AU2014101319B4

AU2014101319B4 - A fertiliser product and method of producing a fertiliser product

Info

Publication number: AU2014101319B4
Application number: AU2014101319A
Authority: AU
Inventors: Adrian Lawrie
Original assignee: FULVIC HUMIC FERTILISERS Pty Ltd
Current assignee: FULVIC HUMIC FERTILISERS Pty Ltd
Priority date: 2014-08-21
Filing date: 2014-10-31
Publication date: 2015-06-04
Anticipated expiration: 2022-10-31
Also published as: AU2014101319A4

Abstract

The present invention comprises of a process for manufacturing a fertiliser product comprising: granulating one or more organic and inorganic/synthetic fertiliser components into granules having a desired size; coating the granules with powdered humic substances and liquid microbe solution; and applying a sealant coating. Figure 3

Description

1 A FERTILISER PRODUCT AND METHOD OF PRODUCING A FERTILISER PRODUCT FIELD OF INVENTION [0001] The present invention relates to the field of fertilisers, particularly fertiliser products that incorporate organic fertiliser together with inorganic/synthetic fertilisers. [0002] In one form, the invention relates to a method of producing a fertiliser product that incorporates organic fertiliser together with inorganic/synthetic fertilisers. [0003] In one particular aspect the present invention enables the provision of a fertiliser product that combines organic and inorganic/synthetic components in a manner that enables favourable distribution of the product to the soil. BACKGROUND ART [0004] The discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor and, moreover, any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms a part of the prior art base or the common general knowledge in the relevant art in Australia or elsewhere on or before the priority date of the disclosure and claims herein. [0005] Throughout this specification the use of the word "inventor" in singular form may be taken as reference to one (singular) inventor or more than one (plural) inventor of the present invention. [0006] It has long been known that the sustained productivity of farming crops depends on the 'fertility' of the soil, which may decline unless nutrients are returned to the soil via bio-fertilisers such as rock dusts, ash, mineral silts, dung, effluents and composted biomass. [0007] However, with the development of synthetic fertiliser technologies many believed that farming and food production had transcended these soil and biological limitations. They believed that these fertilisers could overcome the "last great 2 subsistence crisis in the world", producing abundant food by providing plants with adequate soluble nitrogen, phosphorus and potassium (NPK) chemicals to sustain their growth. [0008] While solid NPK fertiliser, in a soluble form, revolutionised food production far and wide, and produced arguably far more food than the former subsistence farming could have done, the use and dependence on NPKfertilisers has had serious global consequences. These include the serious decline in soil health parameters such as structure, water infiltration, water holding capacity, organic carbon and microbial content of over-fertilised soils. [0009] In nature the availability of plant nutrients is governed mostly by the activity of soil microbes - via their key roles in solubilising, fixing, selectively taking-up and cycling mostly limiting essential nutrients from soil and organic matter so as to sustain productive plant growth. In nature such microbial processes are particularly important since few nutrients are available in soluble forms in the soil solution for the growth of non-microbial plants. [0010] Soil organic carbon (SOC) has a large influence on the productivity of soil. Maintenance of adequate levels of SOC is essential for the function of balanced microbiology and is extremely important in keeping minerals in a form available to plants and contributes to a soil's physical state of friability or compaction. It has been demonstrated that there is a direct link between farm enterprise profitability and SOC - with higher SOC levels being significantly more profitable. [0011] Given that the productivity and integrity of the food we depend on is governed substantially by the availability of the essential nutrients and water for its growth, and given the importance of microbial processes and organic matter in making these available, priority in future farming systems must be given to creating conditions that are conducive to, rather than destroying, these critical processes. [0012] Bio-fertilisers are designed to restore and enhance these conditions and the microbial ecologies that govern the availability of nutrients increasing the health and productivity of our soils and food plants. While current chemically synthesised inorganic fertilisers may have the same objective, they operate via different processes 3 that have radically different impacts on these critical soil processes and food health outcomes. [0013] Bio-fertilisers aim to enhance the natural processes governing the availability of nutrients, whereas chemical fertilisers aim to 'recharge' the level of essential soluble plant nutrients in the soil solution. However as most of the added nutrients are either rapidly bound up chemically on soil surfaces or leached from the soil solution, they become unavailable to plants thus requiring further additions. This can not only lead to fertiliser dependencies, but also excess levels of total nutrients accumulating in soils and wetlands that may become toxic to some plants (and microorganisms and animals) if they become suddenly available. [0014] Bio-fertilisers that are naturally produced (such as manures and composts) can be inexpensive to produce but can suffer from inconsistencies and insufficiencies in levels of necessary nutrients. Specialised organic blends have less problems with inconsistencies but often cost significantly more than inorganic and naturally produced bio-fertilisers. Additionally composts and manures are bulk products physically unsuitable for application with application machinery by the majority of global fertiliser usage, which require a concentrated granular fertiliser. [0015] To provide the benefits of both organic fertilisers and inorganic fertilisers, both types of fertiliser can be applied to the soil. Products have also been developed which contain both types of fertiliser. Combined inorganic and organic fertilisers can have both the fast acting characteristics of inorganic fertilisers with the sustained release characteristics of organic fertilisers. These fertilisers may provide higher yields than inorganic or organic fertiliser alone due to the overall increase in total nutrients. Combined fertilisers also reduce the amount of inorganic fertiliser that the soil is exposed to, reducing the incidence of the problems discussed above concerning the over-application of inorganic fertilisers. [0016] However, the inventor has identified that existing organic inorganic fertiliser products have issues which have limited the uptake of these combined fertilisers. [0017] Previous attempts at the use of combined organic and inorganic fertilisers, for example using powdered biofertiliser blended with liquid microbial fertilisers, whilst successful in the field, have failed to achieve substantial market acceptance due to 4 extra cost and work associated with handling and application of the product with standard farm machinery. This has also been the case for liquid microbial biofertilisers sprayed out onto soil, crops and pasture. [0018] Mixing humate products with synthetic fertilisers has also been successful in farm and trial assessments, but the resulting fertiliser product frequently creates blockages in standard farm seeder machinery from dust and hygroscopic moisture accumulation in storage and handling. SUMMARY OF INVENTION [0019] It is an object of the embodiments described herein to overcome or alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems. [0020] In accordance with the present invention, there is provided a process for manufacturing a fertiliser product comprising: granulating one or more organic and inorganic/synthetic fertiliser components into granules having a desired size; coating the granules with powdered humic substances and liquid microbe solution; and applying a sealant coating. [0021] The granulated organic and inorganic/synthetic fertiliser components may include naturally occurring and synthetic inorganic fertilisers, synthetic organic fertilisers, macro-elements and micro-elements, and is referred to herein as inorganic/synthetic fertiliser. [0022] The granulating operation may include: mixing one or more organic and inorganic/synthetic fertiliser component; milling the organic and inorganic/synthetic fertiliser to a minimum particle size; adding a binder material; mixing to initiate a seed granule; developing the granules in a pelletiser to desired size; and drying the granules.

5 [0023] In one form of the invention the milling operation is carried out to obtain a particle size of less than approximately 200 microns. [0024] The dried granules may be screened in order to obtain granules with sizes in the range of approximately 2-5 mm. [0025] The inorganic/synthetic fertiliser components may include one or more of monoammonium phosphate, urea, sulphate of ammonia, reactive phosphate rock, and/or guano. The inorganic/synthetic fertiliser components may further include one or more of elemental sulphur, gypsum, lime, zinc sulphate mono-hydrate, manganese sulphate, copper sulphate, cobalt sulphate, and/or zinc oxide. [0026] The binder material may be in the form of cellulose derivatives, sulphuric acid, molasses or organic polymers. [0027] The sealant coating may be in the form of polyhydric polymer, olefin polymer, sodium silicate, or potassium silicate. [0028] In accordance with the present invention, there is also provided a combined organic and inorganic/synthetic fertiliser product comprising a granule including an inner core of one or more inorganic/synthetic fertiliser components together with a binder material, wherein the granule is coated with a first layer of microbes, a second layer of powdered humic substances and a third layer of sealant. [0029] The inorganic/synthetic fertiliser may contain one or more of: monoammonium phosphate, urea, sulphate of ammonia, raw phosphate rock and/or guano, which, in some embodiments of the invention, is included in the fertiliser product in the range of up to approximately 85%. [0030] The inorganic/synthetic fertiliser components may include one or more macro-elements and/or micro-elements comprising one of more of: elemental sulphur, gypsum, lime, zinc sulphate mono hydrate, manganese sulphate, copper sulphate, cobalt sulphate and zinc oxide. The proportion of macro-elements and/or micro elements in the fertiliser product may be included in the range of up to approximately 43%.

6 [0031] The proportion of humic substances in the fertiliser product may be in the range between approximately 3% and 70%. In certain embodiments of the invention the proportion of humic substances in the fertiliser product is in the range between approximately 10% and 20%. [0032] The granules of the fertiliser product may have a size in the range of approximately 2mm to 5mm. [0033] In essence, the present invention stems from the realisation of the inventor that organic fertilisers and inorganic/synthetic fertilisers can each make valuable contributions to agricultural productivity, but the majority of farmers have thus far been unable to access or apply a fertiliser product that combines the benefits of both. A fertiliser product that combines inorganic/synthetic and organic fertilisers in manner that preserves the function of the individual components without compromise and retains the physical integrity of the granular product from production through to application, may therefore enable global agriculturalists access to identified benefits of a hybrid inorganic and organic "biological fertiliser". [0034] Embodiments of the present invention are able to provide a number of advantages, such as: * The fertiliser can be stored, handled and applied with standard farm seeder equipment, allowing adoption of combined organic inorganic fertilisers into the full fertiliser market. o The use of the fertiliser with standard farm seeder equipment will save costs in eliminating the need to purchase additional equipment and will also save time. o The fertiliser is easily applied so provides a problem free application of a combined organic inorganic fertiliser while still achieving the benefits of both fertiliser types. * The fertiliser has a similar or less application rate per hectare than existing synthetic fertilisers. * Compared with exclusive synthetic fertilisers, the fertiliser has much enhanced numbers and activity of micro-organisms together with greater root structures and associated organic root exudates.

7 * Application of the fertiliser to soils results in improved yields in cropping and grazing, whilst simultaneously improving the physical, chemical and biological soil parameters. * The fertiliser has the ability to rebuild soil organic carbon (SOC). * The coating of the fertiliser provides dust free and moisture resistant storage and use. [0035] Further scope of applicability of embodiments of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure herein will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS [0036] Further disclosure, objects, advantages and aspects of preferred and other embodiments of the present invention may be better understood by those skilled in the relevant art by reference to the following description of embodiments taken in conjunction with the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the disclosure herein, and in which: Figure 1 is cross-sectional illustration of a fertiliser product granule according to an embodiment of the invention; Figure 2 is a diagrammatic illustration of process apparatus for producing a fertiliser product and Figure 3 is a flow chart diagram setting out a method of producing a fertiliser product in accordance with an embodiment of the invention DETAILED DESCRIPTION [0037] A granular fertiliser product is described hereinbelow, together with the process and apparatus employed to manufacture the fertiliser product. The granular fertiliser product incorporates both inorganic and organic fertiliser components and is manufactured in such a way that the resulting fertiliser granules are able to be distributed or applied with the use of standard farming equipment, such as a seeding 8 machine, without the use of specialised or modified equipment and without causing blockages. [0038] Figure 1 illustrates a generalised cross-sectional view of the structure of a fertiliser granule 10. At the core (12) of the granule 10 is a mixture of inorganic fertiliser components such as 'NPK' type fertilisers, along with micro- and macro elements, held together with a binder material. The core of the granule is surrounded by a layer of microbial material (16) and a layer of humic substances (14). The outer layer (18) is a sealant, which functions to stabilise and seal the fertiliser, assisting in maintaining the integrity of the product for trouble-free storage, handling, transport and application. [0039] The term humic substances is used herein to refer to one or a combination of humic acids, fulvic acids, salts thereof such as humates and fulvates, humin, and related compounds as understood in the art. [0040] Further details of the fertiliser product will become apparent from the following description of a manufacturing process according to an embodiment of the invention. A flow chart diagram of the process steps for the manufacture of the fertiliser granules is shown in Figure 3, and a diagrammatic illustration of the manufacturing apparatus is included in Figure 2 of the drawings, which are referred to below. [0041] The overall fertiliser production process (100) can be considered in three process operations, each including several steps as indicated in Figure 3: A. Mixing B. Granulating C. Coating [0042] Each of the process operations are considered in turn below. A. Mixing [0043] The mixing process operation involves combining the inorganic fertiliser components, which may include monoammonium phosphate (MAP), urea, sulphate of ammonia (SOA), reactive phosphate rock (RPR), guano (e.g. ammonium oxalate and urate, phosphates), along with micro- and macro-elements such as elemental 9 sulphur, gypsum, lime, zinc sulphate mono-hydrate, manganese sulphate, copper sulphate, cobalt sulphate, zinc oxide. The raw input substances are delivered into a bulk receiver hopper in the form of powdered and particulate materials. In order to premix the components (102) the input products are batched into a hopper which feeds to a ribbon mixer (22 in Figure 2). The majority of input material will be fine, but screened to 10mm. Occasional lumps may be managed by a vibrating grid over hopper feed into a mill (24). The input materials are then milled (104) down to approximately 100 -200 microns. Once the core ingredients have been milled to appropriate size the combined material is transferred (106) to a pin mixer (26 in Figure 2) to begin the next process operation. B. GRANULATING [0044] Milled fertiliser powder is transferred into the pin mixer for initial granule formation. A liquid binder such as molasses (viscosity 4000cP) is simultaneously fed (108) to the pin mixer at a rate of approximately litres per tonne. Small 'seed' granules are produced (110) with fertiliser product and binder in the pin mixer. Product from the pin mixer is delivered by a belt conveyor on to a disc pelletiser (28 in Figure 2). The liquid binder is also fed to the disc pelletiser, and with appropriate placement of seed granules and liquid binder on the disc, granules with desired sizes in range of 2-5mm can be formed (112). The amount of liquid binder used in the pin mixer and disc pelletiser may be varied, but a total inclusion rate of approximately 25 litres per tonne has been found to provide a good result in testing. [0045] At this stage, the fertiliser granules have an elevated level of moisture, and so the granules are transferred (114) by belt conveyor from the disc pelletiser to a dryer (30 in Figure 2). The drying process assists in achieving handling characteristics, including desirable compression strength and structure integrity for shatter resistance, so that the product remains in granule form without reverting to powder. The output from the dryer may have a moisture content of approximately 5%. [0046] Once the granules are dried, a belt conveyor is used to deliver the product to a gyrating screen sieve (32 in Figure 2) in order to remove over- and under-sized granules (116). The desired granule size is approximately within the range of 2mm to 5mm dimension. Granules that do not meet the required dimensional specifications determined by the screen sieve may be returned to the mill for re-processing, or may 10 be used for other purposes where granule size is unimportant. The screened granules are then delivered to a coating rotary drum (118), described below. C. COATING [0047] Granules of approximately 2-5mm enter the coating rotary drum (34 in Figure 2) direct from screen. Three coating products are applied in turn as the granules are processed in this stage. First, a liquid microbe solution is applied (122) at the rate of approximately 20 litres per tonne of fertiliser product, sprayed into the CRD in order to coat the granules. These microbes may be fermented on site from a microbe innoculum comprising, for example, bacillus sp subtillus, laterosporus, megatorium, pumilus, licheniformus. Then a coating of powdered humic substances is applied (120), in range of approximately 3% - 70% of finished fertiliser product. In particular formulations detailed hereinbelow, the amount of humic substances comprises approximately 10% - 20% of finished fertiliser product. Stored coating powder may be transferred by loader into a coating powder hopper, which incorporates a small mill at exit, wherein the powder is milled and metered using a metering screw discharge into the coating rotary drum (CRD). Finally, a sealant coating such as liquid sodium silicate is applied (124) sprayed into the CRD at a rate of approximately 20 litres per tonne of fertiliser product. [0048] The CRD will incorporate a variable-speed fan for conditioning and/or cooling the product as required prior to storage (40 in Figure 2). [0049] The resulting combined inorganic organic fertiliser product (Figure 1) has an inner core containing inorganic fertiliser, macro-elements, micro-elements and binder material, a first coating formed from liquid microbe solution, a second coating consisting of humic substances, and an outer layer which acts as a sealant. The outer layer stabilises and seals the fertiliser, assisting in maintaining the integrity of the product for trouble free storage, handling, transport and application. [0050] The requirements for each component may vary depending on a number of factors such as the soil characteristics, temperature, time-of-year of intended use and water availability, amongst other things. Therefore, the exact proportion of each component to the fertiliser product may be varied according to intended application. Table 1 below indicates the proportions of various components in six example fertiliser products.

11 Formula Formula Formula Formula Formula Formula A B C D E F MAP 41.00% 15.00% 15.00% 10.00% 20.00% UREA 30.00% 81.00% 35.00% SOA Crystaline 20.00% Potassium Sulfate 40.00% 15.00% RPR 25.00% 25.00% Guano 10.00% Elemental Sulfur 4.00% 4.00% Gypsum Australia 43.00% 39.45% 25.60% Lime Zinc Sulfate Mono Hydrate 0.50% 0.20% Manganese Sulfate 2.00% Copper Sulfate 0.50% 0.20% Cobalt Sulfate 0.05% Zinc Oxide 0.50% Humic substances 12.00% 14.00% 14.00% 12.00% 12.00% 16.00% Binder, Microbes & coating 3.00% 3.00% 3.00% 3.00% 3.00% 3.00% Total 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% Table 1: Example fertiliser components & formulations [0051] The fertiliser products as described above, resulting from the process of the described embodiment, combine the benefits of concentrated synthetic fertiliser and concentrated humic substances into a 2mm-Smm granule with microbial support. The fertiliser product provides farmers access to a concentrated hybrid/biological fertiliser that requires similar or less application rate per hectare than the current option of 100% synthetic fertiliser. Fertiliser products according to embodiments of the invention should be producible at similar cost to widely available alternatives, with improved crop/pasture performance and physical characteristics that enable consistent, trouble-free storage, handling and application integrity of the product. In particular, the moisture-sealed granular form enables easy spreading with the use of current standard farming equipment, so no specialised equipment is needed at the farm. Furthermore, embodiments of the invention may enable additional benefits, including: " A per-tonne cost comparable to chemical-only fertiliser varieties. * Improved yields in cropping and grazing, whilst simultaneously improving the physical, chemical and biological soil parameters.

12 " The ability to rebuild soil organic carbon (SOC), leading to higher productivity in cropping and grazing. " Higher production for given rain/irrigation levels due to: - Improved water use efficiency - Irrigation water savings - Faster water infiltration - Higher soil water holding capacity * Remediation of soils to high productivity, eg: - Salt affected - Compacted - Sand - Clay - Toxicity from: - Heavy metals - Chemical contamination - Denuded - physically and biologically [0052] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth. [0053] As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. The described embodiments are to be considered in all respects as illustrative only and not restrictive. [0054] Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, 13 the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. [0055] "Comprises/comprising" and "includes/including" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', 'includes', 'including' and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Claims

1. A process for manufacturing a fertiliser product comprising: granulating one or more organic and inorganic/synthetic fertiliser components into granules having a desired size coating the granules with powdered humic substances and liquid microbe solution; and applying a sealant coating.

2. A process according to claim 1 wherein the granulated organic and inorganic/synthetic fertiliser components include naturally occurring and synthetic inorganic fertilisers, organic fertilisers, macro-elements and/or micro-elements and, wherein the granulating operation includes one or a combination of: mixing one or more organic and inorganic/synthetic fertiliser component; milling the organic and inorganic/synthetic fertiliser to a minimum particle size; adding a binder material; mixing to initiate a seed granule; developing the granules in a pelletiser to desired size; and drying the granules.

3. A process according to any one of claims 1 or 2, wherein the binder material comprises cellulose derivatives, sulphuric acid, molasses and/or organic polymers and wherein the sealant coating comprises polyhydric polymer, olefin polymer, sodium silicate and/or potassium silicate.

4. A combined organic and inorganic/synthetic fertiliser product comprising a granule including an inner core of one or more organic and inorganic/synthetic fertiliser components together with a binder material, wherein the granule is coated with a first layer of microbes, a second layer of powdered humic substances and a third layer of sealant.

5. A combined organic and inorganic fertiliser product manufactured according to the process of any one of claims 1 to 3.