Method for reducing emissions from manure

Abstract

The present invention relates to a method for reducing emissions from manure, the method comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7-3.5 g of hydrogen peroxide (H2O2) per 1 kg manure. The invention also relates to a method for improving plant growth. Furthermore, the invention relates to a manure additive for reducing emissions from manure and improving plant growth comprising H2O2 and biochar. Furthermore, the invention relates to an organic fertilizer comprising manure and the manure additive.

Description

[0001] METHOD FOR REDUCING EMISSIONS FROM MANURE

[0002] Field of the invention

[0003] The present invention relates to a method for reducing emissions from manure by adding manure additives, in particular manure additives comprising hydrogen peroxide. The invention also, or alternatively, relates to a method of improving plant growth. Furthermore, the invention also relates to manure additives comprising hydrogen peroxide and an organic fertilizer.

[0004] Background

[0005] The currently recommended and scientifically proven additive for odor and emissions reduction is sulfuric acid. Nevertheless, this compound may lead to operational hazards at the farm level and therefore requires a specific application system which can be expensive. Other compounds, such as nitric acid, effectively reduce methane but lead to higher nitrogen emissions, particularly the greenhouse gas nitrous oxide.

[0006] Other products are commercially available, yet many do not demonstrate effectiveness based on scientific research. Their efficacy may be based on non-substantiated claims and farmer experiences. These additives consist of various chemical and biological compounds as well as minerals and other types of ingredients. The active ingredients are often not disclosed and the mode of action of the products remains unclear. Few commercially available additives are found to be effective in reducing odors and greenhouse gas emissions based on scientific evidence.

[0007] EP 3863 776 Bl relates to a method for treating organic waste comprising: contacting organic waste with a composition that is capable of generating a reactive species; wherein the composition comprises an oxidizing agent, and wherein the reactive species are generated from a source of iodide (G) and the oxidizing agent.

[0008] Biological degradation of manure is the breakdown by microbes (e.g. bacteria, archaea, fungi, etc.) of valuable and useful organic compounds into less valuable smaller organic compounds, which are then further degraded and lost from the waste as gases (e.g. CH4, NH3, CO2, N2, etc.). The larger organic compounds in non-degraded organic waste are useful and valuable because they can act as slow-release sources of fertilizing compounds and also as fiber sources to improve biodiversity and soil health. There is therefore a need to provide methods for treating manure that reduce biological degradation.

[0009] Organic waste comprises fertilizing nutrients (e.g., carbon or nitrogen) containing fertilizing compounds such as amino acids, ammonium (NH ) salts, nitrate (NO3 ) salts, or nitrite (NO2 ) salts. These fertilizing compounds contribute to the ability of manure to fertilize soil when used downstream. Degradation of manure by processes such as denitrification causes the loss of certain fertilizing compounds to the atmosphere, thus reducing the value of manure in downstream applications as a natural organic fertilizer. There is therefore a need for reducing the loss of these fertilizing compounds from manure to maintain the value of the manure in downstream applications.

[0010] Manure can also be degraded by methanogenesis, which is the biological production of methane (CH4). Methanogenesis is normally the final step in the biological decomposition of biomass and is mediated by microorganisms from the Archaea domain, commonly called methanogens. Pathways for methanogenesis include (1) reduction of carbon dioxide, (2) fermentation of acetate, and (3) dismutation (simultaneous reduction and oxidation of a molecule) of methanol or methylamines. The majority (70%) of biologically produced methane originates from the conversion of the methyl group of acetate to methane. Methanogenesis is undesirable because it produces methane, a greenhouse gas, and other gases such as hydrogen sulfide (H2S), which has an undesirable odor.

[0011] Typical dosages of standard acidifying manure additives are in the range of 3-25 kg per m3(approximately 500-1000 kg with dry matter 5-10%) slurry every two to four weeks. For example: Sulfuric acid (H2SO4): 3.5-15 1 for a target pH of 5.5; nitric acid (HNO3): 10-25 1 for a target pH of 5.5; and acetic acid (CH3COOH): 3-14 1 for a target pH of 5.5.

[0012] These additives function by acidifying the manure which reduces microbial activity and diminishes emissions specifically from a pH of 5.5 and below. Although there is a large body of evidence demonstrating that manure acidification is efficient in managing emissions and odors, the operational costs and hazards limit a large-scale application. It would therefore be desirable to provide an alternative solution to limiting emissions and odors from manure by finding a different mode of action that poses a lower threat to agricultural workers. There is therefore a need to find additives that affect the degradation of manure in a different manner and provide additional beneficial effects on the soil and plants.

[0013] Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field.

[0014] Object of the invention

[0015] The objective of the present invention is to improve the state of the art and in particular to provide a method for reducing emissions from manure and / or improve plant growth.

[0016] More particularly, the objective of the invention is to provide livestock effluent management, in particular for the storage of animal manure at farms, and to provide an improved organic fertilizer. The invention addresses the field of manure additives as a treatment for reducing odors and greenhouse gas emissions. The invention also provides, separately or in combination with the other methods described herein, a method of improving plant growth.

[0017] Summary of the invention

[0018] The present invention provides the improvement by the subject matter of the independent claims. The dependent claims further develop the idea of the present invention.

[0019] The present invention provides improved dosages of manure additives based on specific areas of effectiveness to overcome the disadvantages of currently existing solutions. It has been found that the creation of greenhouse gas emissions (referred to herein as “emissions”) can be reduced by using specific manure additives.

[0020] As used herein, reducing “emissions” refers to reducing the emission of at least one greenhouse gas from manure. In one embodiment, the greenhouse gas is selected from nitrous oxide (NO2), methane (CH4) and carbon dioxide (CO2).

[0021] In the first aspect, the present invention relates to a method for reducing emissions from manure and improving plant growth, the method comprising adding to manure 5 - 11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure.

[0022] In a further aspect, the present invention provides a method for reducing emissions and / or improving plant growth, the method comprising adding to manure 5 - 11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure.

[0023] In another aspect, the present invention relates to a method for improving plant growth, the method comprising adding to manure 5 - 11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure.

[0024] In a further aspect, the present inventions provides a method for improving plant growth, the method comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure and applying said manure to the area comprising at least one plant, wherein plant growth is increased relative to a control plant.

[0025] The method according to the invention provides 1) improving nutrient retention for increased fertilization power of natural organic fertilizer, 2) a beneficial effect on the nitrogen fixation cycle (N volatility is reduced and remains fixated in the manure as the mode of action), and 3) a significant reduction of gaseous emissions from manure. These include greenhouse gas emissions, methane (CH4), nitrous oxide (N2O), as well as odorous compounds, such as hydrogen sulfide (H2S) as well as volatile fatty acids (VFAs).

[0026] In a further aspect, the present invention relates to a manure additive comprising iron salt and hydrogen peroxide (H2O2).

[0027] The present invention provides a method for managing the effects of livestock manure storage for fanners interested in reducing odour and greenhouse gas emissions from manure and may as well facilitate handling and field application. The manure handling may be facilitated due to a decreased viscosity, which prevents blocking of equipment and / or distribution tubes etc. and allows for an easier field application.

[0028] In a further aspect, the invention relates to an organic fertilizer comprising manure and manure additives as described in this document, and preferably prepared with a method according to the invention.

[0029] It has surprisingly been found that there is a synergistic effect from combining the manure additives allowing a lower dosage of the additives compared to the recommendation for commercially available manure additives. The serendipitous effect of optionally adding biochar is accelerated plant growth and emissions did not increase compared to the untreated manure.

[0030] As used in this specification, the words “comprises”, “comprising”, and similar words, are not to be interpreted in an exclusive or exhaustive sense. In other words, they are intended to mean “including, but not limited to”.

[0031] In the present context, manure preferably refers to livestock manure from ruminant and swine manure. Most preferably, manure refers to bovine manure, for example cattle manure.

[0032] In the present context, biochar is made up of elements such as carbon, nitrogen, calcium, magnesium, oxygen, phosphorus, and potassium, as well as minerals in the ash fraction. It is produced during pyrolysis, a thermal decomposition of biomass in an oxygenlimited environment.

[0033] In a preferred embodiment of the invention, the biochar is from substrate that is wood. The surface area may vary. Advantageously, the specific surface area is larger than 300 m2per g of biochar.

[0034] In the present context, “recommended dosage (STANDARD)” is the standard dosage recommended in the industry. The standard dosage varies between each component and can be readily accessed in the literature by the skilled person. In the present context, unless specified otherwise, dosages below the standard dosage for a component is referred to as ‘BELOW’, and dosages higher than this standard dosage are referred to as ‘ABOVE’.

[0035] Brief Description of the Drawings

[0036] Figures 1A, IB, 1C, ID show the cumulative emissions of CO2, CH4, N2O, H2S under aerobic conditions at the laboratory scale of manure treated with hydrogen peroxide (H2O2).

[0037] Figure 2 shows the global warming potential (100 years) under aerobic conditions at the laboratory scale of manure treated with hydrogen peroxide (H2O2).

[0038] Figure 3 shows the cumulative emissions of CO2, CH4, N2O, H2S emissions under aerobic conditions at the laboratory scale of manure treated with magnesium sulfate (MgSO4).

[0039] Figure 4 shows the global warming potential (100 years) under aerobic conditions at the laboratory scale of manure treated with magnesium sulfate (MgSCL).

[0040] Figures 5 shows the cumulative emissions of CO2, CEL, N2O, and H2S emissions under aerobic conditions at the laboratory scale of manure treated with iron chloride (FeCh).

[0041] Figure 6 shows the global warming potential (100 years) under aerobic conditions at the laboratory scale of manure treated with iron chloride (FeCh).

[0042] Figure 7 shows the cumulative emissions of CO2 under aerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2) at different dosage ratios and combined with iron chloride (FeC13)). The emissions are shown for: CTRL + 100 FeC13 +100 H2O2; and H2O+FeC13 (75+100; 75 +150; and 100 + 150). Doses ABOVE 100 at 150 were tested in various combinations for effectiveness evaluation.

[0043] Figure 8 shows the cumulative emissions of CEL under aerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2, G) combined with iron chloride (FeCh) at different dosage ratios. The emissions are shown for: Control (A) and FfcCh G) plus FeCh (Fe). 100 represents the standard dosage for H2O2, G and FeCh respectively, 75 represents 25% below the standard dosage and 150% represents 50% above the standard dosage. The emissions are shown for: CONTROL (A) and H2O2 (G) +FeC13 (Fe) (75+100 (B); 75 +150 (C); 100+100 (D); and 100 + 150(E)).

[0044] Figure 9 shows the cumulative emissions of N2O under aerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2) at different dosage ratios and combined with iron chloride (FeCh). The emissions are shown for: CONTROL and H2O2 (G) + FeCh (Fe). 100 represents the standard dosage for H2O2, G and FeCh respectively, 75 represents 25% below the standard dosage and 150% represents 50% above the standard dosage. The emissions are shown for: CONTROL (A) and H2O2 (G) +FeC13 (Fe) (75+100 (B); 75 +150 (C); 100+100 (D); and 100 + 150(E)).

[0045] Figure 10 shows the global warming potential (100 years) under aerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2) combined with iron chloride (FeCh) at different dosage ratios. 100 represents the standard dosage for H2O2, G and FeCh respectively, 75 represents 25% below the standard dosage and 150% represents 50% above the standard dosage. The emissions are shown for: CONTROL (A) and H2O2 (G) +FeC13 (Fe) (75+100 (B); 75 +150 (C); 100+100 (D); and 100 + 150(E)).

[0046] Figure 11 shows the cumulative emissions of CH4 under anaerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2) (G) combined with iron chloride (FeCh) (Fe). The emissions are shown for: CONTROL and H2O2+FeC13 (75+50 and 50+50 ). It is demonstrated that the combination of H2O2+ FeCh at BELOW dosages significantly reduce CEL production from manure compared to CONTROL assays under anaerobic conditions. The emissions are shown for: CONTROL (A) and H2O2 (G) +FeC13 (Fe) (75+50 (B) and 50+50(C).

[0047] Detailed description of the invention The method according to the invention relates to a method for reducing emissions from manure and improving plant growth, the method comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure. By reducing emissions from manure is meant a reduction in the emission of at least one compound (greenhouse gas) from manure compared to the emissions of the at least one compound (greenhouse gas) from a control, untreated sample of manure.

[0048] Furthermore, the emission that can be reduced with the present invention may be selected from the group consisting of CO2, CH4, N2O, H2S, NH3, N2, and a combination thereof. Preferably, the emission is selected from the group consisting of CPU and NO2.

[0049] As shown in Figure 8 and 11, the invention has been shown to significantly decrease methane (CPU) emissions from manure compared to untreated manure. As shown in Figures 9, the invention has been shown to significantly decrease NO2 emissions from manure compared to untreated manure.

[0050] Accordingly, there is provided a method for reducing emissions from manure, the method comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure. Preferably, the method reduces at least CH4 and / or NO2 emissions from manure.

[0051] By a “reduction in emissions” is meant a reduction of at one green-house gas by least 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or more, or 100% or more compared to the level of at least one greenhouse gas emitted from untreated manure or manure-treated soil. The level of a greenhouse gas can be measured using standard techniques in the art. In one embodiment, the at least one green-house gas may be reduced in strict anaerobic or aerobic conditions or atmospheric conditions.

[0052] In another aspect of the invention, there is provided a method for improving plant growth, the method compri sing adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure and applying said manure to an area comprising at least one plant. That is, manure is treated according to the method of the present invention and subsequently applied to an area wherein at least one plant is growing.

[0053] In another embodiment, a method of improving plant growth, comprises adding manure to an area comprising at least one plant, wherein the manure is characterised as comprising 5.0-11.5 g of iron salt per 1 kg manure and 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure. That is, manure produced by a method of the present application is applied to an area wherein at least one plant is growing.

[0054] In one embodiment, the iron salt is selected from the group consisting of ferric chloride (FeCh), ferric nitrate (Fe(NOs)3, and ferric sulfate (F 62(804)3 or a combination thereof.

[0055] In a further embodiment of the methods described herein, the method may further comprise adding magnesium sulfate (MgSO4) in an amount of 25-78 g, preferably 25- 55 g magnesium sulfate per 1 kg manure; and / or 10 - 60 g of biochar per 1 kg manure, preferably 20 - 50 g of biochar per 1 kg manure.

[0056] In another embodiment, the method for improving plant growth comprises adding 5.0- 11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure to manure in an area comprising at least one plant. That is, the components disclosed herein are added to manure already present in an area comprising at least one plant.

[0057] The term ‘plant’ as defined herein may be a monocot or a dicot plant. Preferably, the plant is a crop plant. By crop plant is meant any plant which is grown on a commercial scale for human or animal consumption or use. In a preferred embodiment, the plant is a cereal. In a most preferred embodiment, the plant is selected from rice, wheat, maize, barley, brassica, soybean and sorghum.

[0058] The term "plant" as used herein encompasses whole plants, ancestors and progeny of the plants and plant parts, including seeds, fruit, shoots, stems, leaves, roots (including tubers), flowers, tissues and organs. The invention preferably extends to harvestable parts of a plant of the invention as described herein, but not limited to seeds, leaves, fruits, flowers, stems, roots, rhizomes, tubers and bulbs. The aspects of the invention also extend to products derived, preferably directly derived, from a harvestable part of such a plant, such as dry pellets or powders, oil, fat and fatty acids, starch or proteins. In another aspect of the invention, there is provided a product derived from a plant as described herein or from a part thereof.

[0059] The term ‘improving plant growth’ as defined herein can be taken to comprise any or at least one of the following and can be measured by assessing one or more of (a) increased biomass (weight) of one or more parts of a plant, aboveground (harvestable parts), or increased root biomass, increased root volume, increased root length, increased root diameter or increased root length or increased biomass of any other harvestable part. Increased biomass may be expressed as g / plant or kg / hectare (b) increased seed yield per plant, which may comprise one or more of an increase in seed biomass (weight) per plant or an individual basis, (c) increased seed filling rate, (d) increased number of filled seeds, (e) increased harvest index, which may be expressed as a ratio of the yield of harvestable parts such as seeds over the total biomass, (f) increased viability / germination efficiency, (g) increased number or size or weight of seeds or pods or beans or grain (h) increased seed volume (which may be a result of a change in the composition (i.e. lipid (also referred to herein as oil)), protein, and carbohydrate total content and composition), (i) increased (individual or average) seed area, (j) increased (individual or average) seed length, (k) increased (individual or average) seed width, (1) increased (individual or average) seed perimeter, (m) increased growth or increased branching, for example inflorescences with more branches, (n) increased fresh weight or grain fill (o) increased ear weight (p) increased thousand kernel weight (TKW), which may be taken from the number of filled seeds counted and their total weight and may be as a result of an increase in seed size and / or seed weight (q) decreased number of barren tillers per plant and (r) sturdier or stronger culms or stems. All parameters are relative to a wild-type or control plant.

[0060] By control plant is meant a plant that is not subjected to the methods of the invention, i.e., an untreated plant.

[0061] Preferably, increased plant growth comprises at least one increased biomass (weight) of one or more parts of a plant, aboveground (harvestable parts), or increased root biomass, increased root volume, increased root length, increased root diameter or increased root length or increased biomass of any other harvestable part. Growth is increased relative to a control or wild-type plant. For example, the growth is increased by 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 95% compared to a control plant. In one embodiment, growth may be increased by between 20-50%, more preferably between 5 and 25% or more compared to a control plant.

[0062] Advantageously, in the methods according to the invention the manure is stored with iron salt and hydrogen peroxide (H2O2) and optionally magnesium sulfate (MgSO4) and / or optionally biochar. For example, the manure may be stored for at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9 or at least 10 weeks before being added to the soil to be treated. The manure may be stored under anaerobic or aerobic conditions.

[0063] Alternatively, the manure with the iron salt and hydrogen peroxide (H2O2) and optionally iron salt and / or biochar is distributed onto fields, preferably by spray irrigation, surface spreading, injection, or broadcasting.

[0064] That is, in one embodiment, the method comprises storing the manure with iron salt and hydrogen peroxide (H2O2), and optionally magnesium sulfate (MgSO4) and / or biochar.

[0065] In one embodiment, the method comprises storing the manure with iron salt and hydrogen peroxide (H2O2) and optionally iron salt and / or biochar is distributed onto fields. Distribution is preferably by spray irrigation, surface spreading, injection, or broadcasting.

[0066] The hydrogen peroxide may be provided in the form of pure H2O2 (i.e., 100% H2O2).

[0067] The prior products focus on one specific target area in the context of greenhouse gas emissions and odor reduction, i.e., either methane (CH4) or nitrous oxide (N2O), odor reduction, or texture improvements. The present invention addresses several aspects simultaneously by combining and specifically dosing each component for an optimal result. This improves cost due to the synergies identified, hence a lower amount can be applied. Furthermore, the present invention offers a solution for a variety of manure storage systems with a better chance for broad adoption thanks to additional benefits:

[0068] 1) Greenhouse gas and odor reduction under aerobic conditions

[0069] 2) Nitrogen and carbon retention in the manure due to reduced emissions

[0070] 3) Ammonia (NH3) fixation for improved fertilizing power of manure

[0071] 4) Reduction of odors because of lower hydrogen sulfide (H2S) emissions

[0072] In addition, the present invention may offer the possibility of

[0073] 1) Greenhouse gas and odor reduction under atmospheric conditions

[0074] 2) Greenhouse gas and odor reduction under anaerobic conditions

[0075] Furthermore, it has been found that nitrogen emission has been reduced in the manure treated according to the method of the invention. Without wishing to be bound by theory, it is believed that nitrogen emission reduction results from the binding or retention of nitrogen in the manure, which again provides an increased fertilization power of the manure as an organic fertilizer.

[0076] Accordingly, in one embodiment, there is a method for reducing emissions from manure, the method comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure, wherein the emission is nitrogen emission.

[0077] In summary, this invention addresses the major problems related to long-term livestock manure storage by leveraging the synergistic effects of the combination of additives. These additives consistently limit the production of GHG emissions at aerobic conditions. Additionally, the selected combination at BELOW the STANDARD dose may also diminish unwanted odors from manure storage. Hence, this invention provides reduction of the carbon footprint of livestock farming and mitigate climate change.

[0078] For methods for improving plant growth, the method according to the invention may comprise adding 10 - 60 g of biochar per 1 kg manure to manure, preferably 20 - 50 g of biochar per 1 kg manure. Accordingly, in one embodiment, there is a method of improving plant growth comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure, and further adding 10 - 60 g of biochar per 1 kg manure to manure, preferably 20 - 50 g of biochar per 1 kg manure.

[0079] In another embodiment, there is a method of improving plant growth and / or reducing emissions from manure comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure, and further adding 10 - 60 g of biochar per 1 kg manure to manure, preferably 20 - 50 g of biochar per 1 kg manure.

[0080] Preferably, any of the methods according to the invention comprises the addition of 1.7 to 2.8 g of hydrogen peroxide (H2O2) per 1 kg manure.

[0081] Furthermore, in a preferred embodiment of the invention, iron salt is added in an amount of 5.0-10.5 g of iron salt per 1 kg manure to the manure. This provides the additional advantage of minimizing nitrogen volatilization reducing ammonia (NH3) as such nitrous oxide (N2O) emissions and odor generation due to lowered hydrogen sulfide (H2S) emissions. The mitigation of ammonia (NH3) emission is a precursor of nitrous oxide (N2O), thus a reduction of ammonia will inherently reduce the level of nitrous oxide.

[0082] The iron salt is preferably selected from the group consisting of ferric chloride (FeCh), ferric nitrate (Fe(NOs)3, and ferric sulfate (F 62(804)3 or a combination thereof. The iron salt has been found to reduce odor and separate the solid and liquid fraction which results in less emission as the microorganisms will reduce the consumption of the solids and volatile solids for gas production due to flocculation and segregation.

[0083] In an embodiment of the method of the invention, magnesium sulfate (MgSO4) is added to the manure in an amount of 25-78 g, preferably 25-55 g magnesium sulfate per 1 kg manure.

[0084] In addition, in the method according to the invention the hydrogen peroxide (H2O2), and / or iron salt and / or the biochar limit(s) the generation of gaseous emissions from the manure including greenhouse gases (CO2, CH4, N2O) and odorous compounds (H2S) under strict aerobic conditions as well as atmospheric conditions.

[0085] The iron salt is preferably in powder form.

[0086] Advantageously, in the method according to the invention, iron salt and hydrogen peroxide (H2O2) are added to the manure first and mixed thoroughly, and the optional magnesium sulfate and / or biochar are added subsequently. The mixture is appropriately added to the respective amount of manure.

[0087] The method according to the invention may comprise storage of the manure with iron salt and distribution of the treated manure including the addition of iron salt onto fields for crop fertilization. The iron salt and / or biochar and / or the magnesium sulfate (MgSO4) may be added to the stored manure and distributed on the fields for improved crop fertilization and facilitated manure application. The hydrogen peroxide (H2O2) may be added to the manure to make it more liquid. As such, it is less likely to block the machinery used for transporting and applying the manure on the fields, e.g. by spray irrigation, surface spreading, injection, or broadcasting.

[0088] Alternatively, the iron salt and hydrogen peroxide (H2O2) may be added to the manure first and mixed thoroughly, and the biochar is added subsequently.

[0089] As discussed above, the invention also relates to a manure additive for reducing emissions from manure comprising iron salt and of hydrogen peroxide (H2O2). It is preferred that the manure additive according to the invention comprised 5-31 wt. % of hydrogen peroxide (H2O2).

[0090] Furthermore, preferably the manure additive according to the invention further comprises 23-79 wt. % biochar, preferably 26-59 wt. % biochar.

[0091] In a preferred embodiment of the invention the manure additive comprises 5-11.5 g of iron salt, preferably 5 - 10.5 g of iron salt. In another preferred embodiment of the invention the manure additive comprises 4-31 wt. % of hydrogen peroxide (H2O2), preferably 9-29 wt.% hydrogen peroxide.

[0092] In a further embodiment of the invention, the additive comprises iron salt, preferably in an amount of 65-75 wt. % more preferably 69-71 wt. %, and more preferably the iron salt being selected from the group consisting of ferric chloride (FeCh), ferric nitrate (Fe(NOs)3, and ferric sulfate (Fe2(SO4)s or a combination thereof.

[0093] In a preferred embodiment, the manure additive comprises 9-71 wt. % iron salt, preferably 9-69wt. % iron salt, more preferably 15-35 wt. % iron salt.

[0094] In one embodiment of the invention the manure additive comprises of 59-79 wt. % biochar, 14-29 wt. % iron salt and 7-12 wt. % hydrogen peroxide (H2O2)).

[0095] In another embodiment of the invention the manure additive comprises 23-46 wt. % biochar, 41-62 magnesium sulfate, preferably 9-16 wt. % of iron salt.

[0096] Manure additive according to the invention may be in a liquid or powder form.

[0097] Furthermore, the manure additive according to the invention may comprise additives selected from the group consisting of calcium hydroxide, calcium carbonate, magnesium carbonate, or a combination thereof.

[0098] The manure additive may be mixed with other components before the distribution of the manure additive into the manure. The manure additive may also comprise a filler.

[0099] This combination of hydrogen peroxide (H2O2), biochar, and magnesium sulfate (Mg SO4) is particularly preferred because it provides the advantage of addressing the reduction of methane (CH4) emissions, nitrogen retention in the manure due to the reduction of nitrous oxide (N2O) and hydrogen sulfide (H2S) emissions, and improved carbon content for plant health.

[0100] In the present context, gas emissions are emissions selected from the group consisting of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), as well as odorous compounds, such as hydrogen sulfide (H2S), ammonia (NH3), nitrogen (N2), volatile fatty acids (VFAs) or a combination thereof.

[0101] Advantageously, in the method according to the invention the hydrogen peroxide (H2O2) is added to the manure first and mixed thoroughly, and the biochar and iron salt in powder form, are added as a premix subsequently.

[0102] In the present context, biochar is made up of elements such as carbon, nitrogen, calcium, magnesium, oxygen, phosphorus, and potassium, as well as minerals in the ash fraction. It is produced during pyrolysis, a thermal decomposition of biomass in an oxygenlimited environment.

[0103] As discussed above the invention furthermore relates to an organic fertilizer comprising manure and manure additive as described in this document, and preferably prepared with a method according to the invention. The organic fertilizer according to the invention has a high constant level of nutrients and a reduced odor. The organic fertilizer according to the invention may replace inorganic fertilizers.

[0104] Those skilled in the art will understand that they can freely combine all features of the present invention disclosed herein. In particular, features described for the product of the present invention may be combined with the use of the present invention and vice versa. Furthermore, features described for different embodiments of the present invention may be combined.

[0105] Although the invention has been described by way of example, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the claims.

[0106] Examples

[0107] Example 1 - Laboratory scale trials

[0108] The manure additives according to the invention were tested as follows:

[0109] All laboratory tests are performed batch-wise under aerobic conditions and three different dosages in duplicate in 2.1 1 gas-tight bottles. The additive is applied to 1.5 kg of fresh manure contained in 10 1 vessels. Then, 20 g of the mixture (manure + additive) is transferred into 2.1 1 bottles. The bottles are pressurized up to 500 mbar using compressed air. Headspace conditions are restored by flushing and pressurization whenever the pressure drops under 100 mbar and / or oxygen (O2) concentration drops below 10 % for aerobic tests. Trials are run together with controls (untreated manure with no presence of additive) in a temperature-controlled room at 25°C for 28 days.

[0110] Example 1.1 - Laboratory manure additive trial - Hydrogen peroxide (H2O2)

[0111] The conditions of the trial are as follows:

[0112] 1. Manure slurry: 20 g

[0113] 2. Temperature: 25°C

[0114] 3. Atmosphere: Air (aerobic)

[0115] 4. Number of replicates: 2

[0116] 5. Number of assays: 12

[0117] 6. Pressurized at 500 mbar

[0118] 7. Additive tested: Hydrogen peroxide (H2O2)

[0119] Trial design: Application dosages of hydrogen peroxide (H2O2) for 1.5 kg of manure.

[0120] 3 different conditions are prepared in 10 1 vessels for 1.5 kg of manure.

[0121] Considerations: Hydrogen peroxide (H2O2) is applied directly to the manure and stirred vigorously.

[0122] Characterization of the fresh manure pH 6.97 ± 0.01

[0123] Total solids (%) 12.60 ± 0.17

[0124] Volatile solids (%) 10.41 ± 0.25

[0125] N-NH (mg kg-1 sample) 1278 ± 5

[0126] TKN (mg kg-1 sample) 4919 ± 65 CODt (g O2L-l) 111 ± 5

[0127] NOT, NO3- (mg L-l) 0

[0128] Volatile Fatty Acids (VFAs)

[0129] Acetic (g L-l) 4.61 ± 0.20

[0130] Propionic (g L-l) 1.11 ± 0.04

[0131] Butyric (g L-l) 1.01 ± 0.04

[0132] Isobutyric (mg L-l) 0.06 ± 0.01

[0133] Isovaleric (mg L-l) 0.05 ± 0.01

[0134] Valeric (mg L-l) 0

[0135] Isocaproic (mg L-l) 0

[0136] Hexanoic (mg L-l) 0

[0137] Heptanoic (mg L-l) 0

[0138] Manure treated with hydrogen peroxide (H2O2) - Emission tests (CO2, CH4, N2O, H2S - AEROBIC)

[0139] Figure 1 shows cumulative CO2, CE , N2O, and H2S emissions under aerobic conditions. It is demonstrated that:

[0140] All dosages tested show a similar CO2 production to CONTROL assays under aerobic conditions.

[0141] All dosages tested significantly reduce CH4 production compared to CONTROL assays under aerobic conditions.

[0142] STANDARD and BELOW doses slightly minimize N2O production compared to CONTROL assays.

[0143] Similar behavior in H2S production is observed for all dosages tested.

[0144] Manure with hydrogen peroxide (H2O2) - Global warming potential - aerobic

[0145] (AE) test

[0146] Figure 2 shows the global warming potential (100 years) under aerobic (AE) conditions. It is demonstrated that:

[0147] The global warming potential is highly influenced by N2O production under aerobic conditions.

[0148] - BELOW and STANDARD doses significantly minimize the global warming potential at the end of the experimental time compared to CONTROL assays under aerobic conditions.

[0149] Example 1.2 - Laboratory manure additive trial - Magnesium sulfate (MgSO4 )

[0150] The conditions of the trial are as follows:

[0151] 8. Manure slurry: 20 g 9. Temperature: 25°C

[0152] 10. Atmosphere: Air (aerobic)

[0153] 11. Number of replicates: 2

[0154] 12. Number of assays: 12

[0155] 13. Pressurized at 500 mbar 14. Additive tested: Magnesium sulfate (MgSCN )

[0156] Trial design: Application dosages of Magnesium sulfate (MgSCN ) for 1.5 kg of manure.

[0157] 3 different conditions are prepared in 10 1 vessels for 1.5 kg of manure. Considerations: Magnesium sulfate (MgSCN ) is crushed / ground before application.

[0158] Characterization of the fresh manure pH 7.34 ± 0.01

[0159] Total solids (%) 21.8 ± 0.5

[0160] Volatile solids (%) 9.4 ± 0.2

[0161] N-NH4+(mg kg-1 sample) 2026.9 ± 50.0

[0162] TKN (g kg-1 sample) 4.9 ± 0.2

[0163] CODt (g O2L-l) 121.8 ± 1.9

[0164] NOT, NO3- (mg L-l) 0

[0165] Volatile Fatty Acids (VFAs)

[0166] Acetic (g L-l) 4.4 ± 0.4

[0167] Propionic (g L-l) 1.1 ± 0.1 Butyric (g L-l) 0.8 ± 0.1 Isobutyric (mg L-l) 29.3 ± 4.9 Isovaleric (mg L-l) 94.2 ± 16.0 Valeric (mg L-l) 0 Isocaproic (mg L-l) 0 Hexanoic (mg L-l) 0

[0168] Heptanoic (mg L-l) 0

[0169] Manure with magnesium sulfate (MgSO4 ) - Emission tests (CO2, CH4, N2O, H2S -

[0170] AEROBIC)

[0171] Figures 3 shows cumulative CO2, CPU, N2O, and H2S emissions under aerobic conditions. It is demonstrated that:

[0172] All dosages tested show a reduction in CO2 production compared to CONTROL assays under aerobic conditions.

[0173] The STANDARD and ABOVE doses reduce CH4 production compared to CONTROL assays under aerobic conditions.

[0174] The ABOVE dose reports a lower H2S production than CONTROL tests.

[0175] The following experiments are conducted with the method described above.

[0176] Manure with Magnesium sulfate (MgSO4 ) - Global warming potential - aerobic (AE) tests

[0177] Figure 4 shows the global warming potential (100 years) under aerobic (AE) conditions. It is demonstrated that:

[0178] The global warming potential is highly influenced by N2O production under aerobic conditions.

[0179] ABOVE dosed significantly minimizes the global warming potential compared to CONTROL assays.

[0180] Example 1.3 Laboratory manure additive trial - Iron salt, example Iron chloride (FeC13)

[0181] The conditions of the trial are as follows: 1. Manure slurry: 20 g

[0182] 2. Temperature: 25°C

[0183] 3. Atmosphere: Air (aerobic)

[0184] 4. Number of replicates: 2 5. Number of assays: 12

[0185] 6. Pressurized at 500 mbar

[0186] 7. Additive tested: Iron chloride (FeC13)

[0187] Trial design: Application dosages of Iron chloride (FeC13) for 1.5 kg of manure. 3 different conditions are prepared in 10 1 vessels for 1.5 kg of manure.

[0188] Characterization of the fresh manure pH 6.90 ± 0.02

[0189] Total solids (%) 15.32 ± 0.06

[0190] Volatile solids (%) 12.72 ± 0.11

[0191] N-NH (mg kg-1 sample) 1187 ± 35

[0192] TKN (mg kg-1 sample) 4611 ± 171

[0193] CODt (g O2L-l) 170.6 ± 2.4

[0194] NOT, NO3- (mg L-l) 0 Volatile Fatty Acids (VFAs)

[0195] Acetic (g L-l) 4.82 ± 0.59

[0196] Propionic (g L-l) 1.48 ± 0.09

[0197] Butyric (g L-l) 1.25 ± 0.03

[0198] Isobutyric (mg L-l) 0.07 ± 0.01

[0199] Isovaleric (mg L-l) 0.11 ± 0.01

[0200] Valeric (mg L-l) 0.12 ± 0.01 Isocaproic (mg L-l) Hexanoic (mg L-l) Heptanoic (mg L-l)

[0201] Manure with iron chloride (FeC13) - Emission tests (CO2, CH4, N2O, H2S - AEROBIC)

[0202] Figures 5 shows cumulative CO2, CFU, N2O, and H2S emissions under aerobic conditions. It is demonstrated that:

[0203] All dosages tested show a reduction in CO2 production compared to CONTROL assays under aerobic conditions.

[0204] All dosages tested reduce CH4 production compared to CONTROL assays under aerobic conditions.

[0205] The OPTIMAL and ABOVE dose show a lower N2O production compared to CONTROL.

[0206] The OPTIMAL does reports a slightly lower FES production than the CONTROL test.

[0207] Manure with Iron Chloride (FeC13) - Global warming potential - aerobic (AE) tests

[0208] Figure 6 shows the global warming potential (100 years) under aerobic (AE) conditions. It is demonstrated that:

[0209] The global warming potential is highly influenced by N2O production under aerobic conditions.

[0210] OPTIMAL and ABOVE doses significantly minimize the global warming potential compared to CONTROL assays.

[0211] Example 2 - Dosage optimization - laboratory scale (aerobic)

[0212] Example 2.1 Optimizing dosage of hydrogen peroxide(H20i)

[0213] In the laboratory scale trials manure additives according to the inventions in different dosages were tested under the same laboratory conditions and trial design as described in Example 1. 100 represents the recommended dose STANDARD. Doses BELOW 100 at 50 and 75 were tested in various combinations for effectiveness evaluation. Figure 7 shows the cumulative emissions of CO2 under aerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2) at different dosage ratios and combined with iron chloride (FeC13). The emissions are shown for: CTRL + 100 FeC13 +100 H2O2;and H2O+FeC13 (75+100; 75 +150; and 100 + 150). It is demonstrated that: - All combinations tested show a reduction in CO2 production compared to

[0214] CONTROL assays under aerobic conditions.

[0215] - H2O2 BELOW + FeC13 ABOVE was particularly effective in reducing CO2 emissions. Characterization of the fresh manure pH 8.15 + 0.01

[0216] Total solids (%) 21.7 + 0.25

[0217] Volatile solids (%) 17.7 ± 0.3

[0218] N-NH4+(mg kg-1 sample) 3661 ± 103

[0219] TKN (mg kg-1 sample) 8932 ± 158

[0220] CODt (g O2L-l) 176.1 + 4.3

[0221] NOT, NO3- (mg L-l) 0

[0222] Volatile Fatty Acids (VFAs)

[0223] Acetic (g L-l) 10449 + 116

[0224] Propionic (g L-l) 1926 + 43

[0225] Butyric (g L-l) 110 + 18

[0226] Isobutyric (mg L-l) 1274 ± 7

[0227] Isovaleric (mg L-l) 0

[0228] Valeric (mg L-l) 0

[0229] Isocaproic (mg L-l) 0

[0230] Hexanoic (mg L-l) 0 Heptanoic (mg L-l) 0

[0231] 2.2 Optimizing dosage of HiOi andFeCh

[0232] Next we optimized the dosage of each of H2O2 and FeCl n the combination. For each of H2Og_and FeCh STANDARD refers to the standard dose and is given an arbitrary value of 100, BELOW (75) refers to a 25% reduction in the standard dosage and doses ABOVE correspond to a 50% increase of the standard dosage.

[0233] Combinations of STANDARD, BELOW and ABOVE were tested in various combinations for effectiveness evaluation. Specifically, BELOW H2O2 and STANDARD FeCl3(75G+100Fe); STANDARD H2O2 and High FeCl33 (75G +150Fe); STANDARD H2O2 and STANDARD FeCl3(lOOG+lOOFe); and STANDARD H2O2 and HIGH FeCh (100G + 150Fe).

[0234] Figure 8 shows the cumulative emissions of CO2 under aerobic conditions at the laboratory scale manure treated with hydrogen peroxide (G) combined with iron chloride (FeCl3) at different dosage ratios. The emissions are shown for: Control and H2O2 PIUS FeCl3. All combinations tested show a reduction in CH4 production compared to CONTROL assays under aerobic conditions.

[0235] - H2O2 BELOW + FeCl3ABOVE (i.e., 75G / 150Fe), H2O2 STANDARD + FeCl3STANDARD (i.e., lOOG / lOOFe) and H2O2 STANDARD + FeCl3ABOVE (100G / 150FE) were particularly effective in reducing CH4 emissions.

[0236] The data points for 75G / 150Fe, lOOG / lOOFe and 100G / 150Fe are identical and for ease of representation are represented by the 100G / 150Fe line.

[0237] Figure 9 shows the cumulative emissions of N2O under aerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2) at different dosage ratios and combined with iron chloride (FeCl3). The emissions are shown for: CONTROL and H2O2 (G) + FeCl3(Fe). It is demonstrated that all combinations tested show a complete reduction in N2O production compared to CONTROL assays under aerobic conditions. The data points for 75G / 100Fe, 75G / 150Fe, lOOG / lOOFe and 100G / 150Fe are identical and for ease of representation are represented by the 100G / 150Fe line. Figure 10 shows the global wanning potential (100 years) under aerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2) combined with iron chloride (FeCh) at different dosage ratios. It is demonstrated that promising reductions in GHG emissions with the combinations of FhChand FeCh, with dosages of H2O2 and FeCL3 > 100 % exerting a complete inhibition of methanogenesis and nitrification.

[0238] The data points for 75G / 100Fe, 75G / 150Fe, lOOG / lOOFe and 100G / 150Fe are identical and for ease of representation are represented by the 100G / 150Fe line.

[0239] Example 3 - Dosage optimization - laboratory scale (anaerobic)

[0240] Additional laboratory tests are conducted in batches under anaerobic conditions using different dosages combinations, each performed in triplicate using 150 mL gas-tight bottles. In each bottle, 50 g of manure was placed, and the additive was applied in solution to the 50 g of fresh manure. The headspace anaerobic atmosphere was provided by flushing with a mixture of 70% N2 and 30% CO2. Headspace conditions were restored by flushing as needed. Trials are conducted alongside controls (untreated manure without additive addition) in a temperature-controlled room maintained at 25°C for 11 days. Dosages of 75 and 50 represents 25% and 50% lower than the standard dosages (BELOW).

[0241] Figure 11 shows the cumulative emissions of CH4 under anerobic conditions at the laboratory scale manure treated with hydrogen peroxide (H2O2) (G) combined with iron chloride (FeCh) (Fe). The emissions are shown for: CONTROL and H2O2+ FeCh (75+50 and 50+50 ). It is demonstrated that the combination of H2O2+ FeCh at BELOW dosages significantly reduce CH4 production from manure compared to CONTROL assays under anaerobic conditions.

Claims

Claims1. Method for reducing emissions from manure, the method comprising adding to manure 5.0 - 11.5 of iron salt per 1 kg manure; and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure.

2. Method for improving plant growth, the method comprising adding 5.0-11.5 g of iron salt per 1 kg manure and adding 1.7 - 3.5 g of hydrogen peroxide (H2O2) per 1 kg manure and applying said manure to an area comprising at least one plant, wherein plant growth is increased relative to a control plant.

3. Method according to any of the preceding claims, the method comprising adding 1.7 - 2.8 g of hydrogen peroxide (H2O2) per 1 kg manure.

4. Method according to any of the preceding claims, wherein iron salt is added in an amount of 5.0-10.5 g of iron salt per 1 kg manure, the iron salt preferably being an iron salt selected from the group consisting of ferric chloride (FeCh), ferric nitrate (FefNCh and ferric sulfate (F 62(804)3 or a combination thereof.

5. Method according to any of the preceding claims, where magnesium sulfate (MgSO4) is added to the manure in an amount of 25-78 g, preferably 25-55 g magnesium sulfate per 1 kg manure.

6. Method according to any of the preceding claims, wherein 10 - 60 g of biochar is added per 1 kg manure to the manure, preferably 20 - 50 g of biochar per 1 kg manure is added to the manure.

7. Method according to any of the preceding claims, wherein the manure is stored with iron salt and hydrogen peroxide (H2O2) and optionally biochar, or the manure with the iron salt and hydrogen peroxide (H2O2) and optionally biochar is distributed onto fields, preferably by spray irrigation, surface spreading, injection, or broadcasting.

268. Method according to any of the preceding claims, wherein the iron salt and hydrogen peroxide (H2O2) are added to the manure first and mixed thoroughly, and the biochar is added subsequently.

9. Method according to any of the preceding claims, wherein the emission is selected from the group consisting of CO2, CH4, N2O, H2S, NH3, N2, and a combination thereof.

10. Manure additive comprising iron salt and hydrogen peroxide, the iron salt preferably being an iron salt selected from the group consisting of ferric chloride (FeCh), ferric nitrate (Fe(NOs)3, and ferric sulfate (F 62(804)3 or a combination thereof.

11. Manure additive according to claim 10 comprising 9-71 wt. % iron salt, preferably 9-69 wt. % iron salt, more preferably 15-35 wt. % iron salt.

12. Manure additive according to claims 10-11 comprising 4-31 wt. % of hydrogen peroxide (H2O2), preferably 9-29 wt.% hydrogen peroxide.

13. Manure additive according to claims 10-12, wherein the additive comprises iron salt, preferably in an amount of 65-75 wt. %, more preferably 69-71 wt. %, and more preferably the iron salt being selected from the group consisting of ferric chloride (FeCh), ferric nitrate (Fe(NO3)3, and ferric sulfate (F 62(804)3 or a combination thereof.

14. Manure additive according to claims 10-13, wherein the additive comprises 23- 79wt. % biochar, preferably 26-59 wt. % biochar.

15. Manure additive according to claims 10 - 14, wherein the manure additive comprises a filler.

16. Manure additive according to claims 10 - 15, wherein the iron salt is in powder form.

17. Manure additive according to claims 10 - 16, wherein the manure additive comprises additives selected from the group consisting of calcium hydroxide, calcium carbonate, magnesium carbonate, or a combination thereof.

18. Organic fertilizer comprising manure and manure additive according to claims10 - 17, preferably prepared with a method according to claims 1 and 3- 8.

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