AU2014218451B2 - Improvements in and relating to fertiliser compositions - Google Patents

Abstract

A fertiliser composition which includes a nutrient source in the form of a fertiliser granule or chip, or a mineral, fertiliser granule or chip coated with a coating composition comprising a mixture of clay and water wherein the ratio of clay to water falls within a range substantially between 30:70 and 90:10. Figure 5 :nmm Figure 6 NW,

Description

IMPROVEMENTS IN AND RELATING TO FERTILISER COMPOSITIONS TECHNICAL FIELD The present invention relates to improvements in and relating to fertiliser compositions. In particular the present invention relates to coated fertiliser compositions. BACKGROUND ART The use of fertiliser compositions in agriculture is well known. For illustrative purposes the present invention will now be discussed in relation to one major type of fertiliser in use in agriculture today namely urea. However, it should be understood that the principles of the present invention can be applied to other types of fertiliser and hence any discussion in relation to urea should not be seen as limiting. Urea is a popular fertiliser due to its high nitrogen content which can be easily broken down into plant assimilable ammonia and nitrate by soil bacteria. However, the solubility and availability of urea means that it is susceptible to nitrogen leaching shortly after being applied to a pasture which is non-ideal. It would therefore be useful if there could be provided a way in which the nitrogen content of urea could be released in a controlled manner over a sustained period of time following application. Another problem with urea is that the granules when they contact one another during transportation, or handling produce a lot of dust which is problematic and can clog agricultural equipment and also be a health risk if inhaled. 1 Moreover, it would be useful if urea could be formulated to additionally provide additional nutrients and/or trace elements to a pasture. It would also be useful if urea could be formulated to be capable of being blended with mature acidulated phosphate fertilisers which have a temperature of 300C or below so as to avoid double salt formation. It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country. Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only. DEFINITIONS The term 'fertiliser' as used herein refers to any substance added to soil, land or other plant growth medium in order to increase fertility. 2 The terms 'granule' and 'chip' as used herein are used interchangeably and refer to a small compact particle of substance. The particle will generally be of a size in the order of substantially between 1 mm -10mm and most preferably between 2mm-5mm. The granule/chip may be naturally occurring or may be fashioned by human manipulation. The term 'mineral' as used herein refers to a solid naturally occurring substance which is beneficial to a plant or animal life. Some non-limiting exemplary examples will be detailed subsequently herein. The term 'wax' as used herein refers to a synthetic or naturally occurring compound which is generally malleable at fairly wide band of room temperatures (i.e. around 50C - 450C) and liquid above 450C and insoluble in water but soluble in organic non-polar solvents. Some non-limiting exemplary examples will be detailed subsequently herein. The term 'oil' as used herein includes plant based oils and other biodegradable oils with similar properties. The term 'plant based oil' as used herein refers to: a) a lipid material produced by a plant which is liquid at room temperatures of around 50C - 450C and is viscous compared to water; b) a lipid material which is chemically similar to, or is derived from, a lipid material produced by a plant which is liquid at room temperatures of around 50C - 450C and is viscous compared to water; c) a lipid based material in a) or b) above which includes one or more additives yet remains liquid at room temperatures of around 50C 450C and is viscous compared to water. 3 The term 'derived' as used herein refers to something which is formed or developed from something else. The term 'uncoated fertiliser' refers to uncoated granule or chip of fertiliser. The term 'trace elements' as used herein refers to a chemical element found in small quantities in plants and/or the earth and which is used by organisms, including plants and animals, and is essential or beneficial, to their physiology. Some non-limiting exemplary examples will be detailed subsequently herein. The term 'assimilable' as used herein refers to a substance which is able to be absorbed by a plant or animal. The term 'mature superphosphate' as used herein refers to an acidulated phosphate fertiliser having a temperature of 300C or below. DISCLOSURE OF THE INVENTION According to a first aspect there is provided a fertiliser coating composition which includes a nutrient source and in the form of a fertiliser granule or chip, or a mineral, fertiliser granule or chip coated with a coating composition comprising a mixture of clay and water wherein the ratio of clay to water falls within a range substantially between 30:70 and 90:10. In some embodiments, the ratio of water to clay may be 50:50. In one embodiment, the ratio of clay to water may be substantially 3:1 and the composition may also include an acrylic emulsion polymer to aid drying of the mixture. According to a second aspect there is provided a fertiliser composition which includes a nutrient source in the form of a fertiliser coated with a coating 4 composition comprising a mixture of clay and oil wherein the ratio of clay to oil falls within a range substantially between 40:60 and 90:10. Preferably, the ratio of clay to oil may be 50:50. Preferably, the oil is a plant based oil or other biodegradable oil. According to a third aspect there is provided a fertiliser composition which includes a mixture of clay and an oil/water emulsion wherein the ratio of clay to emulsion falls within a range substantially between 30:70 and 90:10. Preferably, the ratio of oil to clay may be 50:50. Preferably, the oil is a plant based oil or other biodegradable oil. According to a fourth aspect there is provided a fertiliser composition which includes 66% water (w/v) 33.7% clay (w/v) and 0.3% Xanthan or Guar gum (w/v). According to a fifth aspect there is provided a fertiliser composition which includes 66% oil (w/v) 33.7% clay by (w/v) and 0.3% Xanthan or Guar gum (w/v). According to a sixth aspect there is provided a fertiliser composition substantially as described above which includes 5-10% (w/v) MgO wherein said MgO has a particle size of less than 45 microns. According to a seventh aspect there is provided a fertiliser composition substantially as described above which includes 5-10% (w/v) powdered carbon or at least one trace element, wherein said carbon and trace element(s) has/have a particle size of less than 45 microns. According to an eighth aspect there is provided a coated fertiliser which includes a core comprising a fertliser granule/chip, or mineral granule/chip, wherein the core 5 is coated with a first layer comprising the coating composition substantially as described above. Preferably, the fertiliser granule/chip, or, mineral granule/chip, may include a second layer comprising a powdered trace element. In one embodiment the fertiliser granule/chip may be a urea. According to a ninth aspect there is provided a fertiliser blend which includes a quantity of uncoated fertiliser and a quantity of a coated fertilser composition substantially as described above. According to a tenth aspect there is provided a fertiliser blend wherein the uncoated fertiliser mature superphosphate, which has a temperature of 300C or below and the coated fertiliser composition is urea. According to a 11th aspect there is provided a coating composition which in use is capable of, providing a complete coat to a fertilizer granule or chip, or a mineral granule or chip, the coating composition comprising a mixture of clay and water wherein the ratio of clay to water falls within a range substantially between 30:70 and 90:10 wherein the clay has a particle size of less than 20 microns and is inert. In some embodiments, the ratio of water to clay may be 50:50. According to a 12th aspect there is provided a coating composition which in use is capable of, providing a complete coat to a fertilizer granule or chip, or a mineral granule or chip, the coating composition comprising a mixture of clay and oil wherein the ratio of clay to oil falls within a range substantially between 40:60 and 90:10 wherein the clay has a particle size of less than 20 microns and is inert. Preferably, the ratio of clay to oil may be 50:50. Preferably, the oil is a plant based oil or other biodegradable oil. 6 According to a 13th aspect there is provided a coating composition which in use is capable of, providing a complete coat to a fertilizer granule or chip, or a mineral granule or chip, the coating composition comprising a mixture of clay and an oil/water emulsion wherein the ratio of clay to emulsion falls within a range substantially between 30:70 and 90:10 wherein the clay has a particle size of less than 20 microns and is inert. Preferably, the ratio of oil to clay may be 50:50. Preferably, the oil is a plant based oil or other biodegradable oil. According to a 14th aspect there is provided a coating composition which includes 66% water (w/v) 33.7% clay (w/v) and 0.3% Xanthan or Guar gum (w/v). According to a 15th aspect there is provided a coating composition which includes 66% oil (w/v) 33.7% clay by (w/v) and 0.3% Xanthan or Guar gum (w/v). According to a 16th aspect there is provided a coating composition substantially as described above which includes 5-10% (w/v) MgO wherein said MgO has a particle size of less than 45 microns. According to a 17th aspect there is provided a coating composition substantially as described above which includes 5-10% (w/v) powdered carbon or at least one trace element, wherein said carbon and trace element(s) has/have a particle size of less than 45 microns. According to a 18th aspect there is provided a fertiliser blend which includes a quantity of a coated urea composition substantially as described above, together with, a quantity of mature superphosphate which has a temperature of 300C or below. 7 BRIEF DESCRIPTION OF THE DRAWINGS Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which: Figure 1 shows a control mixture of uncoated urea and mature superphosphate just after mixing; Figure 2 shows the mixture of from Figure 1 again after 72 hours; Figure 3 shows a mixture of coated urea from Example 2 and mature superphosphate just after mixing; Figure 4 shows the mixture of from Figure 3 again after 72 hours; Figure 5 shows a mixture of coated urea from Example 3 and mature superphosphate just after mixing; Figure 6 shows the mixture of from Figure 5 again after 72 hours; Figure 7 shows a mixture of coated urea from Example 4 and mature superphosphate just after mixing; Figure 8 shows the mixture of from Figure 7 again after 72 hours; Figure 9 shows a mixture of coated urea from Example 5 and mature superphosphate just after mixing; and Figure 10 shows a mixture of coated urea from Figure 9 and mature superphosphate just after mixing. BEST MODES FOR CARRYING OUT THE INVENTION EXAMPLE 1 8 MC50/50 Coating Manufacture 500g kaolin clay powder is added to 500g water and blended together until a homogenised mixture is produced. MC50/50 Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add Ig of MC50/50, to the Urea and start coating drum 3) When all Urea granules are coated with MC50/50 add 1 Og of MagOx E45 Magnesium Oxide by Sibelco (herein "E45") powdered Magnesium Oxide to the mix and start coating drum again 4) When all Urea granules are evenly coated with E45 and are free flow, generally after around 2 -3 minutes, remove product from coating drum. EXAMPLE 2 CR 1 Coatingy Manufacture 50g kaolin clay powder is added to 50g boiled linseed oil and blended together until a homogenised mixture is produced. CR I Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add I g of CR 1, to the Urea and start coating drum 3) When all Urea granules are coated with CR 1 add 1 Og of powdered E45 Magnesium Oxide to the mix and start coating drum again 9 4) When all Urea granules are evenly coated with the Magnesium Oxide and are free flow, remove product from coating drum. EXAMPLE 3 WC 1 Coating Manufacture 330g kaolin clay powder and 11 g glycol is added to 660g of water and blended. WC 1 Coated Urea Manufacture 1) Take 89gof Urea and place in rotating coating drum 2) Add 1 g of WC 1, to the Urea and start coating drum 3) When all Urea granules are coated with WC 1 add 1 Og of E45 powdered Magnesium Oxide to the mix and start coating drum again 4) When all Urea granules are evenly coated with E45 Magnesium Oxide and are free flow, generally after around 2 -3 minutes, remove product from coating drum. EXAMPLE 4 WCG 1 Coating Manufacture 330g of kaolin clay and 3g xanthan gum is added to 666g of water and blended. WCG 1 Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add 1g of WCG1 1 50/50, to the Urea and start coating drum 3) When all Urea granules are coated with WCGI 50/50 add I Og of E45 powdered Magnesium Oxide to the mix and start coating drum again 10 4) When all Urea granules are evenly coated with the Magnesium Oxide and are free flow, generally after around 2 -3 minutes, remove product from coating drum. EXAMPLE 5 SSMR15 Coating Manufacture 180g kaolin clay and 3g xanthan gum is added and then blended with a pre-mix of 720g water, 30g Primal EK and 67g calcium lignin sulfonate together with 1.94g of Anticide 50 fungicide by Thor. SSMR15 Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add 1 g of SSMR15 50/50, to the Urea and start coating drum 3) When all Urea granules are coated with SSMR15 50/50 add 1Og of E45 powdered Magnesium Oxide to the mix and start coating drum again 4) When all Urea granules are evenly coated with the Magnesium Oxide and are free flow, generally after around 2- 3 minutes, remove product from coating drum. EXAMPLE 6 MC250/50 Coating Manufacture 500g kaolin clay powder is added to 5OOg water and blended together until a homogenised mixture is produced. MC250/50 Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add I g of MC250/50, to the Urea and start coating drum 11 3) When all Urea granules are evenly coated and have become free flow, as coating dries, generally after around 6 -7 minutes, remove product from coating drum. EXAMPLE 7 WCG IM Coating Manufacture 330g of kaolin clay, 99g MgO and 3g guar gum are added to 666g of water and blended. WCG IM Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add 1 g of WCG1 M 1 50/50, to the Urea and start coating drum 3) When all Urea granules are coated with WCG1 M 50/50 add 1Og of 45 micron powdered zinc to the mix and start coating drum again 4) When all Urea granules are evenly coated with the zinc and are free flow, generally after around 2-3 minutes, remove product from coating drum. EXAMPLE 8 WCG I W Coating Manufacture 330g of kaolin clay, 99g palm wax and 3g guar gum are added to 666g of water and blended. WCG I W Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add Ig of WCG1W 1 50/50, to the Urea and start coating drum 12 3) When all Urea granules are coated with WCG W 50/50 add 1 Og of 45 micron powdered silicon dioxide to the mix and start coating drum again 4) When all Urea granules are evenly coated with silicon dioxide and are free flow, generally after around 2-3 minutes, remove product from coating drum. EXAMPLE 9 EC50/50 Coating Manufacture 5OOg kaolin clay powder is added to 5OOg water/castor oil emulsion and blended together until a homogenised mixture is produced. EC50/50 Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add Ig of EC50/50, to the Urea and start coating drum 3) When all Urea granules are coated with EC50/50 add 10 g of powdered 45 micron Copper Oxide to the mix and start coating drum again 4) When all Urea granules are evenly coated with powdered copper oxide and are free flow, generally after around 2 -3 minutes, remove product from coating drum. EXAMPLE 10 DC50/50 Coating Manufacture 5OOg kaolin clay powder is added to 500g water and blended together until a homogenised mixture is produced. DC50/50 Coated DAP Manufacture 1) Take 89g of DAP and place in rotating coating drum 13 2) Add 1 g of DC50/50, to the Urea and start coating drum 3) When all Urea granules are coated with DC50/50 add 1 Og of powdered E45 Magnesium Oxide to the mix and start coating drum again 4) When all Urea granules are evenly coated with powdered magnesium oxide and are free flow, generally after around 2 -3 minutes, remove product from coating drum. EXAMPLE 11 WCG IR Coating Manufacture 330g of kaolin clay, 99g C9 petroleum resin by Connell Bros Company Australasia Ltd. and 3g guar gum are added to 666g of water and blended. W/CG IfR Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add I g of WCG1 R 1 50/50, to the Urea and start coating drum 3) When all Urea granules are coated with WCG 1R 50/50 add I Og of E45 powdered MgO to the mix and start coating drum again 4) When all Urea granules are evenly coated with silicon dioxide and are free flow, generally after around 2-3 minutes, remove product from coating drum. EXAMPLE 12 SS 19 Coating Manufacture 14 250g kaolin clay powder is added to: a pre-mixture of 720g water, 5g Xanthan gum, 2.5g of Anticide 50 fungicide by Thor, 30g 3% Primal EK acrylic emulsion and 67g calcium lignin sulfontate; and the clay and water pre-mix are blended together until a homogenised mixture is produced. EXAMPLE 13 MC90/10 Coating Manufacture 900g kaolin clay powder is added to 1 og water and blended together with an open impeller pump unit until a homogenised mixture is produced. MC90/1 0 Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 2) Add I g of MC90/1 0, to the Urea and start coating drum 3) When all Urea granules are coated with MC90/10 add 1 Og of MagOx E45 Magnesium Oxide by Sibelco (herein "E45") powdered Magnesium Oxide to the mix and start coating drum again 4) When all Urea granules are evenly coated with E45 and are free flow, generally after around 2 -3 minutes, remove product from coating drum. EXAMPLE 14 CR90/10 Coating Manufacture 900g kaolin clay powder is added to 1 og boiled linseed oil and blended together with an open impeller pump unit until a homogenised mixture is produced. CR90/1 0 Coated Urea Manufacture 1) Take 89g of Urea and place in rotating coating drum 15 2) Add 1g of CR901/10, to the Urea and start coating drum 3) When all Urea granules are coated with MC90/1 0 add 1Og of MagOx E45 Magnesium Oxide by Sibelco (herein "E45") powdered Magnesium Oxide to the mix and start coating drum again 4) When all Urea granules are evenly coated with E45 and are free flow, generally after around 2 -3 minutes, remove product from coating drum. In practice when the invention is used to make commercial quantities the above examples are scaled up and the ingredients are mixed together either by: - blending with an open impeller centrifugal pump circulating water through a tank for aqueous mixtures; or - shearing with a high shear pump for oil and water mixtures. One suitable pump for such purposes is made by Silverson. Results In Figure 1 there is shown a control comprising uncoated urea which has just been mixed with mature superphosphate in an environment having a temperature of 300C at 80% relative humidity. Figure 2 shows how the urea and superphosphate react and form a double salt after 72 hours have elapsed from the time of mixing. In Figure 3 there is shown the CR 1 coated urea of Example 2 which has just been mixed with mature superphosphate in an environment having a temperature of 300C at 80% relative humidity. In Figure 4 it can be seen that there has been no noticeable reaction between the superphosphate and the urea. In Figure 5 there is shown the WC 1 coated urea of Example 3 which has just been mixed with mature superphosphate which has a temperature of 300C and 80% 16 humidity. In Figure 6 it can be seen that there has been no noticeable reaction between the superphosphate and the urea. In Figure 7 there is shown the WCG 1 coated urea of Example 4 which has just been mixed with mature superphosphate in an environment having a temperature of 300C at 80% relative humidity. In Figure 8 it can be seen that there has been no noticeable reaction between the superphosphate and the urea. In Figure 9 there is shown the SSMR1 5 coated urea of Example 5 which has just been mixed with mature superphosphate in an environment having a temperature of 300C at 80% relative humidity. In Figure 10 it can be seen that there has been no noticeable reaction between the superphosphate and the urea. ALTERNATE WAYS TO IMPLEMENT THE INVENTION The clay may be any clay which has a particle size of less than 20 microns and is inert. In one embodiment the clay may be kaolin clay. In one embodiment 90% of the kaolin clay particles may be under 10 microns in size. In another embodiment the clay be calcium bentonite may have a particle size of under 20 microns. In some embodiments the compositions of the present invention may include wax or resin to increase the water resistant properties of the coating. The wax may be any wax. The wax may be a petroleum wax. In one preferred embodiment the wax may be paraffin wax. 17 In another preferred embodiment the wax may be palm wax. In a further preferred embodiment the wax may be Galoryl ATH 709 as supplied by Lake Industries, Australia. The resin may be any resin. In another preferred embodiment the resin may be a resin which has a melting point of 110 C. In one preferred embodiment the resin may be C9 petroleum resin as supplied by Connell Bros Company Australasia Ltd. In another preferred embodiment the resin may be a plant resin. The plant based oil may be any plant oil provided it doesn't react with urea or other acidulated fertilisers. In one preferred embodiment the oil may be a vegetable based oil. In some preferred embodiments the oil may be a naturally occurring oil. In one preferred embodiment the oil may be boiled linseed oil. In some preferred embodiments the oil may be a plant based oil. In further preferred embodiments the plant based oil may include one or more further additives. The trace elements may be any trace elements it is desired to deliver to a plant. In some cases the trace elements may benefit the plant (e.g. for increased growth or other desired physiological response) and in other cases the trace elements may be for delivery to an animal via the animal's ingestion of a plant. 18 Some non-limiting exemplary examples of suitable powdered trace elements for the coating include plant and/or animal assimilable forms of: * Magnesium * Silicon * Copper * Boron * Selenium * Zinc * Iron * Manganese * Iodine * Calcium However this list is not exhaustive. The purpose of the trace elements is in many cases to enhance the value of the plant to an animal. For example, the inclusion of selenium in a plant increases the levels of selenium within an animal which ingests said plant. In one preferred embodiment the powdered trace element may be in the form of magnesium oxide. The inventor has found that where MgO particles of 45 microns or less are used in the coating composition this increases the encapsulation of the urea core and helps prevent or significantly delay any reaction occurring between superphosphate and the coated urea in a blend thereof. 19 In another preferred embodiment the powdered trace element may be in the form of silicon dioxide. The minerals may be any minerals it is desired to deliver to a plant. In some cases whilst the minerals may primarily benefit the plant (e.g. for increased growth or other desired physiological response) the minerals may also be beneficial to an animal upon delivery thereto via the animal's ingestion of a plant. Some non-limiting exemplary examples of suitable minerals for the core include plant assimilable forms of: * Phosphorous * Nitrogen * Potassium * Carbon However this list is again not exhaustive. The purpose of the minerals is generally to improve the physiology of a plant, or in some cases plant and/or animal which assimilates the mineral. It should be note that carbon can as well as forming a core of a fertiliser also be used in powdered form having a particle size of less than 45 microns in a manner similar to trace elements such as MgO. In some preferred embodiments the minerals may be selected from one or more of the following assimilable forms: * Single super phosphate * Diammonium phosphate 20 * Monoammonium phosphate * Ammonium Polyphosphate * Ammonium sulphate * Potassium chloride * Potassium Sulphate * Potash e.g. potassium carbonate or potassium hydrochloride Again this list is not intended to be exhaustive. The acrylic emulsion used when creating a plurality of layers around the granule/chip may be any suitable stable emulsion having regard to the composition and its intended use. The acrylic emulsion may be PRIMALTM - E-1 764K Acrylic Emulsion Polymer from ROHM HAAS. Other acrylic emulsions are envisaged which have similar characteristics to PRIMAL Acrylic Emulsion Polymer. 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. 21

Claims (24)

1. A fertiliser composition which includes a nutrient source in the form of a fertiliser granule or chip, coated with a coating composition comprising a mixture of clay and water wherein the ratio of clay to water falls within a range substantially between 30:70 and 90:10 and wherein the clay particle size is less than 20 microns and the clay is inert.

2. A fertiliser composition as claimed in claim 1 wherein the ratio of clay to water is 50:50.

3. A fertiliser composition as claimed in claim 1 wherein the ratio of clay to water is substantially 3:1 and the composition also includes an acrylic emulsion polymer to aid drying of the mixture.

4. A fertiliser composition which includes a nutrient source in the form of a fertiliser coated with a coating composition comprising a mixture of clay and oil wherein the ratio of clay to oil falls within a range substantially between 40:60 and 90:10 and wherein the clay particle size is less than 20 microns and the clay is inert.

5. A fertiliser composition as claimed in claim 4 wherein the ratio of clay to oil is 50:50.

6. A fertiliser composition as claimed in any one of claims 1 to 5 which includes 0.3% Xanthan or Guar gum (w/v).

7. A fertiliser coating composition for fertiliser, granules or chips which includes 66% oil (w/v) 33.7% clay by (w/v) and 0.3% Xanthan or Guar gum (w/v). 22

8. A fertiliser composition as claimed in any one of claims 1 to 5 which includes 5-10% (w/v) MgO wherein said MgO has a particle size of less than 45 micronGs.

9. A fertiliser composition as claimed in any one of claims 1 to 5 which includes 5-10% (w/v) powdered carbon or at least one trace element, wherein said carbon and trace element(s) has/have a particle size of less than 45 microns.

10. A fertiliser composition which includes a core comprising a fertliser granule/chip, wherein the core is coated with a first layer comprising the coating composition as claimed in any one of the preceding claims and wherein the clay particle size is less than 20 microns and the clay is inert.

11. A fertiliser composition as claimed in claim 10 wherein the coated fertiliser composition includes a second layer comprising a powdered trace element.

12. A fertiliser composition as claimed in claim 10 or claim 11 wherein the fertiliser granule/chip is a urea.

13. A fertiliser blend which includes a quantity of uncoated fertiliser and a quantity of a coated fertiliser composition as claimed in claim any one of claims 1 to 9.

14. A fertiliser blend as claimed in claim 13 wherein the uncoated fertiliser is mature superphosphate, which has a temperature of 300C or below and the coated fertiliser composition is urea.

15. A coating composition which in use is capable of, providing a complete coat to a fertiliser granule or chip, or a mineral granule or chip, the coating composition comprising a mixture of clay and water wherein the ratio of clay to water falls within a range substantially between 30:70 and 90:10 wherein the clay has a particle size of less than 20 microns and is inert. 23

16. A composition as claimed in claim 15 wherein the ratio of clay to water is 50:50.

17. A coating composition as claimed in claim 15 wherein the ratio of clay to water is substantially 3:1 and the composition also includes an acrylic emulsion polymer to aid drying of the mixture.

18. A coating composition which in use is capable of, providing a complete coat to a fertiliser granule or chip, or a mineral granule or chip, the coating composition comprising a mixture of clay and oil wherein the ratio of clay to oil falls within a range substantially between 40:60 and 90:10 wherein the clay has a particle size of less than 20 microns and is inert.

19. A composition as claimed in claim 18 wherein the ratio of clay to oil is 50:50.

20. A coating composition as claimed in any one of claims 15 to 19 which includes 0.3% Xanthan or Guar gum (w/v).

21. A coating composition for fertiliser, granules or chips which includes 66% oil (w/v) 33.7% clay by (w/v) and 0.3% Xanthan or Guar gum (w/v).

22. A coating composition as claimed in any one of claims 15 to 19 which includes 5-10% (w/v) MgO wherein said MgO has a particle size of less than 45 microns.

23. A coating composition as claimed in any one of claims 15 to 19 which includes 5-10% (w/v) powdered carbon or at least one trace element, wherein said carbon and trace element(s) has/have a particle size of less than 45 microns.

24. A coating composition which in use is capable of, providing a complete coat to a fertilizer granule or chip, or a mineral granule or chip, the coating 24 composition comprising a mixture of clay and an oil/water emulsion wherein the ratio of clay to emulsion falls within a range substantially between 30:70 and 90:10 wherein the clay has a particle size of less than 20 microns and is inert. 25