Woody biomass incinerated ash fertilizer

Abstract

To provide a fertilizer that uses incinerated ash produced by burning in a single fuel combusting boiler a woody biomass fuel, such as branch leaf material, bark material, trunk material, small diameter tree, and stool material, where an elution amount of hexavalent chrome is equal to or less than the soil environmental standards (0.05 mg / L) even without rendering hexavalent chrome harmless, and that is useful for growing plants.SOLUTION: A woody biomass incinerated ash fertilizer includes: incinerated ash of a woody biomass fuel configured of at least one kind of a woody material selected from a group consisting of branch leaf material, bark material, trunk material, small diameter tree, stool material, lumbering leavings, and palm coconut shells, where the branch leaf material is contained in an amount of 50.0 mass% or more; and at least one kind of organic fertilizer selected from a group consisting of poultry manure, swine dung, cow dung, horse dung, and food recycled methane fermentation residue.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a woody biomass incineration ash fertilizer. [Background technology]

[0002] Many biomass power plants have been built since the renewable energy feed-in tariff (FIT) scheme was launched in 2012. Of these, it has been reported that there will be 129 wood biomass power plants in operation as of the end of 2022 (Circulation Economy Newspaper, December 12, 2022 issue).

[0003] Currently, incineration ash generated by biomass power generation is hardly utilized effectively and is instead disposed of in landfills as waste.

[0004] In this situation, the Ministry of the Environment issued a notice (Environment Waste No. 1306282, dated June 28, 2013) stating that ash generated by burning wood pellets or wood chips in a dedicated boiler (excluding ash generated by co-firing waste wood containing or likely to contain paint or chemicals, or pellets or chips manufactured using said waste wood as a raw material) that can be effectively utilized and is not considered unnecessary does not qualify as industrial waste. This has opened the way to effectively utilize the ash from incinerated wood materials, but effective methods for its utilization are still unknown.

[0005] As a method for using incineration ash as fertilizer, for example, the method described in Patent Document 1 is known. This document discloses a method for producing an organic mixed fertilizer containing fully matured organic fertilizer and MAP (a recycled fertilizer that uses incineration ash from sludge, etc., and extracts the phosphorus component from the incineration ash in a state of enhanced solubility), and the organic mixed fertilizer produced by this method.

[0006] According to the soil environmental standards (Environmental Agency Notification No. 46), the amount of hexavalent chromium eluted must be below the soil environmental standards (0.05 mg / L), and this standard must be met even when incineration ash is used as fertilizer. Patent Document 2 describes a method for detoxifying hexavalent chromium in incineration ash. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2001-247389 A [Patent Document 2] Patent No. 7169601 Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide a fertilizer that uses incineration ash produced by burning wood biomass fuel, such as branches, bark, trunks, small diameter trees, and root materials, in a dedicated boiler, and that has an amount of hexavalent chromium eluted below the soil environmental standard (0.05 mg / L) even without going through a process of rendering the hexavalent chromium harmless, and is useful for growing plants. [Means for solving the problem]

[0009] The present invention provides the following: [1] (A) branches and leaves, bark, trunks, small diameter trees, and roots, and (B) sawdust thereof (i.e., sawdust of (A)), and (C) palm kernel shells. The incineration ash of wood biomass fuel is composed of at least one wood material selected from the group consisting of branches and leaves, bark, trunks, small diameter trees, and roots, and the content of the branches and leaves is 50.0% by mass or more. A woody biomass incineration ash fertilizer comprising at least one organic fertilizer selected from the group consisting of chicken manure, swine manure, cow manure, horse manure, and food recycling methane fermentation residue. [2] The wood biomass incineration ash fertilizer described in [1], wherein the wood material is provided as wood pellets or wood chips. [3] A wood biomass incineration ash fertilizer according to [1] or [2], containing the organic fertilizer in an amount of 2 to 8 parts by mass in terms of nitrogen content per 100 parts by mass of the incineration ash. [4] A method for improving the available silicon content of soil, comprising mixing the wood biomass incineration ash fertilizer according to any one of [1] to [3] into soil. [5] A method for reducing the number of soil nematodes or their egg sacs, comprising mixing the wood biomass incineration ash fertilizer according to any one of [1] to [3] into soil. [6] A method for increasing the silicon content in plant roots, comprising mixing the wood biomass incineration ash fertilizer according to any one of [1] to [3] into soil in which a plant is planted or soil to which a plant will be planted. [7] A method for growing plants, comprising mixing the woody biomass incineration ash fertilizer according to any one of [1] to [3] into soil in which a plant is planted or into which a plant will be planted. [8] A method for increasing the seed yield of a plant, comprising mixing the woody biomass incineration ash fertilizer according to any one of [1] to [3] into soil in which a plant is planted or soil to which a plant will be planted. [9] A method for strengthening the hypocotyl of a plant, comprising mixing the woody biomass incineration ash fertilizer according to any one of [1] to [3] into soil in which the plant is planted or into which the plant will be planted. Effect of the Invention

[0010] According to the present invention, a fertilizer is provided that uses incineration ash produced by burning wood biomass fuel, such as branches, bark, trunks, small diameter trees, and root materials, in a dedicated boiler, and that has an amount of hexavalent chromium eluted that is equal to or less than the soil environmental standard (0.05 mg / L) even without going through a process of rendering the hexavalent chromium harmless, and that is useful for growing plants.

[0011] By making the content of branches and leaves in woody biomass fuel 50.0% by mass or more, not only can the amount of elution of hexavalent chromium from woody biomass fuel be kept below the soil environmental standard (0.05 mg / L), but the incineration ash can also be combined with organic fertilizer and used as a fertilizer that can be used in organic agriculture. According to the present invention, it is also possible to keep the amount of harmful substances such as heavy metals and arsenic other than hexavalent chromium (e.g., cadmium, cyanide, organic phosphorus, lead, arsenic, mercury, alkyl mercury, PCB, dichloromethane, carbon tetrachloride, chloroethylene, 1,2-dichloroethane, 1,1-dichloroethylene, 1,2-dichloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene, 1,3-dichloropropene, thiuram, simazine, thiobencarb, and benzene) below the soil environmental standard. For example, the amount of elution of arsenic can be kept below 0.01 mg / L.

[0012] In addition, since the content of hexavalent chromium in the organic fertilizer in wood biomass incineration ash fertilizer is at a negligible level, if the amount of hexavalent chromium eluted from the wood biofuel that becomes the incineration ash is 0.05 mg / L or less based on Environment Agency Notification No. 46, the amount of hexavalent chromium eluted from the entire wood biomass incineration ash fertilizer will also be 0.05 mg / L or less based on Environment Agency Notification No. 46. Since the amounts of the above-mentioned harmful substances other than hexavalent chromium in the organic fertilizer are also at a negligible level, the amount of elution of the above-mentioned harmful substances from the entire wood biomass incineration ash fertilizer can be kept below the soil environmental standards. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 shows the silicon content in soybean roots grown in pots for two months. [Diagram 2] FIG. 1 shows the density of soybean cyst nematodes (SCN) in soil after two months of potted soybean cultivation. [Diagram 3] FIG. 1 shows the silicon content in the roots of bell peppers grown in pots for two months. [Figure 4]FIG. 13 is a graph showing the number of egg sacs of root-knot nematodes on the roots of peppers grown in pots for two months. [Diagram 5] FIG. 1 is a diagram showing the growth status of soybeans in a test field in a soybean cultivation test. [Figure 6] FIG. 1 is a graph showing soybean seed yield in field A (kg / 10a, 60° C. dry weight). [Figure 7] FIG. 1 shows the relationship between grain weight (fresh) and underground weight in field A. [Figure 8] FIG. 1 is a graph showing the relationship between grain weight (fresh) and aboveground weight in field A. [Figure 9] FIG. 13 is a graph showing soybean seed yield in field M (kg / 10a, 60° C. dry weight). [Figure 10] FIG. 1 shows the relationship between grain weight (fresh) and main stem length of plants in field M. [Figure 11] FIG. 1 shows the relationship between grain weight (fresh) and above-ground parts of plants in field M. [Figure 12] FIG. 1 shows the relationship between grain weight (fresh) and the underground part of the plant body in field M. [Figure 13] 14 shows the relationship between soybean yield and the physicochemical properties of the soil at the time of sowing: (a) is the relationship between grain yield and total carbon, (b) is the relationship between grain yield and total nitrogen, (c) is the relationship between grain yield and available nitrogen, (d) is the relationship between grain yield and available phosphorus, (e) is the relationship between grain yield and available silicon, (f) is the relationship between grain yield and exchangeable K, (g) is the relationship between grain yield and soil pH, and (h) is the relationship between grain yield and exchangeable calcium. [Figure 14] This is a graph comparing the bending strength (kgf) of hypocotyls in field N in an untreated area, an area with chicken manure applied, and an area with wood ash + chicken manure applied. [Figure 15] This is a graph comparing the aboveground weight (excluding pods) of edamame in field N in an untreated area, an area with chicken manure applied, and an area with wood ash + chicken manure applied. [Figure 16] This is a graph comparing the saleable yield (with pods) of Field N in an untreated area, an area with chicken manure applied, and an area with wood ash + chicken manure applied. [Figure 17] This is a graph showing the yield increase effect (compared to no fertilization) due to the application of wood ash and chicken manure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The woody biomass incineration ash fertilizer according to the embodiment contains (1) at least one wood material selected from the group consisting of branches and leaves, bark, trunks, small diameter trees, roots, and sawdust thereof, and palm kernel shells, and contains 50.0% or more by mass (i.e., 50.0 to 100.0% by mass) of the branch and leaf material, and (2) an organic fertilizer. The woody biofuel contains at least branches and leaves, and may be at least one type of sawdust consisting of branches and leaves and only branches and leaves, or may be a mixture of (i) at least one type of sawdust consisting of branches and leaves and only branches and leaves, and (ii) at least one type of wood material consisting of bark, trunks, small diameter trees, roots, and sawdust thereof, and palm kernel shells, as long as the content of the branch and leaf material is 50.0% or more by mass based on the total amount of the woody biomass fuel.

[0015] The lower limit of the content of branch and leaf materials based on the total amount of wood biomass fuel may be 55.0 mass%, 76.0 mass%, 77.0 mass%, 78.0 mass%, or 80.0 mass%. The upper limit of the content of branch and leaf materials based on the total amount of wood biomass fuel may be 100.0 mass%, 99.0 mass%, or 98.5 mass%. These lower and upper limits can be combined in any manner.

[0016] The wood material may be provided as wood pellets or wood chips. The tree species of the branch and leaf material, bark material, trunk material, small diameter tree and base material may be any, but may be at least one of coniferous and broad-leaved trees. Examples of coniferous trees include cedar, cypress and pine (larch, etc.), while examples of broad-leaved trees include oak, oak and zelkova. Generally, the branch and leaf material tends to be made of broad-leaved trees, while other materials (trunk material, etc.) tend to be made of coniferous trees.

[0017] The applicant of the present application requested General Health Center Co., Ltd. to analyze the woody biomass fuel (provided as at least one of the woody materials selected from the group consisting of branches and leaves, bark, trunks, small diameter trees, roots, and sawdust thereof) composed of at least one of the above-mentioned coniferous and broad-leaved trees. The amounts of hexavalent chromium and arsenic eluted based on the soil environmental standard (Environmental Agency Notification No. 46) are shown below together with the branch and leaf ratio. By making the branch and leaf ratio 50.0 mass% or more, the amount of hexavalent chromium eluted can be kept below the soil environmental standard (0.05 mg / L), and the amount of arsenic eluted can also be kept below the soil environmental standard (0.01 mg / L). By combining such woody biomass fuel with an organic fertilizer, a woody biomass incineration ash fertilizer according to the embodiment can be obtained.

[0018] [Table 1]

[0019] Wood pellets are wood materials made by finely grinding dried wood and compressing and molding it under pressure into a specific shape (for example, a cylindrical shape with a diameter of 6 to 8 mm and a length of 5 to 40 mm), while wood chips are wood-based raw materials that have been cut, crushed, or otherwise shaped into pieces. Although the shape is arbitrary, examples of the wood chips include cutting chips cut with a knife and crushed chips crushed with a grinder.

[0020] From the viewpoints of environmental consideration and effective utilization of resources, it is preferable that the above-mentioned wood material is obtained from thinned wood.

[0021] The incineration ash is preferably produced based on the description in Kanwaisanhatsu No. 1306282. That is, it is preferably ash obtained by incinerating woody biomass resources in a dedicated combustion boiler (a boiler for exclusively burning biomass).

[0022] The components or characteristics of incineration ash can be found in, for example, Mokuzai Gakkaishi Vol. 67, No. 1, p. 33-43 (2021) "Properties of combustion ash derived from chips or firewood collected from small to medium-sized wood-only combustion boilers" (Orihashi et al.). In other words, incineration ash can be a fine powder equivalent to coarse sand to silt, and is strongly alkaline. The main inorganic components contained are CaO, K2O, MgO, SiO2, Al2O3, P2O5, MnO, Fe2O3, etc.

[0023] The incineration ash may have, for example, a pH (actual material:deionized water = 1:10, 23°C) of about 9.5 to 13.0, a total nitrogen content (N) of about 0.01 to 0.45, a total phosphoric acid content (P2O5) of about 0.3 to 2.3, a total potassium content (K2O) of about 1.2 to 6.0, a total silicate content (SiO2) of about 45.0 to 60.0, a soluble silicate content (SiO2) of about 0.04 to 8.0, a total lime content (CaO) of about 3.0 to 11.5, a total magnesium content (MgO) of about 1.16 to 1.60, and a total iron oxide content (Fe2O3) of about 2.4 to 3.6.

[0024] The incineration ash may have a particle size (average particle size) of 5 to 150 μm and a bulk specific gravity of 0.7 to 0.8.

[0025] The organic fertilizer to be combined with the incineration ash is selected from chicken manure, swine manure, cow manure, horse manure, and food recycling methane fermentation residue, and these may be used alone or in combination of two or more kinds.

[0026] Food recycling methane fermentation (methane gasification) refers to, for example, the decomposition of food using various anaerobic microorganisms to produce methane gas and carbon dioxide. The decomposition process of methane gas includes (1) solubilization and hydrolysis to decompose food into low molecular weight organic matter, (2) acidogenesis to produce organic acids (propionic acid, butyric acid, etc.), (3) acetic acid production to produce acetic acid and hydrogen, and (4) methanogenesis to produce methane and carbon dioxide. (For example, https: / / www.env.go.jp / recycle / waste / biomass / foundation.html)

[0027] Therefore, the food recycling methane fermentation residue refers to the residue obtained when food recycling methane fermentation is carried out by the method described above.

[0028] Incineration ash and organic fertilizer can be combined in any ratio, but it is preferable to include organic fertilizer so that the nitrogen content is 2 to 8 parts by mass per 100 parts by mass of incineration ash. It is more preferable to include organic fertilizer so that the nitrogen content is 4 to 6 parts by mass per 100 parts by mass of incineration ash. Since the nitrogen content of chicken manure or pig manure, which are typical organic fertilizers, is about 4 to 5% by mass, in order to achieve a nitrogen content of 4 to 6 parts by mass per 100 parts by mass of incineration ash, it is sufficient to mix incineration ash:organic fertilizer (chicken manure and / or pig manure) at a mass ratio of 1:1.

[0029] Since woody biomass incineration ash fertilizer may be provided in a light powder form, the woody biomass incineration ash fertilizer may be granulated in order to ensure efficient and reliable fertilization.

[0030] The granulation method is arbitrary, and examples of binders used for granulation include ash molasses, lignin, rice bran, and the like.

[0031] Woody biomass incineration ash fertilizer can be used for various purposes. For example, by mixing woody biomass incineration ash fertilizer into soil, it is possible to increase the available silicon content in the soil. Also, by mixing woody biomass incineration ash fertilizer into soil, it is possible to reduce the number of soil nematodes or their egg sacs.

[0032] Furthermore, by mixing woody biomass incineration ash fertilizer into the soil in which or to which plants are to be planted, it is possible to increase the silicon content in the roots of the plants. Therefore, by carrying out a plant growing method in which woody biomass incineration ash fertilizer is mixed into the soil in which or to which plants are to be planted, it is possible to grow the plants while providing them with sufficient nutrients and preventing damage from nematodes and the like.

[0033] In addition, by mixing woody biomass incineration ash fertilizer into soil in which a plant is planted or into which a plant will be planted, it is possible to increase the seed yield of the plant. Furthermore, by mixing woody biomass incineration ash fertilizer into soil in which a plant is planted or into which a plant will be planted, it is possible to strengthen the hypocotyl of the plant. EXAMPLES

[0034] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples. In the following examples, "incineration ash of woody biomass fuel" may be abbreviated to "wood ash".

[0035] In the examples, wood ash obtained by burning wood biofuel consisting of unused small diameter trees, branches, leaves, and roots from thinning in a fluidized bed boiler was used.Typical properties of this wood ash were pH 12.5, total nitrogen 0.02%, total phosphorus 0.77%, total potassium 1.28%, total lime 7.92%, carbon-nitrogen ratio 18.5, moisture content 4.6%, organic carbon 0.37%, total silicic acid 59.8%, soluble silicic acid 4.42%, average particle size 44.1 μm, and median size 37.0 μm.

[0036] In the following [Available silicon content of incineration ash], [Effect of incineration ash application on silicon content and soybean cyst nematode density in soybean roots grown in soil contaminated with soybean cyst nematode], [Effect of incineration ash application on silicon content and sweet potato root-knot nematode density in bell pepper roots grown in soil contaminated with sweet potato cyst nematode], and (Edamame growth test in a university field), the content of branches and leaves based on the total amount of wood biomass fuel from which wood ash is made was 81.4%. Also, in the following (Soybean growth test in an actual farm), the content of branches and leaves based on the total amount of wood biomass fuel from which wood ash is made was 98.5%, and the elution amounts of hexavalent chromium and arsenic in wood biomass fuel based on Environment Agency Notification No. 46 were less than 0.043 mg / L and 0.001 mg / L, respectively.

[0037] [Available silicon content of incineration ash] Using the phosphate buffer extraction method (Moesumi, M.; Tachibanada, Y.; Kubo, S.; Mizuochi, K. 2002. Evaluation of available silicon in paddy soil using phosphate buffer extraction method. Dohi Journal, 73, 383-390), the available silicon content of incineration ash, a mixture of incineration ash and chicken manure, and a commercially available silicon fertilizer, calcium silicate (trade name: Keikaru), was measured. The available silicon content was 254mg / kg for calcium silicate, 442mg / kg for incineration ash, and 403mg / kg for the mixture of incineration ash and chicken manure, indicating that incineration ash contains more available silicon than commercially available calcium silicate fertilizer. The available silicon content of chicken manure alone was 200mg / kg. Incidentally, calcium silicate (Kical), a commercially available silicon fertilizer, generally contains approximately 30-41%, 35-45%, 3-7%, and 0.3-1.7% of silicic acid (SiO2), lime (CaO), magnesia (MgO), and manganese (Mn), respectively, as well as trace amounts of iron, copper, zinc, molybdenum, and other elements.

[0038] [Effect of incineration ash application on silicon content in roots of soybeans grown in soil contaminated with the soybean cyst nematode and on the density of the soybean cyst nematode] (I) Soil contaminated with soybean cyst nematode (hereinafter sometimes referred to as "SCN") (black soil, Miura City, Kanagawa Prefecture) was thoroughly mixed and homogenized, and then 800 g was placed in a 1 / 10,000 are pot, to which the following fertilizers (1) to (5) were added, mixed thoroughly, and the moisture content was adjusted to 60% of the maximum water capacity. Seven of these were prepared for each of the fertilizers (1) to (5), and pre-cultured for two weeks. (1) Chemical fertilizer area N:P:K = 14:14:14 was applied at 5 kg nitrogen per 10 ares (equivalent to 200 mg nitrogen per kg soil (200 mg nitrogen / kg soil)). (2) Chemical fertilizer + wood ash area In addition to (1), 500 kg of granulated incineration ash was applied per 10 ares. The granulated incineration ash was a mixture of 500 kg of incineration ash and 75 kg of rice bran. Rice bran contains nitrogen, which is equivalent to 17.3 mg of nitrogen / kg of soil. Therefore, the amount of nitrogen per 1 kg of soil is 217.3 mg. The mass ratio of chemical fertilizer to wood ash was 1:100. (3)Chicken manure area 500 kg of chicken manure (organic fertilizer) was applied per 10 ares. Because chicken manure contains a high concentration of nitrogen, this is equivalent to 230 mg of nitrogen / kg of soil. (4)Chicken manure + wood ash area In addition to (3), 500 kg of wood ash material (2) was applied per 10 ares. The result was 230 + 17.3 mg nitrogen = 247.3 mg nitrogen / kg soil. The mass ratio of chicken manure to wood ash was 1:1. (5) Chemical fertilizer + calcium carbonate In addition to (1), calcium carbonate was added to the soil so that the amount was 400 kg (recommended amount) per 10 ares. This is equivalent to 200 mg of nitrogen / kg of soil. The mass ratio of chemical fertilizer to calcium carbonate was 1:80.

[0039] (II) Two edamame seeds (Yuagari Musume (registered trademark)) were sown in each of the above soils to form double plants.

[0040] (III) The plants were grown in a greenhouse for approximately two months, during which time they were watered appropriately to adjust the moisture content to 60% of their maximum water capacity.

[0041] (IV) After two months, the plants were harvested, the soil particles attached to the roots were carefully removed, and the roots were cut into small pieces with scissors for each pot. The silicon content in the roots was measured by the method of Saito et al. (2005) (Rapid, Micro-Methods to Estimate Plant Silicon Content by Dilute Hydrofluoric Acid Extraction and Spectrometric Molybdenum Method I. Silicon in Rice Plants and Molybdenum Yellow Method. Soil Science and Plant Nutrition 51, 29-36).

[0042] (V) The soil in the pot was thoroughly mixed, and 100 g of the soil was passed through a 2 mm sieve, dried at 60°C overnight, and then stored at -25°C.

[0043] (VI) Soil DNA was extracted using the method of Sato et al. (2011) (Quantification of Pratylenchus penetrans in radish fields using a combination method of soil compaction and real-time PCR to determine the economic threshold, Soil Science and Plant Nutrition, 57, 213-220), and the number of SCN eggs was quantified using the method of Shirai & Toyota (2019) (Optimisation of a species-specific primer set to quantify the soybeancyst nematode, Heterodera glycines, in soil using real-time PCR, Nematology, 21,1037-1042).

[0044] Figure 1 shows the silicon content in the roots of soybeans (Yuagari Musume (registered trademark)) cultivated in pots for two months (N=7). Different letters indicate significant differences.

[0045] The silicon content was lowest in the chemical fertilizer plot, and was significantly higher in the chemical fertilizer + calcium carbonate plot, confirming that the application of calcium carbonate increases the silicon content in the roots (Figure 1). Meanwhile, it was found that the plot where wood ash was applied to the chemical fertilizer had a higher silicon content than the calcium carbonate plot. The chicken manure plot and chicken manure + wood ash plot also had significantly higher silicon content than the chemical fertilizer + calcium carbonate plot. These results show that wood ash is a more effective silicon fertilizer than calcium carbonate.

[0046] Figure 2 shows the density of soybean cyst nematodes (SCN) in soil after two months of pot cultivation of soybeans (N=7). Different letters indicate significant differences.

[0047] The soybean cyst nematode density at harvest was significantly lower in the chemical fertilizer + wood ash plot than in the chemical fertilizer plot, and was also significantly lower in the chicken manure + wood ash plot than in the chicken manure plot (Figure 2). In addition, the nematode density was significantly lower in the chemical fertilizer + wood ash plot and the chicken manure + wood ash plot than in the chemical fertilizer + calcium carbonate plot, indicating that wood ash has an inhibitory effect on the proliferation of soybean cyst nematodes.

[0048] [Effect of incineration ash application on silicon content and Meloidogyne density in roots of peppers grown in Meloidogyne-infected soil] (I) Nematode-contaminated soil (Kamisu City, Ibaraki Prefecture) was thoroughly mixed and homogenized, and then 800 g was placed in a 1 / 10,000 are pot, and the above fertilizers (1) to (5) were added, mixed thoroughly, and the moisture content was adjusted to 60% of the maximum water capacity. Seven of these were prepared for each of the fertilizers (1) to (5), and pre-cultured for two weeks.

[0049] (II) Bell pepper seedlings (Kyoto Midori (registered trademark)) that had been cultivated for two weeks in nursery soil manufactured by Takii Seed Co., Ltd. were transplanted one per pot.

[0050] (III) The plants were grown in a greenhouse for approximately two months, during which time they were watered appropriately to adjust the moisture content to 60% of their maximum water capacity.

[0051] (IV) After 2 months, the plants were harvested, the soil particles attached to the roots were carefully removed, the roots were immersed in a phloxine B solution for 1 minute, the egg sacs were stained, and the number of egg sacs attached to the roots was counted. Then, the roots of each pot were cut into small pieces with scissors, and the silicon content in the roots was measured by the method of Saito et al. (2005) (Rapid, Micro-Methods to Estimate Plant Silicon Content by Dilute Hydrofluoric Acid Extraction andSpectrometric Molybdenum Method I. Silicon in Rice Plants and Molybdenum Yellow Method. Soil Science and Plant Nutrition 51, 29-36).

[0052] 3 is a diagram showing the silicon content in the roots of bell peppers (Kyoto Midori (registered trademark)) cultivated in pots for two months (N=7). Different letters indicate significant differences.

[0053] In soybeans, the silicon content of plant roots was significantly higher when calcium carbonate was used compared to the chemical fertilizer treatment, but in bell peppers, the application of calcium carbonate did not increase the silicon content (Figure 3). On the other hand, when wood ash was added to the chemical fertilizer, the silicon content of the roots was significantly higher. The application of chicken manure alone also increased the silicon content of the roots compared to chemical fertilizer, but the application of wood ash to the chicken manure further increased the silicon content in the roots significantly. These results show that wood ash is a more effective silicon fertilizer than calcium carbonate, even in bell peppers.

[0054] Figure 4 shows the number of egg sacs (= an index of the degree of nematode proliferation) of root-knot nematodes on the roots of peppers grown in pots for two months (N=7). Different letters indicate significant differences.

[0055] Compared to the chemical fertilizer plots, the application of wood ash or calcium hydroxide reduced the number of egg sacs by about 30 to 40 percent (Figure 4). Also, in the chicken manure plot, the number of egg sacs was about 50 percent lower than in the chemical fertilizer plot, but the chicken manure + wood ash plot had an even lower number. From the above, it can be seen that wood ash has an inhibitory effect on root-knot nematode proliferation, and that a combination of wood ash and chicken manure has the greatest inhibitory effect on root-knot nematode proliferation.

[0056] (Soybean growth test in an actual farm) The following soybean growth test was carried out at Farm 1 and Farm 2. The soybeans used were Enrei (soybean variety name). The test at the farms was carried out in a state where it was not recognizable to third parties other than the present inventor or applicant, so as not to be publicly known or used. 1) Establishment of the survey site [Farm 1] Field A: 3 treatments (no fertilization, chicken manure (500 kg / 10a), chicken manure + wood ash (500 kg / 10a each)) x 2 replicates = 6 areas in total Field B: In addition to the fertilized area (chicken manure + wood ash (500 kg each / 10a)), some areas were set as non-fertilized areas. Field C: In addition to the fertilized area (chicken manure + wood ash (500 kg / 10a)), a non-fertilized area was set up in part. [Farm 2] Field M: Fertilized area (chicken manure + wood ash (500 kg / 10a each) and non-fertilized area For soybeans, the available nitrogen content, an indicator of soil fertility, was measured in advance. Field A had the lowest value of 20.5 mg / kg, followed by fields B and C, which also showed low values ​​of 22 to 24 mg / kg, while field M had the highest value of 30.2 mg / kg.

[0057] 2) Growth survey: August 1, 2022 A cultivation survey was conducted on August 1, 2022 for soybeans that began cultivation on June 1, 2022. The results were as follows (Figure 5). - Soybeans grew well in all fields, reaching a height of about 110 cm, with no difference observed between the fields. Walking around the fields, we found that many plants had fallen in fields A, B, and C, but there were almost no plants in field M. Compared to the growth of nearby conventional soybean fields, all of the fields surveyed this time performed well. The SPAD value (an index of leaf chlorophyll content), which is an index of growth, was low in field A, where available nitrogen was the lowest. The SPAD value was highest in field M, where available nitrogen was the highest, suggesting that available nitrogen affects the growth of aboveground parts. When the growth stage transitions from vegetative to reproductive, field M, which has high available nitrogen, is expected to continue to have high yields due to the high nitrogen supply capacity from the soil.

[0058] 3) Harvest survey: October 18, 2022 Eight plants were collected from each plot, the soybean seeds were removed, the fresh weight was measured, and then they were air-dried indoors and the weight was measured. A portion was then taken and dried at 60°C for two days to calculate the drying coefficient, and the 60°C dry weight for each plot was calculated. As shown in Table 2 and Figure 6, in Field A, which had the lowest available nitrogen content and was thought to have the lowest soil fertility, application of chicken manure increased yields by about 50%, and application of chicken manure + wood ash increased yields by about 90%.

[0059] [Table 2]

[0060] In order to consider the factors determining yield, we looked at the relationship between yield and above-ground and below-ground part weights of the plant (Figures 7 and 8). There was no correlation with the below-ground part weight, but a negative correlation with the above-ground part weight. In Field A, many plants were found to have fallen during the growth survey in August, suggesting that the larger the above-ground part, the higher the risk of lodging in the latter half of growth, which may have led to lower yields.

[0061] Even in field M, which had the highest soil fertility, fertilization increased yields by 20%, proving the fertilizing effect of chicken manure and wood ash (Figure 9). Also, in field M, where there were few lodged plants, there was a positive relationship between aboveground weight and yield, suggesting that if there was no lodging, the better the plant growth, the higher the yield would be (Figures 10, 11, and 12).

[0062] Next, we looked at the relationship between the physicochemical properties of the soil at the time of sowing and soybean yield [Figure 13 (a)-(h)], and found a close relationship in items related to soil fertility and soil fertility, such as total carbon, total nitrogen, and available nitrogen. This reaffirmed the fact that improving soil fertility is an effective way to improve soybean yields. Field A was analyzed using the average yield data of the three treatment areas, while field M was analyzed using yield data from the fertilized area, which accounted for the majority of the field.

[0063] (Growth test of edamame in a university field) A edamame cultivation experiment was conducted at the Tokyo University of Agriculture and Technology's Field N (Honmachi rice paddy field). The details are as follows. Edamame [Yuagari Musume (registered trademark)] was sown on July 29, 2022, and cultivated in field N until October 11, 2022, and a yield survey was conducted. The bending strength (kgf) of the hypocotyl was also measured. The treatment areas were untreated, chicken manure (500 kg / 10a), and chicken manure + wood ash (500 kg / 10a each), with three or four repetitions each. The bending strength was about 20% higher in the chicken manure application area than in the untreated area, and was significantly higher by about 30% in the wood ash + chicken manure application area (Figure 14). The bending strength means that the higher the value, the stronger the strength and the less likely it is to fall. From the above, it was found that the risk of soybeans falling can be reduced by applying wood ash + chicken manure.

[0064] The aboveground weight of edamame (excluding pods) (g / individual) and the marketable yield (with pods) (g / m 2 ) was measured in the untreated area, the area treated with chicken manure, and the area treated with wood ash + chicken manure, and a comparison was made. Figure 15 shows the aboveground weight, and Figure 16 shows the saleable yield. The yield of edamame increased significantly by 18% with chicken manure application and 30% with wood ash + chicken manure, confirming the effectiveness of wood ash + chicken manure as a fertilizer.

[0065] When we looked at the relationship between the yield increase effect of wood ash + chicken manure compared to no fertilization and the available nitrogen in the soil in Farm 1 Field A, Farm 2 Field M, and Tokyo University of Agriculture and Technology Field N in 2022 (Figure 17), we found that the yield increase effect was greater in fields with low fertility. In addition, even in fertile fields such as Field M, where the available nitrogen exceeds 30 mg / kg, a 20% yield increase effect was observed, so it can be said that wood ash + chicken manure can be expected to have a fertilizer effect in a wide range of soil types.

Claims

1. The incineration ash of wood biomass fuel is composed of at least one wood material selected from the group consisting of branches and leaves, bark, trunks, small diameter trees, roots, and sawdust thereof, and palm kernel shells, and the content of the branches and leaves is 50.0% by mass or more; A woody biomass incineration ash fertilizer comprising at least one organic fertilizer selected from the group consisting of chicken manure, swine manure, cow manure, horse manure, and food recycling methane fermentation residue.

2. The wood biomass incineration ash fertilizer of claim 1 , wherein the wood material is provided as wood pellets or wood chips.

3. The wood biomass incineration ash fertilizer according to claim 1, wherein the organic fertilizer is contained in an amount of 2 to 8 parts by mass as a nitrogen content relative to 100 parts by mass of the incineration ash.

4. A method for improving the available silicon content of soil, comprising mixing the wood biomass incineration ash fertilizer according to any one of claims 1 to 3 into soil.

5. A method for reducing the number of soil nematodes or their egg sacs, comprising mixing the wood biomass incineration ash fertilizer according to any one of claims 1 to 3 into soil.

6. A method for improving the silicon content in plant roots, comprising mixing the woody biomass incineration ash fertilizer according to any one of claims 1 to 3 into soil in which a plant is planted or into which a plant will be planted.

7. A plant cultivation method comprising mixing the woody biomass incineration ash fertilizer according to any one of claims 1 to 3 into soil in which a plant is planted or into which a plant will be planted.

8. A method for increasing the seed yield of a plant, comprising mixing the woody biomass incineration ash fertilizer according to any one of claims 1 to 3 into soil in which a plant is planted or into which a plant will be planted.

9. A method for strengthening the hypocotyl of a plant, comprising mixing the woody biomass incineration ash fertilizer according to any one of claims 1 to 3 into soil in which a plant is planted or into which a plant will be planted.

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