The coir fibres are long fibrous strands, whilst the coir pith are small floccose, or “fuzzy”, particles that bind the coir fibres together in the mesocarp.

In further embodiments the first aspect and second aspect of the present invention, the dehydrated growing medium material comprises coconut coir, preferably, the dehydrated growing medium material comprises a mixture of coconut coir pith and coconut coir fibres. In other embodiments, the dehydrated growing medium material consists essentially of coconut coir pith.

According to the first aspect and second aspect of the present invention, the dehydrated growing medium material may have undergone a step of pre-conditioning to adjust its properties such that it is suitable for plant growing. Such a step of pre conditioning may include particle size assortment, pre-washing and/or buffering. The dehydrated growing medium material may be pre-washed using a suitable volume of water, preferably, fresh water. It will be appreciated that, by subjecting raw unwashed growing medium to a washing step in order to form a washed growing medium, the subsequent dehydrated growing medium material will contain fewer undesirable elements. In particular, when the dehydrated growing medium material comprises coconut coir, the pre-washing step reduces the sodium and potassium levels within the washed growing medium. The washed growing medium can then be dried using any suitable drying technique in order to form the dehydrated growing medium material as described herein. For example, when the dehydrated growing medium material comprises coconut coir, the washed growing medium may be dried under sunlight whilst being turned (manually or automatically) to form the dehydrated growing medium material. Alternatively, the washed growing medium may be dried using an oven, heating fans or feed and turn dryer. Typically, the washed growing medium is dried for approximately 24 hours under the sun or at a temperature of approximately 70 - 80°C for approximately 12 - 24 hours using a feed and turn dryer to form the dehydrated growing medium material.

According to the first aspect and second aspect of the present invention or any embodiments thereof, the dehydrated growing medium material may be buffered. It will be understood that a buffered dehydrated growing medium material refers to a medium which has undergone a step of chemical treatment using a buffering agent. As will be understood by the skilled person, buffered coconut coir is formed by subjecting raw unwashed or washed coconut coir material to a treatment or pre-conditioning step which alters the sodium, potassium, calcium and/or magnesium levels within the medium. This can be done via a cation exchange process. Typically, buffered coconut coir will undergo a treatment or conditioning step which lowers the sodium and potassium levels within the coir medium. This makes the coconut coir suitable for growing a wider range of plants. Buffered coconut coir is particularly suitable for young plants, as young plants are typically susceptible to problems caused by high levels of potassium and sodium. Typically, unwashed raw or washed coconut coir as described herein will be treated with a suitable buffering agent to form a buffered coconut coir. The buffered coconut coir may, in some instances, undergo a further washing step after buffering to ensure that any excess buffering agent is removed. The buffered coir growing medium is then dried using any suitable drying method as described herein to form the dehydrated growing medium material according to the present invention. Suitable buffering agents according to the present invention include calcium nitrate (Ca(NC>3)2) or a form of calcium sulfate dehydrate (CaS0₄-2H₂0) (e.g. gypsum). In embodiments of the first aspect and second aspect of the present invention of any embodiments thereof, the buffered coconut coir has undergone a step of buffering using calcium nitrate.

It will be appreciated that when the dehydrated growing medium material comprises coconut coir, the coconut coir may be a buffered coconut coir. The buffered coconut coir may have a pH of from about 5.0 to about 7.0, from about 5.2 to about 6.8, from about 5.4 to about 6.6, from about 5.6 to about 6.4, from about 5.8 to about 6.2, from about 6.0 to about 6.2, from about 5.2 to about 7.0, from about 5.4 to about 7.0, from about 5.6 to about 7.0, from about 5.8 to about 7.0, from about 6.0 to about 7.0, from about 6.2 to about 7.0, from about 6.4 to about 7.0, from about 6.6 to about 7.0, from about 6.8 to about 7.0, from about 5.0 to about 6.8, from about 5.0 to about 6.6, from about 5.0 to about 6.4, from about 5.0 to about 6.2, from about 5.0 to about 6.0, from about 5.0 to about 5.8, from about 5.0 to about 5.6, from about 5.0 to about 5.4 or from about 5.0 to about 5.2. Preferably, the buffered coconut coir may have a pH of from about 6.0 to about 6.4. In some embodiments, the buffered coconut coir may have a pH of about 6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6, about 6.7, about 6.8, about 6.9 or about 7.0. It will be appreciated that pH measurements for the buffered coconut coir according to the present invention are carried out using a standard Extraction Method 1:1.5 (volume/volume) with deionised water and a suitable pH meter.

In embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material has a moisture content of from about 5% to about 40%, from about 10% to about 35%, from about 15% to about 30%, from about 20% to about 25%, from about 10% to about 40%, from about 15% to about 40%, from about 20% to about 40%, from about 25% to about 40%, from about 30% to about 40%, from about 35% to about 40%, from about 5% to about 35%, from about 5% to about 30%, from about 5% to about 25%, from about 5% to about 20%, or from about 5% to about 15%. In other embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material has a moisture content of from about 10% to about 20%, 15% to about 20% or 10% to about 15%. Preferably, the dehydrated growing medium material has a moisture content of from about 10% to about 20%. It will be appreciated that moisture content measurements for the dehydrated growing medium material according to the present invention are carried out using a suitable moisture meter (e.g. Digitronics DMT-05 BLEX1).

In further embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material comprises coconut coir and has a moisture content as described herein, preferably, the dehydrated growing medium material comprises coconut coir and has a moisture content of from about 10% to about 20%. The present inventors have established that the moisture content of the dehydrated growing medium material, typically coconut coir, must be carefully controlled to (i) ensure that the resultant compressed growing medium of the first aspect and second aspect remains compact enough to ensure the structural stability of the compressed medium but also (ii) to concurrently make certain that the moisture content does not cause the premature release of nutrients from the controlled release fertiliser and/or slow release fertiliser dosed within the compressed growing medium via hydrolytic degradation of the controlled release fertiliser and/or slow release fertiliser. Where the moisture content of the dehydrated growing medium material falls below 5%, the compressed growing medium will have a tendency to fall apart. It will be appreciated that the moisture content of the dehydrated growing medium material according to the first aspect and second aspect of the invention will have moisture content level which is substantially the same as the moisture content of the compressed growing medium according to the first aspect and second aspect of the invention.

The dehydrated growing medium material according the first aspect and second aspect of the present invention or any embodiments thereof may have a density of from about 50 kg/m³ to about 90 kg/m³. In some embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material has a density of from about 60 kg/m³ to about 90 kg/m³, from about 70 kg/m³ to about 90 kg/m³ _, from about 80 kg/m³ to about 90 kg/m³, from about 50 kg/m³ to about 80 kg/m³, from about 50 kg/m³ to about 70 kg/m³ or from about 50 kg/m³ to about 60 kg/m³. In other embodiments, the dehydrated growing medium material has a density of from about 65 kg/m³ to about 85 kg/m³ or from about 70 kg/m³ to about 80 kg/m³. In embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material has a density of from about 65 kg/m³ to about 85 kg/m³.

It will be appreciated that the density of the dehydrated growing medium material is measured when the medium is in loose form (uncompressed). Typically, the density of the dehydrated growing medium material can be measured by placing loose dehydrated growing medium material into a suitable container of a given volume until the container is fully occupied by the dehydrated growing medium material. The density is then measured as the weight of the dehydrated growing medium material within the container (kg) / volume of the container (m³).

According to embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material is a particulate material. It will be appreciated that the dehydrated growing medium material according to first aspect and second aspect of the present invention may be a particulate material typically with a range of particle sizes distributed within a nominal particle size range. For example, the particles may be in the range of from about 1 mm to about 5 mm, and the distribution of the particles in this range may define a bell curve (or part of a bell curve).

As used herein, a “particulate material” is any material that is composed of a substantially granular structure of small particles. The particles in the particulate material will have a range of particle sizes, although this range could be selected to be relatively narrow or relatively large depending upon the plant to be grown in the growing medium. Particulate materials are well suited to use as a growing medium, as the individual particles permit plant roots to grow therebetween. As used herein, the term “particulate material” refers to the volume of material as a whole, and not to any individual constituent particle of the material. The particulate material may be any suitable particulate material, for example compost or peat, but is preferably coconut coir.

In some embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material is a particulate material with a particle size range of less than or equal to about 30 mm, or less than or equal to about 15 mm. In embodiments, the dehydrated growing medium material is a particulate material with a particle size range of from about 1 mm to about 30 mm or from about 1 mm to about 15 mm.

In further embodiments of first aspect and second aspect of the present invention, the dehydrated growing medium material (typically comprising coconut coir) is a particulate material with a particle size range of from about 5 mm to about 30 mm, from about 10 mm to about 30 mm, from about 15 mm to about 30 mm, from about 20 mm to about 30 mm, from about 25 mm to about 30 mm, from about 5 mm to about 25 mm, from about 5 mm to about 20 mm, from about 5 mm to about 15 mm, from about 5 mm to about 10 mm, from about 10 mm to about 25 mm or from about 15 mm to about 20 mm. In other embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material is a particulate material with a particle size range of less than or equal to 30 mm, less than or equal to 25 mm, less than or equal to 20 mm, less than or equal to 15 mm, less than or equal to 10 mm, less than or equal to 5 mm.

In yet further embodiments of first aspect and second aspect of the present invention the dehydrated growing medium material comprising coconut coir is a particulate material with a particle size range of from about 5 mm to about 30 mm, from about 10 mm to about 30 mm, from about 15 mm to about 30 mm, from about 20 mm to about 30 mm, from about 25 mm to about 30 mm, from about 5 mm to about 25 mm, from about 5 mm to about 20 mm, from about 5 mm to about 15 mm, from about 5 mm to about 10 mm, from about 10 mm to about 25 mm or from about 15 mm to about 20 mm. In other embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material comprising coconut coir is a particulate material with a particle size range of less than or equal to 30 mm, less than or equal to 25 mm, less than or equal to 20 mm, less than or equal to 15 mm, less than or equal to 10 mm, less than or equal to 5 mm.

It will be appreciated that a given dehydrated growing medium material, for example a dehydrated growing medium material comprising coconut coir, may be separated into separate fractions of particular particle size range by any suitable technique. One such suitable technique known to the skilled person involves sieving a particulate growing medium material through mesh screens containing suitable pore diameters in order to separate particles of certain sizes. This can be done using an electromagnetic vibratory shaker to aid the sieving process. It has been established that particles having smaller particle sizes are more likely to bind to one another, and this can prevent drainage in the final compressed growing mediums of the present invention, when used in some applications, thus preventing sufficient oxygen delivery to the plant roots during use. In some instances, by removing particles less than a certain size from the growing medium, the drainage of the growing medium and oxygen distribution within the growing medium can be improved. The specific size range of such problematic particles may vary depending the other properties and parameters of the final compressed growing mediums.

In accordance with embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material has an electrical conductivity of from about 10 pS/cm to about 2000 pS/cm, from about 10 pS/cm to about 1000 pS/cm, from about 10 pS/cm to about 500 pS/cm, from about 10 pS/cm to about 250 pS/cm, from about 10 pS/cm to about 100 pS/cm, from about 10 pS/cm to about 50 pS/cm, from about 250 pS/cm to about 2000 pS/cm, from about 500 pS/cm to about 2000 pS/cm, from about 1000 pS/cm to about 2000 pS/cm, from about 1500 pS/cm to about 2000 pS/cm or from about 1750 pS/cm to about 2000 pS/cm.

In some embodiments of the first aspect and second aspect of the present invention, the dehydrated growing medium material has an electrical conductivity of from about

100 pS/cm to about 200 pS/cm, from about 110 pS/cm to about 200 pS/cm, from about

120 pS/cm to about 200 pS/cm, from about 130 pS/cm to about 200 pS/cm, from about

140 pS/cm to about 200 pS/cm, from about 150 pS/cm to about 200 pS/cm, from about 160 pS/cm to about 200 pS/cm, from about 170 pS/cm to about 200 pS/cm, from about

180 pS/cm to about 200 pS/cm, from about 190 pS/cm to about 200 pS/cm, from about

100 pS/cm to about 190 pS/cm, from about 100 pS/cm to about 180 pS/cm, from about

100 pS/cm to about 170 pS/cm, from about 100 pS/cm to about 150 pS/cm, from about

100 pS/cm to about 140 pS/cm, from about 100 mS/cm to about 130 pS/cm, from about

100 pS/cm to about 120 pS/cm, from about 100 pS/cm to about 110 mS/cm, from about

110 pS/cm to about 190 pS/cm, from about 120 pS/cm to about 180 pS/cm, from about

130 mS/cm to about 170 pS/cm or from about 140 pS/cm to about 160 pS/cm.

Preferably, the dehydrated growing medium material according to the first aspect and second aspect of the present invention may have an electrical conductivity of from about 100 pS/cm to about 150 pS/cm or from about 110 pS/cm to about 140 pS/cm. It will be appreciated that the electrical conductivity of the dehydrated growing medium material may vary depending on the intended downstream use of the material. It will also be known that electrical conductivity measurements for a dehydrated growing medium material according to the present invention are carried out using a standard Extraction Method 1:1.5 (volume/volume) with deionised water and a suitable EC meter.

The first aspect of the present invention includes a step of adding a controlled release fertilisers and/or slow release fertiliser to the dehydrated growing medium material to form a dosed growing medium material.

It will be appreciated that this step of adding controlled release fertiliser and/or slow release fertiliser to the dehydrated growing medium material can be performed using any suitable conditions. As understood, the step of adding controlled release fertiliser and/or slow release fertiliser to the dehydrated growing medium material may result in the controlled release fertiliser and/or slow release fertiliser being dispersed across the bulk of the growing medium material. Alternatively, the step of adding controlled release fertiliser and/or slow release fertiliser to the dehydrated growing medium material may result in the controlled release fertiliser and/or slow release fertiliser being dispersed within a focussed region of the growing medium material. For example, in embodiments, the controlled release fertiliser and/or slow release fertiliser may be dispersed only within a region of the growing medium which is exposed to the root of the plants during use (e.g. the root zone). It is envisaged that the controlled release fertiliser and/or slow release fertiliser may also be dispersed only within a surface region of the medium (e.g. a region in close proximity to the surface of the ground but distanced from the root zone during use).

In embodiments of the first aspect of the present invention or any embodiment thereof, the step of adding a controlled release fertilisers and/or slow release fertiliser to the dehydrated growing medium material to form a dosed growing medium material comprises mixing the fertiliser into the medium with a paddle mixer (e.g. manual mixing with a paddle mixer), using a vibratory mixing machine, ribbon blender and/or using a conveyer mixing machine. It will be appreciated that the force asserted on the dehydrated growing medium material during the act of mixing is controlled so as to maintain the structural integrity of the controlled release fertilisers and/or slow release fertiliser during this step. That is, the controlled release fertilisers and/or slow release fertiliser do not break or rupture during the step ofmixing.

It will also be understood that the controlled release fertiliser according to the first aspect and second aspect of the present invention may comprise one or more controlled release fertilisers. In addition or alternatively, the slow release fertiliser according to the first aspect and second aspect of the present invention may comprise one or more slow release fertilisers. In embodiments of the first aspect and second aspect of the present invention, the controlled release fertiliser and/or slow release fertiliser may include a blend of one or more controlled release fertilisers and one or more slow release fertilisers. In embodiments of the first aspect and second aspect of the present invention, the one or more controlled release fertilisers, one or more slow release fertilisers or blend thereof may be formulated to allow for the staggered (or phased) release of nutrients over a given period of time. This staggered (or phased) release profile may be controlled by any suitable nutrient release stimulus, for example, microbial activity, pH, moisture content, temperature or any combination thereof. For example, a blend of one or more controlled release fertilisers may include a first controlled release fertiliser which releases nutrients with a first nutrient release stimulus (e.g. at a first moisture content level) and a second controlled release fertiliser which releases nutrients with a second nutrient release stimulus (e.g. at a second moisture content level higher than the first moisture content level). A controlled release fertiliser according to the first aspect and second aspect of the present invention or any embodiment thereof may be a coated fertiliser which is coated, or encapsulated, within at least one shell formed around a core and wherein the core comprises nutrients and/or micronutrients.

The controlled release fertiliser, including coated fertilisers, of the first aspect and second aspect of the present invention may be in granular or prilled form comprising a plurality of controlled release fertiliser particles. It will be appreciated that the particles may have diameter of from about 1 mm to about 4 mm. Preferably, the controlled release fertiliser particles have a diameter of from about 1 mm to about 3 mm, from about 1 mm to about 2 mm, from about 2 mm to about 4 mm, from about 2 mm to about 4 mm, about 1 mm, about 2 mm, about 3 mm or about 4 mm. It will be known that any suitable method known in the art can be used to measure the diameter of controlled release fertiliser particles.

Coated fertilisers according to the first aspect and second aspect of the present invention or any embodiment thereof may have a coating thicknesses of from about 5 pm to about 200 pm or from about 20 pm to about 100 pm. It will be understood that coating thickness refers to the thickness of the shell formed around the core of the coated fertiliser. Where there is more than one shell formed around the core of the coated fertiliser, the coating thickness includes the combined thickness of all of the shells surrounding the core. In embodiments, the coating thicknesses is from about 15 pm to about 95 pm, from about 20 pm to about 90 pm, from about 25 pm to about 85 pm, from about 30 pm to about 80 pm, from about 35 pm to about 75 pm, from about 40 pm to about 70 pm, from about 45 pm to about 65 pm, from about 45 pm to about 60 pm or from about 50 pm to about 60 pm.

In some embodiments, the coating thicknesses is from about 20 pm to about 50 pm. In other embodiments, the coating thicknesses is from about 20 pm to about 40 pm, or from about 20 pm to about 30 pm, or from about 30 pm to about 50 pm, or from about 40 pm to about 50 pm.

In embodiments of the first aspect and second aspect of the present invention, the coated fertiliser is polymer coated fertiliser. The polymer coated fertiliser may be a sulfur coated urea fertiliser or polymer sulfur coated urea fertiliser. In addition or alternatively, the controlled release fertilizer may include at least one permeable or semi-permeable shell around its core.

In further embodiments the first aspect and second aspect of the present invention, the polymer coated fertiliser may include at least one shell comprising a thermosetting material. In some embodiments, the polymer coated fertiliser may include at least one shell comprising vinyl resins (such as poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene chloride), poly(vinyl pyrrolidone), poly(vinyl acetal), poly(vinyl methylacetamide)), polyolefines (such as polyethylene, polypropylene, polyisobutylene), styrene-based polymers, acrylic polymers, polyesters (such as poly(alkylene terephthalate), poly(caprolactone)), poly(oxy alkylene)s (such as poly(ethylene oxide), polypropylene oxide)), cellulose derivatives (such as celluloseacetate), polyamides, polyamines, polycarbonates, polyimides, polysulfones, polysulfides, polysaccharides or any combination thereof. In embodiments the first aspect and second aspect of the present invention, the polymer coated fertiliser may include at least one shell comprising polyesters (such as alkyds or modified alkyds), epoxy resins, urethane resins and aminoplastics. In particular, the polymer coated fertiliser may include at least one shell comprising a copolymer of dicyclopentadiene (DCPD) and either linseed oil or an alkyd resin based on a soy bean oil. Such polymer coatings may be a dicyclopentadiene (DCPD) based polymeric product containing an alkyd resin, such as the commercially available Osmocote® Resin. In embodiments, the polymer coated fertiliser comprises at least one shell comprising a copolymer of dicyclopentadiene (DCPD) and linseed oil. In embodiments, the polymer coated fertiliser may include at least one shell comprising a copolymer of dicyclopentadiene (DCPD) an alkyd resin based on a soy bean oil.

It will be appreciated that certain polymer coated fertilisers according to the first aspect and second aspect of the present invention include shell materials containing pores / micro-pores. Such polymer coated fertilisers may allow water to enter the core of the coated fertiliser through the pores / micro-pores. This causes a build-up of osmotic pressure in the core of the fertiliser. As a result, the pore / shell can expand or defects in the shell coating occur allowing for the nutrients within the core to flow out of the core, through the coating and into the surrounding environment for plant uptake. In embodiments of the first aspect and second aspect of the present invention or embodiments thereof, the controlled release fertiliser is a polymer coated fertiliser comprising at least one shell comprising a copolymer of dicyclopentadiene (DCPD) and either linseed oil or an alkyd resin based on a soy bean oil. In such embodiments, the polymer coated fertiliser is granular or prilled and may have diameter of from about 1 mm to about 4 mm, and the polymer coated fertiliser has a coating thickness of from about 5 pm to about 200 pm or from about 20 pm to about 100 pm but preferably from about 20 pm to about 50 pm.

The nutrients contained within the core of the coated controlled release fertilizer may be based on, or derived from, ammonium sulfate, potassium nitrate, potassium sulfate, urea, ammonium nitrate, monopotassium sulfate, ammonium phosphate, super phosphate, dicalcium phosphate, basis calcium phosphate, potassium phosphate, potassium chloride, magnesium oxide, magnesium sulfate and or any combination thereof.

The core may also include secondary nutrients such as calcium, magnesium, sulfur and/or micronutrients. Micronutrients include iron, copper, zinc, chloride, silica, manganese, boron, cobalt, chlorine, sodium, molybdenum or combinations thereof.

Controlled release fertilisers of the first aspect and second aspect of the present invention may include commercially available products such as Nutricote®, Osmocote®, Osmocote® Plus, Osmocote® Plus Hi Start, Osmocote® Mini, Osmocote® Exact, Osmocote® Exact Protect, Osmocote® Exact Hi. End, Osmocote® Exact High K, Osmocote® Exact Tablet, Osmocote® Pro, Osmocote® Bloom, Osmocote® Topdress, Osmocote® Start, Harrell's Polyon® in any array of longevities, NPK content, and physical form, Osmocote® Pro, Multicote®, Basacote®; Plantacote® NPK, Plantacote® Blends, Plantacote® Pluss, Trikote®, Duration®, ESN®) or any combination thereof. Preferably, the controlled release fertilisers of the present invention is Osmocote® Exact in any array of longevities, NPK content and physical form. It is envisaged that the controlled release fertiliser may comprise any combination or blend of two or more controlled release fertilisers described herein.

A slow release fertiliser according to the first aspect and second aspect of the present invention may be a fertiliser which releases the nutrients into its surrounding environment for an extended period of time. In embodiments, the slow release fertilisers may be formed of urea formaldehyde, sulphur coated urea, sulfonyl urea, methylene urea or isobutylidene diurea.

The nutrients released by the slow release fertiliser may be based on, or derived from, ammonium sulfate, potassium nitrate, potassium sulfate, urea, ammonium nitrate, monopotassium sulfate, ammonium phosphate, super-phosphate, dicalcium phosphate, basis calcium phosphate, potassium phosphate, potassium chloride, magnesium oxide, magnesium sulfate and or any combination thereof. The slow release fertiliser may also include secondary nutrients such as calcium, magnesium, sulfur and/or micronutrients. Micronutrients include iron, copper, zinc, chloride, silica, manganese, boron, cobalt, chlorine, sodium, molybdenum or combinations thereof.

The release of nutrients by the slow release fertiliser may be controlled by microbial activity, pH, moisture content, temperature or any combination thereof.

According to the first aspect of the present invention the controlled release fertiliser and/or slow release fertiliser may be added to the dehydrated growing medium material at from about 0.1 wt% (by weight of the dehydrated growing medium material) to about 5 wt% (by weight of the dehydrated growing medium material) to form a dosed growing medium material. It will be appreciated that the “wt %” used in this context refers to percentage weight of controlled release fertiliser and/or slow release fertiliser added based on the total weight of the dehydrated growing medium material. In embodiments, the controlled release fertiliser and/or slow release fertiliser is added to the dehydrated growing medium material at from about 0.5 wt% (by weight of the dehydrated growing medium material) to about 5 wt% (by weight of the dehydrated growing medium material), from about 1 wt% (by weight of the dehydrated growing medium material) to about 5 wt% (by weight of the dehydrated growing medium material), from about 2 wt% (by weight of the dehydrated growing medium material) to about 5 wt% (by weight of the dehydrated growing medium material), from about 3 wt% (by weight of the dehydrated growing medium material) to about 5 wt% (by weight of the dehydrated growing medium material), from about 4 wt% (by weight of the dehydrated growing medium material) to about 5 wt% (by weight of the dehydrated growing medium material), from about 0.1 wt% (by weight of the dehydrated growing medium material) to about 4 wt% (by weight of the dehydrated growing medium material), from about 0.1 wt% (by weight of the dehydrated growing medium material) to about 3 wt% (by weight of the dehydrated growing medium material), from about 0.1 wt% (by weight of the dehydrated growing medium material) to about 2 wt% (by weight of the dehydrated growing medium material), from about 0.1 wt% (by weight of the dehydrated growing medium material) to about 1 wt% (by weight of the dehydrated growing medium material) or from about 0.1 wt% (by weight of the dehydrated growing medium material) to about 0.5 wt% (by weight of the dehydrated growing medium material). In some embodiments, the controlled release fertiliser and/or slow release fertiliser is added to the dehydrated growing medium material at from about 0.5 wt% (by weight of the dehydrated growing medium material) to about 2 wt% (by weight of the dehydrated growing medium material).

According to the second aspect of the present invention the controlled release fertiliser and/or slow release fertiliser may be dosed within the dehydrated growing medium material at from about 0.1 wt% (by weight of the compressed growing medium) to about 5 wt% (by weight of the compressed growing medium). It will be appreciated that the “wt %” used in this context refers to percentage weight of controlled release fertiliser and/or slow release fertiliser dosed based on the total weight of the compressed growing medium according to the second aspect of the present invention. In embodiments of the second aspect of the present invention, the controlled release fertiliser and/or slow release fertiliser may be dosed within the dehydrated growing medium material at from about 0.5 wt% (by weight of the compressed growing medium) to about 5 wt% (by weight of the compressed growing medium), from about 1 wt% (by weight of the dehydrated growing medium material) to about 5 wt% (by weight of the compressed growing medium), from about 2 wt% (by weight of the compressed growing medium) to about 5 wt% (by weight of the compressed growing medium), from about 3 wt% (by weight of the compressed growing medium) to about 5 wt% (by weight of the compressed growing medium), from about 4 wt% (by weight of the compressed growing medium) to about 5 wt% (by weight of the compressed growing medium), from about 0.1 wt% (by weight of the compressed growing medium) to about 4 wt% (by weight of the compressed growing medium), from about 0.1 wt% (by weight of the compressed growing medium) to about 3 wt% (by weight of the compressed growing medium), from about 0.1 wt% (by weight of the compressed growing medium) to about 2 wt% (by weight of the compressed growing medium), from about 0.1 wt% (by weight of the compressed growing medium) to about 1 wt% (by weight of the compressed growing medium) or from about 0.1 wt% (by weight of compressed growing medium) to about 0.5 wt% (by weight of the compressed growing medium). In some embodiments, the controlled release fertiliser and/or slow release fertiliser may be dosed within the dehydrated growing medium material at from about 0.5 wt% (by weight of the compressed growing medium) to about 2 wt% (by weight of the compressed growing medium.

According to the first aspect of the present invention there is a step of compressing the dosed growing medium material to form the compressed growing medium. It will be appreciated that the step of compressing can be performed using any suitable compression means or apparatus. In embodiments of the first aspect of the present invention, the step of compressing is carried out using a pneumatic or hydraulically actuated press or the like. The step of compressing the dosed growing medium material may be performed in a horizontal or vertical direction (e.g. horizontally or vertically actuated using a pneumatic or hydraulic press). Preferably, the step of compressing comprises compressing the growing medium in a vertical direction, for example downwards into a container holding the uncompressed dosed growing medium material, typically, to form a modular unit (e.g. block, briquette etc.) of compressed growing medium. Using a vertically actuated compressor it has been found to result in less spillage of particulate material. In embodiments of the first aspect of the present invention, the step of compressing the dosed growing medium material is performed using vertical grow bag machine comprising a vertically actuated press.

It will be appreciated that the step of compressing comprises applying a compression force suitable for forming a compressed growing medium which is compact to the extent that it does not fall apart when free standing (i.e. not housed within a container or supported by packaging) whilst also maintaining the structural integrity of the controlled release fertiliser and/or slow release fertiliser dosed within the compressed growing medium (i.e. keeping the controlled release fertiliser and/or slow release fertiliser intact without breaking or rupturing). This is particularly important where the controlled release fertiliser is granular, particulate or prilled and/or the controlled release fertiliser comprises a polymer coating. It will be appreciated that the exact compression force required to achieve this will depend on a variety of factors, such as, the chemical and structural properties of the controlled release fertiliser and/or slow release fertiliser as well as the parameters of the growing medium being used. In embodiments of the first aspect of the present invention, the step of compressing comprises applying a compression force of from about 1,000 Psi to about 3,000 Psi to the dosed growing medium material. In some embodiments, the step of compressing comprises applying a compression force of from about 1,000 Psi to about 2,000 Psi to the dosed growing medium material. In further embodiments, the step of compressing comprises applying a compression force of from about 1,000 Psi to about 2,900 Psi, from about 1,000 Psi to about 2,800 Psi, from about 1,000 Psi to about 2,700 Psi, from about 1,000 Psi to about 2,600 Psi, from about 1,000 Psi to about 2,500 Psi, from about 1,000 Psi to about 2,400 Psi, from about 1,000 Psi to about 2,300 Psi, from about 1,000 Psi to about 2,200 Psi, from about 1,000 Psi to about 2,100 Psi from about 1,000 Psi to about 1,900 Psi, from about 1,000 Psi to about 1,800 Psi, from about

1,000 Psi to about 1,700 Psi, from about 1,000 Psi to about 1,500 Psi, from about

1,000 Psi to about 1,400 Psi, from about 1,000 Psi to about 1,300 Psi or from about 1,000 Psi to about 1,200 Psi to the dosed growing medium material. In other embodiments, the step of compressing comprises applying a compression force of from about 1,500 Psi to about 2,400 Psi, from about 1,600 Psi to about 2,300 Psi, from about 1,700 Psi to about 2,300 Psi, from about 1,800 Psi to about 2,200 Psi, from about 1,900 Psi to about 2,100 Psi, from about 1,500 Psi to about 1,900 Psi, from about 1,500 Psi to about 1,800 Psi, from about 1,500 Psi to about 1,700 Psi or from about 1,500 Psi to about 1,600 Psi to the dosed growing medium material. The step of compressing may comprise applying a compression force of from about 1,000 Psi to about 1,400 Psi to the dosed growing medium material.

The step of compressing the dosed growing medium material as described herein may also be performed to achieve a compression ratio (volume to volume) of from about 2:1 to about 8:1 to form the compressed growing medium. In some embodiments of the first aspect of the present invention, the compression ratio (volume to volume) is from about 2:1 to about 5:1. In other embodiments, the compression ratio is from about 2:1 to about 4: 1 , preferably, about 3: 1.

The compressed growing medium of the first aspect and second aspect of the present invention or embodiments thereof, may have an electrical conductivity from about 10 pS/cm to about 2000 pS/cm, from about 10 pS/cm to about 1000 pS/cm, from about 10 pS/cm to about 500 pS/cm, from about 10 pS/cm to about 250 pS/cm, from about 10 pS/cm to about 100 pS/cm, from about 10 pS/cm to about 50 pS/cm, from about 250 pS/cm to about 2000 pS/cm, from about 500 pS/cm to about 2000 pS/cm, from about 1000 pS/cm to about 2000 pS/cm, from about 1500 pS/cm to about 2000 pS/cm or from about 1750 pS/cm to about 2000 pS/cm.

In accordance with embodiments of the first aspect and second aspect of the present invention, the compressed growing medium has an electrical conductivity of from about 100 pS/cm to about 200 pS/cm, from about 110 pS/cm to about 200 pS/cm, from about

140 pS/cm to about 200 pS/cm, from about 150 pS/cm to about 200 pS/cm, from about

160 pS/cm to about 200 pS/cm, from about 170 pS/cm to about 200 pS/cm, from about

100 pS/cm to about 140 pS/cm, from about 100 pS/cm to about 130 pS/cm, from about

100 pS/cm to about 120 pS/cm, from about 100 pS/cm to about 110 pS/cm, from about

130 pS/cm to about 170 pS/cm or from about 140 pS/cm to about 160 pS/cm.

Preferably, the compressed growing medium according to the first aspect and second aspect of the present invention may have an electrical conductivity of from about 100 pS/cm to about 150 pS/cm or from about 110 pS/cm to about 140 pS/cm.

In some embodiments of the first aspect and second aspect of the present invention the electrical conductivity of the dehydrated growing medium material is substantially the same as the compressed growing medium. The present inventors have established that by controlling the compression force applied during the compressing step as described herein it is possible to ensure that the controlled release fertiliser and/or slow release fertiliser which is dosed, embedded and/or dispersed within the dehydrated growing medium remains intact. That is, the controlled release fertiliser and/or slow release fertiliser (e.g. granules prills or the like) do not break under the compression force which is required to ensure that a structurally stable compressed growing medium is formed after the step of compressing. This avoids the premature release of nutrients from the fertiliser during the step of compressing which can be observed by an increase in the electrical conductivity of the growing medium after the step of compression. It will be appreciated that the electrical conductivity levels of both the dehydrated growing medium material and the resultant compressed growing medium may vary depending on the downstream end use of the growing medium. When the electrical conductivity of the dehydrated growing medium material is substantially the same as the compressed growing medium, it will be understood that the controlled release fertiliser and/or slow release fertiliser within the growing medium remains intact.

In embodiments, the electrical conductivity of the dehydrated growing medium material is from about 100 pS/cm to about 150 pS/cm and the electrical conductivity of the compressed growing material is from about 100 pS/cm to about 150 pS/cm. It will be appreciated that electrical conductivity measurements for a compressed growing medium according to the present invention are carried out using a standard Extraction Method 1:1.5 (volume/volume) with deionised water and a suitable EC meter.

It will be understood that the compressed growing medium according to the second aspect of the present invention has previously undergone a step of compressing during its formation. In embodiments of the second aspect of the present invention, the compressed growing medium comprises a dehydrated growing medium material which has been dosed with controlled release fertiliser and/or slow release fertiliser prior to the step of compressing. In further embodiments, the a step of compressing performed during the formation of the compressed growing medium according to the second aspect of the present invention is as described for the step of compressing according to the first aspect of the present invention or embodiments thereof.

In accordance with the first aspect and second aspect of the present invention, the compressed growing medium may have a density of from about 300 kg/m³ to about 700 kg/m³ In some embodiments, the compressed growing medium has a density of from about 300 kg/m³ to about 600 kg/m³. In other some embodiments, the compressed growing medium has a density from about 300 kg/m³ to about 550 kg/m³, from about 300 kg/m³ to about 500 kg/m³, from about 300 kg/m³ to about 450 kg/m³, from about 300 kg/m³ to about 400 kg/m³, from about 300 kg/m³ to about 350 kg/m³, from about 350 kg/m³ to about 600 kg/m³, from about 400 kg/m³ to about 600 kg/m³, from about 450 kg/m³ to about 600 kg/m³, from about 500 kg/m³ to about 600 kg/m³ or from about 550 kg/m³ to about 600 kg/m³. In other embodiments, the compressed growing medium has a density of from about 400 kg/m³ to about 500 kg/m³ or from about 350 kg/m³ to about 450 kg/m³. In further embodiments, the compressed growing medium has a density of from about 450 kg/m³ to about 550 kg/m³ or from about 250 kg/m³ to about 350 kg/m³.

It will be appreciated that density of the compressed growing medium is measured when the medium is compressed, as described herein. The density is measured to be the weight of the compressed growing medium (kg) / the volume that the growing medium occupies (m³).

The method according to the first aspect of the present invention or embodiments thereof may further comprise, subsequent to the step of compressing the dosed growing medium, hydrating the resulting compressed growing medium. Hydrating the growing medium causes it to expand, so that it is suitable for receiving a plant and supporting plant growth. If the compressed growing medium is not hydrated, there is not enough space between the particles to allow root growth. By “subsequent to”, it will be appreciated that the hydration step may take place at any point after the compression step. In particular, compression may take place at the location where the growing medium is manufactured, and hydration may take place after the growing medium has been shipped to the location where it will be used for growing plants.

In embodiments of the fourth aspect of the present invention the modular unit is selected from the group consisting of a bale, block, growing container (e.g. grow bag, pop-up grow bag), disk, and briquette. In embodiments, wherein the modular unit is a growing container, the growing container comprises at least one planting hole and/or at least one drainage slit. The term “growing container” as used herein refers to any type of container suitable for holding a growing medium in a manner to support the growth of a plant within the growing medium. Such growing containers may be modular units such as plant pots, grow bags, or troughs. A growing container may be made of any suitable material and have any suitable shape. The size and shape of the growing container may be chosen in dependence upon the type of plant grown and the number of plants grown. Growing containers may range, for example, from around 5 cubic centimetres for supporting the growth of small or young plants, up to, for example, around 250 litres for supporting the growth of large bushes. Such a growing container may receive one or more growing mediums according to the present invention. In a fifth aspect of the present invention there is provided a use of a compressed growing medium according to the second aspect or third aspect or any embodiment thereof, or a modular unit according to the fourth aspect or any embodiment thereof, for horticulture or agriculture.

In embodiments of the first aspect of the present invention, the dehydrated growing medium material comprises coconut coir, the step of compressing may comprise applying a compression force of from about 1,000 Psi to about 2,000 Psi to the dosed growing medium material, the dehydrated growing medium material has a moisture content of from about 10% to about 20%, the controlled release fertiliser is added at from about 0.5 wt% (by weight of the dehydrated growing medium material) to about 2 wt% (by weight of the dehydrated growing medium material) to form a dosed growing medium material, wherein the controlled release fertiliser is a polymer coated fertiliser. In such embodiments, the controlled release fertiliser may be a polymer coated fertiliser comprising at least one shell comprising a copolymer of dicyclopentadiene (DCPD) and either linseed oil or an alkyd resin based on a soy bean oil. Also, in such embodiments, the polymer coated fertiliser may be granular or prilled and may have diameter of from about 1 mm to about 4 mm, and the polymer coated fertiliser may have a coating thickness of from about 5 pm to about 200 pm or from about 20 pm to about 100 pm. Furthermore, the electrical conductivity of the dehydrated growing medium material may be substantially the same as the compressed growing medium.

In some embodiments of the second aspect of the present invention, the dehydrated growing medium material comprises coconut coir, the dehydrated growing medium material has a moisture content of from about 10% to about 20%, the controlled release fertiliser is dosed at from about 0.5 wt% (by weight of the compressed growing medium) to about 2 wt% (by weight of the compressed growing medium), wherein the controlled release fertiliser is a polymer coated fertiliser. In such embodiments, the controlled release fertiliser may be a polymer coated fertiliser comprising at least one shell comprising a copolymer of dicyclopentadiene (DCPD) and either linseed oil or an alkyd resin based on a soy bean oil. Also, in such embodiments, the polymer coated fertiliser may be granular or prilled and may have diameter of from about 1 mm to about 4 mm, and the polymer coated fertiliser may have a coating thickness of from about 5 pm to about 200 pm or from about 20 pm to about 100 pm. The compressed growing medium, in such embodiments, has a density of from about 300 kg/m³ to about 600 kg/m³. Furthermore, the compressed growing medium may have an electrical conductivity of from about 100 pS/cm to about 150 pS/cm.

Description of Figures

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying Figures in which:

Figure 1 is a plot illustrating the average electrical conductivity (pS/cm) versus compression pressure (Psi) applied to a range of growing mediums according to the present invention.

Figure 2 is photographic image of a growing medium according to the present invention which has been compressed at a pressure of 2700 Psi.

Figure 3 is a schematic showing a method for manufacturing a compressed growing medium in accordance with the present invention.

Detailed description of the Invention

The invention will be further described, by way of example only, with reference to the accompanying Figures.

A method for manufacturing a compressed growing medium in accordance with the present invention is provided in the schematic illustrated in Figure 3. The exemplary method shown in Figure 3 is described for a coconut coir based dehydrated growing medium material. The dehydrated growing medium material is produced using a raw coconut coir material which is produced by cutting the mesocarp of a coconut into smaller pieces known as “coco chips”. Such coco chips may comprise both fibres and pith that have not been separated, so that the fibres and pith may still bound to one another as they would be in the mesocarp. The coco chips are then typically screened into different ranges of particle sizes using a series of sieves as described in connection with the pre-conditioning steps herein below. It will be appreciated that the raw coconut coir material according to the exemplary method of Figure 3 comprises a mixture coir pith and coir fibres wherein some of the coir fibres in the raw material have been separated from the pith. Such separation is achieved using a pair of oppositely facing rollers having stiff bristles configured to penetrate the mesocarp and prise the fibres away from one another to separate them from the pith. The fibres and pith are then be screened from one another using a sieve.

Raw coconut coir material, in loose form, is then be subjected to a pre-conditioning step (1) shown in Figure 3. The pre-conditioning step includes, particle size assortment (less than or equal to 30 mm), washing, buffering and drying to provide a dehydrated growing medium material based on coconut coir.

During step (1), the raw coconut coir material is placed within a mixing tank and washed with fresh water for approximately 6 hours whilst agitating. The washed material then undergoes a buffering step within the same mixing tank using a suitable buffering agent, such as, dilute calcium nitrate (Ca(NC>3)2. The buffered material is then washed further using fresh water before then undergoing drying. It will be appreciated that the pre-conditioning step (1) includes the step of drying so as to dehydrate and reduce the moisture content level of the dehydrated growing medium material to an appropriate level subsequent to the washing and buffering steps. The drying step is performed by evenly spreading the pre-conditioned material on a concrete surface which is surrounded with barriers/walls to avoid contamination. The material is then dried under the sun whilst being turned at regular intervals to form the dehydrated growing medium material. Typically, the drying process is performed to form a dehydrated growing medium material with a moisture content level desirable for a particular downstream use or application. Moisture content levels for dehydrated growing medium materials according to the present invention are, preferably, less than 20%.

As shown in Figure 3 at step (2), the dehydrated growing medium material is then dosed with a controlled release fertiliser (e.g. Osmocote® Exact typically at 0.5 wt% - 2 wt%). The step of dosing involves dispersing the controlled release fertiliser within the dehydrated growing medium material before then mixing or agitating (e.g. manually using a paddle mixer) to provide a dosed dehydrated growing medium material. The compressing step (3) in Figure 3 is then performed using a grow bag machine including an actuated press which is loaded with the dosed growing medium material. Once compressed, the overall volume of the growing medium is reduced, thus making the growing medium easier to package, transport and/or store as shown as step (4) in Figure 3. Furthermore, compressing the dosed growing medium material causes the medium to form a compact modular unit (e.g. a single block) of compressed growing medium which is easier to handle during transportation. Once the compressed growing medium arrives at its destination, the user can simply hydrate the growing medium to cause it to re-expand for use.

Electrical conductivity vs compression force/pressure measurements

It will appreciated that the electrical conductivity (pS/cm) of compressed growing mediums of the present invention is determined using a standard Extraction Method 1:1.5 (volume/volume) with deionised water and a suitable EC meter

An exemplary compressed growing medium was produced using the method illustrated in Figure 3. A dehydrated coconut coir growing medium material demonstrating an average EC value of 130 pS/cm, average moisture content level of approximately 17% and density of approximately 70-75 kg/m³ was used. The dehydrated coconut coir growing medium (1420g) was dosed with the controlled release fertiliser Osmocote® Exact (9g). Once dosed with the fertiliser, samples of the dosed coconut coir growing medium material were then compressed at different compression forces. The electrical conductivities for each of the resulting compressed growing medium samples were measured and are illustrated in Table 1 below. Figure 1 illustrates a plot of the average electrical conductivity (pS/cm) versus compression force (Psi) for each of the resulting compressed growing medium samples.

Table 1: EC values (pS/cm) for growing mediums containing controlled released fertiliser produced at different compressions forces (Psi)

As shown by the data presented in the Table 1 above, the electrical conductivity of the compressed growing medium samples steadily increase as the compression force is elevated. This is indicative of a gradual decline in the structural integrity of the controlled release fertiliser within the medium. As more of the controlled release fertiliser is ruptured or broken at increasing compression pressures, an increase in electrical conductivity is observed due to the release of nutrients from the core of the controlled release fertiliser into the bulk of the medium. It can be seen from the photographic image shown in Figure 2 that the growing medium sample compressed at a pressure of 2700 Psi contains controlled release fertiliser showing visible signs of rupture (see broken circle in Figure 2). Also of note is that the growing medium samples compressed at pressures of less than 2000 Psi have electrical conductivity values substantially the same as that of the dosed dehydrated starting material. This indicates that the controlled release fertiliser remains intact in the medium. The experimental information provided represents an exemplary example of the present invention only and it will be appreciated that the relative change in the electrical conductivities after compression can also be observed for dehydrated growing medium materials possessing lower or higher baseline electrical conductivity values.

It will be appreciated that numerous modifications to the above described compressed growing medium and a method of manufacturing the same may be made without departing from the spirit and scope of the invention, for instance, the scope of the invention as defined in the appended claims. Moreover, any one or more of the above aspects/embodiments could be combined with one or more feature of the other aspects/embodiments and all such combinations are intended with the present disclosure. Optional and/or preferred features may be used in other combinations beyond those explicitly described herein and optional and/or preferred features described in relation to one aspect of the invention may also be present in another aspect of the invention, where appropriate.

The described and illustrated embodiments are to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all change and modifications that come within the scope of the invention as defined in the claims are desired to be protected. It should be understood that while the use of words such as “preferable”, “preferably”, “preferred”, or “more preferred” in the description suggest that a feature so described may be desirable, it may nevertheless not be necessary and embodiments lacking such a feature may be contemplated as within the scope of the invention as defined in the appended claims. In relation to the claims, it is intended that when words such as “a”. “an” or “at least one” are used to preface a feature there is no intention to limit the claim to only one such feature unless specifically stated to the contrary in the claims.

Claims

CLAIMS:

1. A method of manufacturing a compressed growing medium, comprising: providing a dehydrated growing medium material; adding a controlled release fertiliser and/or slow release fertiliser to the dehydrated growing medium material to form a dosed growing medium material; and compressing the dosed growing medium material to form the compressed growing medium.

2. A method according to claim 1, wherein the dehydrated growing medium material comprises coconut coir; optionally wherein the dehydrated growing medium material comprises a mixture of coconut coir pith and coconut coir fibres.

3. A method according to claim 2, wherein the coconut coir is a buffered coconut coir.

4. A method according to any preceding claim, wherein the compressing comprises applying a compression force of from about 1,000 Psi to about 3,000 Psi to the dosed growing medium material; preferably the compressing comprises applying a compression force of from about 1,500 Psi to about 2,000 Psi to the dosed growing medium material.

5. A method according to any preceding claim, wherein the compressing achieves a compression ratio (volume to volume) of from about 2:1 to about 8:1 to form the compressed growing medium.

6. A method according to any preceding claim, wherein the dehydrated growing medium material has a moisture content of from about 5% to about 40%.

7. A method according to any preceding claim, wherein the dehydrated growing medium material has a density of from about 65 kg/m³ to about 85 kg/m³.

8. A method according to any preceding claim, wherein the compressed growing medium has a density of from about 300 kg/m³ to about 600 kg/m³.

9. A method according to any preceding claim, wherein the controlled release fertiliser and/or slow release fertiliser is added at from about 0.1 wt% (by weight of the dehydrated growing medium material) to about 5 wt% (by weight of the dehydrated growing medium material) to form a dosed growing medium material.

10. A method according to any preceding claim, wherein the fertiliser is a controlled release fertiliser; optionally wherein the controlled release fertiliser is a polymer coated fertiliser.

11. A method according to claim 10, wherein the polymer coated fertiliser has a coating thickness of from about 5 pm to about 200 pm or from about 20 pm to about 100 pm.

12. A method according to any preceding claim, wherein the dehydrated growing medium material is a particulate material with a particle size range of less than or equal to about 30 mm.

13. A compressed growing medium, comprising: a dehydrated growing medium material; and a controlled release fertiliser and/or slow release fertiliser dosed within the dehydrated growing medium material.

14. A compressed growing medium according to claim 13, wherein the dehydrated growing medium material comprises coconut coir; optionally wherein the dehydrated growing medium material comprises a mixture of coconut coir pith and coconut coir fibres.

15. A compressed growing medium according to claim 14, wherein the coconut coir is a buffered coconut coir.

16. A compressed growing medium according to any of claims 13 to 15, wherein the dehydrated growing medium material has a moisture content of from about 5% to about 40%.

17. A compressed growing medium according to any of claims 13 to 16, wherein the compressed growing medium has a density of from about 300 kg/m³ to about 600 kg/m³.

18. A compressed growing medium according to any of claims 13 to 17, wherein the controlled release fertiliser and/or slow release fertiliser is dosed at from about 0.1 wt% (by weight of the compressed growing medium) to about 5 wt% (by weight of the compressed growing medium).

19. A compressed growing medium according to any of claims 13 to 18, wherein the fertiliser is a controlled release fertiliser; optionally wherein the controlled release fertiliser is a polymer coated fertiliser.

20. A compressed growing medium according to claim 19, wherein the polymer coated fertiliser has a coating thickness of from about 5 pm to about 200 pm or from about 20 pm to about 100 pm.

21. A compressed growing medium according to any of claims 13 to 20, wherein the dehydrated growing medium material is a particulate material with a particle size range of less than or equal to about 30 mm.

22. A compressed growing medium obtained according to a method of any of claims 1 to 12.

23. A modular unit comprising a compressed growing medium according to any of claims 13 to 22; optionally wherein the modular unit is a growing container.

24. Use of a compressed growing medium according to any of claims 13 to 22 or a modular unit of claim 23 for horticulture or agriculture.