Pellets containing fungal microorganisms used in plant growing environments

Abstract

A pellet for improving a growing environment, wherein the pellet comprises a growing medium, wherein the pellet comprises a fungal biome. Suitably the concentration of fungi in the pellet is at least 5 µg / ml. The pellets are an efficient vehicle to deliver plant growth-enhancing fungi and if wished other growth promoting materials such as fertilizer and trace minerals. in a targeted and efficient way. The pellets may also promote carbon capture in the growing environment.

Description

PELLETS CONTAINING FUNGAL MICROORGANISMS USED IN PLANT GROWING ENVIRONMENTS

[0001] The present invention relates to pellets used to improve growing environments; and to the production thereof.

[0002] The use of pellets is known in agriculture.

[0003] The Chinese company Yu Shunxin offers a 'Compost Pellet Machine' for pelletisation of compost and describes this at web page https: / / manuretofertilizer.com / compost-pellet-machine / Fermented manure is described as a favoured feedstock. The size of the pellets produced is not defined but in an image in the internet article cited above they appear to be bead-like.

[0004] Chicken manure pellets are widely available. They are described at web pageThe size of the pellets produced is not defined but they appear to be extruded and chopped sections, apparently, on average, a few millimetres in diameter and about a centimetre long.

[0005] It is known to provide compost in a compressed form. For example the company Geo Emporium offers discs of dry compressed coir, each one wrapped around its circumference by a band. The band is an FSC-certified (Forest Stewardship Council™) paper. The discs are described at web page https: / / www.e-pots.co.uk / product / coco-coir-plant-starter-pellets-36mm-x-20 / Each disc is, when sold, 36 mm in diameter and 5 mm in thickness. When soaked with water each disc is said to expand to up to 3 cm centimetres in thickness; diametric expansion is prevented by the band. The weight of the discs is not given but, with knowledge of the density of coir, I would expect them to weigh a few grams when the discs are in their dry, compressed form. When the coir has expanded, it is simply coir of the type that might otherwise be purchased in its loose form, in bags. No benefit is apparent, arising from the supply of coir in the form of compressed discs. Rather, the benefit is to the producer or supplier, in reducing their transportation costs, because of the compressed state of the coir.

[0006] Clearly, therefore, pellets are used to improve growing environments in different ways and pellet-forming technologies are available.

[0007] My work in developing improvements in growing media has focused on the role of fungi. I have sought to develop a way of reliably delivering fungi in a controlled manner to environments in which plants are grown, or are to be grown. Such environments include agriculture, horticulture, forestry and woodland management.

[0008] In accordance with a first aspect of the present invention there is provided a pellet for improving a growing environment, wherein the pellet comprises a growing medium, wherein the pellet comprises a fungal biome. Suitably the concentration of fungi in the pellet is at least 5 pig / ml.

[0009] In accordance with a second aspect of the present invention there is provided a method of producing a pellet for improving a growing environment, wherein the pellet comprises a growing medium, wherein the pellet comprises a fungal biome, wherein the method comprises one or more of the following steps:(i) adding fungi to a growing medium precursor to form the growing medium, then forming pellets of the growing medium; or forming pellets of the growing medium precursor, then applying fungi to said pellets;(ii) harvesting an ambient growing medium which already contains said fungal biome, then forming pellets of the growing medium;(iii) producing a high-fungal compost to be the growing medium, or to be part of the growing medium, then forming pellets of the growing medium.

[0010] Suitably the concentration of fungi in the pellet is at least 5 ig / ml.

[0011] In accordance with a third aspect of the invention there is provided a method of improving a growing environment by the introduction into the environment of pellets of the first aspect, or of pellets provided by the method of the second aspect.

[0012] In accordance with a fourth aspect of the invention there is provided the use of pellets of the first aspect, or of pellets provided by the method of the second aspect, in the improvement of the growing environment.

[0013] In accordance with fifth aspect of the invention there is provided a growing environment modified by the use of pellets of the first aspect, or of pellets provided by the method of the second aspect.

[0014] Features and aspects of the invention, including optional, alternative and preferred features, will now be described. They apply to all aspects of the present invention unless otherwise stated or unless the context demands otherwise.

[0015] The term 'growing medium' in this specification denotes the material which constitutes the pellets; and a bulk material, suitably having substantially the same high concentration of fungi, which is used to make the pellets. The term 'growing medium precursor' in this specification denotes any material which in production terms is upstream of the growing medium. A growing medium precursor may be a bulk growing material, in loose form, for example soil, compost, andwaste materials which will form compost; in each case having a lower concentration of fungi than the growing medium. The term 'growing environment' denotes the locus to which the pellets are applied, in use. The locus may, for example, be a field, wood, forest, plant container (e.g. a pot or a trough), a body of compost or soil, or a compost heap (i.e. of compost-forming material).

[0016] Fungi are microorganisms, and in this specification we use the term microorganism, and its synonym microbe, and derivative words such as microbial, in a manner which is conventional in the art, to include all fungi irrespective of size, and not just those which are too small to be seen by the naked eye.

[0017] It is an object of embodiments of the invention to provide pellets which comprise a growing medium which is compatible with soil to which they will be applied; for example an agricultural, horticultural or arboreal soil.

[0018] It is an object of embodiments of the invention to provide pellets which comprise a growing medium which has significant characteristics of a soil to which they will be applied; for example an agricultural, horticultural or arboreal soil, especially in terms of its fungal content.

[0019] In some embodiments of the invention the concentration of fungi in the growing medium, (that is, in the pellets) is at least 10 pg / ml, for example at least 20 pg / ml, for example at least 40 pg / ml. In some embodiments the concentration of fungi in the growing medium is at least 60 pg / ml, for example at least 80 pg / ml, for example at least 100 pg / ml. In some embodiments the concentration of fungi in the growing medium is at least 120 pg / ml, for example at least 150 pg / ml, for example at least 175 pg / ml. In some embodiments the concentration of fungi in the growing medium is at least 400 pg / ml, for example at least 800 pg / ml, for example at least 1000 pg / ml. In some embodiments of the invention the concentration of fungi in the growing medium may be at least 1400 pg / ml.

[0020] Of course, the fungal content of pellets will change over time, as the fungal biome develops. In this specification, when we define numerically the fungal concentration of the pellets we mean that the fungal concentration attains the levels we have defined at some point, in the span from pellet formation to application of pellets to a growing environment.

[0021] In some embodiments of the invention the fungal biome is distributed throughout the pellets.

[0022] In other embodiments of the invention the fungal biome may be concentrated in a region or regions of the pellets. For example it may be applied to the surface of a pellets, for example by a rolling or spraying process, in which case the surface of the pellet may be fungi-rich. In embodiments in which the fungal biome is concentrated in a region or regions of the pellets, for example in a coating, the values given herein for the concentration of the fungi in the growingmedium denote the average concentration, calculated across the whole pellet, including any such region. Thus the concentration is calculated by determining the quantum of fungi in a pellet, including in any such region which is present, divided by the volume of the pellet, including any such region.

[0023] The pellets may be produced to have properties of slow or controlled breakdown, and therefore of slow or controlled release and / or growth of the fungal biome. In some embodiments the pellets may degrade quickly, for example when exposed to wet soil or to rainfall. In other embodiments they may degrade slowly, for example as a result of having a dense, compressed, structure as a result of the method of their formation; or as a result of having been given a water- resistant coating. A water-resistant coating may for example be from a gum or starch solution. It may be derived from a tree resin such as pine resin. Optionally a water-resistant coating has the property that fungi can grow through while the coating is still fully or partially intact. Optionally such a coating may itself contain some or all of the fungal biome of the pellets.

[0024] The source of fungi in the present invention may be fungal microorganisms whose habitat is soil or an arboreal environment, for example woodland or forest. An example of soil-living fungi of significance in arboreal environments is the class Deuteromycota, including mycorrhizal fungi.

[0025] Pellets of the invention may, alternatively or additionally, include fungi from the phyla Ascomycota, Basidomycota and Mucoromycota. The Ascotymotae may include A.Pezizomycetes, A.Sordariomycetes, A.Leotiomycetes, A.Dothideomycetes, A.Eurotiomycetes and A.Orbiliomycetes. The Basidomycota may include B.Agaricomycetes and B.Tremellomycetes. The Mucoromycota may include M.Mortierellomycetes.

[0026] Fungi which can form mycorrhizal associations with plants are of interest as fungal components of the pellets.

[0027] Growing media of the invention have undergone DNA testing to determine number of fungal species ('Richness') and diversity (Shannon value based on a-diversity distribution). Growing media used in the present invention have been shown to have Richness values of at least 120, for example at least 140, or at least 160. Some samples have exhibited Richness values in excess of 190. Such samples have shown Shannon values of at least 4.8, for example at least 5.2. A Shannon value of over 5.8 has been achieved.

[0028] In aspects of the invention a pellet as defined herein may have a fungal biome with one, any two or all three of the following characteristics (A), (B) and (C):(A) it contains all of the following fungal classes: Ascomycota Pezizomycetes, AscomycotaSordariomycetes, Ascomycota Leotiomycetes, Ascomycota Dothideomycetes, AscomycotaEurotiomycetes, Ascomycota Orbiliomycetes, Basidomycota Agaricomycetes, Basidomycota Tremellomycetes, Mucoromycota Mortierellomycetes;(B) It has a Richness value of at least 120;(C) it has a Shannon value (a-diversity) of at least 4.8.

[0029] The fungal biome of a growing medium can be assessed by a number of different methods, including DNA studies, and also by microscopy. The microscopy method has been used for the definitions and in the testing described herein. The method was developed by the renowned soil scientist Dr Elaine Ingham, and is referenced in the web page called Complete guide to soil testing in agriculture, at web address https: / / biomemakers.com / complete-guide-to- soil-testing, section headed Microscopy. The microscopy method for determining fungal concentration in growing media(in this case treated with chlorothalonil, a fungicide) is also described in an article 'An appraisal of five methods for the measurement of the fungal population in soil treated with chlorothalonil' by Rosana F Vieira et al, in Pest Manag Sci 56:431- 440 (2000).

[0030] Further, the microscopy technique to assess fungal concentration is described in detail in a video lecture called 'Microscope use for assessing the soil food web' given by Daniel Tyrkiel. This can be found at https: / / www.youtube.com / watch?v=POx3iCvT-rl

[0031] Typically, in the microscope method for example of Tyrkiel et al, a sample is removed at the end of the maturation process and is mixed with filtered water. From microscopic counts of fungi the biomass of fungal organisms is determined. Fungi counts used dilution in water from 5 to 1, to 10 to 1, total volume. General morphology can be used as a differentiator of the elements present in the soil. This method was used to generate results set out in the examples.

[0032] Separately, DNA methods identified species by their known genetic information. Specialist institutes such as FERA in York, UK are available to carry out such testing, and were contracted to do the DNA testing described in examples in this specification.

[0033] Pellets with a high fungal content may be highly suitable for use in providing a growing medium for germinating tree seeds and planting trees, including saplings. Pellets with a lower fungal content may be highly suitable for use in providing a growing medium for ericaceous plants. Pellets with a still lower fungal content may be suitable for use in providing a growing medium for plants in horticultural or market garden applications.

[0034] Thus certain pellets of the present invention may be highly suitable for any tree planting or tree seed germination, for example in a forest, woodland, orchard, park, garden, playground or grass verge. When compared to outcomes from planting in native soil or in composts with lower concentrations of microbes, in particular fungi, growing media of the invention may improvesurvival rate of saplings and promote faster growth, and may improve the germination rate of tree seeds.

[0035] Pellets of the invention may find application in ground cover application, as a mulch or mulch mat. This has the property that it can increase the biological activity in the soil beneath and promote later healthy growth from that area.

[0036] Tree planting of saplings in sterile ground, following construction of roads, buildings and the like is notoriously problematic. For example, the UK Government agency National Highways has reported that out of 850,000 saplings planted along the new A14 road near Cambridge, UK in 2020, more than 637,000 have died. Lack of water was said to be one issue but the UK Government Highways Agency stated that the main issue was the quality of soil along the planting route. The use of pellets of the invention, containing live growing media, especially those having a high fungal content, can improve sapling and tree planting outcomes even in such unpromising environments.

[0037] It will be appreciated that the present invention can employ natural biological processes. Variations in fungal content in compositions cannot be avoided, even when they apparently have undergone the same regime. In reality, no growing medium or batch of pellets will have undergone exactly the same process as another - there will be unavoidable variations, for example in composting materials, sun, temperature, wind, rain, shade, worm population, pelletisation and proximity of fungal sources.

[0038] A pellet may weigh at least 0.1 g, for example at least 0.2 g, or at least 0.5 g. In some embodiments a pellet may weigh at least 1 g, or at least 2 g. In some embodiments a pellet may weigh at least 4 g, or at least 8 g.

[0039] A pellet may weigh up to 150 g, for example up to 120 g, or up to 100 g. In some embodiments a pellet may weigh up to 80 g, or up to 60 g. In some embodiments a pellet may weigh up to 40 g, for example up to 20 g.

[0040] Pellets may not be identical in weight. The weight values given herein are mean values taken across a substantial sample.

[0041] Pellets of the invention may contain plant seeds, for example tree seeds, edible crop seeds, grass seeds and green manure seeds. Green manure is grown to improve soil fertility and structure. Green manure seeds may be selected from for example, grass, crimson clover, mustard, phacelia and fodder radish, alfalfa, alsike clover, bitter blue lupin, buckwheat, red clover, grazing rye, mustard, trefoil, winter field bean and winter tares.

[0042] Pellets of the invention must contain a defined concentration of fungi but beyond that requirement, they can be tailored to the particular growing needs of the environment, which mayfor example be an agricultural, horticultural, forest or woodland management site. For example, the addition of a nitrogen-based fertilizer, a phosphorus-based fertilizer or a potassium-based fertilizer, or any combination thereof, for example a combined NPK fertilizer, is contemplated as an option in the present invention. In another example, pellets for use with ericaceous plants may if necessary have addition of pH adjusting components, for example, sulphur.

[0043] Thus the addition of a nitrogen-based fertiliser, a phosphorus-based fertiliser or a potassium-based fertiliser, or any combination thereof, for example an NPK fertiliser, is not excluded in the present invention. Such a fertiliser could be of value in fast-growing food crops, such as lettuces. Such fertilisers are commonly the products of chemical synthesis and may typically comprise compounds such as ammonium nitrate, ammonium sulphate, ammonium phosphate and potassium nitrate. Chemically synthesised fertilisers have a very large carbon footprint, partly because of the manufacture of the fundamental precursor compound ammonia by the Haber-Bosch process. Several other problems arise from the use of chemically synthesised fertiliser. Excess nitrogen in the soil can deplete soil of its richness and microbial biodiversity, cause soil acidification, damage plant growth, contribute to the leaching of nutrients into waterways and release nitrous oxide, a potent greenhouse gas. Excess phosphorus and potassium also cause environmental detriment. The chemical compounds in chemically synthesised fertilisers are highly soluble in water and when applied at a location they are substantially immediately present in the soil. Unless careful assays have been taken of the soil chemistry prior to application and unless careful application to the soil is carried out the result can be uncontrolled excessive use of chemically synthesised fertilisers, with detrimental consequences.

[0044] Growing media in the pellets in embodiments of the present invention may be rich in nutrients and / or rich in fungi which may assist plants in accessing nutrients. Together these may be sufficient for the growing needs of plants, such as young trees, without the need for the addition of any further nutrition.

[0045] In many preferred embodiments of the invention no product or method of any aspect of the present invention includes the addition of a nitrogen-based fertiliser, a phosphorus-based fertiliser or a potassium-based fertiliser, or any combination thereof, for example an NPK fertiliser. In those cases when additional nutrition is needed, the addition of chemically synthesised fertiliser is not excluded but it is preferred to add a biologically-derived fertiliser. A biologically-derived fertiliser will not have many of the problems associated with immediately-soluble chemically synthesised fertilisers. Examples of suitable biologically-derived fertilisers include seaweed, hoof and horn, dried blood, fish blood & bone, bone meal, poultry manure pellets and liquid comfrey orliquid nettle feeds. Such materials may be useful as components of pellets of the invention, to bring the content of N, P or K to a required level, if needed at all.

[0046] Fungi in the soil help build the structure of the growing medium by creating micro- and macro-aggregates, which benefit the water retention of the growing medium. Furthermore, the by-products of microbial activities, e.g. humic acid, also increase the moisture holding capacity. Water usage may thus be reduced by use of growing media of the present invention.

[0047] Advantages of the invention include that the fungi-containing pellets of the present invention may have a high content of fungi, and may have excellent water retention. In addition they may have good binding properties. Such properties lead to good handling and potting characteristics.

[0048] The use of pellets offers several important further benefits over use of loose materials. For example: pellets can be dried in a controlled manner leading to reduced weight and reduced volume of material to be transported; the growing medium may be compressed on pelletisation leading to reduced volume of material to be transported; pellets lend themselves to easy and accurate distribution at intended sites without needing specialist spreading equipment; pellets can be given a coating, for example to resist moisture ingress or egress, or to control breakdown kinetics, or to reduce dusting, or to deliver nutrients; pellets can if wished be made to release their contents slowly; pellets can contain seeds; pellets are more likely to stay in the intended sites than loose materials, which are more likely to be washed away in wet weather, or blown away in dry weather.

[0049] Pellets of the invention may, due to the fungal biome, assist in the retention of carbon in the growing environment to which they are to be applied. This may be due firstly to carbon sequestration action of the fungal biome present in the pellets at the time of application. Secondly, and more significantly, it may be due to the modification of the growing environment caused by the development of the fungal biome, growing into that growing environment, as time passes.

[0050] Different trace minerals (which may include compounds and elements) may be added to optimise the growing medium for different intended end uses. A chemical assay may be made and a decision can then be taken, as to whether any mineral additions are needed; and if they are, which additions would be beneficial to the particular circumstances. An assay to determine the content of such trace minerals may be of the growing medium prior to pelletisation. On completion of the assay the required trace minerals may be added to the growing medium to be pelletised or may be included in a coating applied to the formed pellets.

[0051] Trace minerals added to support healthy plant function may include salts of boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo), nickel (Ni),sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), aluminium (Al) selenium (Se), phosphorus (P), sulphur (S), as well as nitrate ions, ammonium ions and sugars.

[0052] When trace minerals are added to the growing medium they may be added in very low amounts, for example less than 4% on total growing medium (weight / weight), for example less than 2%, for example less than 1%, preferably less than 0.5%.

[0053] Pellets in accordance with the invention suitably have water content not exceeding 20 % (by weight on total weight of said other pellet), suitably not exceeding 15 % and preferably not exceeding 12%.

[0054] A growing medium as defined in the second aspect of the of the invention may, in certain embodiments, be mixed with another substrate, e.g. biomass, soil or other compost, to obtain desired or tailored properties.

[0055] Said other substrate may comprise or consist of biomass, for example plant-derived biomass or animal-derived biomass.

[0056] Plant-derived biomass may comprise residues of trees, including wood, bark, husks, fibre, coir and leaves; cereal waste products, for example straw and husks; seaweed; and other crop residues, for example from sugar cane, molasses, oilseed rape and sugar beet, or plants of the family Gramineae, including mown grass, and hay.

[0057] Animal-derived biomass may include animal-derived digestive biomass, and animal- derived tissue biomass.

[0058] Animal-derived digestive biomass may comprise manure e.g. from horses, pigs, cattle, goats and chickens.

[0059] Animal derived tissue biomass may be derived from animal bodies or parts, including blood and bones, and may come for example from horses, pigs, cattle, goats and chickens; and from fish. Commercial sources of such biomass are well known under names such as blood and bone, fish blood and bone, and bonemeal.

[0060] Additional biomass sources suitable for use in the invention include derivatised biomass, for example peat, biochar and digestate (a product of anaerobic digestion which may typically employ as feedstock materials livestock manures, crop material or other non-farm organic materials such as food waste).

[0061] Said other substrate suitably has a water content not exceeding 30 % (by weight on total weight of substrate), suitably not exceeding 25 %, suitably not exceeding 20 %, suitably not exceeding 15 %, and preferably not exceeding 12%.

[0062] A growing medium used in pelletisation may suitably contain at least 5% of the material specified in the second aspect, in parts (i), (ii) or (iii); suitably at least 10%; suitably at least 15%. A growing medium used in pelletisation may suitably contain up to 40% of the material specified in the second aspect, in parts (i), (ii) or (iii); suitably up to 30%; suitably up to 25%. Ratios here are given as vol / vol of the total growing medium.

[0063] In embodiments which use a material specified in the second aspect (i.e. in parts (i), (ii) or (iii)) in admixture with another substrate, and optionally trace minerals, the components may be mixed together to form a growing medium, which may be pelletised immediately or may be kept for a dwell time before pelletisation. They may alternatively or in addition be kept for a dwell time after pelletisation. A dwell time before pelletisation may be at least 2 weeks, for example at least 4 weeks, for example at least 6 weeks. An additional or alternative dwell time after pelletisation may be at least 2 weeks, for example at least 4 weeks, for example at least 6 weeks. A dwell time, in which said other substrate is exposed to the fungally 'live' material specified in the second aspect, (i.e. in parts (i), (ii) or (iii)) may have a rapid fungal growth-promoting effect.

[0064] Said other substrate used in embodiments of the invention suitably provides up to 95% of the growing medium. In some embodiments of the invention said other substrate provides up to 90% of the growing medium. In some embodiments of the invention said other substrate provides up to 85% of the growing medium.

[0065] Said other substrate used in this aspect of the invention suitably provides at least 60% of the growing medium. In some embodiments of the invention said other substrate provides at least 70% of the growing medium. In some embodiments of the invention said other substrate provides at least 75% of the growing medium.

[0066] Suitably said other substrate used in this aspect of the invention comprises a tree bark component. This may comprise or consist of tree bark chippings; suitably fine bark chippings which are quick to compost (or compost further, if they are already part-composted). A tree bark component may comprise or consist of tree bark fines. These may be uncomposted, but are preferably composted, before mixing with the compost composition. Tree bark fines used in this invention suitably have a water content not exceeding 20 % (by weight on total weight of tree fines), suitably not exceeding 15 % and preferably not exceeding 12%.

[0067] A bark component, for example bark fines, may assist in the retention of carbon in the growing environment.

[0068] In an embodiment of the invention the growing medium used to produce the pellets may be produced by mixing composted bark fines with soil from an arboreal environment and retainingthe resulting mixture for a maturation period, or by keeping the composted bark fines in an arboreal environment for a maturation period, the maturation period being sufficient in each case for the growing medium to be colonised by fungi to a concentration of at least 175 pig / ml, suitably to a concentration of at least 400 pig / ml, for example to a concentration of at least 800 pg / ml. The maturation period may be at least 2 months. In embodiments the maturation period may be at least 6 months. In some embodiments of the invention the maturation period may be at least 12 months. In embodiments the maturation period may be up to 24 months. In some embodiments the maturation period may be up to 18 months. In some embodiments the maturation period may be up to 14 months.

[0059] The presence of peat or a peat derivative, for example in some embodiments up to 40% (by weight on total weight of composition), or in some embodiments up to 20%, or in some embodiments up to 10%, is not excluded in the present invention. Preferably, however, no product or method of any aspect of the present invention includes the addition of peat or a peat derivative.

[0070] The presence of coir, for example in some embodiments up to 40% (by weight on total weight of composition), or in some embodiments up to 20%, or in some embodiments up to 10%, is not excluded in the present invention. Preferably, however, no product or method of any aspect of the present invention includes the addition of coir.

[0071] Pelletisation, sometimes called granulation, is readily achievable using commercially available technology and I make no claim to any improvements in pelletisation per se. Existing pelletisation methods are suitable for making the pellets of my invention.

[0072] By way of example only, pellets of the present invention may be made by a wet granulation process in which a growing medium is agglomerated under wet conditions, without use of pressure, by tumbling or rotating the growing medium in a disc pelletiser or rotary drum to bring about agglomeration. Pellets formed in this way have a high moisture content. Moisture may be removed by a subsequent drying step if required.

[0073] Preferred pellets of the present invention may be made by a dry granulation process in which a growing medium is subjected to pressure, without addition of moisture. The pressure may arise due to the extrusion through rollers. The growing medium is suitably low in moisture, for example less than 15% weight / weight. If necessary the growing medium may undergo a drying step prior to dry granulation. The direct result of dry granulation is firm pellets of growing medium, which generally do not require any further step, for example of heating or drying. Such pellets have a low water content, and are favoured in terms of their storage and transportation, as well as shelf life.

[0074] Preferably a growing medium, pre-pelletisation or once formed into pellets, is not heated above 30°C. This is to avoid damage to the fungal biome.

[0075] The shape of the pellets is not considered to be of high importance, but they could in different embodiments be generally round or ovoid or cylindrical. Pellets may not be identical in shape.

[0076] The pellets may in some embodiments be approximately cylindrical in shape, produced by extrusion and chopping. In other embodiments the pellets may be bolus shaped, produced by separating the growing medium precursor into slugs, and rolling them. In other embodiments the pellets may be produced by forming sheets of the growing medium, and cutting it into pieces, or stamping pieces from it.

[0077] The growing medium may in some cases be such that on being compressed it can form pellets which are shape stable without the support of an external body, such as a band or pot. If needed, however, the growing medium may be additised by a binder, which assists in pellet formation and promotes stability. Suitably a binder, when used, is a material which is accepted as a neutral or as a beneficial addition to soil. Examples may include pulverised rocks (for example clay, gypsum, limestone, magnesium carbonate, calcium carbonate, sandstone, shale, silica, quartz, silicates, basalt, pumice, marble, perlite, vermiculite and slate), animal glue, pulverized bone, cereal flour and starch. Some of these binders may function also as soil improvers and as fertilizers.

[0078] A binder, when used, is suitably a powdered material but in some cases it may be a slurry. A binder can be used to maintain the integrity of the pellets during packaging, transportation and storage but not to significantly retard the physical degradation of the pellets under ambient conditions in their final environment.

[0079] Pellets may be coated is some embodiments. Coating may be effected using a binder which helps to maintain the integrity of the pellets during handling, storage and application. As noted above a coating may include fungi and / or nutrients. Their provision on the surface of the pellets may promote rapid dispersal of the fungi and / or nutrients into the soil at an intended site.

[0080] In other embodiments pellets may be uncoated.

[0081] The invention may be used in many different ways, in the fields of agriculture, horticulture, forestry or woodland management. For example, pellets may be placed in or on the soil adjacent to a tree or shrub. They may be spread across a field or may be deposited on, or inserted into, soil in rows, for example when planting seeds. They may be added to compost and growing bags. They may be spread in a forest area after tree clearance to advance rejuvenation. They may be appliedin woodland to promote the establishment and growth of a desired fungal biome. This may advantageously be done after removal of fallen tree waste ('brash').

[0082] In the second aspect of the invention option (i) mentioned above may entail adding fungi to a growing medium precursor to form the growing medium, then forming pellets of the growing medium. Alternatively it may entail forming pellets of the growing medium precursor, then applying fungi to said pellets. In either case the method can entail the addition of lab-grown fungi. It can alternatively entail adding a fungi-rich medium from any source, to a growing medium precursor to form the growing medium.

[0083] In some embodiments a source of fungi used in invention option (i) of this invention may be a refined or concentrated compost, a liquid compost, and / or a compost extract. A liquid compost or a liquid compost extract may be made by liquefying a fungi-containing compost with water and draining it to separate liquid and solid phases, and optionally concentrating the liquid phase.

[0084] When a portion is taken from a fungi-containing compost it is preferred that said portion provides at least 2% (wt / wt) of the growing medium precursor, preferably at least 4%, and more preferably at least 8%. It is preferred that it provides up to 20% (wt / wt) of the growing medium precursor, preferably up to 15%, and more preferably up to 12%.

[0085] In the second aspect of the invention option (ii) mentioned above entails harvesting a growing medium which already contains said fungal biome, then forming pellets of the growing medium. The growing medium may be a natural soil, for example woodland and forest soil. I have found that woodland and forest soils are often very rich in fungi, quantitatively and qualitatively. Such a soil may be suitable as growing medium which can be used to make pellets in the present invention.

[0086] In the second aspect of the invention option (iii) mentioned above entails the development of fungi within composting materials to form a growing medium, or a material which can be used with benefit in a growing medium. In this option (iii) (which I will call 'Aspect 2 (iii)' hereafter) a compost may be formed using a compostable mixture which comprises:(a) a first composting material;(b) optionally, a second composting material; and one or both of the following components (c) and (d);(c) a source of microorganisms added in a predetermined amount, for example having regard to the amount and type of composting material(s);(d) a microorganism support added in a predetermined amount, for example having regard to the amount and type of composting material(s).

[0087] In this Aspect 2 (iii), the compostable mixture is suitably retained for a maturation period.

[0088] Essentially in this Aspect 2 (iii), a composting process takes place in which the compostable mixture transforms into a compost that can be used as the growing medium, or as a component of the growing medium, used in the present invention.

[0089] In Aspect 2 (iii), the first composting material is a material which is often called a green composting material and / or a high nitrogen composting material, in this art.

[0090] In Aspect 2 (iii), a green composting material may be manure with light bedding (such as from poultry, horse, sheep, and / or cow). In some embodiments, the green composting material may be coffee grounds. In some embodiments, the green composting material may be hay. In some embodiments, the green composting material may be silage. In some embodiments, the green composting material may be clover and / or other legume residues. In some embodiments, the green composting material may be food waste (such as vegetable scraps / peelings and / or fruit pulps). In some embodiments, the green composting material may be horticultural industry residues (such as root crop tops, fresh leaf prunings, and / or non-consumable produce). In some embodiments, the green composting material may be fresh grass clippings. In some embodiments, the green composting material may be seaweed. In some embodiments, the green composting material may be wood ash. In some embodiments, the green composting material may be wheat bran. In some embodiments, the green composting material may be milling industry residue (such as grain dust). In some embodiments, the green composting material may be distillery waste (such as grape marc). In embodiments of the invention the first composting material may comprise spoiled silage. Spoiled silage is silage which has become unfit for bovine nutrition, usually due to oxidative processes. In some embodiments the green composting material may be digestate (the material remaining after the anaerobic digestion of a biodegradable feedstock).

[0091] In Aspect 2 (iii), a green composting material may have a carbon to nitrogen molar ratio of at least 15:1. In some embodiments, the green composting material may have a carbon to nitrogen molar ratio of at least 18:1.

[0092] In Aspect 2 (iii), the green composting material may have a carbon to nitrogen molar ratio of up to 29:1. In some embodiments, the green composting material may have a carbon to nitrogen molar ratio of up to 23:1.

[0093] In Aspect 2 (iii), high nitrogen composting material may have a lower carbon to nitrogen molar ratio compared to the green composting material.

[0094] In Aspect 2 (iii), a high nitrogen composting material may have a carbon to nitrogen molar ratio of at least 3:1. In some embodiments, the high nitrogen composting material may have a carbon to nitrogen molar ratio of at least 6:1. In some embodiments, the high nitrogen composting material may have a carbon to nitrogen molar ratio of up to 15:1. In some embodiments, the high nitrogen composting material may have a carbon to nitrogen molar ratio of up to 12:1.

[0095] In Aspect 2 (iii), a high nitrogen composting material may be brewery waste (such as spent grain). In some embodiments, the high nitrogen composting material may be distillery waste (such as grape marc). In some embodiments, the high nitrogen composting material may be a residue from fish and / or shellfish (such as mussels, shrimps); or slaughter waste (such as blood, carcasses, and / or hair / fur). In some embodiments, the high nitrogen composting material may be a dairy byproduct (such as cheese whey). In some embodiments, the high nitrogen composting material may be manure (separated from bedding). In some embodiments, the high nitrogen composting material may be wool (such as from sheep shearing). In some embodiments, the high nitrogen composting material may be green sprout (such as grass in early springtime). In some embodiments, the high nitrogen composting material may be cover crop fresh cuts (such as alfalfa, hairy vetch, amaranth and / or purslane). In some embodiments, the high nitrogen composting material may be activated sludge.

[0096] In Aspect 2 (iii), when the first composting material is composed of a mixture of materials, the C and N molar ratio of the mixture is the calculated mean value.

[0097] In Aspect 2 (iii), the second composting material is a material which is often called a brown composting material, in this art. Suitably, the second composting material is a high-carbon material, with a higher carbon to nitrogen molar ratio than the first composting material.

[0098] In Aspect 2 (iii), the second composting material may comprise wood industry residue (e.g. sawdust). In some embodiments, the second composting material may comprise arable land byproduct such as straw (e.g. wheat, oat, rye straw), corn cobs, and / or stalks. In some embodiments, the second composting material may comprise forestry / arboriculture by-product such as wood chips, bark (e.g. from soft-and / or hard-wood trees), and / or fern cuttings. Bark components may include uncomposted bark fines and composted bark fines. In some embodiments, the second composting material may comprise garden waste such as leaves, twigs, and pine needles. In some embodiments, the second composting material may comprise animal bedding. In some embodiments, the second composting material may comprise paper waste such as cardboard, shredded paper / newspaper and / or paper pulp. In some embodiments, the second composting material may comprise nut shells. In some embodiments, the second composting material maycomprise cotton. In some embodiments, the second composting material may comprise mushroom substrate. In embodiments of the invention the second composting material may comprise fresh wood chips and / or partially composted wood chips.

[0099] In Aspect 2 (iii), the second composting material may have a carbon to nitrogen molar ratio of at least 30:1 In some embodiments, the second composting material may have a carbon to nitrogen molar ratio of at least 80:1. In some embodiments, the second composting material may have a carbon to nitrogen molar ratio of at least 130:1. In some embodiments, the second composting material may have a carbon to nitrogen molar ratio of at least 180:1.

[0100] In Aspect 2 (iii), the second composting material may have a carbon to nitrogen molar ratio of up to 400:1. In some embodiments, the second composting material may have a carbon to nitrogen molar ratio of up to 350:1. In some embodiments, the second composting material may have a carbon to nitrogen molar ratio of up to 300:1. In some embodiments, the second composting material may have a carbon to nitrogen molar ratio of up to 250:1.

[0101] In Aspect 2 (iii), when the second composting material is composed of a mixture of materials, the C and N ratio of the mixture is the calculated mean value.

[0102] In Aspect 2 (iii), the compostable mixture may contain both a first composting material and a second composting material. In such embodiments of the invention there may suitably be 1 part of the first composting material to 0.5 to 15 parts of the second composting material, suitably 1 part of the first composting material to 1 to 8 parts of the second composting material, suitably 1 part of the first composting material to 1 to 6 parts of the second composting material, weight / weight.

[0103] In some embodiments the compostable mixture may include biochar in particulate form. Biochar is the residue from the carbonisation of any biological material at a high temperature (for example in the range 300-1000°C), in the absence of oxygen or under oxygen -starved conditions. Biochar may comprise up to 30% wt / wt of the compostable mixture, preferably up to 20% wt / wt, more preferably up to 10% wt / wt. Biochar may aid water retention and promote carbon capture.

[0104] In Aspect 2 (iii), a microorganism support can be of a class which can be digested by a desired microorganism (which I will call microorganism support type (dl)) or of a class which can provide physical support for microorganisms in the compostable mixture (which I will call microorganism support type (d2)). Each such type of microorganism support promotes replication of the microbiome. In embodiments of the invention both types of microorganism support (that is, the digestible type (dl) and the physical support type (d2)), are present and they may work beneficially together in promoting the microbiome.

[0105] A microorganism support of type (d 1) which may be digested by a desired microorganism, may include, for example, one or more of the following organic materials: fish protein, including shellfish protein; dried sea algae, including brown seaweed, or kelp; and pressed cakes of plant matter, which may be left after oil or juice extraction; for example the residues from the pressing of hemp, olives, peanuts, coconut, soybeans, flax seed (linseed), cottonseed and sunflower seeds. A microorganism support (dl) may be an omega oil source; and / or a protein source.

[0106] A microorganism support (dl) may suitably be present in embodiments of the invention in a ratio from 2 kg per 1000 litres of total compostable material. In some embodiments a microorganism support (dl) may be present in a ratio from 3 kg per 1000 litres of total compostable material. In some embodiments a microorganism support (dl) may be present in a ratio from 4 kg per 1000 litres of total compostable material.

[0107] A microorganism support (dl) may suitably be present in embodiments of the invention in a ratio of up to 12 kg per 1000 litres of total compostable material. In some embodiments a microorganism support (dl) may be present in a ratio of up to 10 kg per 1000 litres of total compostable material. In some embodiments a microorganism support (dl) may be present in a ratio of up to 8 kg per 1000 litres of total compostable material.

[0108] A microorganism support of type (d2) which may provide physical support in the compostable mixture may be a particulate inorganic material, and may include naturally occurring rock materials in finely divided form; for example in pulverized form. Examples of rocks that can produce suitable particulates include one or more of sedimentary, igneous and metamorphic rocks. Examples of suitable sedimentary rock sources include magnesium carbonate, calcium carbonate (which may be as chalk or limestone), sandstone, clay, shale and gypsum. Examples of suitable igneous rock sources include silica, quartz, silicates, basalt and pumice. Examples of suitable metamorphic rock sources include marble and slate. As noted above such materials may be used as binders to assist the pelletisation process. Thus they may have more than one function.

[0109] A microorganism support (d 2) may suitably be present in embodiments of the invention in a ratio from 2 kg per 1000 litres of total compostable material. In some embodiments a microorganism support (d2) may be present in a ratio from 4 kg per 1000 litres of total compostable material. In some embodiments a microorganism support (d2) may be present in a ratio from 5 kg per 1000 litres of total compostable material.

[0110] A microorganism support (d 2) may suitably be present in embodiments of the invention in a ratio of up to 15 kg per 1000 litres of total compostable material. In some embodiments a microorganism support (d2) may be present in a ratio of up to 12 kg per 1000 litres of totalcompostable material. In some embodiments a microorganism support (d2) may be present in a ratio of up to 10 kg per 1000 litres of total compostable material.

[0111] In embodiments of Aspect 2 (iii), both types of microorganism support (dl) and (d2) are suitably present, each in the amounts separately defined above. The ratio (weight / weight) is suitably in the range 1 part (dl) to 0.2 - 5 parts (d2); suitably 1 part (dl) to 0.5 - 2 parts (d2); suitably 1 part (dl) to 1 - 3 parts (d2); and preferably 1 part (dl) to 1.1 - 2 parts (d2).

[0112] In Aspect 2 (iii), there may be more than one microorganism support of type (dl) and in such embodiments the amounts and ratios given above denote the total amount of such components.

[0113] In Aspect 2 (iii), there may be more than one microorganism support of type (d2) and in such embodiments the amounts and ratios given above denote the total amount of such components.

[0114] In Aspect 2 (iii), the components - namely the first composting material; the second composting material when present; and 'micro-ingredients' - namely one, two or three of the further components, namely the source of microorganisms, microorganism support of type (dl) and microorganism support of type (d2) - are introduced into the container in layers. However, mixing them before they are introduced into the container is not excluded.

[0115] In Aspect 2 (iii), the compostable mixture may be loaded into a container which has openings in its side walls to promote aeration of the compostable mixture. In some embodiments of the invention the container may be a bulk bag of flexible material, having side walls with perforations. In some embodiments the container may be a rigid framework intended to receive an industrial storage container, for example of the type known as an IBC. The rigid framework may be wrapped in an air- and water-permeable jacket, for example of netting or mesh.

[0116] In Aspect 2 (iii), suitably a container into which the compostable mixture is loaded has a volume in the range from 400 litres to 3000 litres. In embodiments of the invention the container volume is in the range from 600 litres to 1800 litres. In embodiments of the invention the container volume is in the range from 700 litres to 1300 litres.

[0117] In Aspect 2 (iii), the compostable mixture may be loaded into a container which has openings in its bottom wall, or has no bottom wall at all, the container being located out of doors during the maturation period, and subject to the ambient weather conditions, and preferably in an arboreal environment. In such a situation the compostable mixture may be in direct contact with the arboreal soil to facilitate colonisation by fungal species in the arboreal soil.

[0118] In Aspect 2 (iii), the compostable mixture may be formed into a freestanding mass or pile. The pile may be elongate, in the form of windrow. In some embodiments of the invention the pile may be left open to the elements. In other embodiments the pile may be covered with a flexible perforated material.

[0119] Standard horticultural advice is to turn compost to increase aeration. In the method of the present invention the compostable mixture can be turned during the maturation period. However, in Aspect 2 (iii), the compostable mixture is preferably not turned, so that the developing microbiome is not disturbed. Nevertheless the composting process is preferably aerobic.

[0120] Different methods are available for carrying out the method of Aspect 2 (iii). They include hot composting, vermicomposting and the Johnson-Su composting in which a high level of aeration is achieved, without turning the material. The Johnson-Su method uses a container which is permeable to air and water transmission. Large channels are formed in the mixture to be composted, for example by drilling into the material or by having tubes in place as the container is filled, and then withdrawing them when the container is full, straight away after the channels have been formed or after an interval, for example of a few weeks. The Johnson-Su method is aerobic but without intermediate stages of turning the composition. In some embodiments of the invention a combination of techniques can be employed, for example Johnson-Su and vermicomposting. Composting worms can be added to the Johnson-Su composting mixture.

[0121] In Aspect 2 (iii), the compostable mixture is suitably retained for a maturation period. The maturation period starts as soon as the components are mixed to form the compostable mixture. In some embodiments the maturation period may be at least 6 months. In some embodiments of the invention the maturation period may be at least 8 months. In some embodiments the maturation period may be at least 10 months. In some embodiments the maturation period may be up to 24 months. In some embodiments the maturation period may be up to 18 months. In some embodiments the maturation period may be up to 14 months.

[0122] At the end of the maturation period it has been found in embodiments that the compostable mixture has matured into a compost which may have a very rich fungal microbiome, comprising high levels of fungi. A rich microbiome is of benefit because it means that a very wide range of fungi is present. The richer the microbiome, the more likely it is that fungi of particular benefit to plants will be present; and that valuable, mutually beneficial relationships between fungi and plants may develop. Certain fungi may, for example, be particularly effective in assisting plants to access food sources in the soil, or in retaining moisture. Providing rich fungal biome with a diverse range of microorganisms may be especially important in such respects.

[0123] Aspect 2 (iii) may include a step of assessing a compost, for example using a biological assay, or a chemical assay, or both, which may lead to determination of optimal agricultural uses for the eventual pellets , or in some cases to determine if the compost needs modification.

[0124] In some embodiments of Aspect 2(iii) of the invention the concentration of fungi in the pellets is at least 10 pg / ml, for example at least 20 pg / ml, for example at least 40 pg / ml. In some embodiments of Aspect 2(iii) the concentration of fungi in the pellets is at least 60 pg / ml, for example at least 80 pg / ml, for example at least 100 pg / ml. In some embodiments of Aspect 2(iii) the concentration of fungi in the pellets is at least 120 pg / ml, for example at least 150 pg / ml, for example at least 175 pg / ml. In some embodiments of Aspect 2(iii) the concentration of fungi in the pellets is at least 400 pg / ml, for example at least 800 pg / ml, for example at least lOOOpg / ml. In some embodiments of Aspect 2(iii) the concentration of fungi in the pellets may be at least 1400 pg / ml.

[0125] In embodiments of Aspect 2(iii) the fungal biome is distributed throughout the pellets.

[0126] In accordance with Aspect 2 (iii), a modified growing medium may be made by blending a compost as described above with reference to Aspect 2 (iii), with another substrate, e.g. biomass, soil or other compost, to obtain tailored properties. The definitions and descriptions given earlier in this specification for other substates and their amounts apply to embodiment Aspect 2 (iii) of the invention.

[0127] Microorganisms (microbes), including fungi, in the soil help build the structure of the growing medium by creating micro- and macro-aggregates, which benefit the water retention of the growing medium. Furthermore, the by-products of the microbial activities, e.g. humic acid, also increase the moisture holding capacity. Water usage may thus be reduced by use of growing media of the present invention.

[0128] In accordance with a sixth aspect of the present invention there is provided a container containing a plurality of pellets of the first aspect or as produced by a method of the second aspect. Suitably, the container may contain at least 500 g of pellets, preferably at least 2 kg of pellets, for example at leasts kg of pellets. Suitably, the container may contain up to 80 kg of pellets, preferably up to 50 kg of pellets, for example up to 20 kg of pellets. The container may for example be a pot, drum, bag or sack.

[0129] It will be appreciated that the present invention employs natural biological processes. Variations in fungal content in pellets cannot be avoided, even when they apparently have undergone the same regime. In reality, there will be unavoidable variations, for example inupstream compostable materials, sun, temperature, wind, rain, shade, worm population and proximity of ambient fungal sources.

[0130] In this specification when we describe relative amounts of components, ratios are expressed as vol / vol unless otherwise stated.

[0131] The invention will be described, by way of illustration only, with reference to the following examples.EXAMPLES 1 to 3

[0132] Three precursor growing media were prepared, using different compostable materials in differing amounts as described in Table 1. The compostable materials stated for each example were used to fill metal frames for IBC tanks, lm3in volume (lm x lm x lm). The I BC frames had widely separated metal support bars. Before filling the frames had been lined with flexible plastic mesh sheets permitting air flow and water flow.TABLE 1

[0133] The fresh wood chip was beech waste which was approximately 6 weeks old. This was sourced from a tree surgeon using a standard chipper. Chip particles were approximately 2cm long. Fresh wood chip is a 'brown' compostable material which typically has a high carbon / nitrogen weight ratio in the range from 30:1 to 400:1.

[0134] Mature composted chip was a pre-composted wood chip with a maturation time of about 18 months. It was tree surgeon waste woodchip from a mixture of trees which was composted in a 3m x 3m x lm (9m3) open-top pile. Mature composted chip is a 'brown' material and typically has a high carbon / nitrogen weight ratio in the range from 30:1 to 400:1.

[0135] Spoiled silage was sourced from a local farm contractor. Spoiled silage is a 'green' compostable material which typically has a moderate carbon / nitrogen weight ratio in the range from 15:1 to 25:1.

[0136] Fresh coppiced willow chip was sourced from recently cut (coppiced) trees. The advantages of using fresh coppiced willow chip include that it provides young wood which will decompose quickly to reduce particle size within the finished product. Fresh coppiced willow chip is a 'brown' compostable material which typically has a high carbon / nitrogen weight ratio in the range from 30:1 to 400:1.

[0137] Leaves were gathered on-site from the woodland floor on Hardwick Estate woodland, Oxfordshire, UK (diverse mixed woodland). Leaves are a 'green' compostable material which typically has a moderate carbon / nitrogen weight ratio in the range from 15:1 to 25:1.

[0138] A mixture of the first and second compostable materials for each composition was used to fill the frame in layers. Between layers, the microorganism support (micro-ingredient composition) with the components listed in Table 2 was applied such that 12 kg of the microorganism support was used for frame.TABLE 2

[0139] Each filled IBC frame was matured for a year as a Johnson-Su bioreactor (JSB). The frame contains a plurality of layers of compostable material and of microorganism support. The compostable material comprises a mixture of the first and second compostable materials. The microorganism support comprises the inorganic and organic components set out in Table 2. A plurality of columnar voids are formed in the compostable material in each IBC frame, to improve aeration. The columnar voids are formed by drilling into the compostable material in the full IBC frame or by placing a plurality of suitable columns in the IBC frame prior to the addition of the compostable material and microorganism support then removing the columns after the IBC frame has been filled, to leave the voids.

[0140] Thus, a grid of air-holes was formed in the contents of the filled IBC frames.

[0141] A 10ml sample was removed from each IBC frame at the end of a maturation period of 12 months and was mixed with filtered water. Fungi counts used dilution of from 5 to 1, to 10 to 1, total volume. One drop of the dilution was transferred onto a slide and observed under a bright field microscope. From the fungal count, the fungal concentration was derived. The method was that of Tyrkiel described above. General morphology is used as a differentiator of the elements of soil food web present.

[0142] The results obtained are detailed in Table 3 below.TABLE 3

[0143] There is natural variation in the amount of fungi due to uncontrollable ambient biological factors but all the compositions are potentially useful. It should be noted that all these examples of starter compositions have high levels of fungi, from 903 to 1650 pg / ml. The presence of fungi is desirable under most growing conditions. Such high levels of fungi in Examples 1, 2 and 3 suggest that such compositions have the potential to be components of growing media which will support plant growth, including tree growth.

[0144] Examples 1 to 3 can be seen as 'live' growing media which may be formed directly into pellets by dry pelletisation, or which may be mixed with other materials. Examples of the latter, mixed growing media are described in Examples 4 to 6 below.

[0145] The growing media of each of Examples 1 to 3 were mixed before dry pelletisation with potato starch in a proportion of 98 % (weight / weight) growing medium to 2 % (weight / weight) potato starch. In each case dry pelletisation produced generally cylindrical pellets of typical size 12 mm length by 4 mm diameter. These pellets were of high quality, reasonably firm and low in dust production but still having the property of degrading quickly in soil.EXAMPLES 4 to 6

[0146] Three growing media useful in the invention were obtained by mixing approximately 20% by volume of each of the loose growing media of Examples 1 to 3 with approximately 80% by volume of an additional loose composition, namely composted bark fines (CBF), and minor amounts of a balancing mineral composition (BMC). The balancing mineral composition, its components, and the amounts thereof, will depend on the requirements of the plants which will ultimately be grown in the growing media and so will vary. The amounts to be added will be decidedwith the aid of an assay to determine the ambient levels of such compounds within the respective growing medium, before any BMC addition. Typically, the balancing mineral composition, comprising compounds required to support healthy plant function, may be selected from salts of B, Na, K, Fe, Ca, Mg, Mn, Cu, Zn, Mo, Ni, Al, Se, P, Cl, S, as well as nitrate ions, ammonium ions and sugars.TABLE 4

[0147] Examples 4 and 5 were stored for 6 to 8 weeks in an airy environment prior to testing for fungal content, in comparison with composted bark fines (CBF) to which the same Balancing Mineral Compositions (BMCs) had been added. The presence of the BMC in the CBF allowed for a true comparison with Examples 4 and 5, which also contained the BMC. The results are given in Table 5 below.TABLE 5

[0148] Table 5 shows that Examples 4 and 5 both have much higher concentrations of fungi, compared with the comparison composition which had CBF and BMC, but no starter composition.

[0149] The fungi concentrations determined for Examples 4 and 5 are substantially at or exceed the expected values which are derived by calculating weighted averages of the fungal concentrations of the respective admixtures, comprising 20% vol / vol of Examples 1 and 2, and 80% vol / vol CBF + BMC. These calculated notional values are 334 pig / ml for Example 4, and 483 pg / ml for Example 5.

[0150] Growing media substantially in accordance with Examples 4 to 6, in which the growing media of each of Examples 1 to 3 (20 % weight / weight), CBF (78.5 % weight / weight), wheat flour (1 % weight / weight) and agricultural lime (0.5 % weight / weight) were mixed to form new growing media. The CBF had been dried before the mixing to a water content of 12 weight%. In each casedry pelletisation produced generally cylindrical pellets of typical size 12 mm length by 4 mm diameter and with low moisture content; in no case more than 20 % wt / wt. These pellets were of high quality, firm, and low in dust production but still having the property of degrading quickly in soil.EXAMPLE 7

[0151] The fungal microbiomes of the growing media of Examples 4, 5 and 6 were examined by DNA techniques, and compared with that of composted bark fines (CBF), as-supplied except for addition of a Balancing Mineral Composition (BMC). The latter was added to create the closest possible comparison with Examples 4, 5 and 6. Included in the tests was a commercial peat-free compost containing coir, wood derivatives and perlite, sold under the Registered Trade Mark JIFFY. This is called 'peat-free' below.

[0152] For each growing medium 4 replicates were tested. For the growing media to which a BMC was added 6 weeks were allowed between the BMC additions and fungal biome testing.

[0153] DNA metabarcoding was used to measure the underlying fungal diversity found in each sample. The a-diversity (within-sample diversity) using richness (that is, number or organisms detected) and Shannon index metrics (a well-known method of determining diversity within a sample) was determined for each sample.

[0154] The Shannon index is a common way to measure the alpha diversity of microbial samples. To use the Shannon index, the DNA is sequenced and all the microbes in the sample are separated into 'bins' or categories. This identifies the different species that are present.Fungal results

[0155] Fungal community a-diversity results are stated in summary in Table 8 below for each index (Richness, Shannon) and growing medium.TABLE 6

[0156] The samples of the invention contained fungi from the phyla Ascomycota, Basidomycota and Mucoromycota, including A.Pezizomycetes, A.Sordariomycetes, A.Leotiomycetes, M.Mortierellomycetes, A.Dothideomycetes, A.Eurotiomycetes, A.Orbiliomycetes, B.Agaricomycetes and B.Tremellomycetes, in varying proportions. Several of these classes of fungi were not found or were found only in low proportion in the CBF + CMB or peat-free examples. One further observation is that Ascomycota Sordariomycetes was much more prominent in the examples of the invention, than in the other samples.EXAMPLE 8

[0157] The pellets described in Example 5 were used in a trial in a plantation of the fast-growing Empress or Foxglove Tree, Paulownia tomentosa. The object was to determine whether the pellets could in a relatively short period give a worthwhile increase in fungal concentration in the soil adjacent to the grows trees, sufficient to provide benefit to the growing trees. 135 pg / ml is often regarded as a sufficient concentration of fungi to assist trees to access nutrients in the soil without the need for nutritional addition.

[0158] The trial was carried out in Suffolk, UK under confidential conditions. Fungal concentrations in the soil around trees in different loci in a plantation were determined. Pellets were applied around the same trees and were forked into the ground. This was done in a February. 2 litres of pellets were applied around each tree tested.

[0159] The fungal concentrations in the soil around trees in the same loci in a plantation were determined in the following October.

[0160] Different loci were examined because it is inevitable and unavoidable that there will variation due to normal environmental and random factors.

[0161] Findings are set out in Table 7 below.TABLE 7

[0162] 0 (zero) indicates a barren soil in terms of fungal microbiome.

[0163] In each of these assessments a fungal biome was shown to have developed, starting in each case from zero in February. This was achieved in a short period, only 8 months. We regard the finding that the fungal concentration above 135 pg / ml as particularly interesting as it can be expected that there is sufficient concentration of fungi to assist trees to access nutrients in the soil without the need for nutritional addition.

[0164] Control experiments took place in which addition of fungal pellets was not carried out in February. The fungal concentrations were measured at the same time, in February and October.Findings are set out in Table 8 below.TABLE 8Control results:

[0165] It can be seen that only in locus NF was there was any increase in fungal concentration, but the increase was small. In Locus SB the fungal concentration started and remained at zero. In locusAW and locus BH the starting concentrations of fungi were high but they diminished, over the test period.

[0166] It appears from these results that increases in fungal concentration follow the use of fungal pellets, and that the results are not likely to be the result of random or wider environmental factors.

Claims

CLAIMS1. A pellet for improving a growing environment, wherein the pellet comprises a growing medium, wherein the pellet comprises a fungal biome.

2. A pellet as claimed in claim 1, in which the concentration of fungi in the growing medium is at least 5 tg / ml, suitably at least 20 pg / ml, suitably at least 120 pg / ml.

3. A pellet as claimed in claim 1 or 2, in which the concentration of fungi in the growing medium is at least 175 pg / ml, suitably at least 400 pig / ml.

4. A pellet as claimed in claim 2, in which the concentration of fungi in the growing medium is at least 800 pg / ml, suitably at least 1000 pig / ml.

5. A pellet as claimed in any preceding claim, which weighs at least 0.1 g, or at least 0.2 g, or at least 0.5 g, suitably at least 1 g, or at least 2 g, or at least 4 g, or at least 8 g.

6. A pellet as claimed in any preceding claim, which weighs up to 150 g, suitably up to 120 g, or up to 100 g, or up to 80 g, suitably up to 60 g, or up to 40 g, or up to 20 g.

7. A pellet as claimed in any preceding claim, in which the fungal biome has one, any two, or all three of the following characteristics (A), (B) and (C):(A) it contains all of the following fungal classes: Ascomycota Pezizomycetes, Ascomycota Sordariomycetes, Ascomycota Leotiomycetes, Ascomycota Dothideomycetes, Ascomycota Eurotiomycetes, Ascomycota Orbiliomycetes, Basidomycota Agaricomycetes, Basidomycota Tremellomycetes, Mucoromycota Mortierellomycetes;(B) it has a Richness value of at least 120;(C) it has a Shannon value (a-diversity) of at least 4.8.

8. A pellet as claimed in any preceding claim, wherein the pellet has a water content not exceeding 20% (by weight on total weight of the pellet), suitably not exceeding 15 % and preferably not exceeding 12%.

9. A method of producing pellets which comprise a growing medium, wherein the growing medium comprises a fungal biome; wherein the method comprises one or more of the following steps:(i) adding fungi to a growing medium precursor to form the growing medium, then forming pellets of the growing medium; or forming pellets of the growing medium precursor, then applying fungi to said pellets;(i) harvesting an ambient growing medium which already contains said fungal biome, then forming pellets of the growing medium;(ii) producing a high-fungal compost to be the growing medium, or to be part of the growing medium, then forming pellets of the growing medium.

10. A method as claimed in claim 9, wherein the growing medium of Claim 8 is mixed with another substrate, thereby producing a further growing medium, which is the material which is pelletised.

11. A method as claimed in claim 10, wherein the other substrate is biomass selected from one or some or all of the following sources: plant-derived biomass selected from: residues of trees, including wood, bark, husks, fibre, coir and leaves; cereal waste products, for example straw and husks; other crop residues, for example from sugar cane, molasses, oilseed rape and sugar beet; seaweed plants of the family Gramineae, including mown grass, and hay; animal-derived digestive biomass, including manure from horses, pigs, cattle, goats or chickens; animal derived tissue biomass derived from animal bodies or parts, including blood and bones, including from horses, pigs, cattle, goats and chickens; and from fish; derivatised biomass, for example peat, biochar or digestate.

12. A method as claimed in claim 10 or 11, wherein the other substrate or biomass has a water content not exceeding 20 % (by weight on total weight of said other substrate or biomass), suitably not exceeding 15 % and preferably not exceeding 12%.

13. Pellets formed by a method as claimed in any of claims 9 to 12, wherein the growing medium which is the product of the method of claim 8 is mixed with the other substrate to form the growing medium which is to be pelletised, and kept for a dwell time of at least 2 weeks before being pelletised and / or after pelletisation.

14. A method as claimed in any of claims 9 to 13, wherein the other substrate comprises a tree bark component, for example tree bark fines.

15. A method as claimed in claim 14 which comprises:(iii ) producing a high-fungal compost; and mixing the high-fungal compost with tree bark fines to form a growing medium, then forming pellets of the growing medium.

16. Pellets formed by a method as claimed in any of claims 9 to 15.

17. A method of improving a growing environment by the introduction into the environment of pellets as claimed in any of claims 1 to 8, or claim 16, or of pellets provided by the method as claimed in any of claims 9 to 15.

18. Use of pellets as claimed in any of claims 1 to 8, or claim 16, or of pellets provided by the method as claimed in any of claims 9 to 15, in the improvement of the growing environment.

19. A growing environment modified by the use of pellets as claimed in any of claims 1 to 8, or claim 16, or of pellets provided by the method as claimed in any of claims 9 to 15.

20. A container containing a plurality of pellets as claimed in any of claims 1 to 8, or Claim 16, or a plurality of pellets provided by method as claimed in any of claims 9 to 15.

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