FOR PRODUCING SAME Cross-Reference to Related Applications

[0001] The present patent application claims the benefits of priority of American Provisional Patent Application No. 62/937872, entitled “Fertilizer composition comprising tree ashes and method for producing same” and filed at the United-States Patent and Trademark Office on November 20, 2019, the content of which is incorporated herein by reference.

Field of the Invention [0002] The invention relates generally to fertilizer compositions and, more particularly, to fertilizer compositions comprising wood ashes and preferably tree bark ashes. Even more particularly, the present invention relates to an improved method of producing high quality, natural and organic fertilizers comprising mycorrhiza and tree bark ashes. In some embodiments, various other substances are used as raw material such as bone powder, fish and crustaceans residues and algae. The fertilizer formulations disclosed herein are ideal for acidic soils as well as soils with low nitrogen.

Background of the Invention

[0003] The major elements used to synthesize the organic compounds needed to grow trees are carbon (C), oxygen (O) and hydrogen (H). The purpose of incineration of biomass is to release the chemical energy stored in the chemical bonds of the organic molecules as heat energy. This is achieved by oxidation of the organic compounds. During the oxidation the greater part of the organic compounds are volatilised as C02 and H20, the same constituents that the tree once used as building blocks during photosynthesis. N and S are also volatilised as nitrogen oxides (NOx) and sulphur dioxide (S02).

[0004] Around 3% (by weight) of the fuel is left as ash after a complete combustion. The major elements in the ash are Ca, K, Mg, Al, Fe, Na, Mn, P and S. The ash has an alkaline reaction (liming effect) and when mixed with water the pH of the solution becomes higher. Thus, wood ash constitutes a well-balanced nutrient content for fertilizers with the exceptions of carbon and nitrogen lost during combustion. For this reason, wood ash needs to be combined with sources of these elements to create a complete fertilizer. More importantly, using biomass ash as fertilizer constitute a sustainable alternative to chemical fertilizers. However, the release rate of nutrients from the ashes need to be controlled to avoid nutrients shock to plants. Converting the ashes into pellets or granulated ash is a good choice to slow down the release rate of nutrients and prevent dust formation, an important health hazard. However, in doing so, the ashes are very often overly compressed such as to produce a cement like consistency which considerably reduces the release rate into the soil and jams the production equipment.

[0005] Nitrogen could then be added to ash fertilizers by co-granulating the bio-ash with, for example, sewage sludge. In an attempt to synthesize a complete fertilizer from wood ash, one study (Pesonen et ah, 2015) co-granulated wood ash, or bio-ash, with sewage sludge and lime and concluded that the concentrations of nutrients (Ca, K and P) were reasonably high. The sewage sludge provided the nitrogen whereas the addition of lime improved the neutralizing capacity of the granules. Although the fertilizer was complete and of good quality, a pitfall of this particular formulation is the access to sewage sludge which is not necessarily easily accessible in large quantities on farms.

[0006] Another study examined the possibility of mixing wood ash with meat and bone meal which are good sources of nitrogen and phosphorus (Pedersen and Gronlund, 2011). This particular study compared a standard chemical fertilizer NPK (21-4-10) to the mixture of wood ash + meat and bone meal and found that the mixture gave the highest yield of barley compared to the chemical fertilizer, demonstrating the feasibility of using a mixture of wood ash with other organic sources of nitrogen.

[0007] Other sources of nitrogen include manure. Amongst the various manure, poultry manure was used in one study to synthesize granulated mixtures of poultry manure with wood ash in different proportions (Mieldazys et ah, 20191. Although the content of the granules are complete to make a good quality fertilizer, a major pitfall of these granulated fertilizer is their slow and even lack of release into the grounds. Thus, although their content is adequate, their delivery is less than optimal and consequently, their effective content is of poor quality. Some preliminary studies have even suggested that this possibility may not be feasible due to the very low recovery of nutrients after granulation (Dede and Ozer, 2018; Pesonen et al., 2017). We also investigated the effects of granulating poultry manure with wood ash and found that the bioavailability of nutrients such as Ca, K, Mg, P, S and N after granulation was too low to be used as an efficient fertilizer.

[0008] Taken together, there is a need for an improved wood ash-based fertilizer formulation that significantly improves delivery into the soils and improves the overall bioavailability of the nutrients.

Summary of the Invention [0009] It is therefore an object of the present invention to disclose a formulation that uses wood ash and manure as building blocks for a nutrient-complete and bioavailable fertilizer that is optimally released into the ground.

[0010] It is the object of the present invention to address the pitfalls of the prior art. The fertilizer composition according to the present invention comprises wood ash that is not granulated using traditional granulation equipment but that is rather agglomerated to form less dense clusters that can be combined with organic matter using the method disclosed to create a complete and more optimal bioavailable fertilizer for use in agriculture.

[0011] Amongst the other organic matter, granules or clusters of manure such as poultry manure can be added to the wood ash as a source rich in nitrogen. Other substances which may be used in the present invention are dried and powdered fish and crustaceous residues, bone powder, mycorrhizae, and binders such as algae, fish residues or Lignosol® pelleting aid. Additional sources of manure can also be used and in a separate embodiment of the present invention such as equine manure.

[0012] It is another object of the present invention to disclose the method for producing the fertilizer of the present invention.

[0013] Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. Brief Description of the Drawings

[0014] The above and other aspects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which: [0015] Figure 1 is a flowchart which illustrates a prior art method for granulating all components of the fertilizer at once which limits bioavailability;

[0016] Figure 2 is a flowchart which illustrates an embodiment of the invention; and

[0017] Figure 3 shows the different liming power of the lime (dotted line) compared to free (i.e. ungranulated) wood ash (solid line). Detailed Description of the Preferred Embodiment

[0018] A novel fertilizer composition comprising tree ashes and method for producing same will be described hereinafter. Although the invention is described in terms of specific illustrative embodiments, it is to be understood that the embodiments described herein are by way of example only and that the scope of the invention is not intended to be limited thereby.

[0019] Typical element concentrations contained in wood ash produced from the combustion of Quebec (Lac St-Jean region) tree barks:

Table 1: Typical element concentrations in wood ash (mg/kg) Table 2: Typical metal concentrations in wood ash (mg/kg)

[0020] Examples of the composition of fertilisers made in accordance with the teachings of the present invention are provided hereunder:

[0021] Example 1 of Fertilizer Formulation

[0022] Example 2 of Fertilizer Formulation

[0023] Example 3 of Fertilizer Formulation

[0024] Example 4 of Fertilizer Formulation

[0025] The percentage (by weight) of wood ash can vary between 30% and 55% depending on the need to increase the pH of the soil. The more wood ash, the greater the liming effect.

[0026] The percentage (by weight) of manure can vary between 30% and 60% depending on the need to add Nitrogen to the soil.

[0027] The percentage (by weight) of fish/crustacean/bone powder can vary between 10% and 15%. [0028] Mycorrhizae may be added (between 0% and 5%) to increase the formation Mycorrhizal networks which are underground hyphal networks created by mycorrhizal fungi that connect individual plants together and transfer water, carbon, nitrogen, and other nutrients and minerals.

[0029] It is particularly important that the organic components be granulated or agglomerated together and that the inorganic components be separately agglomerated to form clusters but not granulated.

[0030] A binder such as algae, fish residues or Lignosol® pelleting aid may be used as needed to form granules or clusters with the organic materials.

[0031] The humidity content of the fertilizer should be adjusted to be in the range of between 7% and 15%.

[0032] An embodiment of the method of producing a fertilizer according to the invention will now be described.

[0033] Step 1: Mixing wood ashes together as needed to form clusters.

[0034] Step 2: Adding bone powder to the clusters formed in Step 1.

[0035] Step 3: Mixing the manure, the mycorrhizae and the binder to form granules or clusters.

[0036] Step 4: Mixing the wood ash clusters with the organic granules or clusters.

[0037] Step 5: Putting the mixed granules and clusters of Step 4 in bags or other containers.

[0038] Another important aspect the formulation of the fertilizers described herein is the role of the bone powder in controlling the release of nutrients into the soil to prevent the shock usually observed when the wood ashes are not granulated. Preferably, the bone powder is used to create a coating on the wood ash granules so as to slow down but not prevent the release of the nutrients from the wood ash into the soil. This can be done by missing the wood ash and the bone powder together at the same time or by mixing the wood ash so as to form clusters and then adding the bone powder which will form a coating on the wood ash clusters. [0039] Ideally, the fertilizer composition of the invention is spread on the soil in late fall.

[0040] While illustrative and presently preferred embodiments of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.

Prior art references

Dede OH and Ozer H. (2018). Enrichment of poultry manure with biomass ash to produce organomineral fertiliser. Environ. Eng. Res. 23(4): 449-455.

Haraldsen TK, Pedersen PA, Gronlund A. (2011). Mixtures of Bottom Wood Ash and Meat and Bone Meal as NPK Fertilizer. Recycling of Biomass Ashes. 33-44.

Kartlun et al. (2008). Wood ash recycling - possibilities and risks. Sustainable Use of Forest Biomass for Energy: A Synthesis with Focus on the Baltic and Nordic Region. Chapter 4: 79-108.

Maljanen M, Liimatainen M, Hytonen J and Martikainen PJ. (2014). The effect of granulated wood-ash fertilization on soil properties and greenhouse gas (GHG) emissions in boreal peatland forests. Boreal Environment Research 19: 295-309.

Mieldazys R, Jotautiene E and Jasinskas, A. (2019) The Opportunities of Sustainable Biomass Ashes and Poultry Manure Recycling for Granulated Fertilizers. Sustainability. 77(16): 4466.

Pesonen J, Kuokkanen V, Kuokkanen T, Illikainen, M. (2016). Co-granulation of bio-ash with sewage sludge and lime for fertilizer use. J. Env. Chem. Eng. 4(4): 4817-4821.

Pesonen, J, Kuokkanen, T, Rautio P and Lassi U. (2017) Bioavailability of nutrients and harmful elements in ash fertilizers: Effect of granulation. Biomass and Bioenergy. 100: 92-97.

Pitman RM. (2006). Wood ash use in forestry - a review of the environmental impacts. Forestry: An International Journal of Forest Research. 79(5): 563-588.