WO 95108521 PCT/NZ94/00099 FERTILISERS COMPRISING NUTRIENT PHOSPHATE SOLUBILISING
FUNGUS
TECHNICAL FIELD The present invention is directed towards fertilisers. More specifically, many embodiments are directed to provide fertilisers for the introduction and rapid establishment of useful fungi and micro organisms in the soil. The use of a liquid carrier comprising a plant nutrient, and which includes fungus, micro organisms and/or reproductive material therefor, is investigated. Fertilising compositions based on the aforesaid liquid fertilising composition and a rock phosphate are also described.
BACKGROUND ART The role of fungus and micro-organisms in the soil has been well investigated. For instance, many micro organisms are known to assist in the uptake of nitrogen and other nutrients by the roots of some plants.
Other fungus and bacteria may have other roles in the soil, such assisting in the breakdown of plant matter, or making nutrients available to plants. Others having found to be beneficial for assisting in the germination of seeds, or in the rapid growth of germinated seedlings. In some cases, seeds have been coated with fungus or microorganism containing coatings.
However, the art has not produced a method by which desirable fungi and micro organisms can be introduced into the soil, especially by a farmer using normal farm spray equipment. Fungus and micro organisms have long been available to the domestic gardener, in a dried form, for inclusion in compost pits to accelerate the composting process. However, the distribution of a dried powder or light material is not generally accomplished by spray techniques and neither is this form desirable for a large area such as a paddock as the wind could quickly remove any deposited material. Furthermore, unless the dried material was ploughed or mixed into the soil, establishment could be slow unless wetted immediately afterwards.
Another consideration is that establishment of the fungus or micro-organism in soil could be relatively slow, especially if the soil is relatively poor in nutrients. Consequently, the use of dried material may result in some delay before the material is able to take advantage of any available nutrients in the soil and establish itself.
A further matter for consideration is the introduction of the phosphorus to the soil.
Superphosphates have been widely used as a reasonably soluble phosphate material.
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WO 95/08521 PCT/NZ94/00099 However, superphosphate can significantly increase the acidity of soil and often requires the co-application of lime to balance the soil pH. The use of rock phosphate is becoming more popular, especially where organically grown plant material is sought. Rock phosphate is acceptable for the cultivation of organically grown produce whereas superphosphate is not. However the problem with rock phosphate is its slow solubility.
It may sometimes take the order or years before any appreciable amount of the rock phosphate enters the soil. It would therefore be desirable if some alternative means of accelerating the release of phosphorus from natural rock phosphate, into the soil, could be provided.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.
DISCLOSURE OF INVENTION According to one aspect of the present invention there is provided a liquid fertilising composition, substantially free of solid matter, comprising a plant nutrient in a liquid form, and at least one introduced fungus, micro-organism, and/or reproductive material therefor.
According to a further aspect of the present invention there is provided a liquid fertilising composition, substantially free of solid matter, comprising: a plant nutrient, a diluent or carrier, at least one introduced fungus, micro-organism and/or reproductive material therefor, and a binding agent, said composition being characterised that when applied to a surface, there is formed a coating having at least one of the properties of being porous, slowly soluble, and degradable through weathering or the action of the introduced fungus, micro-organism and/or reproductive material therefor, said coating retaining at least a portion of said introduced fungus, micro-organism and/or reproductive material therefor.
According to another aspect of the present invention there is provided a liquid fertilising composition, substantially as described above, wherein said introduced fungus, microorganism, and/or reproductive material therefor, are phosphate solubilising.
According to another aspect of the present invention there is provided a liquid fertilising composition, substantially as described above wherein said introduced fungus, micro- WO 95/08521 PCT/NZ94/00099 organisms and/or reproductive material therefor, are able to act on a contained nitrogenous nutrient to liberate free ammonia.
According to another aspect of the present invention there is provided a liquid fertilising composition, substantially as described above in which said plant nutrient is a fish based nutrient composition.
According to another aspect of the present invention there is provided a liquid fertilising composition, substantially as described above which includes a viscosity increasing agent.
According to a further aspect of the present invention there is provided a liquid fertilising composition in combination with a phosphate rock.
According to yet a further aspect of the present invention there is provided a fertilising composition comprising a phosphate rock impregnated with a composition substantially as described above.
According to yet a further aspect of the present invention there is provided a fertilising composition comprising a phosphate rock coated with a composition substantially as described above.
The term "liquid plant nutrient" wherever used herein shall refer to a substance suitable as a plant nutrient, a substance commonly used or recognised as a plant fertilising or nutrient substance, and/or a prepared composition the equivalent of the foregoing. While a wide range of materials could fit the role as a plant nutrient, most liquid plant nutrients within the above definition shall be a source of at least one of the NPKS elements. Quite often, it will also be a source of two or more of these elements and may also be a source of plant available trace elements.
Most embodiments of the present invention will be in liquid form and substantially solid free, other than introduced fungus, micro organisms and/or reproductive material therefor, and variations which include phosphate rock. Consequently, most of the nutrients will be in a liquid form, or in a very fine form. They may be present as a colloid or suspension, though typically a composition should be able to be applied with normal fluid spray application equipment. It is envisaged that occasionally solid material, which may accidentally escape any manufacturing process, may sometimes be present.
However, as a general rule the compositions according to the present invention are fluid and substantially free of any, other than finely divided, solid material.
A wide range of plant available nutrients may be used. Many inorganic fertilisers are known which are readily soluble in water and may be incorporated into compositions.
WO 95/08521 PCTNZ94/00099 Similarly, organic-derived nutrients may be employed, such as compositions prepared plant material, from fish and marine material, or waste from meat processing plants.
These 'organic' based nutrients/fertilisers may in some cases be advantageous as they may contain other nutrients and substances which are better able to support introduced fungus, micro organisms and their reproductive material.
In some instances it is desirable to include a nitrogenous nutrient source. This is especially so in the case where there is introduced fungi, micro-organisms or reproductive material therefor, whose primary purpose is the liberation of ammonia from nitrogenous materials. This may be desirable to assist, in some cases, with the break down and solubilisation of phosphate materials. In some other instances, it may be desirable to rely on the liberation of ammonia for introducing nitrogen into the soil, or to adversely affect undesirable organisms in the soil.
In some cases the liquid portion of a composition may be thickened to increase its viscosity. The degree of thickening is largely a matter of user choice though it is envisaged that up to gel like consistencies may be employed in some instances. The planting of seeds in a gel carrier is known and a gel like composition according to the present invention may be used in such an application. So that the newly germinating seed is not over fertilised, it may be desirable to reduce the plant nutrient proportion to a relatively low level or to incorporate such a composition into another gel-like preparation.
In some cases it is desirable that a composition according to the present invention is able to coat materials to which it is applied. In many instances a gel-like coating will be acceptable.
A coating may be useful for a number of functions. For instance, the coating may contain introduced fungii, micro-organisms and/or reproductive material therefor. The coating may provide a suitable growing support for the initial establishment of these organisms. In other instances the coating may serve to protect (until use) or to retard the rate of establishment or release of the contained nutrients and organisms. In such instances it is considered most likely that the compositions will be applied to coat a fertilising material such as natural rock phosphate. For such a porous mineral material, a significant proportion of the composition will be absorbed though a semi-protective coating may remain, depending on the nature of the compositions.
Coatings may be formed in a variety of ways. Perhaps the simplest method of providing a coating is for there to be removal of a carrier or diluent present in the composition.
This may be by evaporation (which may be accelerated by heating) or by absorption into the substance to which the composition is applied. Other coatings may set or cure when applied, or over a period of time. Various other techniques and varying combinations of techniques may also be employed.
WO 95/08521 PCT/NZ94/00099 The properties of the coating, where provided, may vary. Preferably the coating should have at least one of the properties of: being porous, being at least slowly soluble, being degradable by weathering, being degradable by contained organisms, and/or being degradable during the growth and establishment of organisms in a composition. A wide variety of materials may therefore be relied upon to form a coating. Preferred substances include the use of a seaweed based materials agars, carrageenan etc.), polysaccharide gums, other gums and resins (typically plant based), silica gels etc. In many cases these materials which are readily able to form gels which typically possess at least one of the preferred coating properties.
The coating may itself contain at least a portion of the introduced organisms and/or nutrients of the composition. This may assist in the rapid establishment of fungal and/or micro-organism colonies in the coating while the more gradual or delayed release of other organisms within the substrate material may ensue over time.
The choice of fungii and micro-organism which may be incorporated into various compositions according to the present invention, are varied. Some of these organisms will be targeted because of their ability to breakdown substances in the soil and release plant available nutrients. An example is the inclusion of organisms which are able to release phosphorous from insoluble phosphate rock. Other organisms are noted as biological control agents and in another example, compositions according to the present invention may also act as a suitable vehicle for the introduction of these bacterial biocontrol agents. For instance, Sayre and Walter (Annu .Rev. Phytopathal. 29 (1991) p149-166) discuss nematode suppressive soils infected with fungal and bacterial antagonists. Such antagonists may be incorporated in embodiments of the present invention.
Vesicular-arbuscular mycorrhizas (VAM) are known to improve plant growth by stimulating the uptake of nutrients, and suppressing the detrimental effects of root pathogens (Bio-Technology In Agriculture, p 1 4 1 1 74, (1988) Publ. Alan R Liss, Inc.).
Once again, compositions according to the present invention represent a useful vehicle for the introduction of such micro organisms to soils, and their inclusion at the time of sowing (see gel planting method above) represents a useful method of the introduction of beneficial organisms into the soil.
As can be appreciated, a wide variety of organisms may be introduced via the present invention. One potentially realisable advantage of compositions according to the present invention is that they can be specifically targeted for application to effective specific areas. For instance, VAMs may be introduced in seed drills at the time of sowing seed by sowing the seeds in the gel comprising a suitable composition according to the present WO 95/08521 PCT/NZ94/00099 invention. Alternatively, a liquid composition could be sprayed or injected into seed drills immediately after sowing. In both these cases, a desirable fungus, micro-organism and/or their reproductive material may be efficiently and selectively introduced to soil (or plant support medium) using existing farm and agricultural equipment.
Examples of organisms which may be included in embodiments of the present invention include members of the genus Aspergillus, Fusarium and Penicillium. Most members of these fungal groups are useful though in particular the following may be specifically targeted: Fusarium oxysporum, Fusarium solani, Aspergillus Niger, Aspergillus candidus, Aspergillus flavus, Aspergillus ustus, Penicillium janthinellum, Penicillium sp., Sclerotium rolfsii and Cylindrocladium sp.
Some other micro-organisms which may be targeted for establishment include bacillus Megatherium phosphaticum and strains thereof, gram-positive bacteria and members of the genus Pseudomonas. However it is to be noted that the foregoing lists are not meant to be exhaustive but are provided by way of example only.
The above listed organisms will generally be included where is desirable to release for plants, nutrients locked into the soil. Many of the foregoing exhibit phosphate solubilising properties and are useful where less soluble forms of phosphate fertilisers rock phosphate) have been applied to a soil. Some of the micro-organisms are also able to liberate free ammonia from nutrients present in the soil. This may be useful for some plants, though it has been noted that the liberation of free ammonia can sometimes increase the solubility of phosphates in the soil.
Examples of other organisms which may be included in various composition include VAMs (refer article by I R Hall in Bio-Technology in Agriculture, p 14 1 -1 74 (1988) Publ. Alan R Liss, Inc.). Other mycorrhizal fungi may be incorporated. Ericoid and Ectomycorrhizal fungi inoculum can be growth in artificial cultures and may be commercially produced. These may be readily introduced into compositions according to the present invention. Plant growth-promoting rhizobacteria (PGPR) are also known and may be included in various compositions according to the present invention.
It is noted however that some of the fungi and micro-organisms are sensitive to their environment and thus some consideration will need to be given to the liquid carrier and plant nutrient. Some are quite sensitive to pH levels and nutritional balances.
Consequently, it may be desirable to tailor a carrier or plant nutrient so that it falls within the acceptable limits of a particular included fungus or micro organism. This information is, normally, readily available enabling a skilled addressee of the art to readily tailor a liquid composition to support included fungi, micro-organisms and/or reproductive WO 95/08521 PCT/NZ94/00099 material. In instances where an incompatibility problem remains, the combination of the fungal or micro organism material within twelve hours (or a shorter duration) of application may be preferable. Combination immediately prior to, or during application of the composition may also be considered in some cases.
Many of the introduced fungi, micro organisms and reproductive material may be introduced from a suitable culture or inoculum. In some instances, a composition may also be created which is able to act as a growth medium for the included organisms. A composition may be used as a culture medium, from which aliquots are drawn and added to new, non-inoculated batches of a liquid carrier for the preparation of a fertilising composition. However, the shelf life of such products may be relatively short if they are stored under conditions overly amenable to the rapid growth and advancement of the contained species. As the conditions will differ for each possible species, some minor experimentation may be required to determine likely shelf lives of various possible compositions.
Substantially liquid or gel like compositions may be readily applied to soil, pasture, seeds, and plants etc. It may be desirable in some instances to apply the liquid fertilising composition to other substrates before introduction to soil etc. The use of coatings have been previously discussed, and there it was disclosed that various mineral substrates, including rock phosphates, could be useful. Accordingly, some compositions of the present invention may be impregnated into normal materials. These may include natural phosphates, as well as other minerals dolomite, lime etc.) commonly applied to plants and their growing media. Where compositions include a binding or coating material, then the application will typically be more of a coating rather than solely impregnation, though typically there will be a combination of both. The resulting products may then be applied as required to plants and/or their growing media, or according to other uses as may be envisaged.
BEST MODES FOR CARRYING OUT THE INVENTION Further aspects and advantages of the present invention will become apparent from the ensuing examples, which are not intended to be restrictive but to illustrate the potential scope and some of the many aspects of the present invention.
Example One The liquid carrier in this example comprises a fish based fertiliser such as available from Sieber Agricultural Research Limited or Moana Fertilisers Limited, both of Baldhill Road, Waiuku, New Zealand. Another option is the use of a nutrient broth or extract such as the liquid waste of many meat and offal processing plants.
WO 95/08521 PCT/NZ94/00099 It each case, the nutrients should be relatively free of solid material. Depending on the intended method of application of the final product, it may be desirable to screen or filter the liquid carrier to remove any material which may clog fertiliser spray-application nozzles. Generally, filtering through a screen removing the bulk of particles greater than 0.1 mm is size will be satisfactory for most applications, though eliminating particles greater than 0.05 mm in size would be more desirable. Most preferable would be to eliminate particles greater than 0.02mm in size, though the end use of the composition and user requirements may impose different restrictions and parameters. These general particle size guidelines are applicable for other embodiments of compositions according to the present invention.
Each of the above nutrients are relatively rich in proteins and amines. These are typically plentiful in plant available nitrogen and both of these types of nutrients will commonly be suitable for the rapid establishment of fungal or microbial colonies.
It has been found by the applicant that a fish fertiliser composition (such as available from Sieber/Moana) will readily support the growth of many of the desired fungi and micro-organisms. In trials, a nutrient broth comprising the liquid fish based fertiliser has been used to culture a range of various fungi and micro-organisms. Portions have been removed from this master culture (which has been subsequently replenished) and added to non-inoculated portions of fish based fertiliser. If only a trace amount of the master culture is added, then a period of time may be required for the level of the introduced organisms to increase in the new product batch. Alternatively, higher levels may be introduced into the non-inoculated batch if it is to be used in the immediate future.
Consequently, one option is to supply users with both inoculated and non-inoculated batches which can be subsequently used to prepare compositions for application to pasture etc. This may solve problems of a sometimes limited shelf life, and the problems of storing large volumes of a 'living' product.
Example Two The following are a range of compositions found to be suitable by the applicant during preliminary trials. In the general composition the fish base liquid fertiliser may be that marketed by Moana Fertilisers/Sieber Agricultural Research Limited of Baldhill Road, Waiuku, New Zealand. Other equivalent fertiliser compositions may also be substituted.
WO 95/08521 PCT/NZ94/00099 Example 2 A A composition comprising, by weight up to a total of 100%: Percentage by weight 90-99.999% 0.001-10% Component liquid fish based fertiliser at least one fungus, micro-organism or reproductive material therefor As an option, additional nutrients and/or trace elements may be incorporated into the mixture. At least Moana Fertilisers/Sieber Agricultural Research produce a liquid fish base fertiliser which is fortified by the addition of additional nutrients and/or trace elements. This may be a convenient way of introducing additional nutrients, or altering the nutrient balance of the composition. A finely divided phosphate material, blood and bone, and other substantially insoluble fertilisers/nutrients may also be included. It may be desirable to follow the guidelines on particle size mentioned previously.
Example 2 B A composition comprising, by weight up to a total of 100%: Percentage by weight 90-99.999% 0.001-10% Component protein based fertiliser composition such as from meat processing plant at least one fungus, micro organism or reproductive material therefor Trials by the applicants have indicated that the above composition will also be especially suitable for supporting the growth and establishment of fungus, micro organisms and their reproductive material. The balance of nutrients in meat based fertiliser extracts differ from fish based extracts (which are relatively high in phosphorous).
Consequently, it is envisaged that many embodiments based on fish and meat fertiliser compositions will make use of the attributes of both to yield a more balanced or tailored overall composition. By way of example: Example 2 C A composition comprising, by weight up to a total of 100%: Percentage by weight 0-98% 0-98% 0.001-10% Component liquid fish base fertiliser protein based fertiliser composition from meat processing plant at least one fungus, micro organism or reproductive material therefor WO 95/08521 PCT/NZ94/00099 In the foregoing examples, it is convenient to introduce the fungus, micro organisms and/or reproductive material therefor in the form of a culture. This may be performed by traditional, accepted methods and while specific cultures may be cultivated on laboratory plates or agar, it has been found by the applicants that their liquid fish based fertiliser is capable of supporting a wide range of fungus, micro organisms and their reproductive material. Consequently, in preliminary trials, the applicants have used the liquid fish based fertiliser to culture a range of organisms which are then divided out and introduced into other batches. In some instances the use of a thickened liquid fish fertiliser may be advantageous, both for culturing and for the final product (see previously gel planting of seeds).
It is noted that Moana Fertilisers/Sieber Agriculture Research will commercially produce a thickened (predominantly by seaweed) fish based fertiliser on request. This may be useful for growing cultures as an alternative to the laboratory agar plates. It is also noted that this thickened composition will also be useful for embodiments where a coating is to be applied to a substrate material. In this case, the seaweed component can be used to form a gel like coating about substrate materials such as granular or particulate rock phosphate.
The viscosity of the gel coating will affect the thickness and integrity of the resulting coating. The viscosity will also affect the manner in which the liquid composition can be introduced to the phosphate material. Traditional blending techniques may be relied upon to introduce the liquid component to the solid material. One technique is the spray or drip application of the liquid or gel portions to the solid matter in a rotating drum or blending vat. Similar techniques have long been used for confectionery manufacture.
Example Three The compositions of Example Three are based on inorganic fertiliser compositions and nutrients.
Example 3 A A composition comprising, by weight up to a total of 100%: Percentage by weight Component 0-99.999% solution or composition including plant available nutrients, comprising at least a plant available source of at least one of the NPKS elements 0-99.9% liquid fish based fertiliser and/or meat-based fertiliser 0.001-10% at least on fungus micro organism or reproductive material therefor WO 95/08521 PCT/NZ94/00099 A wide range of plants available nutrient solutions and compositions may be used. It is envisaged that typically these will be based on inorganic and mineral type fertilising elements though organic and semi-organic derived nutrients may also be included.
Examples of some inorganic type nutrients include urea, the nitrates of many metals, ammonium compounds, soluble phosphate compounds, soluble sulphur and oxysulfur, soluble potassium compounds. Examples of some organically derived nutrients include liquid nutrients, substantially free of solid matter (other than in the form of a colloid or suspension, or very finely divided form) derived from plants and/or animal products.
Example Four The following examples describe compositions directed to solubilising nutrients which may already be present in the soil and/or making them available to plants. It is noted that the list of fungi and micro organisms given is not meant to be restrictive, but merely by way of example only.
Example 4 A A composition comprising, by weight up to a total of $100%: Percentage by weight Component 0-99.999% solution or composition including plant available nutrients, comprising at least a plant available source of at least one of the NPKS elements 0-99.9% liquid fish based fertiliser and/or meat-based fertiliser 0.001-10% at least one fungus, micro organism and/or reproductive material therefor.
The fungus and micro-organisms may comprise at least one member of a group comprising: Fusarium oxysporum, Fusarium solani, Aspergillus niger, Aspergillus candidus, Aspergillus flavus, Aspergillus ustus, Penicillium janthinellum, Penicillium sp., Sclerotium rolfsii, Cylindrocladium sp, Megatherium phosphaticum (and strains thereof), gram-positive bacteria, and members of the genus Pseudomonas.
Many of these organisms have illustrated an ability to help make nutrients available to plants. Some are specifically useful because they assist in the liberation of phosphorus from insoluble phosphates present in the soil. Accordingly, the following method of use is proposed: WO 95/08521 PCT/NZ94/00099 Example 4 B To a soil or plant supporting base hydroponics and non-soil based growth techniques) which is rich in insoluble phosphates, a composition such as described in at least Example 4 A may be applied. If possible, the liquid composition should be applied such that it can come in to contact with the phosphate material, which will accelerate the rate by which phosphate solubilising organisms affect the phosphate material. One method of application for a farmer would be to apply phosphates by normal spreader techniques to pasture, soil etc. Before the phosphate material is turned into the soil, a liquid composition (such as described in Example 4A) is then applied over the same area.
It is generally preferable that the liquid composition is applied secondly so that it has a chance of impregnating the phosphate material.
If possible, the phosphate and liquid compositions may be applied simultaneously. It is possible that the two may be merged prior to spreading though it is noted that typical spreader techniques do not usually successfully operate for wet or damp material.
Consequently it is envisaged that one solution is to use a tractor or vehicle equipped with a spray boom or applicators to spray the liquid composition immediately after phosphate spreading and distribution by the same vehicle, or to spray the liquid composition onto the solid material as it leaves the vehicle.
Example Five Another composition, given by way of example only, illustrates compositions useful for introducing VAMs and PGPRs into the soil.
Example 5 A A composition comprising, by weight up to a total of 100%: Percentage by weight Component 0-99.999% solution or composition comprising plant available nutrients, comprising at least a plant available source of at least one of the NPKS elements 0-99.9% liquid fish based fertiliser and/or meat-based fertiliser 0.001-10% at least on fungus micro organism or reproductive material therefor.
The fungus and micro-organisms may comprise at least one member of a group comprising: Vesicular-arbuscular mycorrhizas, plant growth promoting mycorrhizal bacteria, Pseudomonas (especially fluorescent members), Serratia liquefaciens, Glomus tenuis.
WO 95/08521 PCT/NZ94/00099 The above bacteria have generally exhibited tendencies to improve the root growth and establishment of plants. It is envisaged that the compositions of this example will typically be applied to soil and plant supporting bases near the time of planting or seeding, or soon thereafter. However advantages may also be obtained at other points in the growth cycle. One possible example illustrating use of the invention is as follows: Example Five B A composition, at least as described in Example 5A is applied to soil, pasture, etc. near the time of planting or seeding. Preferably, the liquid composition is applied to seed rows or troughs, and especially where it is likely to come in to contact by the roots of the developing plants. If possible, the composition may be sprayed or applied directly to the seeds or roots of plants. However, care should be taken not to burn the roots of the plants and dilution of the composition may be preferable where warranted.
Example 5 C A thickened composition, such as described in Example Six is prepared. Seeds are dispersed within this gel. The seeds may be newly germinated. The gel support is then used to insert the seeds into the soil using known techniques.
Example Six These examples comprise thickened compositions. The compositions may be based on any of the specific examples given in this specification, or other compositions possible within the scope of the present invention. Generally the viscosity will be increased so that the composition attains a syrupy or gel like consistency. This may be achieved by the use of a thickened fertiliser base such as the seaweed thickened composition available from Moana Fertilisers/Sieber Agriculture Research. This may be used as added thickening agent or may comprise the liquid nutrient portion in its own right. Other accepted thickening agents may also be incorporated to achieve the required consistency.
Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.