FERTILISER AND FEED SUPPLEMENT COMPOSITION
FIELD OF THE INVENTION
This invention relates to a fertiliser and/or animal feed supplement and method of producing a fertiliser and/or animal feed supplement. In particular the invention relates to a fertiliser based on at least one by-product of alcohol distillation from sugar cane, preferably arising from fermentation of molasses. In some circumstances, the fertiliser may also be the same as the an animal feed supplement.
BACKGROUND OF THE INVENTION
Many attempts have been made to fertilise plants and supplement animal diets. At least some of these attempts originated virtually simultaneously with the first efforts of human kind to farm and herd animals. The earliest approaches are understood to have been based on the use of animal manures to enhance soil nutrient level for plants.
Modern mining and chemical techniques have also been applied to produce enhanced natural products and even synthetic fertilisers. A very widely used form of fertiliser is superphosphate which is a mixture of gypsum and monobasic calcium phosphate resulting from the action of sulphuric acid on phosphate rocks.
Sugar refining results in the production of molasses which may in turn be subject to fermentation and distillation to produce ethanol. A by-product of this process is a liquid material which is sometimes called "dunder", a term originally arising from the rum distillation process. This material is also sometimes known as vinasse or molasses stillage. Dunder is usually a dark brown to black liquid with a sharp odour similar to molasses and a pH around 4.7. Dunder has been applied and supplied by the applicant as a fertiliser and also as an animal feed supplement. For example, dunder has been applied to fields dedicated to growing sugar cane,
through truck or tractor drawn tanks. One advantage of the application of a liquid fertiliser is a more precise distribution to crops then in dry fertiliser application. While having a rich supply of a number of nutrients, dunder is deficient in phosphorus both as a fertiliser and a feed supplement.
Various attempts have been made by the applicant to add phosphorus to dunder to produce a material which is more nutritionally balanced both for plants and animals. The most common form of phosphorus used in dry and complete fertiliser mixtures is di-ammonium phosphate ("DAP"). Attempts to dissolve or evenly disperse DAP in the liquid dunder fertiliser or feed supplement resulted in problems arising from insufficient solubility coupled with variable solubility of the product. Two significant disadvantages of this result are immediately apparent. The first is an inability to combine an adequate amount of phosphorous to produce a balanced fertiliser or animal feed supplement. The second is a major problem in quality control. With variation intra- and inter-batch, it is not possible to produce a consistent product, even one that is phosphorus deficient. It is therefore impossible to provide accurate labelling of a product without individual batch analysis. Such a fertiliser would be unsuitable for accurate assessment of phosphorous status of the material and consequent application rate to land without ongoing scientific analysis of the product and treated land. This is clearly impractical.
The usual process in the use of dunder is to provide a supplementary dry phosphorus fertiliser application to the land along with dunder. Likewise, animal feeds may require phosphorous supplementation when using the dunder product. This clearly complicates the application process requiring two separate procedures using different equipment in land fertilisation. It would be advantageous to provide a single liquid material comprising dunder and adequate reasonably stable phosphorous levels to produce a soil fertiliser or feed supplement.
SUMMARY OF THE INVENTION
In one form although it need not be the only or the broadest form, the invention resides in a composition formed from a by-product derived directly or indirectly from the sugar refining process and small monoammonium phosphate ("SMAP") mixed with or dissolved in the by-product.
Preferably the by-product is dunder wherein the dunder is formed from an alcohol distilling process carried out on molasses. The alcohol distilling process preferably produces ethanol. The dunder is preferably a liquid material containing one or more of the following approximate levels of inorganic components, nitrogen 0.8% W V, phosphorus 0.05% W/V, potash 3.0% W/V, calcium 0.7% W/V, magnesium 0.45% W/V and sulphur 0.3% W/V.
The SMAP is preferably substantially of a particle size of 2mm or less. More preferably the particle size is 1 mm or less. Most preferably the particle size is 0.85mm or less. The SMAP may be present in the composition at a rate sufficient to give a phosphorous content of up to 5% W/V. Preferably the phosphorus content is up to 3% W/V. Most preferably the phosphorus content is in the range of 0.5% to 1.5 % W/V.
In a second aspect the invention resides in a method of producing a composition as a fertiliser or animal feed supplement said method comprising the steps of providing dunder in a liquid form and mixing SMAP into the dunder to provide a desired level of phosphorus. Preferably the desired level of phosphorus is up to 5% W/V. The desired level of phosphorus may be 3% W/V or less or most preferably the desired level of phosphorus is in the range of 0.5% to 1.5% W/V.
In a third aspect the invention resides in a method of fertilising soil said method comprising the step of distributing onto soil a composition as described above or formed according to the process described above.
ln a fourth aspect the invention resides in a method of supplementing stock feed said method comprising the steps of providing a composition as described above or as produced according to the method described above and; allowing stock, such as cattle, to have access to the product.
The method may include the step of mixing the product with other dietary ingredients.
BRIEF DESCRIPTION OF FIGURES
Figure 1 is a graph of nitrogen loss plotted against time.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Dunder as a fertiliser has a wide range of advantages. Figure 1 is a graph of cumulative loss of nitrogen plotted against time, in days, after application. The highest loss of ammonia vapour occurs when urea alone is placed on the surface of a trash blanket. If urea is mixed with dunder its loss is significantly reduced. If the urea is present in an enhanced dunder ("Liquid One Shot" or "LOS"), the loss is even further reduced. Retention of ammonia provides an ongoing accessible nitrogen store for plant growth and is therefore of considerable advantage.
Dunder contains around 8 kilograms of nitrogen per cubic metre. Approximately half of this material is available to a crop, such as a sugar cane crop, within 2 months of application.
The enhanced dunder product or LOS may be produced by adding additional urea and preferably also sulphuric acid. Once form of this preferred formulation results in a total nitrogen concentration of around 47.5 kilograms per cubic metre of fertiliser product. As dunder is an acid product in its own right, it has a stabilising effect on reducing ammonia volatilisation which is a problem causing nitrogen loss
from urea. Some data has shown the virtual absence of nitrogen loss for up to 5 days after application and a 30% reduction of nitrogen loss compared to urea when spread onto a trash blanket. Potassium at a rate of 30 kilograms per cubic metre is also a major nutrient added to soil from dunder and in fact recycled to the soil in relation to further sugar cane growth. Potassium is in a soluble form and therefore immediately available to a crop upon entering the soil profile.
Existing sulphate in dunder is approximately 3 kilograms per cubic metre. Calcium and magnesium are also present at approximately 7 kilograms and 5 kilograms respectively per cubic metre.
Enhanced dunder may be produced by combining urea and sulphuric acid with dunder to produce a nutritionally concentrated product. In one formulation the enhanced dunder may have 47.5 kilograms per cubic metre of nitrogen as compared to 8 kilograms of nitrogen per cubic metre of dunder. Such an improved material may also have an additional 32.8 kilograms of sulphur.
One method of forming enhanced dunder or LOS involves first forming a concentrate. The concentrate may be formed by mixing granulated urea with dunder. The relative proportions may be 14,380 kg of dunder and 5,300 kg urea. Once the materials are mixed they may be combined with 420 L of sulphuric acid to provide a liquid concentrate, sometimes referred to as "Liquid Top Dressing" or "LTD". A similar method and formulation may be obtained using 5050 kg of Urea, 14,380 kg of dunder and 650 kg of sulphuric acid providing a ratio of approximately 0.25:0.72:0.03 on a weight basis. This concentrate may in certain circumstances, be used alone. Alternatively the concentrate may be mixed with raw dunder in any proportions chosen to provide a desired level of nutrients. The calculation of relative proportions is well known to persons skilled in the art.
However, as previously noted, both dunder and enhanced dunder are markedly deficient in phosphorus. Attempts by the applicant to produce a phosphorus enriched version of the dunder fertiliser failed due to poor and variable solubility
with an additional detraction of a tendency for phosphorus to precipitate out of solution. This presents serious problems in relation to supplying a product to end users which is both adequate in absolute phosphate levels as well as quality assured and stable. Variability in the quality of the product will result in an unpredictable effect in treated paddocks.
The advantages of dunder and its transportability have been increased by more effective distillery processes which have reduced the amount of water in the product. While levels of dissolved solids of 8-7% were common in dunder, resulting transportation of the product required considerable amount of effort and expense devoted to basically transferring water. New process efficiencies now produce up to 27% dissolved solids in dunder making for a commercially more attractive product in the supply chain. However the phosphate deficiency has until now not been addressed. It should be noted that the present invention extends to use of both lower and higher concentrated forms of dunder as well as enhanced and raw dunder.
Table 1 shows a basic break down of the contents of one form of dunder. The phosphorous level can be seen to be a low 0.05% W/V.
Constituents of Dunder
Organic contents: % mass at 30% solids Inorganic contents: % w/v
Water 70 Nitrogen 0.8
Gums 7 Phosphorus 0.05
Fatty Acids 6 Potash 3.0
Sugars 4 Calcium 0.7
Protein 4 Magnesium 0.45
Glycerol 2 Sulphur 0.3 -j Vitamins 1.8
Trace elements: mg/l
Copper 1.3
Zinc 7
Iron 100
Manganese 60
PH 4.5
Conductivity: ms/cm 43
Density kg/I 1.15
BOD ppm total 220000
Viscosity, CP@ 30*C 6
The applicant has attempted to use di ammonium phosphate (DAP) to provide a more balanced product and preferably one, which provides the entire phosphorous requirement for the fertilising process. Results of four samples are shown in Table 2. Of the four product results, Samples 1 and 4 show attempts to use DAP in solution with enhanced dunder. The resulting phosphorous dunder concentration shows a low and a varying level between the two products (0.32 - 0.21% W/V) highlighting the difficulties of phosphorus supplementation by addition of commonly used products. The levels in dunder alone (sample 4) and enhanced dunder (sample 3) are also seen to be very low. It has therefore been traditionally found that use of DAP and of monoammonium phosphate (MAP) are unsuitable for producing a stable phosphorus supplemented product.
TABLE 2
Surprisingly however the inventor has found that the use of a fine untreated form of MAP ("SMAP") provides a product that is both stable and has high levels of phosphorous retention. This SMAP product displays compatibility characteristics that were unsuspected and are suitable in generating a new liquid fertiliser and animal feed product with relatively high phosphorous. Monoammonium phosphate is also known as ammonium dihydrogen phosphate and has the formula (NH4) H2P04. SMAP is preferred in a form in which 99% of the material is 0.85mm or less in particle size. It is usually a granular solid which is grey/brown in colour. This product is available from Incitec Fertilisers Limited of Paringa Road, Gibson Island, Murrarie, Brisbane, Australia.
The following examples are given by way of non-limiting disclosures and without wishing to restrict the scope of the invention.
EXAMPLE 1
A laboratory trial was conducted using SMAP.
77.8 g SMAP (~77.8g/1.25g/ml = 62.24 ml) + 1L concentrate (77.8gSMAP/1.0624L) were added to provide a concentration of 73.23 g SMAP/L (0.73g/10ml) 0.07323 kg SMAP/L = 0.0157 kg P/L = 1.57 % W/V P The concentrate was LTD formed according to the above description.
SMAP and concentrate were mixed in a stirred beaker. Samples were taken at 10, 20 & 30 minutes of stirring and placed into 10 ml measuring cylinders. Measurement of solids was carried out after 48 hrs settling. Additional precipitate on first addition of SMAP is approximately proportional to the amount of SMAP added. Measured P in solution was measured with Inductively Coupled Plasma Mass Spectroscopy ("ICP").
Theoretical P = P added from SMAP + P from concentrate
= 1.57% W/V + 0.04% W/V = 1.61 % W/V P
TABLE 3
%P
1.61
100.5
102.3
99.2
The results are shown in Table 3.
The test samples showed a high percentage of actual phosphorus content in comparison to the theoretically estimated amount of phosphorus present. The level of phosphorus expected (1.61%) was largely attained and is much higher than that obtained with earlier attempts at phosphorus addition. Further, the phosphorus stayed in solution over a significant time.
EXAMPLE 2
A laboratory trial was conducted using SMAP.
151.4 g SMAP (~ 151.4g/1.25g/ml = 121.12 ml) + 1L concentrate of LTD concentrate were combined to provide a concentration of (151.4g SMAP/1.121 L) which is 135.04 g SMAP/L (1.35/10ml) or 0.13504 kg SMAP/L = 0.02903 kg P/L = 2.9% W/V P
The concentration of P present was determined using ICP and after stirring.
Theoretical P = P added from SMAP + P from concentrate
=2.90% W/V + 0.04% W/V =2.94% W/V P
TABLE 4
Error ± 5%.
The results are shown in Table 4. The left hand column indicates stirring time with precipitate virtually disappearing after 10 minutes stirring.
The level of SMAP added is approximately twice that of Example One. The percentage level of phosphorus is also theoretically twice that of Example One. Surprisingly the theoretical level of phosphorus was substantially attained in practical terms and was stable over the period of the test.
EXAMPLE 3
SMAP was combined with concentrate (LTD) in a pilot plant trial.
65 kg SMAP (65000g SMAP/1.25g/ml = 52000 ml SMAP = 52 L) and 890 L concentrate (LTD) were combined to give a concentration of 65 kg SMAP/942 L = 0.069 kg SMAP/L or 0.01484 kg P/L with a phosphorous concentration of 1.48% W/V P
The solution was mixed and samples taken for ICP analysis at various time intervals.
Theoretical P = P added from SMAP + P from concentrate =1.48% W/V + -0.04% W/V =1.52 W/V P
TABLE 5
%P
1.52
96.9
90.2
92.4
Average 91.93
SMAP + cone was then diluted with dunder to form the final product.
Theoretical P = P added from SMAP + P from dunder =0.49% W/V + -0.04% W/V
=0.53% W/V P
TABLE 6
Results of check test 0.74 0.48 0.41 0.53 2.78
Results are set out in Table 6.
The percentage of phosphorous obtained was high in the concentrate mixture and diluted further to around 0.5% W/V with the addition of dunder. Again the levels of P actually obtained were very close to the theoretical level predicted and the material was stable in its mixed state.
EXAMPLE 4 A trial was conducted to investigate the suitability of Monoammonium phosphate (MAP) in a non fine form.
112 kg MAP (112 kg MAP /1.8g/ml = 62.2 L MAP) and 1238 L concentrate (LTD) were combined. The mixture was 112 kg MAP/1302 L = 0.086 kg MAP/L. This gave 0.01852 kg P/L with 1.85 % W/V P
The solution was mixed and samples taken for ICP analysis at various time intervals.
Product = above solution + 1091 L dunder
Theoretical P = P added from MAP + P from concentrate = 1.85% W/V + -0.04% W/V = 1.89% W/V P
TABLE 7
%P
1.89
37.2
51.9
61.4
67.3
72.9
74.0
90.7
The results are shown in Table 7.
This formulation, including phosphorus, provided a higher level of stably dissolved phosphorus but still lower in percentage terms than SMAP and effectively a phosphorous deficient formulation. There was also rapid settling 60 minutes post cessation of stirring even after 22 hours stir time.
EXAMPLE 5
13.2g SMAP (13.2g SMAP/1.25g/ml = 10.56 ml SMAP) and 100ml concentrate (LTD) were combined.
This provided 13.2g SMAP/110.56 ml which is 0.1194 g SMAP/ml and 0.1194 kg SMAP P/L (ie SMAP phosphorus per ml).
This provides 0.02567 kg P/L or 2.57% W/V P
The solution was mixed and samples taken for ICP analysis at various time intervals.
Theoretical P = P added from SMAP + P from concentrate =2.57% W/V + -0.04% W/V
=2.61 % W/V P
The product was a combination of the above and dunder on the ratio 1 :1.2 (above mix: dunder)
Theoretical P (Product)
= P added from SMAP + P from dunder =1.167% W/V + -0.04% W/V =1.21% W/V P
TABLE 8
The resulting product included a relatively high and stable phosphorous level as shown in Table 8.
EXAMPLE 6
SMAP was added to enhanced dunder ("Liquid One Shot") to provide around 5kg of phosphorous (0.50% W/V) per cubic metre of finished product. To test the stability, a truck was filled with the product and samples were initially taken. The truck load of product was dispersed and two samples were taken towards the end of the load. In the first truck the initial concentration was 0.5% W/V of phosphorus and the final average test gave a result of 0.51 % W/V of phosphorus. In a repeat of the test the initial result was 0.48% W/V of phosphorus at the start and 0.50%
W/V of phosphorus as an averaged end result. This trial established that the product produced according to the present invention is stable in the essential commercial context of a transport and dispersal vehicle.
The inventor has surprisingly discovered a means of elevating the level of phosphorous in a useful by-product of ethanol production from a sugar cane refining by-product. The invention provides a stable product with acceptable phosphorous levels that may be distributed commercially for soil fertilisation and animal feed supplementation. Mixing may be by any suitable means preferably using a mechanical stirring device. High shear mixing may be utilised. The SMAP may be added to a concentrate such as LTD to provide a mixing solution for addition to dunder or for use by itself as a fertiliser or indeed a feed additive.
Advantages to farmers are multiple and of commercial significance. A single high quality product can be used in a single application or spaced sequential applications to provide high levels of plant nutrition. Recycling of a by-product of the sugar refining process also is very real in that enormous volumes of dunder are produced in a year. Creating an application and market for a fully balanced product beyond the market currently existing for dunder is of great advantage. Phosphorus is also a vital ingredient of the diet of an animal being of particular importance in the bone growth, lactation and intracellular biochemical system. Balancing the substance provides a benefit to farmers particularly those raising ruminants.
Application of the liquid product to soil may be accomplished by any suitable known means, including by spraying, wetting and other dispersal means. Application rates will depend on soil tests. An example of average use in the sugar industry ranges between 15 to 30 kgs of finished product per hectare as an annual maintenance level to sustain phosphorus for root development.
When used as a feed supplement, the required rate will vary with the condition and nutritional status of the livestock. Many coastal soils are phosphorous deficient,
generating a need for supplementation. Dairy cattle may be exposed to the supplement through addition to grain rations during milking. Range animals such as beef, cattle and sheep may be supplemented by provision of licks and/or mixing with hay rations for distribution.
The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in any country.
Throughout the specification the aim has been to describe the preferred embodiments of the invention without limiting the invention to any one embodiment or specific collection of features. Those of skill in the art will therefore appreciate that, in light of the instant disclosure, various modifications and changes can be made in the particular embodiments exemplified without departing from the scope of the present invention. All such modifications and changes are intended to be included within the scope of the appendant claims.