Method for producing soil improvement material and method for controlling black rot disease

Abstract

To provide a soil amendment capable of performing pest control of black rot sclerotia without using a medicine or carrying-out special operation and a manufacturing method of the soil amendment and a pest control method of the black rot sclerotia.SOLUTION: A soil amendment and a pest control method for controlling black rot sclerotia is a germination inducer that is mixed into the soil in the absence of allium plants to remove the sclerotia of the black rot sclerotia fungus that remains in the soil. The allium odor causes them to germinate all at once. The germinated mycelium is then starved to death in the absence of a host plant. As a result, black rot sclerotia, which is difficult to exterminate, can be effectively controlled without using drugs or special efforts. Moreover, the soil amendment and its manufacturing method can manufacture the soil amendment having the above-mentioned black rot sclerotia control function entirely from waste. This allows manufacturing at extremely low material costs. Furthermore, it is possible to reuse waste, thereby reducing the environmental load.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention provides a method for the prevention of black rot disease, which is a disease of onion crops. Soil The present invention relates to a method for producing a soil improvement material and a method for controlling black rot disease using the soil improvement material. [Background technology]

[0002] Continuous cultivation of the same crop in the same place disrupts the balance of the soil ecosystem, causing continuous crop damage such as disease and nutritional disorders. The main cause of this damage is the proliferation of parasitic nematodes and pathogenic bacteria that are harmful to the crop. The most common method of preventing this damage is to sterilize the soil with pesticides or Bordeaux mixture (a mixture of copper sulfate and lime). However, the use of these chemicals further destroys the soil ecosystem and causes the soil to become barren. In addition, excessive use of these chemicals reduces the effectiveness of preventing continuous crop damage, and there are concerns about residual pesticides flowing into rivers and other waterways and health damage to agricultural workers.

[0003] In addition to the parasitic nematodes that are harmful to crops, nematodes that live in the soil also include predatory nematodes that prey on other nematodes and saprophytic nematodes that feed on animal and plant remains and bacteria. These predatory and saprophytic nematodes are collectively called self-active nematodes. Predatory nematodes are expected to suppress continuous crop damage by preying on parasitic nematodes. Among saprophytic nematodes, bacterivorous nematodes are expected to suppress continuous crop damage by preying on pathogenic bacteria.

[0004] In addition, Bacillus subtilis is a bacterium that attaches to rice straw and other plants, and is known to have the ability to secrete antibacterial substances and kill pathogens such as mold and bacteria that cause plant diseases.

[0005] For this reason, the inventors of the present application have made the inventions described in Patent Document 1 and Patent Document 2, which relate to a method for producing a soil improvement material by mixing sludge containing Bacillus bacteria with a cellulose source that is easy for spontaneously active nematodes to live in and fermenting the mixture at a predetermined temperature. By mixing this soil improvement material in which Bacillus bacteria and spontaneously active nematodes live in large numbers into soil, it has become possible to restore the soil ecosystem and suppress damage caused by continuous cropping through the antibacterial substances secreted by the Bacillus bacteria and the predation by the spontaneously active nematodes.

[0006] Furthermore, the inventors of the present application have made the invention described in Patent Document 3, which relates to a soil improvement material that contains a hatching inducer for cyst nematodes and can effectively control cyst nematodes, which are said to be extremely difficult to control. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4226065 [Patent Document 2] Patent No. 6057312 [Patent Document 3] Patent No. 6893378 Summary of the Invention [Problem to be solved by the invention]

[0008] Incidentally, black rot disease, which has been causing widespread damage nationwide in recent years, is one of the diseases of Allium crops, such as green onions, onions, garlic, scallions, and Chinese chives. This black rot disease is a soil-borne disease caused by the filamentous fungus Sclerotium cepivorum, a type of mold. Sclerotium cepivorum (hereafter referred to as black rot disease fungus) remains dormant in the soil of farmland in the form of sclerotia, and when a host Allium plant is planted, it germinates in response to its odor (component) (hereafter referred to as Allium odor). The mycelium then penetrates the host plant, grows, and causes the disease, and is highly infectious. The optimum temperature for the growth of black rot sclerotin fungus is between 10°C and 15°C, and it spreads in spring and autumn, but its growth rate slows down when temperatures exceed 20°C, and it is said that it cannot survive in the form of hyphae if temperatures remain above 25°C. In addition, when in the form of sclerotia, this black rot sclerotin fungus shows strong resistance to dryness, low temperatures, and chemical substances such as pesticides, and is said to be one of the pathogens that is difficult to eradicate once established in agricultural land where high-temperature sterilization of soil is practically impossible. It is also known that this sclerotium reacts to the odor (components) of the Allium genus and germinates even at temperatures above 20°C.

[0009] The present invention has been made in consideration of the above circumstances, and is capable of controlling black rot fungus without the use of chemicals or special work. Soil The present invention aims to provide a method for producing a soil improvement material and a method for controlling black rot disease. [Means for solving the problem]

[0010] The present invention relates to (1) a seed nematode source inhabiting free-living nematodes, a seed soil inhabiting a Bacillus bacterium secreting an antibacterial substance, and a cellulose source serving as a nutrient for the Bacillus bacterium; Dewatered dredged soil and A first mixing step S202 of mixing the above ingredients; A first fermentation step S204 in which the mixed soil obtained in the first mixing step S202 is fermented at 20°C to 60°C to make the Bacillus bacteria predominant in the mixed soil and promote the proliferation of the self-active nematodes; A second mixing step S206 of mixing a germination inducer made from an onion plant and promoting germination of the sclerotia of the pathogen of black rot disease into the mixed soil after the first fermentation step; The above-mentioned problems are solved by providing a method for producing a soil improvement material, characterized by having a second fermentation step S208 in which the mixed soil obtained in the second mixing step S206 is re-fermented to enhance the Allium odor of the germination inducer. (2) The above problems are solved by providing a method for producing a soil improvement material as described in (1) above, characterized in that unnecessary parts or waste products of plants of the Allium genus are used as the germination inducer. (3 )(1) above to ( 2) The above-mentioned problem is solved by providing a method for controlling black rot sclerotinia, which comprises mixing a soil improvement material produced by the above-described manufacturing method into soil, causing sclerotia of a pathogen of black rot sclerotinia to germinate due to the Allium odor of a germination inducer contained in the soil improvement material, and controlling the germinated pathogen by causing it to starve to death in the absence of a host plant. ( 4 ) soil improvement material is mixed on days when the daytime temperature is 20°C or higher, and germinated pathogens of black rot disease are controlled by starvation due to heat and the absence of host plants. 3 The above-mentioned problems are solved by providing a method for controlling black rot disease as described in 。 Effect of the Invention

[0011] The present invention relates to Black The method for controlling black rot sclerotinia is to mix the sclerotia of black rot sclerotinia fungus remaining in the soil into the soil in the absence of Allium plants, and then germinate them all at once due to the Allium odor of the germination inducer. The germinated mycelium is then starved to death in the absence of a host plant, and the number of sclerotia capable of germinating can be reduced to zero or significantly reduced. This allows the present invention to be applied to the Black The method for controlling black rot can effectively control black rot, which is difficult to eradicate, without using chemicals or special labor. MaterialThe production method can produce the soil improvement material with the above-mentioned black rot disease control function entirely from waste materials. This allows production at extremely low material costs. In addition, waste materials can be reused, reducing the environmental burden. [Brief description of the drawings]

[0012] [Figure 1] 1 is a flowchart showing a method for producing a soil improvement material according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention relates to Soil The embodiment of the method for producing a soil improvement material and the method for controlling black rot sclerotinia will be described with reference to the drawings. Here, Fig. 1 is a flow chart showing the method for producing a soil improvement material according to the present invention. In addition, the Allium plant here basically refers to Allium crops such as long green onions, onions, chives, garlic, Chinese chives, shallots, chives, etc. In addition, the Allium odor here refers to odorous components emitted by the Allium genus, such as green onion odor, garlic odor, and Chinese chive odor, which are mainly composed of disulfides and which cause the black rot sclerotinia fungus to germinate.

[0014] The method for producing the soil improvement material according to the present invention includes a first mixing step S202 for mixing a seed nematode source inhabited by self-active nematodes, a seed soil inhabited by Bacillus bacteria secreting an antibacterial substance, and a cellulose source serving as a nutrient for the Bacillus bacteria, a first fermentation step S204 for fermenting the mixed soil obtained in the first mixing step S202 at 20°C to 60°C, a second mixing step S206 for mixing a germination inducer made from an Allium plant as a raw material with the mixed soil after the first fermentation step, and a second fermentation step S208 for re-fermenting the mixed soil obtained in the second mixing step S206 to enhance the Allium odor of the germination inducer. Note that in the first mixing step S202, dredged soil obtained by dehydrating dredged soil is mixed in addition to the seed nematode source, the seed soil, and the cellulose source. do.

[0015] Next, the germination inducer, which is a characteristic feature of the present invention, will be described. The germination inducer of the present invention is made from an Allium plant, which is a host plant for black rot sclerotinia sclerotinia. In addition, it is preferable to use unnecessary parts of Allium crops, such as the outer skin, roots, and leaves of long green onions, and the roots, stems, and leaves of onions, garlic, and scallions, as the raw material for the germination inducer. It is also preferable to use waste products of these Allium crops. In these configurations, unnecessary parts and waste products of Allium crops, which are waste products, are used as the raw material for the germination inducer, so that the material cost of the soil improvement material can be reduced. In addition, it is possible to reuse the waste, and it is possible to reduce the amount of garbage discharged and the environmental load. In addition, since the germination inducer is derived from a plant, it also functions as a cellulose source. Therefore, it is also possible for the germination inducer to constitute a part of the cellulose source.

[0016] Next, the seed nematode source in the present invention will be described. The seed nematode source in the present invention is compost, leaf mold, or other cellulose source in which self-active nematodes (predatory nematodes and saprophytic nematodes) live, and it is particularly preferable to collect or leave an appropriate amount of soil improvement material after production as the seed nematode source. In addition, when self-active nematodes live in the cellulose source described below, the cellulose source may also serve as the seed nematode source.

[0017] The seed soil in the present invention is soil or sludge in which Bacillus bacteria live, and can be sewage treatment dried cake, agricultural village wastewater surplus sludge, dehydrated sewage treatment sludge, dehydrated water treatment sludge, other sewage treatment sludge, etc. Among them, it is particularly preferable to use dehydrated sludge of treated water from food factories, which contains almost no heavy metal components, from the viewpoint of safety. It is also preferable to dry the sludge or sterilize it with sodium hypochlorite or the like. Although the sterilization kills or reduces the number of miscellaneous bacteria, the Bacillus bacteria survive in a spore state, so that the Bacillus bacteria can be dominant in the fermentation process. The seed soil can be made of commercially available liquid Bacillus (Bacillus bacteria cultured in liquid). In addition, an appropriate amount of the soil improvement material after production can be collected or left to serve as the seed nematode source and seed soil. As described above, Bacillus bacteria are known to have the ability to secrete antibacterial substances to kill pathogenic bacteria such as mold and bacteria that cause plant diseases, and the soil improvement material according to the present invention in which Bacillus bacteria are predominant has the effect of suppressing the proliferation of pathogenic bacteria harmful to crops, etc. This bactericidal effect is also considered to be effective against the mycelium of black rot sclerotinia sclerotinia that has not yet invaded the host plant.

[0018] The dredged soil in the present invention is obtained by dredging the soil, sand, silt, fallen leaves, garbage, sludge, etc., that have accumulated at the bottom of reservoirs such as lakes and marshes, moats, artificial ponds, and agricultural reservoirs, and then removing large impurities such as pebbles, sand, garbage, and fallen leaves and dehydrating the soil. The method of obtaining dredged soil suitable for the present invention is to first lower a suction device such as a pump to the bottom of the lake or marsh where dredging is to be performed, and suck up the bottom soil together with the water. Next, the impurities in the sucked bottom soil water are separated and removed. Next, an inorganic neutral coagulant mainly composed of calcium is added to the bottom soil water from which the impurities have been removed, and the bottom soil is coagulated and precipitated. Next, the precipitated and concentrated bottom soil is appropriately extracted and dehydrated using a belt press or the like. This results in dredged soil with a moisture content of about 50% to 55% suitable for the present invention. In addition, the inorganic neutral flocculant mainly composed of calcium fixes phosphorus components in the water, so that phosphorus components that cause eutrophication of lakes and marshes can be removed at the same time as dredging. In addition, when an inorganic neutral flocculant mainly composed of calcium is used as the flocculant, the calcium component of the flocculant and the fixed phosphorus component function as fertilizer for plants, so that the amount of calcium and phosphorus fertilizer applied to farmland can be reduced or eliminated.

[0019] In addition, the bottom soil of general lakes, marshes, reservoirs, etc. is rich in silt and clay containing silica, mineral components such as magnesium, and organic components. Silica is a nutrient necessary for Bacillus bacteria to form spores, and various mineral components and organic components are excellent nutritional sources for Bacillus bacteria and spontaneously active nematodes. Therefore, by using dredged soil as the soil improvement material of the present invention, it is possible to promote the proliferation of Bacillus bacteria and spontaneously active nematodes in the fermentation process.

[0020] The cellulose source in the present invention is a plant material that serves as nutrition for the Bacillus bacteria, and may be any of pruned branches, bark of cedar, pine, cypress, etc., waste mushroom beds from log and mushroom bed cultivation, leaf mold, sawdust, bean sprout residue, charcoal such as charcoal and bamboo charcoal, bran, rice bran, corn bran, beer lees, whiskey lees, shochu lees, cotton lees, paper such as cardboard, crushed tree trunks and root stumps, grass generated by weeding work, etc. Also, a mixture of multiple types may be used. Furthermore, when the cellulose source is a hard one such as bark or branch, it is preferable to crush it to a size of 3 mm to 1 cm, especially about 5 mm. It is particularly preferable to reuse these cellulose sources that are basically waste from the viewpoint of cost and waste reduction.

[0021] Next, a method for producing a soil improvement material according to the present invention will be described. Here, a method for producing a soil improvement material in which dredged soil is added to the material will be described. First, a cellulose source is obtained (step S104). Dredged soil dehydrated by the above-mentioned method is obtained (step S102). If necessary, dried sludge is obtained from a water treatment facility or the like as seed soil (step S106). If necessary, compost or the like in which spontaneously active nematodes have been confirmed to live is obtained as a seed nematode source (step S108). As described above, the seed soil and the seed nematode source are obtained from elsewhere only the first time, and from the next time onwards, an appropriate amount of the previously prepared soil improvement material may be collected or left to serve as the seed nematode source and seed soil. In parallel with this, an Allium plant that is the raw material for the germination inducer is obtained from, for example, a farmer or a field (step S100). As described above, it is preferable to use unnecessary parts or waste products of Allium crops as the Allium plant.

[0022] Next, the cellulose source, the dredged soil, the seed soil, and the seed nematode source are mixed to prepare a mixed soil (first mixing step S202). Any mixing method may be used at this time.

[0023] Next, the mixed soil is fermented (first fermentation step S204). Generally, in this first fermentation step S204, the Bacillus bacteria in the seed soil grow rapidly using the cellulose source as nutrients and become dominant. The fermentation temperature at this time rises to nearly 60°C (high-temperature fermentation phase S204A). Note that if the fermentation temperature exceeds 40°C, it is unsuitable for the survival of self-active nematodes, including bacteriophagous nematodes, and the self-active nematodes will be concentrated in the relatively low-temperature surface layer. This allows the Bacillus bacteria to continue to grow without being preyed upon by bacteriophagous nematodes. In addition, by raising the fermentation temperature to nearly 60°C, it is possible to sterilize other heat-sensitive bacteria and heat-kill the weed seeds in the mixed soil.

[0024] After several days, the proliferation of the Bacillus species subsides, the fermentation temperature drops, and fermentation continues at a temperature of 20°C to 40°C (maturation fermentation stage S204B). During this maturation fermentation stage S204B at 20°C to 40°C, the activity of the self-active nematodes becomes active, and the bacteriophagous nematodes feed on the Bacillus bacteria and proliferate. Next, the predatory nematodes that prey on the bacteriophagous nematodes proliferate. Furthermore, during the maturation fermentation stage S204B, multiple species of Bacillus bacteria are generated, which is more effective in restoring the soil ecosystem and suppressing continuous crop damage. As a result, the Bacillus bacteria and the self-active nematodes become dominant in the mixed soil. The fermentation temperature during the high-temperature fermentation stage S204A and maturation fermentation stage S204B may be artificially controlled. For example, when the fermentation temperature exceeds 60°C in summer, the fermentation temperature may be lowered by adding a cellulose source such as pruning branches or bark with a slow fermentation rate or by dissipating heat through stirring. In addition, in winter or other seasons where the fermentation temperature is below 20° C., the fermentation temperature may be increased by adding a cellulose source with a fast fermentation rate, such as rice bran or soybean lees. The period of the first fermentation step S204 (fermentation period) varies depending on the outside temperature, the cellulose source used, and the like, but is generally about several weeks to one month.

[0025] At this stage, the ratio of each material is preferably 30wt%-50wt% dredged soil, 30wt%-50wt% cellulose source including germination inducer, and 5wt%-10wt% seed soil and seed nematode source, by dry weight, and it is most preferable that the ratio of dredged soil to cellulose source is 1:1. Also, it is preferable that the moisture content of the soil improvement material at this stage is approximately 30%-60%.

[0026] Next, the Allium plant, which serves as a germination inducer, is mixed into the mixed soil obtained in the first fermentation step S204 (second mixing step S206). Any mixing method may be used at this time, as in the first mixing step S202. It is preferable that the Allium plant to be mixed is cut to an appropriate size in advance and mixed. The amount of the germination inducer to be mixed at this time is preferably about 10 wt% to 20 wt% by wet weight and 2 wt% to 5 wt% by dry weight with respect to the mixed soil after the first fermentation step.

[0027] Next, the mixed soil mixed with the Allium plant is re-fermented (second fermentation step S208). This second fermentation step S208 causes the Allium plant to ferment and emit a strong Allium odor mainly composed of disulfide. This completes the soil improvement material of the present invention having a control function against black rot disease. The Allium odor decreases over time. For this reason, it is preferable to plan and adjust the production timing of the second mixing step S206 and the second fermentation step S208 by counting backwards from the time of use so that the soil improvement material can be used in the field while the Allium odor is still maintained.

[0028] In addition, the soil improvement material according to the present invention MaterialIn the manufacturing method, after the first fermentation step S204 and the second fermentation step S208, compost made mainly of livestock manure may be mixed to prepare the fertilizer components with approximately the same total nitrogen, phosphorus, and potassium content. Examples of livestock manure compost include pig manure compost, cow manure compost, chicken manure compost, and mixed composts of these. Among them, it is particularly preferable to use pig manure compost. The soil improvement material obtained in this way contains a well-balanced mixture of the three major nutrients necessary for plant growth, so it can be used as a basic fertilizer, and the amount of fertilizer applied to farmland can be reduced or fertilization itself can be eliminated. The total nitrogen, phosphorus, and potassium content of the soil improvement material and the livestock manure compost to be mixed vary depending on the materials used, etc., so the selection and mixing amount of the livestock manure compost are appropriately adjusted according to the soil improvement material after the first fermentation step or the second fermentation step. However, the mixing amount is approximately 10 wt% to 20 wt% of the soil improvement material.

[0029] Next, a preferred embodiment of the method for producing the soil improvement material according to the present invention and a method for controlling black rot sclerotinia using the soil improvement material will be described. First, steps S104 to the first fermentation step S204 are carried out to prepare a mixed soil in which the self-active nematodes and Bacillus bacteria are dominant. On the other hand, when the harvest of Allium crops is completed, the black rot sclerotinia fungus remains in the soil in the form of sclerotia. The harvested Allium crops are distributed as products through the appropriate route after unnecessary parts are removed.

[0030] Then, for example, in early spring, unnecessary parts and waste products of the Allium crops that are discharged during the manufacturing period of the soil improvement material according to the present invention are obtained as raw materials for the germination inducer (step S100). The obtained raw materials for the germination inducer are cut into appropriate sizes as necessary. Next, the raw materials for the germination inducer (unnecessary parts and waste products of the Allium crops) are added to the mixed soil after the first fermentation step, and a second mixing step S206 is performed. Next, a second fermentation step S208 is performed to re-ferment these components and enhance the Allium odor of the germination inducer. This completes the soil improvement material according to the present invention that has a function of preventing black rot sclerotinia disease.

[0031] Next, a method for controlling black rot disease using this soil improvement material will be described. The soil improvement material prepared as described above is applied to a field after harvest at a rate of, for example, 3 t / 10 a (3000 kg / 100 m) while the Allium odor is maintained. 2 ) and mixed in the soil. This causes the sclerotia of the black rot sclerotinia to germinate all at once in response to the Allium odor (components) emitted by the germination inducer in the soil improvement material. However, since there are no Allium plants in the field, the germinated mycelia cannot obtain nutrients from the host plant and starve to death. At this time, the Bacillus bacteria in the soil improvement material secrete an antibacterial substance, which also acts to kill the germinated black rot sclerotinia. This kills the germinated black rot sclerotinia, and the number of sclerotia that can germinate can be reduced to zero or significantly reduced. This prevents the black rot sclerotia from occurring, and even if Allium crops are sown or planted in the field, the occurrence of black rot sclerotia can be prevented.

[0032] As mentioned above, the sclerotia of the black rot sclerotinia fungus germinate in response to the Allium odor even at temperatures above 20°C. However, the mycelium of the black rot sclerotinia fungus does not grow even when parasitized on a host plant at temperatures above 20°C, and cannot survive at temperatures above 25°C. Therefore, it is preferable to mix the soil improvement material into the field on a day when the daytime temperature is above 20°C, more preferably above 25°C, and this temperature continues for several days. In this configuration, the black rot sclerotinia fungus can be weakened or killed not only by starvation but also by heat.

[0033] As described above, the present invention Black The method for controlling black rot sclerotinia is to mix the sclerotia of black rot sclerotinia fungus remaining in the soil into the soil in the absence of Allium plants, and the germination inducer Allium odor causes the sclerotia of black rot sclerotinia fungus remaining in the soil to germinate all at once. The germinated hyphae are then starved to death in the absence of a host plant, and the number of sclerotia capable of germination is reduced to zero or significantly reduced. This allows the present invention to be implemented. Black The method for controlling black rot can effectively control black rot, which is difficult to eradicate, without using chemicals or special labor.

[0034] In addition, the present invention YoThe soil improvement material contains Bacillus bacteria and spontaneously active nematodes that are dominant, and by mixing this with farmland etc., it is possible to increase the beneficial nematodes and thereby regenerate the soil ecosystem. Furthermore, the Bacillus bacteria contained in the soil improvement material secrete antibiotics to suppress the growth of mold and bacteria that are harmful to crops, including black rot sclerotinia sclerotinia. Furthermore, the predatory nematodes contained in the spontaneously active nematodes prey on parasitic nematodes that are harmful to crops. This makes it possible to prevent the occurrence of continuous crop damage in farmland etc. Furthermore, the present invention Yo The soil improvement materials used in this study function as excellent fertilizers themselves, making it possible to reduce or eliminate the need for fertilizer application to farmland.

[0035] Furthermore, the soil improvement material according to the present invention Material The production method can produce the soil improvement material with the above-mentioned black rot disease control function using all waste materials such as dredged soil, unnecessary parts or waste products of Allium crops, water treatment sludge, bark bark, etc. This allows production at extremely low material costs. In addition, it allows the reuse of waste materials, thereby reducing the environmental burden.

[0036] The method for producing the soil improvement material according to the present invention and the method for controlling black rot disease are also described in the present example. Law The configuration is one example, and the methods used in each process, the types of germination inducers, dredged soil, seed nematode source, seed fungus soil, and cellulose source used, etc. are not limited to the above examples, and the present invention can be modified and implemented within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0037] S202 First mixing process S204 First fermentation process S206 Second mixing process S208 Second fermentation process

Claims

1. A first mixing step of mixing a seed nematode source inhabiting free-living nematodes, a seed soil inhabiting Bacillus bacteria secreting an antibacterial substance, a cellulose source serving as nutrients for the Bacillus bacteria, and dehydrated dredged soil; a first fermentation step in which the mixed soil obtained in the first mixing step is fermented at 20°C to 60°C to make the Bacillus bacteria predominant in the mixed soil and promote the proliferation of the self-active nematodes; a second mixing step of mixing a germination inducer made from a plant of the Allium genus and promoting germination of sclerotia of the pathogen of black rot disease with the mixed soil after the first fermentation step; A method for producing a soil improvement material, comprising: a second fermentation step of re-fermenting the mixed soil obtained in the second mixing step to enhance the Allium odor of the germination inducer.

2. 2. The method for producing a soil improving material according to claim 1, wherein unnecessary parts or waste products of plants of the Allium genus are used as the germination inducer.

3. A method for controlling black rot sclerotinia disease, comprising mixing a soil improvement material produced by the manufacturing method described in claim 1 or claim 2 into soil, causing sclerotia of a pathogen of black rot sclerotinia disease to germinate due to the Allium odor of a germination inducer contained in the soil improvement material, and controlling the germinated pathogen by causing it to starve to death in the absence of a host plant.

4. The method for controlling black rot disease according to claim 3, characterized in that the soil improvement material is mixed on a day when the daytime temperature is 20°C or higher, and germinated black rot disease pathogens are controlled by starvation due to heat and the absence of a host plant.

Images