USE AS A GROWTH PROMOTER

Related Application

[001] Priority is claimed to Australian provisional patent application 2021902543, filed 16 August 2021. The content of AU 2021902543 is incorporated herein by reference in its entirety.

Field of the Invention

[002] The invention relates to enhancement of by-products of plant industries possessing allelopathic carboxyl group compounds for their use in plant cultivation applications wherein the growth or survival of living plants are liable to be adversely affected by their non aerial portions being in the presence of inappropriate levels of allelopathic carboxylic acids and of their allelopathic dissociation products, by treatment of the by-products with water soluble carbonates and as necessary followed by removal of water soluble compounds before the introduction of plant material.

Background of the Invention

[003] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

[004] Significant attention is focussed on improving agricultural production both for returns on the amount of water used and for applied nutrients for plant production and maintenance, whether for production of food or raw material crops, for the production of grazing animals, for the production of decorative plants, or the maintenance of gardens, parks and recreational and sports grounds, and so on.

[005] The effects of climate insecurities, of land degradation including desertification, of the need to feed expanding populations, and higher quality of life expectations, etc mean that there is a demand for making better use of plant growing inputs and minimising inefficient use. In addition to incorporation into soilless substrates there are numerous areas on the planet such as Australia where the soils are frequently low in organic contents and where the addition of plant materials to provide increased organic contents can increase soil water and nutrient holding capacities.

[006] Additionally, for both sustainably and reduction of carbon dioxide being released to the atmosphere from peat mining reasons there is a desire to reduce the use of peat as a component of soilless media, and suitably treated by-products of plant industries offer effective alternatives.

[007] Given the problems with smoke from burning cane fields the practice has been banned or proposed to be banned in different regions and applications for the sugar cane leaves and tops are being sought. Many by-products of plant industries of plant industries are generated in quantities of millions of tonnes per year, such as rice hulls, but which when in contact with water result in carboxylic acids and their dissociation products containing solutions that are allelopathic, that is are harmful to one more other plant species, so restricting many applications in plant growing medias or substrates and for mulching.

[008] Thus, there are vast amounts of by-products from plant industries which are sustainably produced, such as bark from harvested pine plantations, sugar cane tops from sugar cane fields, but which require their plant growth affecting carboxylic acid and dissociation products contents to be reduced before being utilised in plant cultivation. Conventional processing of such by-products to achieve this can be laborious, take extended time, occupy large spaces, and involve significant costs such as for staff and equipment. It is highly advantageous to have countering technologies which are more effective for costs and space and equipment utilisation.

[009] The acidity of by-products of plant industries has been countered in various ways, conifer bark for example either fresh or aged can be processed to counter carboxylic acids by addition of ground lime or dolomite in order to raise the pH to a suitable growing range. However it is known that this may require weeks to stabilize the pH and can still leave unwanted levels of allelopathic carboxylates in the plant growth media, thus it is necessary to apply lime or dolomite dosages which achieve longevity of liming effects greater than the duration of acidity release from the materials, additionally the selected lime or dolomite dosages have to be sufficient to allow for the acidifying effects of mineral fertilisers employed while being at the same time not excessive that is end up raising the growing media pHs to non-optimal levels for the plant species being grown. [010] Conifer bark can be variously composted to reduce acidity. However, this is a lengthy process, in the state of Queensland commercial pine bark composting is for 3 to 4 months, in the state of Victoria for 3 months. While in Western Australia the recommended procedure involves moistened pine bark optionally by use of a soil wetting agent, adding urea, heaped to approximately metre high, kept moist and turned regularly, when the middle of the heaps is kept at 30 to 35°C composting can take up to about 8 weeks and the pH of the bark changed from about 4.5 to about 6.0 to 6.5, as detailed in ‘Potting mixes’, Internet page last updated: Thursday, 8 September 2016, https://www.agric.wa.gov.au/nursery-cutflowers/potting-mixes , report from the Agriculture and Food division of the Department of Primary Industries and Regional Development of Western Australia, incorporated herein by reference. The compositing process can be further modified such as by inoculating bark with selected microbes and alternative fertilising materials such as piggery and poultry slurries, as well as incorporating further non-bark plant materials, but the processing still involves significant durations of time.

[Oil] After seeding or introduction of plants into growth media carboxylic acids being released can be countered by irrigation with water containing alkalinity factors, again a treatment involving extended time durations, plus a need to carefully monitor so the eventual medium pH reached is optimal for specific plant species and crops such as tomatoes.

[012] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[013] Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

[014] Although the invention will be described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Summary of the Invention

[015] The invention relates to enhancement of by-products of plant industries possessing allelopathic carboxylic acids and of their allelopathic dissociation products which can adversely affect plant establishment, growth, and maintenance, by appropriate penetration treatment of pieces with dissolved water soluble carbonates, followed as necessary by one or repeated separation of aqueous soluble compounds, before the introduction of plant material. Treatments which can take only periods of hours or days rather than requiring weeks or months.

[016] According to a first aspect of the present invention there is provided use of plant industry by-product material possessing leachable carboxyl group compounds in plant cultivation applications wherein the growth and/or survival of living plants are liable to be adversely affected by non-aerial vegetal portions being in the presence of inappropriate levels of allelopathic carboxylic acids and of their allelopathic hydration products, by

[017] (a) physical structure preserving mild treatment of the material with piece penetrating, pH raising quantities of water soluble carbonates, and

[018] (b) optionally subsequent removal of water soluble compounds, before the material is ultilised in plant cultivation.

[019] In an embodiment, the utilisation of the treated plant by-product material or materials in plant cultivation is in a plant growth media or substrate.

[020] In an embodiment, the utilisation of the treated plant by-product material or materials in plant cultivation is as a mulch.

[021] In an embodiment, the mild treatment involves not employing intense heat conditions and utilising excessively alkaline conditions.

[022] In an embodiment, the mild treatment involves not employing intense heat conditions.

[023] In an embodiment, the mild treatment involves not generating material utilising excessively alkaline conditions.

[024] In an embodiment, the water soluble carbonate is a metal cation or ammonium carbonate.

[025] In an embodiment, the water soluble carbonate is a metal cation or ammonium hydrogen carbonate.

[026] In an embodiment, the water soluble carbonate is selected from the group consisting of sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, magnesium bicarbonate, calcium bicarbonate, or a combination thereof.

[027] In an embodiment, the treatment of the materials with piece penetrating pH raising quantities of water soluble carbonates, is selected from the group consisting of: is by absorption of applied prepared solutions of dissolved carbonates; is by applying non dissolved carbonates and subsequently a dissolving liquid; is by hydrating the pieces of the materials and applying non dissolved carbonates to the pieces of the materials and achieving dissolving of the carbonates in the water present with diffusion of carbonates into the pieces; or a combination thereof. [028] In an embodiment, the plant cultivation leaching of the material or its preparations yield aqueous solutions in applications with pH values favourable for the requirements of the plant species being cultivated in a soilless media.

[029] In an embodiment, the plant cultivation leaching of the material or its preparations yield aqueous solutions in applications with pH values favourable for the requirements of the plant species being cultivated in a modified soil media.

[030] In an embodiment, the plant cultivation leaching of the material or its preparations yield aqueous solutions in applications with pH values favourable for the requirements of the plant species being cultivated in a modified sand media.

[031] In an embodiment, the plant cultivation leaching of the material or its preparations yield aqueous solutions in applications with pH values favourable for the requirements of the plant species being mulched.

[032] In an embodiment, the pH raising quantity of water soluble carbonates achieves aqueous pH values within the pieces of the material which increases the solubility and the extractability of phenolic carboxyl group compounds held therein.

[033] In an embodiment, the by-products materials are selected from one or more of conifer barks, sugar cane leaves and tops, tropical saw dusts, rice hulls and coffee grinds. [034] In an embodiment, the ultilisation in plant cultivation involves generation of plant growth media consisting partially or completely of treated plant by-product material or materials, and subsequently the introduction of plant material.

[035] In an embodiment, the introduction of plant material, is selected from the group consisting of the placement of living plant material and seeds onto plant growth media, the placement of living plant material and seeds into plant growth media, planting of seeds, planting of seedlings, planting of established plants, layering on or partially into the surface, surface depositing of spores, partial or complete inserting of cuttings, rhizomes, runners, bulbs, corms, tubers and fungal mycelium, or a combination thereof. [036] In an embodiment, the optional subsequent removal of water soluble compounds involves removal of water soluble compounds with negative attributes for plants by separating these compounds out in dissolved forms from the treated material, or from partial or from complete preparations of plant growth media before the introduction of plant material.

[037] In an embodiment, the optional subsequent removal of water soluble compounds reduces the contents of salt, or of sodium ions, or of hydrogen ions, or of allelopathic carboxylic acids, or of allelopathic carboxylates, or of allelopathic non carboxyl compounds, or combinations thereof, which are associated with the treated materials. [038] In an embodiment, the allelopathic non carboxyl compounds are flavonoids, or procyanidins, or proanthocyanins, or combinations thereof.

[039] In an embodiment, the allelopathic carboxylic acids and their allelopathic hydration products comprise phenolic acids and phenolic carboxylates.

[040] In an embodiment, the allelopathic carboxylic acids and their allelopathic hydration products comprise diterpene acids and diterpene carboxylates.

[041] According to a second aspect of the present invention there is provided a plant cultivation input for use in applications wherein the growth and/or survival of living plants are liable to be adversely affected by non-aerial vegetal portions being in the presence of inappropriate levels of allelopathic carboxylic acids and of their allelopathic hydration products, generated from plant industry by-product material possessing leachable carboxyl group compounds by

[042] (a) physical structure preserving mild treatment of the material with piece penetrating, pH raising quantities of water soluble carbonates, and

[043] (b) optionally subsequent removal of water soluble compounds, before the material is ultilised in plant cultivation.

[044] In an embodiment, the utilisation of the treated plant by-product material or materials in plant cultivation is in a plant growth media or substrate.

[045] In an embodiment, the pH raising quantity of water soluble carbonates achieves aqueous pH values within the pieces of the material which increases the solubility and the extractability of diterpene carboxyl group compounds held therein.

[046] In an embodiment, the utilisation of the treated plant by-product material or materials in plant cultivation is as a mulch.

[047] In an embodiment, the water soluble carbonate is a metal cation or ammonium carbonate.

[048] In an embodiment, the water soluble carbonate is a metal cation or ammonium hydrogen carbonate.

[049] In an embodiment, the water soluble carbonate is selected from the group consisting of sodium carbonate, potassium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, magnesium bicarbonate, calcium bicarbonate, or a combination thereof.

[050] In an embodiment, the treatment of the materials with piece penetrating pH raising quantities of water soluble carbonates, is selected from the group consisting of: is by absorption of applied prepared solutions of dissolved carbonates; is by applying non dissolved carbonates and subsequently a dissolving liquid; is by hydrating the pieces of the materials and applying non dissolved carbonates to the pieces of the materials and achieving dissolving of the carbonates in the water present with diffusion of carbonates into the pieces; or a combination thereof.

[051] In an embodiment, the plant cultivation leaching of the material or its preparations yield aqueous solutions in applications with pH values favourable for the requirements of the plant species being cultivated in a soilless media.

[052] In an embodiment, the plant cultivation leaching of the material or its preparations yield aqueous solutions in applications with pH values favourable for the requirements of the plant species being cultivated in a modified soil media.

[053] In an embodiment, the plant cultivation leaching of the material or its preparations yield aqueous solutions in applications with pH values favourable for the requirements of the plant species being cultivated in a modified sand media.

[054] In an embodiment, the plant cultivation leaching of the material or its preparations yield aqueous solutions in applications with pH values favourable for the requirements of the plant species being mulched.

[055] In an embodiment, the pH raising quantity of water soluble carbonates achieves aqueous pH values within the pieces of the material which increases the solubility and the extractability of phenolic carboxyl group compounds held therein.

[056] In an embodiment, the by-products materials are selected from one or more of conifer barks, sugar cane leaves and tops, tropical saw dusts, rice hulls and coffee grinds. [057] In an embodiment, the pH raising quantity of water soluble carbonates achieves aqueous pH values within the pieces of the material which increases the solubility and the extractability of diterpene carboxyl group compounds held therein.

[058] In an embodiment, the ultilisation in plant cultivation involves generation of plant growth media consisting partially or completely of treated plant by-product material or materials, and subsequently the introduction of plant material.

[059] In an embodiment, the introduction of plant material, is selected from the group consisting of the placement of living plant material and seeds onto plant growth media, the placement of living plant material and seeds into plant growth media, planting of seeds, planting of seedlings, planting of established plants, layering on or partially into the surface, surface depositing of spores, partial or complete inserting of cuttings, rhizomes, runners, bulbs, corms, tubers and fungal mycelium, or a combination thereof. [060] In an embodiment, the optional subsequent removal of water soluble compounds involves removal of water soluble compounds with negative attributes for plants by separating these compounds out in dissolved forms from the treated material, or from partial or from complete preparations of plant growth media before the introduction of plant material.

[061] In an embodiment, the optional subsequent removal of water soluble compounds reduces the contents of salt, or of sodium ions, or of hydrogen ions, or of allelopathic carboxylic acids, or of allelopathic carboxylates, or of allelopathic non carboxyl compounds, or combinations thereof, which are associated with the treated materials. [062] In an embodiment, the allelopathic non carboxyl compounds are flavonoids, or procyanidins, or proanthocyanins, or combinations thereof.

[063] In an embodiment, the allelopathic carboxylic acids and their allelopathic hydration products comprise phenolic acids and phenolic carboxylates.

[064] In an embodiment, the allelopathic carboxylic acids and their allelopathic hydration products comprise diterpene acids and diterpene carboxylates.

Brief Description of the Drawings

[065] A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:

[066] Figure 7 is a photograph contrasting the comparative growth rates and development stages of tomato plants grown for 37 days in trays of bark (a) without and (b) with applying the present invention by hydrating 1 kilogram of dry hybrid Pinus Pine Bark with 1.1 litre of an aqueous solution containing 6 grams potassium hydrogen carbonate for approximately 20 hours followed by a single flushing with 1 litre of water. The seedling plants were established on the same day in 5 cm deep beds of bark and were subject to the same light, atmosphere and watering regimen throughout. The only difference was the application, or otherwise, of the present invention.

[067] Figure 2 is a photograph contrasting the comparative growth rates and development stages of tomato plants grown for 52 days in trays of bark (a) without and (b) with applying the present invention by hydrating 1 kilogram of dry hybrid Pinus Pine Bark with 1.1 litre of an aqueous solution containing 6 grams potassium hydrogen carbonate for approximately 20 hours followed by multiple flushing with 1 litre batches of water. The seedling plants were established on the same day in 5 cm deep beds of bark and were subject to the same light, atmosphere and watering regimen throughout. The only difference was the application, or otherwise, of the present invention.

Detailed Description of the Invention

[068] Pre-treatment of acid releasing plant by-products, including residues, to enhance their supportive attributes for living plants when utilised as ingredients for soilless media, soil organic enrichment, and mulching ingredients, by helping to achieve productive rootzone pH and chemistry.

[069] There are by-products of plant industries which are generated in massive amounts and theoretically could be used in plant growth media and in mulching roles if their plant growth inhibitory carboxylic acids and dissociation products were countered. These carboxylic acids and the carboxylate and proton ion dissociation products, affect the non aerial portions of plants either directly altering plant root cellular biochemistry or indirectly such as by damaging root hairs, and root associated arbuscular mycorrhiza, thus reducing nutrient and water supplies to plants. Additionally, soil acidity can also inhibit plants by reducing the bioavailability of plant nutrient mineral cations.

[070] By-products of plant industries include but are not limited to tree barks, tree and bush wood materials such as shavings and saw dusts, sugar cane toppings, sugar cane tops, sugar cane leaves, sugar cane straw, sugar cane trash, seed hulls such as rice hulls, seed shells such as pecan shells, seed skins such as peanut skins or testas, coffee grinds, leaves and needles.

[071] By-products of plant industries are not limited to fresh or raw by-products but can be stored or aged material such as weathered or aged pine barks which contain carboxylic acids and of their dissociation products capable of adversely affecting plant cultivation. [072] Plant industry by-products include some materials described or referred to as agricultural waste, agriculture waste, agrowastes also spelt as agro-wastes and agro wastes, waste produced from agricultural operations, agricultural residues, forestry wastes, forestry residues, vegetal biomass, and further terms.

[073] The by-products of plant industries possessing carboxyl group compounds can be single source materials or mixtures of such materials or be combinations with other materials both organic or inorganic such as cotton fibres or sand.

[074] It has been discovered that by-products of plant industries materials possessing carboxyl group compounds, can be treated by penetrating the pieces of the materials with sufficient dissolved carbonate, which is able to modify the materials for their utilisation in plant cultivation applications. That is to counter effects on non aerial vegetal portions resulting from the presence of inappropriate levels of carboxylic acids and of their hydration products in plant growth media, and which can adversely affect the establishment, growth, or survival, or combinations thereof, of living plants.

[075] The treatment of by-products of plant industries possessing carboxylic acids and of their dissociation products adversely affecting plant establishment by appropriate penetration treatment of pieces with dissolved water soluble carbonates, is followed as necessary by one or repeated separating out water soluble compounds before the introduction of plant material. Treatments of the invention rather than taking weeks or months can require only periods of hours or days.

[076] The carbonate may be applied or introduced as a solid preferable a fine particular material, or as a solution, to dry or pre-dampened solid plant by-product material, or in any combination thereof, for example dry carbonate may be applied to dry or damp plant material and then water or solution applied or repeatedly applied, alternatively carbonate solution may be applied to dry or damp plant material and then further water or solution applied or repeatedly applied, alternatively the plant material may be hydrated and then non dissolved carbonates applied and the carbonates dissolved in the water present and diffuse into the pieces of the material, or other method, provided the result is that dissolved carbonate ions are present in sufficient quantities in the interior of the plant material pieces to achieve a necessary modification.

[077] The solvent or solvent mixture for dissolving carbonates for delivery into or within the by-products can be any which dissolves the specific carbonate or carbonates but preferred is water or aqueous based solutions, in the case of solutions the other components can be liquids or dissolved solids including plant nutrient compounds, provided these components leave no noxious residues.

[078] Water soluble carbonates selected for the invention are to be safe for use in the environment and can be carbonate salts and hydrogen carbonates which are also known as bicarbonates. Water soluble carbonates useable in solid form can include sodium carbonate, potassium carbonate, ammonium carbonates, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, and combinations thereof. Water soluble carbonates useable in solution form can include sodium carbonate, potassium carbonate, ammonium carbonates, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, magnesium bicarbonate, calcium bicarbonate and combinations thereof.

[079] Physical factor considerations for the treatment can include temperature, time, raw material properties such as minimum piece thickness, pore sizes in pieces, degree of hydrophobicity, and so on, all can interact. Thus, new raw materials should be tested to ensure the treated material’s acidity and further negative factors for plant growth, are within acceptable ranges.

[080] The penetration dynamics, provided other parameters are constant, is determined by the smallest piece dimension that is the thickness of the by-product pieces. The pieces of by-products can be of any thickness for which sufficient extent of dissolved carbonate provided penetration is achieved in a convenient time period. Where there is a desire for faster or more complete penetration of carbonate solutions, particularly with by-products possessing rigid complex and or lower porosity natures, the thickness of the by-products should be reduced to being as small as possible sizes conveniently handled by thickness reducing technology, however the resulting piece sizes should also be appropriate for their eventual use such as for mulch application which is wind stable. Further mechanisms of accelerating penetrations or achieving more complete penetrations such as pressurising or treating at higher temperatures, or utilisation of soil wetting agents are also options, particularly for thicker pieces.

[081] While treatment can be speeded up by processing under warmer temperatures, carbonate treatment does not necessarily require elevated temperatures for appropriate penetration, but non ambient temperature treatment can be utilised particularly in cold climate regions.

[082] The dosage or quantity of carbonate per weight of by-product should be checked per batch of by-product as the amounts of soluble carbonate salt required can be affected by source plant species, even for batches from the same genus such as for members of the Pin s genus, additionally dosage requirements can be affected by the strain, cultivar or variety of the source plant material, the age of the plant portion material such as whether taken from younger or older parts of the plants, the specific plant portions used such as bark or inner wood, location where the source plants were grown, the season of harvesting, storage history after harvesting, and combinations thereof.

[083] Additionally, the quantity of carbonate per weight of by-product should be checked whenever the soluble carbonate salt or mixture is changed, such as changing from sodium bicarbonate to potassium bicarbonate, as even when equimolar amounts are utilised the effect can differ.

[084] The quantity of carbonate per weight of by-product should be adjusted to yield the desired or target pH levels of the solution in the substrate which has contact with. This pH value or range can depend on factors such as the pKa value of the carboxylic acid or acids, the pH preference of individual plant species, whether the growth media is soilless, or is mineral soil based, or is a combination of sand and organics, or has pH requirements for countering a soil pathogen.

[085] Concentration of carbonate solutions should be sufficient to appropriate hydrate the by-product with the amounts of carbonate to achieve the desired pH levels of the water in contact with the by-product pieces.

[086] While plants can survive growth media with unfavourable pHs, it is desirable that plant growth media have values within favourable pH ranges and preferably optimal pH values for plant survival and growth. These favourable and optimal pH ranges for media vary between plant species, plants’ preferences being roughly divided into strongly acid, moderately acid, and slightly acid to alkaline. Though different races of a single plant species can differ in acid sensitivity. Additionally, the preferred pH values are dependent on the type of plant growth media so that the pH range for plants grown in organic soils or soilless mixes can be around 1.0 to 1.5 pH units lower than the pH range for the same plants grown in mineral soils.

[087] Furthermore, the preferred pH of the growth media for specific plant species can be expanded by changes in the amount of critical fertiliser nutrients and additionally by plant roots being surrounded by mycorrhizal fungi, particularly ectomycorrhizal fungi. Where possible the desirable pH for the type of the plant growth media, fertilising and mycorrhiza combination to be used should be determined and so enable the plant byproduct material to be appropriately treated with soluble carbonate to achieve a desirable pH. Similarly, where possible the suitable pH range for a target mulch soil should be identified in order to enable the plant by-product material to be suitably treated with soluble carbonate to achieve an appropriate pH.

[088] In the event of the presence or addition of pH altering compounds in the plant growing media such as lime, or dolomite, or aluminium sulphate, or powered sulphur, or the presence of alkalinity in irrigation water, then these should be allowed for when selecting or determining the desired pH values for treated plant industry by-products. [089] The technology of the invention offers flexibility in achieving pH values of the materials, as different degrees of partial neutralisation can achieve solutions with different but relatively constant pHs. Without being limited in any way, this is deduced to be the result of achieving buffers or pH buffering mixtures due to the formation of combinations differing in the ratios of protonated acid molecules to unprotonated carboxylate molecules. These different ratios result in different values of buffered pH in treated materials, so materials can be tailored to supply the growth media that is the rootzone pH preferences for individual plant species.

[090] The pH values obtained are dependent only on the ratios of protonated and unprotonated acid molecules, but also on the chemically individual acids present. Additionally, the buffered pH values obtained are influenced the dosage and type of carbonate applied and the nature of the material being treated which involves the plant by-product species, the plant portion or portions and ratios, age and stage of growth of the original harvested plant material. Thus, the behaviour of individual batches of materials should be tested.

[091] Within pores in the pine bark etc pieces is retained aqueous buffering solutions of combinations of carboxylic acids and carboxylate entities. Buffering solution diffuses out and modifies the pH inter-piece water of the pure bark and of growth media or the substrate for plant growth. To measure the approximate pH which could be expected in growing media dominated by treated bark, a refinement of the ‘Pour-through Leachate’ method can be utilised in order to minimise effects of dilution. Samples of treated bark are held in cylinders over mesh and systematically leached with proportionally small volumes of distilled water until the pH of the resulting flushings stabilised showing that the inter-particulate water of the material has been effectively replaced.

[092] Then these hydrated samples were rested overnight or longer so a near equilibrium between the pore solution and the inter-piece liquid could be established. The rested sample was leached again with a series of small volumes of distilled water and the pHs of the flushings recorded, plotting of the flushing pHs against the accumulated volume of leaching water enables an extrapolation back to the pH value for zero flushing volume to give the near equilibrium pH value.

[093] The determined near equilibrium values of treated material can be quite stable, with multiple repeated complete flushings then overnight restings followed by further series of leachings giving near equilibrium pH guidance values which only vary slightly vary. However, the overnight rest values while a good guide can be about 0.2 pH units higher than the pH values obtained with adjustment times of two and a half days or three and a half days, or the approximate equilibrium values of the hydrated material.

[094] These equilibrium pH values are a guide only as if a media has incorporated lime or dolomite, plus if irrigation water used is high in alkalinity, factors that can modify the pH in the growing media experienced by the roots and soil mycorrhiza an should be allowed for such as by monitoring leach water pH values. [095] Carboxylic acids and of their hydration products, the latter being unprotonated carboxyl ground compounds or carboxylates and proton ions. The proton ion is variously referred as hydrogen ion, hydrated hydrogen ion, H3O ⁺ ion, oxonium ion, hydronium, hydroxonium, and different protonated water clusters. Dissolved or hydrated hydrogen ions are the acidifying agents which can lower growth media pHs to acidic levels which hinder plant growth, or damage or kill plants and soil microbes such as arbuscular mycorrhiza.

[096] In addition to direct effects of simply altering the quantity of acid experienced by subsurface plant portions and associated mycorrhiza, the raising of the pH can indirectly lessen nonacidic allelopathy effects, by reducing the direct exposure to uncharged protonated allelopathic compounds such as phenolic acids and diterpene acids, and charged or unprotonated allelopathic compounds such as phenolic and diterpene carboxylates.

[097] Specific carboxylic acids and their non acidifying unprotonated carboxylates can be allelopathic agents. The non ionised carboxylates tending to be more allelopathic than the ionised carboxylates apparently due to having greater ease of penetration into plant tissues. Allelopathy effects are dependent on the specific chemicals, and the specific plant or plants being grown.

[098] Phenolic acids are frequent allelopathic carboxyl group compounds found in of by-products of plant industries, variously affecting the germination and root growth of various plant species. There are a multiple of allelopathic phenolic acids, including but not limited to anisic acid, benzoic acid, caffeic acid (3,4-dihydroxycinnamic acid), caffeoylquinic acids, e.g., carnosic acid, chlorogenic acid, Zrans-Cinnamic acid, o-,m-, and p-coumaric acids, 3,5-dinitrobenzoic acid, ferulic acid (3-methoxy-4- hydroxycinnamic acid), gallic acid (3,4,5-trihydroxybenzoic acid), gentisic acid, p- hydroxybenzoic acid, protocatechuic acid (3,4-dihydroxybenzoic acid), caffeoylquinic acids such as chlorogenic acid (3-trans-Caffeoylquinic acid) and 3,5-dicaffeoylquinic acid methyl ester, salicylic acid, syringic acid, vanillic acid, and alternative names of these compounds.

[099] Diterpene acids are multi-ring, usually tricyclic molecules, also known as resin or resinic acids. Examples include but are not limited to abietic acid, dehydro abietic acid, neoabietic acid, levopimaric acid, palustric acid, pimaric acid, isopimaric acids, and alternative names of such compounds.

[0100] Allelopathy can be concentration sensitive thus phenolic and diterpene acids such as caffeic and ferulic and abietic acids need not be completely removed or completely ionised, and it actually may be advantageous to not do so because many compounds can show hormesis and changing from having negative to having promotional effects as their concentrations fall.

[0101] The technology of the invention counters allelopathic phenolic and diterpene acid effects by greater extraction from pieces as the compounds are ionised to a greater extent and more soluble at raised pHs and so able to be more completely removed when treated materials are flushed or washed with applied water or solutions. Additionally, even when present in solution at higher pHs associated with the treated material the ionised compounds tend to have lowered allelopathy compared to their un-ionised parent acids. [0102] The treatment should be mild enough to appropriately preserve the physical structure of the materials being treated. Processing of bark and other plant industry byproduct materials for extracts are not required to preserve the structure of the yielded processed material, with processing routinely being seriously physically destructive. Yet for use as plant growth media the materials utilised need to have sufficient structurally functional integrity, that is have necessary quantities of organised physical three- dimensional structure rather than consisting of having inappropriate degrees of collapsed structures or even of sludge like material. Spatially organised physical structures being desired for achieving plant growth supporting factors in plant growth media such as: allowing good root penetration, not suffering from lack of porosity and restricted access to sufficient oxygen, for enabling good soil microbe development, for avoiding the development anaerobic pockets, for achieving good water holding by having a structure with large surface areas to which water is able to adhere yet be available to be accessed by plants. In order to significantly conserve structurally functional integrity, the treatment of the plant industry by-product materials by harsh processing is to be avoided, such as avoiding intense heat treatments, and avoiding excessively alkaline treatments.

[0103] Intense heat treatments involve combinations of heating temperatures and durations of heating which in association with or without other processing factors yield processed material with physically disrupted material which is of poor quality for use in plant cultivation, preferably the treatment temperature does not reach above 49 degrees Celsius, more preferably the treatment temperature does not reach above 59 degrees Celsius.

[0104] Excessively alkaline treatments involve caustic conditions which in association with or without other processing factors yield processed material with physically disrupted material which is of poor quality for use in plant cultivation, the treated material after treatment with water soluble carbonate and not subsequently treated with acid or otherwise processed having associated final solutions with pHs being preferably not above pH 9.5, and more preferably not above pH 9.75, and more preferably not above pH 9.9.

[0105] Following treatment of the by-products with water soluble carbonates, the materials may be as necessary have water soluble, including poorly water soluble, components partly or completely removed, the removal can be by flushing, or leaching or washing, sluicing, rinsing etc with water or solutions before the introduction of plant material. This can be a single or repeated process. This is carried out to remove soluble and solubilised plant inhibiting carboxyls and reduce the quantities which would be later released to reach plant tissues. The optional subsequent processing can be to remove factors such as salts, sodium ions if use sodium bicarbonate, allelopathic carboxylates. In addition the processing can be to remove or reduce allelopathic non carboxylates compounds such as flavonoids, epicatechin gallate, proanthocyanins, or procyanidins when present in inhibitory levels. The flushing can take before, or after the growth media is partially or completely prepared.

[0106] After treatment of the material with or without extra processing to remove potentially negative water soluble factors, treated materials may be dried out for better storage or lower transport costs before eventually utilised for plant production and maintenance roles.

[0107] Applications of the treated materials are primarily for aiding plant growth and survival by enhancing water holding capacities of plant growth media or plant growth substrates such as forming or being incorporated into soilless growth media, modified soils, modified sands, acting as soil amendments, being incorporated in mulches, or being utilised as mulches. Other roles include increasing nutrient holding capacities and supporting soil microbe populations, and in the case of mulches decreasing water evaporation. Untreated mulches which release carboxylic acids can be damaging to plant growth especially to shallow rooted plants, even perennial crops such as macadamias. [0108] The technology creates materials from waste resources which more enable improved water and fertiliser use efficiency and further benefits when utilised such as in: gardening, nursery operations and potted plant production, productive horticulture, orchards and truffieres, forestry, landscaping, and as substrate for the generation fungal materials including mushrooms and soil inoculant, etcetera. The phenomena of global warming and there being extensive regions of the world experiencing exceptional water stress, occurrences of drought and dangerous effects on food security, the invention provides materials needed for more efficient use of water for in urban and agricultural regions. Provides materials which can be used to increase organic matter in soils for better water and fertiliser holding capacities and provide reservoirs or sanctuaries for beneficial soil microbes particularly in thin poor or sandy soils.

Terminology and Definitions

[0109] As used herein, the plural forms are intended to include the singular forms as well, and the singular forms are intended to include the plural forms as well unless the context clearly indicates otherwise.

[0110] Adverse effects include but are not limited to prevention of germination, reduced plant growth and stunting, reduced resistance to diseases and parasites, reduced quantities of marketable produce, poorer quality produce - fruits, vegetables, flowers, and plant death.

[0111] Allelopathy, allelopathic, compounds released from plant materials which direct or indirect effects on other plants. Allelopathy can be defined as any direct or indirect harmful or beneficial effect by one plant on another through the production of chemical compounds released into the environment. Effects resulting from either directly altering plant root cellular biochemistry or indirectly such as by damaging root hairs, and root associated arbuscular mycorrhiza and so reducing nutrient and water supplies to plants. Acid caused adverse effects can include by direct damage of delicate tissues such as root hairs by acid ions, in addition to disruption of intra-tissue biochemistry by the properties of specific compounds. Additionally, by-product materials of plant industries can include limited solubility non carboxylic acid allelopathic compounds such as proanthocyanins, procyanidins, and flavonoids including catechins.

[0112] By-products of plant industries include but are not limited to tree barks such as pine and other conifer barks, tree and bush wood materials such as shavings and saw dusts, sugar cane toppings, sugar cane tops, sugar cane leaves, sugar cane straw, sugar cane trash, rice hulls, coffee grinds, seed hulls, seed skins, leaves and needles. Byproducts are not limited to fresh or raw by-products but can be stored or aged material such as weathered or aged pine barks which contain carboxylic acids and of their dissociation products adversely affecting plant cultivation.

[0113] Carboxyl group compounds are protonated carboxylic acid and unprotonated carboxyl group compounds or carboxylates.

[0114] Carboxylic acids and of their hydration products, the latter being unprotonated carboxyl compounds or carboxylates and proton ions. The proton ion is variously referred as hydrogen ion, hydrated hydrogen ion, H3O ⁺ ion, oxonium ion, hydronium, hydroxonium, and different protonated water clusters. Dissolved or hydrated hydrogen ions are the acidifying agents which can lower growth media pHs to acidic levels which hinder plant growth, or damage or kill plants and soil microbes such as arbuscular mycorrhiza.

[0115] Coffee grinds or coffee grounds are the waste products resulting from roasted coffee beans being ground and extracted by brewing with heated water.

[0116] Diterpene acids also known as resin or resinic acids, consist of a multiple linked rings portion, and a carboxylic acid group, the carboxyl group being attached to a terminal ring.

[0117] Hormesis occurs where an agent at a low dose has a stimulation or beneficial effect while a high dose has an inhibitory or toxic effect.

[0118] Introduction of plant material, the placement of living plant material and seeds onto or into plant growth media, such as of planting of seeds, planting of seedlings, planting of established plants, layering on or partially into the surface, surface depositing of spores, partial or complete inserting of cuttings, rhizomes, runners, bulbs, corms, tubers and fungal mycelium.

[0119] Mulch, material applied as a layer upon the surface of soil or other plant growth media rather than incorporated into soil or other growth media. Can consist of treated byproducts of plant industries alone or combined with other components.

[0120] Modified medias mean that they have been modified by the incorporation of treated material of the invention, but does not exclude addition modifications.

[0121] Non aerial portions of plants include viable seeds, spores, sprouting seeds, sprouting spores, seedlings, established plants, bulbs, corms, stem tubers, root tubers, stem tubers, tubers with at least one eye, rhizomes, stolons, runners, cuttings, cane portions, ratoons and sprouts.

[0122] Phenolic Acids also known as phenolcarboxylic acids, consist of a phenol portion, that is a benzene ring with an attached OH or hydroxyl group, and a carboxylic acid group -C=O(OH), the carboxyl group can directly attach to the benzene ring or have one or more intervening atoms between the carboxyl group and the benzene ring.

[0123] Piece can be a separate item, such as an object regarded as a unit of a kind or class; or be a limited portion or quantity of something. A piece of the by-product either being whole item such as a rice hull or husk, or a limited portion of the original material such as a piece of pine bark.

[0124] Plant cultivation, or the cultivation of plants, such as the establishment, growing and propagation, and maintenance of plants.

[0125] Plant cultivation utilisation is involved in but is not limited to gardening, plant nursery operations, production of potted plants, productive horticulture, orchards and truffieres, viniculture, forestry, agriculture, windbreaks, decorative and ambiance enhancing landscaping, turf production, lawns, parks, golf courses and sports grounds, reclamation and rehabilitation of degraded and contaminated areas, rehabilitation of quarries and mine sites, establishment and maintenance of vegetation for stabilization of slopping land and of hedges and of windbreaks, reestablishment of natural vegetation and reforestation, establishment of wildlife friendly landscapes, fungus and soil inoculant production.

[0126] Plant Growth Media (or Substrate) includes growing media materials that plants grow in or on, and support plant growth and can either be a solid or a liquid. Unless otherwise specified all references to plant growth media are to solid media. Plant growth media can include but are not limited to mineral soils, sand, organic soils including muck or sapric or mull or moder or mor soils, modified soils; or soil substitutes such as soilless growth media, potting mixes, modified sands, loose mixtures of synthetic material or of non synthetic materials; used in but not limited to non heaped ground or field applications; to growth media restricted by physical barriers such as nursery trays, plant pots, walled raised beds, cliff holes, pots, troughs; or not retained by solid wall applications such as heaped raised beds and ridges, and mesh held media for epiphytes. [0127] Plant industries, those industries processing plant materials such as but not only harvested crops and trees, including but are not limited to production horticulture such as fruits, vegetables, nuts; agriculture such as sugar cane, coffee, tea, fibres; and forestry. [0128] Plants are lifeforms with cell walls, including arbuscular mycorrhiza and other fungi.

[0129] Soil amendment is any material added to a soil to improve its physical properties, such as water retention, which provides an enhanced environment for roots.

[0130] Vegetal relates to plants.

[0131] Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial or detrimental effects on the target organisms and the community.

Advantages of the Invention

[0132] The technology eliminates the need for lengthy aging, weathering or composting processing of materials which are employed to prevent negative effects on plant and vegetation production and maintenance.

[0133] The invention helps to meet the desire for better environmental responsibility, utilises renewable raw material, enables sustainability and replacement of peat in plant raising operations and industries. Reducing the burden of waste disposal problems for plant industry by-products.

[0134] The technology provides new application for sugar cane leaves and tops, which around much of the world are eliminated by burning generating smoke and causing unpleasant conditions and asthmatics suffering.

[0135] The technology creates materials from waste resources which more enable improved water and fertiliser use efficiency in gardening, nursery and potted plants, landscaping, productive horticulture, orchards, forestry, rehabilitation of quarries and mine sites, establishment of vegetation, sloping land stabilisation, and in many other applications. The phenomena of global warming and there being extensive regions of the world experiencing exceptional water stress, occurrences of drought and dangerous effects on food security, the invention provides materials needed for more efficient use of water for in urban and agricultural regions. Provides materials which can be used to increase organic matter in soils for better water and fertiliser holding capacities and provide reservoirs or sanctuaries for beneficial soil microbes particularly in thin poor or sandy soils, and act as soil amendments.

Examples

[0136] The invention will now be described with the following non-limiting examples demonstrating reductions in acid release from treated materials and flexibility available from altering dosages, also the beneficial effects of treatments for plant cultivation. [0137] By-products of plant industries were taken from the sugar cane and forestry industries.

[0138] Sugar cane leaves and tops were a commercial dry mulch product produced in Queensland, ‘Rocky Point’s’ organic Sugar Cane Mulch. [0139] Queensland raw pine bark was harvested from pine trees which are a hybrid of Pinus elliotii var. elliottii crossed with Pinus caribaea var. hondurensis processed in a blender (a Breville Blender Kintetix Task BBL550, and the puree and or pulse power settings) to yield mixtures of powder, fragments and flakes with a maximum thickness of approximately 1 mm.

[0140] Queensland composted pine bark was made from harvested from pine trees which are a hybrid of Pinus elliotii var. elliotii crossed with Pinus caribaea var. hondurensis, composted for thirteen weeks, from Bassett Barks Pty Ltd, Queensland, Australia.

[0141] Pine Bark harvested in Western Australia from locally grown pine trees which the majority of which Pinus radiata, with a minority of Pinus pinaster, processed in a blender (a Breville Blender Kintetix Task BBL550, and the puree and or pulse power settings) to yield mixtures of powder, flakes, fragments, together with a small portion of coarse fragments with a maximum thickness of approximately 2 mm.

[0142] Carbonates utilised, both sodium hydrogen carbonate NaHCCL and potassium hydrogen carbonate KHCO3 were both at least 99% pure.

[0143] Water, for treatments and pH measurements distilled water was used. For plant trials tap water with a stated average pH of 7.5 and total Alkalinity mg/L as CaCOs of 46.4 was used.

[0144] All treatments took place at ambient temperature.

[0145] Radishes for growing trial: Radish seeds (Raphanus raphanistrum subspecies sativus) used were a round or globe shaped root, red exterior, white interior, kitchen garden variety.

[0146] Tomatoes for growth trials. Tomato seedlings (Solanum lycopersicum) were of a single variety ‘Pot Prize’ also known as Patio Tomato or Patio Prize, described as a compact determine variety and growing an average height of 0.5 metres with staking, purchased from a retail garden centre. Monitoring of aerial plant size, plus root development where plants were growing in clear plastic pots, additionally plant stages were monitored: side stem development, flower budding, flowering, and fruit development. The optimum pH range for soilless raising of tomatoes is variously stated to be about 5.5 to 6.0, or acceptable 5.0-5.6, optimal 5.7-6.5. No tomato plants displayed oblivious visual appearances of mineral deficiencies.

[0147] Acidity, to deduce the approximate pH which could be expected in growing media dominated by treated materials, two alternative methods were utilised. The first: the modified ‘Pour-through Leachate’ method as described previously. The second, ‘batch leaching’ a modified form of ‘Saturated Media Extract’ or S.M.E. method, by leaching of material held in plastic bag wherein 1 litre of material is soaked with an added 1 litre of water for 23 hours, and then the leachate separated off for measurement of its pH. The procedure can be repeatedly performed for a number of days.

Trials and results

Example 1: Treatment of sugar cane industry by-product, Commercial Queensland dried sugar cane leaves and tops, after being size reduced by chopping.

[0148] Example 1 A, 1 kilogram of dry leaves was hydrated for 48 hours with 1.1 litre of water without carbonate treatment, and when tested by batch leaching gave an approximate inter-piece solution pH value of 4.8.

[0149] Example 1 B, 1 kilogram of dry leaves was hydrated for approximately 20 hours with 1.1 litre of water with 5 grams of potassium hydrogen carbonate treatment, and when tested by batch leaching gave an approximate inter-piece solution pH value of 5.8.

Example 2: Trial evaluating material generated by the technology of the invention on plants.

[0150] The treated and untreated sugar cane materials after rinsing by leaching were placed in two separate trays in 5 centimetre deep beds. One half of each tray planted with young tomato seedlings and one half sown with seeds of round red radishes. These trays were kept in growth chambers under artificial lighting, at ambient temperature, and kept damp and fertilised with water soluble fertiliser, and monitored for 37 days.

[0151] With the untreated batch the radish seeds did not yield established plant and eventually disappeared, in the treated batch the radishes germinated and grew to the point of having above ground swollen roots of harvestable sizes. In the untreated batch the tomato seedlings grew but were drastically smaller than the same aged seedlings grown in the treated sugar cane media, who additionally displayed stem branches and flowers.

Thus demonstrating the countering of factors in the material which adversely affect the growth or survival of living plants, by treatment with water soluble carbonates.

Example 3: Treatment of pine plantation industry by-product, milled Queensland hybrid Pinus Pine Bark.

[0152] Example 3 A, 1 kilogram dry bark was hydrated for 2% days with 1.1 litre of water without carbonate treatment, and when tested by stepwise flushing gave an approximate equilibrium inter-piece solution pH value of 3.8, resting and further stepwise flushings, gave inter-piece solution pH values of approximately 4.6, and 4.7.

Demonstrating that acid properties of barks can change between batches from species of even the same genus, in this case the Pin s genus, see example 3A, and thus the optimal dosage range for carbonate treatments is material and batch specific.

[0153] Example 3 B, 1 kilogram of dry bark was hydrated with 1.1 litre of an aqueous solution containing 5 grams of potassium hydrogen carbonate for approximately 20 hours.

[0154] When tested by stepwise flushing gave an approximate equilibrium inter-piece solution pH values of 5.1 +/- 0.3 for three repeated determinations. Thus, while the use of water soluble carbonate effectively counters the carboxylic acids present in this bark sample, this dosage of KHCO3 used was sufficient for acid favouring plants such as Blueberries and Azaleas, but is regarded as too acidic for most soilless plant raising applications.

[0155] Example 3 C, 1 kilogram of dry bark was hydrated with 1.1 litre of an aqueous solution containing 7.5 grams of potassium hydrogen carbonate for approximately 23 hours.

[0156] When tested by stepwise flushing gave initially approximate equilibrium interpiece solution pH values of 5.1 and 5.2, before settling repeatedly on approximately 6.0. Thus, the use of water soluble carbonate effectively counters the carboxylic acids present in this bark sample, this dosage of KHCO3 used was sufficient to achieve pH which matches the upper edge of the pH range stated to be referred for almost all crops, and for flowers such as hydrangeas, and plants for which pH 6.0 is the lower end of their preferred pH ranges such as geraniums, celosia, dianthus, and African marigolds, as well as ivy.

[0157] Example 3 D, 1 kilogram of dry bark was hydrated with 1.1 litre of an aqueous solution containing 6 grams potassium hydrogen carbonate for approximately 20 hours. Afterwards the treated bark was flushed with a litre of water, and a fresh litre of water was introduced in the container, after 23 hours contact, this was drained off and the pH measured. The pH of the leachate water was 5.4.

[0158] Example 3 E, 1 kilogram of dry bark was hydrated with 1.1 litre of an aqueous solution containing 6 grams potassium hydrogen carbonate for approximately 20 hours. Subsequently the treated bark was flushed with a litre of water, and afterwards a further litre of water was introduced into the container, after 23 hours contact, the liquid was drained off and the pH measured. To investigate the potential for removal of low solubility allelopathic compounds from treated bark, the leaching and draining was carried out a further 5 times. The pH of the drained water was very constant, values of 5.7, 5.6, 5.8, 5.9, 6.1, 6.1 being observed.

[0159] Example 3 F, 1 litre volume of composted hybrid Pin s Pine Bark was hydrated with 1 litre of water without carbonate treatment, and when leached by 300 mL of water a time the measured flushing pH values went from an initial 5.8, then to pH 6.4, and then to pH 6.3 Repeating leachings over the next two days gave flushings pH values of 6.3 and 6.3. This is in line with published Australia results, quoted in prior art, where the pH value of composted pine bark was about 6.0 to 6.5.

Example 4: Trials evaluating materials generated by the technology of the invention on plants.

[0160] Tomato seedling were planted in different pure hybrid pine bark media, untreated raw, carbonate treated and once flushed, carbonate treated followed by multi leaching, and commercial composted barks, planted in either in 5 cm deep beds in trays, or alternatively in 1.5 litre pots.

[0161] Example 4 A: Comparison of tomatoes grown in trays of untreated raw and carbonate treated and once flushed: after 37 days the plants grown in the treated pine bark were much larger and additionally had developed side stems and had flower buds just about to open.

[0162] Example 4 B: Comparison of tomatoes grown in trays of untreated raw and carbonate treated and multiply flushed: after 52 days the plants grown in the treated pine bark were much larger and additionally had large side stems and had many well developed green fruit, while the plants grown in the untreated bark were much smaller, possessed side stems but were only at the start of flowering stage.

[0163] Example 4 C: Comparison of tomatoes grown in black pots of composted and carbonate treated and once flushed: after 41 days the plant grown in the composted pine bark was larger and had a side stem developing and was in flower, while the plants grown in the carbonate treated and once flushed bark were much smaller, with side stems and young buds.

[0164] Comparison of tomatoes grown in clear plastic pots of composted and carbonate treated and once flushed: after 19 days the plant grown in the composted pine bark was far larger and had a far greater amount of roots.

[0165] Example 4 D: Comparison of tomatoes grown in clear plastic pots of composted and carbonate treated and multiply flushed: after 51 days the plant grown in the composted pine bark was smaller and had a lesser amount of roots, the plant grown in the treated pine bark was the plants grown in the treated pine bark were much larger and additionally had large side stems

[0166] Plant growth trials results showed that bark which had been carbonate treated and multiply leached gave better plant aerial plant size and development, and more extensive root development compared with the commercial composted pine bark; which in turn gave superior results to the use of carbonate treated and once leached pine bark; with the least amount of growth occurring with tomato seedlings grown in untreated that is raw pine bark. Thus, demonstrating that the technology of the invention counters factors in the material which adversely affect the growth or survival of living plants. Additionally, treatment of pine bark with water soluble carbonates and suitable flushing of the material, is able to provide a superior plant growth media than treating pine bark by composting, while involving a much briefer processing time.

Example 5: Treatment of pine plantation industry by-product, milled Western Australian Pin s radiata dominated Pine Bark.

[0167] Example 5 A, 1 kilogram dry bark was hydrated for approximately 20 hours with 1.5 litre of water without carbonate treatment, and when tested by stepwise flushing gave an approximate equilibrium inter-piece solution pH value of 3.6, restings and further stepwise flushings, gave inter-piece solution pH values of approximately 3.6 and 3.8. [0168] Example 5 B, 1 kilogram of dry bark was hydrated with 1.5 litre of an aqueous solution containing 50 grams of sodium hydrogen carbonate for approximately 24 hours. After the treated material was washed by leaching, the hydrated material was rested for 2 days, allowing time for the pore held liquid and the outer inter-piece liquid to approximately equilibrise, then testing by stepwise flushing gave an indicated inter-piece solution pH value of 7.8, then repeating the procedure with days resting gave a pH value of 7.6. Thus, while the use of water soluble carbonate effectively counters the carboxylic acids present in this bark sample, the dosage of NaHCCE used was excessive for most plant raising applications.

[0169] Example 5 C, 1 kilogram of dry bark was hydrated with 1.5 litre of an aqueous solution containing 20 grams sodium hydrogen carbonate for approximately 20 hours. After the treated material was washed by leaching, the hydrated material was rested for

22.5 hours, allowing time for the pore held liquid and the outer inter-piece liquid to near equilibrise, then testing by stepwise flushing gave an indicated inter-piece solution pH value of approximately 6.7. Thus, while the use of water soluble carbonate effectively counters the carboxylic acids present in this bark sample, the dosage of NaHCCh used was excessive for most plant raising applications.

[0170] Example 5 D, 1 kilogram of dry bark was hydrated with 1.5 litre of an aqueous solution containing 9.6 grams potassium hydrogen carbonate for approximately 38 hours. After the treated material was washed by leaching, the hydrated material was rested for

16.5 hours, allowing time for the pore held liquid and the outer inter-piece liquid to near equilibrise, then testing by stepwise flushing gave an indicated inter-piece solution pH value of 5.5, then repeating the procedure 5 more times gave values of 5.7 to 6.0.

Indicating the use of KHCO3 at this dosage on this carboxyl group compounds possessing by-product of a plant industries achieves modified and robust buffering for delivering pH levels suitable for many plant raising applications.

Industrial Applicability

[0171] The technology eliminates the need for lengthy aging, weathering or composting processing of materials which are employed to prevent negative effects on plant and vegetation production and maintenance.

[0172] The technology enables more efficient use of human and physical resources more effective for costs and space and equipment utilisation, as conventional processing of such by-products of plant industries can be laborious, take extended time, occupy large spaces, and involve significant costs such as for staff and equipment.

[0173] Although the invention has been described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

References

[0174] ‘Potting mixes’, Internet page last updated: Thursday, 8 September 2016, https://www.agric.wa.gov.au/nursery-cutflowers/potting-mixes , report from the Agriculture and Food division of the Department of Primary Industries and Regional Development of Western Australia.