Soil reduction disinfectant and soil reduction disinfection method

Abstract

To provide a reductive disinfectant for soil which does not need to use a chemical agrochemical and a soil disinfectant that must be handled with care and have a problem in safety, dispenses with a facility for soil heating, does not depend on soil environment, is excellent in convenience, versatility and workability, and can disinfect the soil at low cost, and a reductive disinfection method for soil using the same.SOLUTION: A reductive disinfectant for soil that contains a cultured waste liquid of bread yeast, in which an amount of the total solid content in the cultured waste liquid of the bread yeast is 40-55 mass%, and an amount of total sugar is 3-10 mass%; and a reductive disinfection method for soil which includes adding the reductive disinfectant for soil to soil and fermenting the mixture into reduced condition, and thereby disinfecting the soil.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a soil reducing disinfectant using a culture waste solution of baker's yeast and a soil reducing disinfection method using the soil reducing disinfectant. [Background technology]

[0002] It is known that repeated cultivation of a single crop in fields or facilities can lead to an increase in pathogenic bacteria in the soil, resulting in poor growth and subsequent withering of the crop, leading to problems such as bacterial wilt, tomato wilt, tomato root rot, and gray mold caused by soil-borne microorganisms, resulting in significant agricultural losses.

[0003] To combat the above-mentioned continuous crop damage, soil sterilization is generally carried out using chemical pesticides such as chloropicrin or soil fungicides. However, for example, chloropicrin must be handled with care due to its lachrymatory and irritating properties, and improper handling can cause problems such as damage from its pungent odor.

[0004] Therefore, a soil reduction disinfection method has been proposed, which involves keeping the soil in an anaerobic state by keeping it sufficiently moist and organic matter, thereby stimulating the activity of microorganisms in the soil and killing pathogens.

[0005] As a soil reduction disinfection method, for example, a method has been proposed in which undecomposed organic matter is added to the soil, and the soil is irrigated to cover the soil surface, and hot water is then supplied to the soil (see, for example, Patent Document 1). However, this proposal requires the installation of pipes or the like for supplying hot water to the soil, which results in high equipment costs, and there are problems in that only the soil in the area where the pipes or the like are installed can be disinfected, and it is not possible to disinfect a large area of ​​soil or soil in any desired location.

[0006] In addition, in the soil reduction disinfection method, methods have been proposed that use granulated materials consisting mainly of wheat bran and / or flour (see, for example, Patent Document 2), that use an aqueous molasses solution (see, for example, Patent Document 3), and that use low-concentration ethanol (see, for example, Patent Document 4). However, because wheat bran is a powder, its effect is limited to the surface layer of the soil, making it difficult to achieve an effect on the entire plow layer or subsoil. As mentioned above, it must be granulated, which is time-consuming. The method using molasses has the problem that its high viscosity makes it difficult to dilute around the field, making it difficult to apply uniformly. It also has the risk of attracting insects such as ants. While low-concentration ethanol solutions contain less than 60% ethanol by volume and are not considered hazardous materials under the Fire Service Act, they are problematic in terms of flammability and odor within facilities.

[0007] Therefore, there is a strong demand for the prompt provision of a technology that can disinfect soil at low cost, without the need for chemical pesticides or soil fungicides that require careful handling and have safety issues, without the need for soil heating equipment, and that is not affected by the soil environment, is simple, versatile, and easy to work with. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-265050 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-61003 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-323395 [Patent Document 4] International Publication No. 2007 / 129467 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention addresses these demands, breaks through the current situation, solves the above-mentioned conventional problems, and achieves the following objectives: The present invention aims to provide a soil reducing and disinfecting agent that does not require the use of chemical pesticides or soil fungicides that require careful handling and have safety issues, does not require soil heating equipment, is not affected by the soil environment, is simple, versatile, and easy to use, and can disinfect soil at low cost, and a soil reducing and disinfecting method using the same. [Means for solving the problem]

[0010] As a result of extensive research to achieve the above object, the present inventors have found that culture wastewater of baker's yeast exhibits excellent effects as a soil reducing disinfectant, and have thus completed the present invention.

[0011] The present invention is based on the above findings of the present inventors, and the means for solving the above problems are as follows: <1> A soil reducing disinfectant containing baker's yeast culture wastewater, The soil reducing disinfectant is characterized in that the total solid content in the culture waste liquid of the baker's yeast is 40 to 55% by mass and the total sugar content is 3 to 10% by mass. <2> The total organic carbon (TOC) in the culture wastewater of the baker's yeast is 50,000 to 300,000 mg / L. <1> The soil reducing disinfectant is described in the above. <3> The viscosity of the culture waste liquid of the baker's yeast at 25°C is 1 to 100 cP. <1> or <2> The soil reducing disinfectant is described in the above. <4> The biochemical oxygen demand (BOD) of the culture wastewater of the baker's yeast is 100,000 to 500,000 mg / L. <1> ~ <3> The soil reducing disinfectant according to any one of the above items. <5> The total amount of nitrogen in the culture wastewater of the baker's yeast is 0.5 to 2% by mass. <1> ~ <4> The soil reducing disinfectant according to any one of the above items. <6> The baker's yeast culture waste liquid is a culture liquid using blackstrap molasses. <1> ~ <5> The soil reducing disinfectant according to any one of the above items. <7> The aforementioned <1> ~ <6> The present invention relates to a method for soil reduction and disinfection, characterized in that the method comprises adding the soil reduction and disinfection material according to any one of the above items to soil, causing fermentation, and thereby disinfecting the soil by bringing it into a reducing state. [Effects of the Invention]

[0012] According to the present invention, it is possible to solve the above-mentioned problems of the prior art and achieve the above-mentioned object, and to provide a soil reduction disinfectant and a soil reduction disinfection method using the same, which do not require the use of chemical pesticides or soil fungicides that require careful handling and have safety issues, do not require soil heating equipment, are not affected by the soil environment, are simple, versatile, and easy to use, and can disinfect soil at low cost. [Brief explanation of the drawings]

[0013] [Figure 1A] FIG. 1A is a diagram showing an outline of the test in Test Example 1. [Figure 1B] FIG. 1B is a diagram showing an outline of the test in Test Example 1. [Figure 1C] FIG. 1C is a diagram showing an outline of the test in Test Example 1. [Figure 2] FIG. 2 is a diagram showing the results of temperature measurement in Test Example 1. [Figure 3] FIG. 3 is a diagram showing the results of the oxidation-reduction potential measurement in Test Example 1. [Figure 4] FIG. 4 is a diagram showing the results (theoretical values) of the oxidation-reduction potential measurement of the present invention group in Test Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0014] (soil reduction disinfectant) The soil reducing disinfectant of the present invention contains at least a culture waste liquor of baker's yeast, and may further contain other components as required.

[0015] <Baker's yeast culture wastewater> The baker's yeast culture waste liquid (hereinafter sometimes referred to as "culture waste liquid") is a waste liquid remaining after removing the baker's yeast from a culture of baker's yeast, and has a dark brown appearance. The culture waste liquid is readily soluble in water.

[0016] The physical properties (total solid content, viscosity) of the culture waste liquid are as follows. -Total solids- The amount of total solids in the culture waste liquid is not particularly limited as long as it is 40 to 55% by mass, and can be selected appropriately. The method for measuring the total solid content in the culture wastewater is not particularly limited, and any known method can be appropriately selected, for example, centrifugation, heat drying, etc. An example of the heat drying method is a method in which the solid content is weighed after drying in an oven at 100 to 120°C for 24 hours.

[0017] -viscosity- The viscosity of the culture waste liquid at 25° C. is not particularly limited and can be selected appropriately, but is preferably 1 to 100 c.P. (centipoise), more preferably 5 to 30 c.P. Since the culture waste liquid is in a liquid state, it can be easily diluted and sprayed. The method for measuring the viscosity of the culture wastewater is not particularly limited, and any known method can be appropriately selected. For example, the viscosity can be measured at 25°C using a B-type viscometer.

[0018] Other physical properties of the culture waste liquid include, for example, a pH of about 4 to 5.5 and a specific gravity of about 0.5 to 3. The pH and specific gravity can be measured by known methods.

[0019] The amounts of components (total sugars, total nitrogen) contained in the culture wastewater are as follows:

[0020] -Total sugar- The amount of total sugars in the culture waste liquid is not particularly limited as long as it is 3 to 10% by mass, and can be selected appropriately. The method for measuring the total sugars is not particularly limited, and any known method can be appropriately selected. For example, the total sugars can be measured by the phenol-sulfuric acid method, liquid chromatography using HPLC or the like, or the like.

[0021] -Total amount of nitrogen- The total amount of nitrogen in the culture wastewater is not particularly limited and can be selected appropriately, but is preferably 0.5 to 2% by mass. When the culture wastewater contains nitrogen, nitrogen can be supplied during soil disinfection. The method for measuring the total amount of nitrogen is not particularly limited, and any known method can be appropriately selected. For example, the total amount of nitrogen can be measured by the Kjeldahl method (Testing Methods for Fertilizers, etc. (2017) - National Institute for Food and Agricultural Materials Inspection and Research, Independent Administrative Institution), the sulfuric acid method (Fertilizer Analysis Method (National Institute for Agro-Environmental Sciences, Ministry of Agriculture, Forestry and Fisheries Method (1992 edition)), the summation method, ultraviolet absorptiometry, hydrazinium sulfate reduction copper method, or cadmium column reduction method (all of which are factory wastewater testing methods subject to total amount regulations; JIS K 0102).

[0022] The range of the amount of other components contained in the culture waste liquid includes, for example, the following. Total phosphorus: 0.03 to 0.08 mass% · Ash content ··· 9~13% by mass · Crude fat ··· 0~2% by mass Potassium 1 to 5% by mass Calcium: 0.7 to 2.3% by mass Silicic acid (SiO2) 0.2 to 0.3 mass% Magnesium 0.2 to 0.5 mass% Sodium: 0.17 to 0.36 mass% Chlorine: 1.5 to 3.0 mass% · Sulfur ··· 0.39% by mass · Nitrate radical ··· 0.57% by mass

[0023] -Total organic carbon- The total organic carbon (hereinafter sometimes referred to as "TOC") of the culture wastewater is not particularly limited and can be selected appropriately, but is preferably 50,000 to 300,000 mg / L. The method for measuring the TOC is not particularly limited, and any known method can be appropriately selected. For example, the TOC can be measured using a combustion oxidation type total organic carbon meter, a TOC meter (total organic carbon meter), or the like.

[0024] -Biochemical oxygen demand- The biochemical oxygen demand (hereinafter sometimes referred to as "BOD") of the culture wastewater is not particularly limited and can be selected as appropriate, but is preferably 100,000 to 500,000 mg / L. Because the culture wastewater has the above-mentioned BOD, it serves as nutrients for anaerobic microorganisms (Clostridium genus) in the soil, causing the anaerobic microorganisms to grow and creating a reducing condition. Note that the microorganisms that cause disease are aerobic, and therefore cannot survive in the soil and die. The method for measuring the BOD is not particularly limited, and any known method can be appropriately selected. For example, the BOD can be measured by the industrial wastewater test method (JIS K0102), as well as the concentration method, pressure method, etc.

[0025] The method for preparing the culture waste liquid is not particularly limited, and the culture waste liquid can be prepared by removing baker's yeast from a baker's yeast culture that has been cultured by a known method. For example, the culture waste liquid can be obtained by culturing baker's yeast using blackstrap molasses as a culture medium, and then centrifuging the resulting culture to remove the baker's yeast.

[0026] The blackstrap molasses is a viscous, dark brown liquid that contains components other than sugar and is produced during sugar refining. The method for preparing the blackstrap molasses is not particularly limited, and any known method can be appropriately selected.

[0027] The baker's yeast is Saccharomyces cerevisiae. The strain of the baker's yeast is not particularly limited and can be selected appropriately.

[0028] The conditions for culturing the baker's yeast are not particularly limited, and conditions such as temperature and time usually used for culturing baker's yeast can be appropriately selected.

[0029] The culture waste liquid is preferably concentrated. The concentration method is not particularly limited, and a known method can be appropriately selected. The degree of concentration is not particularly limited, and can be appropriately selected taking into consideration the total solid content, the total sugar amount, etc.

[0030] The content of the culture waste liquid in the soil-reducing disinfectant is not particularly limited and can be selected appropriately. The soil-reducing disinfectant may consist solely of the culture waste liquid.

[0031] <Other ingredients> The other components are not particularly limited and can be selected appropriately as long as they do not impair the effects of the present invention. The content of the other components in the soil reducing disinfectant is not particularly limited and can be selected appropriately.

[0032] <Application> The amount of the soil reducing disinfectant to be applied is not particularly limited and can be selected appropriately. 2 The amount is preferably 0.1 to 10 L per 100 ml, more preferably 0.5 to 5 L per 100 ml. If the amount is within the above-mentioned preferred range, it is advantageous in that the cost required for treatment can be reduced while the soil can be brought into a reduced state more quickly and efficiently.

[0033] The amount of the soil reducing disinfectant to be applied is not particularly limited and can be selected appropriately. 2 The amount of carbon per unit of soil is preferably 15 to 1,500 g, more preferably 75 to 700 g, which is advantageous in that the soil can be brought to a reduced state more quickly.

[0034] The soil reducing disinfectant of the present invention can also be used together with microbial materials, minerals (vermiculite, perlite, zeolite, diatomaceous earth, etc.), soil conditioners, ordinary fertilizers, special fertilizers, etc. These may be blended into the soil reducing disinfectant or added separately to the soil.

[0035] (Soil reduction disinfection method) The soil reduction and disinfection method of the present invention includes at least a soil disinfection step of disinfecting soil using the soil reduction and disinfectant of the present invention described above, and may further include other steps as necessary.

[0036] <Soil disinfection process> The soil disinfection step is a step of disinfecting the soil by adding the above-described soil reducing disinfectant of the present invention to soil and fermenting it to bring it into a reducing state.

[0037] In the soil disinfection step, the soil reducing disinfectant is added to the soil, water is then added, and the soil is irrigated to a certain level. The soil surface is then covered with a sheet or the like, and anaerobic fermentation is carried out, thereby bringing the soil into a reducing state and disinfecting it.

[0038] The type of soil to be targeted is not particularly limited as long as it requires disinfection and can be selected appropriately, for example, soil for growing plants and crops (vegetables such as fruit vegetables, leafy vegetables, and root vegetables, flowers, fruit trees, etc.). The soil may be any of ordinary black soil, red soil, sandy soil, clay soil, or a mixture thereof, and in terms of pH, may be any of acidic soil, neutral soil, and alkaline soil.

[0039] The targets of disinfection of the present invention are not particularly limited and can be selected appropriately as long as they can be controlled by reducing soil disinfection, and examples include nematodes, plant pathogens, insect larvae, adult insects, and plant viruses.

[0040] The amount of the soil reducing disinfectant to be added is not particularly limited and can be selected appropriately, for example, the same as that described in the "Application" section of the soil reducing disinfectant above.

[0041] The type of water is not particularly limited and can be appropriately selected as long as it does not impair the effects of the present invention, and examples include agricultural water, well water, tap water, rainwater, river water, lake water, etc. These may be used alone or in combination of two or more types.

[0042] The degree of watering is not particularly limited and can be selected appropriately as long as it can create anaerobic conditions, and can be, for example, to the extent that the soil surface is covered with water.

[0043] The means used for covering the soil is not particularly limited as long as it can create anaerobic conditions, and can be appropriately selected. For example, an agricultural vinyl mulch sheet can be used. The degree of covering is not particularly limited and can be selected appropriately as long as it can create anaerobic conditions, but it is preferable to cover the entire surface of the soil.

[0044] The period of soil disinfection (hereinafter sometimes referred to as the "culture period") is not particularly limited and can be appropriately selected depending on the degree of soil temperature rise, the degree of disinfection, etc., and can be, for example, about 1 to 4 weeks.

[0045] The conditions for the soil disinfection, such as soil temperature and light / dark time, are not particularly limited, and known conditions can be appropriately selected.

[0046] <Other processes> The other steps are not particularly limited and can be selected appropriately as long as they do not impair the effects of the present invention.

[0047] The soil reduction and disinfection method of the present invention may be carried out at a location (on-site) where soil originally exists, such as a field, or may be carried out on soil prepared in advance outside the site, such as collected soil or adjusted soil.

[0048] The soil reduction disinfectant and soil reduction disinfection method of the present invention achieve the effect of reduction disinfection in the entire topsoil layer, regardless of whether it is the surface or subsoil. Furthermore, since the active ingredient is baker's yeast culture wastewater, it is safe for human contact and safe even if accidentally ingested. Furthermore, it is easy to handle, without the risk of fire or unpleasant odors. Furthermore, the culture wastewater of baker's yeast is a by-process product generated in the yeast manufacturing process, but can be effectively utilized by the present invention. [Example]

[0049] The present invention will be explained below by showing production examples and test examples, but the present invention is not limited to these production examples and test examples.

[0050] (Production Example 1: Production of soil reduction disinfectant) Culture wastewater generated during the production of Oriental Yeast (regular) at the Tokyo factory of Oriental Yeast Co., Ltd. (using the blackstrap molasses described below as the culture medium) was used as culture wastewater for baker's yeast. <Molasses approximate value> pH 5.0 Specific gravity 1.390 Monosaccharides: 47% by mass Glucose: 9.0% by mass Fructose 11.0% by mass Sucrose: 27.0% by mass Phosphorus: 25.0 mg / 100 g Nitrogen: 50-100mg / 100g

[0051] A concentrated solution of the baker's yeast culture wastewater was obtained using an evaporative concentration apparatus (VVCC+RHCF (FTC), manufactured by Sasakura Co., Ltd.), and used as a soil reducing disinfectant.

[0052] The obtained soil reducing disinfectant had a dark brown liquid appearance and was readily soluble in water. Its physical properties are shown below. <Physical properties> pH 4.83 Viscosity: 13 cP (at 25°C, measured using a Brookfield viscometer) · Specific gravity ··· 1.19 · Total solid content ··· 41.8% by mass

[0053] <Analysis value> Total nitrogen content: 1.2% by mass Total phosphorus: 0.05% by mass · Ash content ··· 11% by mass · Crude fat ··· 1% by mass Total sugars: 6% by mass (measured after hydrolysis) Potassium 3% by mass Calcium 1.5% by mass Silicic acid (SiO2) 0.2% by mass Magnesium 0.3% by mass Sodium 0.26% by mass Chlorine 2.2% by mass Sulfur: 0.39% by mass (measured by barium sulfate method) Nitrate ion: 0.57% by mass (measured by ion chromatography)

[0054] The biochemical oxygen demand (BOD) of the obtained soil reduction disinfectant was 250,000 mg / L, and the total organic carbon (TOC) was 150,000 mg / L.

[0055] (Test Example 1: Reduction Confirmation Test) Using the test method below, it was confirmed whether the soil transitioned to a reducing state after the soil reducing disinfectant produced in Production Example 1, which is an example of the present invention, was applied to the soil.

[0056] <Test Method> The test method was as follows: An outline of the test is shown in Figures 1A to 1C. Test soil: Black soil found in Chikusei City, passed through a 5mm mesh. 500g per pot. Culture vessel: Neubauer pot. Treatments were replicated in triplicate. Covering: Agricultural vinyl mulch sheet. Covering the soil surface to cut off oxygen supply. Temperature: 30℃ (constant temperature) (cultured in an incubator) Light / dark time (light / dark): 0 hours / 24 hours Culture period: 14 days Frequency of measuring redox potential: At the start of the test, and on the 2nd, 4th, 6th, 8th, 11th, and 14th days after the start of the test. Oxidation-reduction potential measurement method: platinum electrode method Measurement of the effect of temperature rise: Measurements were taken at the start of the test, and on the second, fourth, sixth, eighth, and fourteenth days after the start of the test. To measure the effect of temperature rise, pots were prepared for incubation at room temperature and the temperature of the filled soil was measured.

[0057] -Setting the amount of material to be applied and the treatment area- Test area 1: Soil reduction disinfectant (small amount) from Production Example 1 The application rate is 10 mL / 100 cm 2 (Add about 20% of the carbon content of the low-concentration ethanol disinfectant.) After adding, water until the water level reaches a certain level (so that the soil surface is covered with water. Same below). Test area 2: Soil reduction disinfectant (medium) from Production Example 1 The application rate is 25 mL / 100 cm 2 (Add about 50% of the carbon content of the low-concentration ethanol disinfectant.) After adding, water until the water level reaches a certain level. Test area 3: Soil reduction disinfectant (manufacturing example 1) The application rate is 50 mL / 100 cm 2 (The carbon content is equivalent to that of low-concentration ethanol disinfection (780g-C / m 2 After adding, water the soil until the water level reaches a certain level. Test group 4: Low concentration ethanol (positive control) The application rate is 15 mL / 100 cm 2(Use 99.5% ethanol. Apply the net amount of ethanol used for low-concentration ethanol disinfection.) After application, water until the water level reaches a certain level. Test group 5: Control (1) No application. No irrigation. Test area 6: Control (2) No application. Irrigation.

[0058] <Result> -temperature- The results of temperature measurements are shown in Figure 2. No differences in temperature were observed in any of the treatment plots on the same measurement day.

[0059] -Oxidation-reduction potential- The results of the oxidation-reduction potential (hereinafter sometimes referred to as "Eh") measurements (average of triplicate values) are shown in Figure 3. Note that the control (1) (no irrigation) had a high Eh value (greater than 1,999 mV) in all measurements, so it is not shown in the figure. In the treatment areas where the soil-reducing disinfectant of Production Example 1 was used, Eh dropped sharply on the second day from the start of the test in all treatment areas. Furthermore, in the treatment areas where the soil-reducing disinfectant of Production Example 1 was used, Eh became negative in fewer days than in the control area and the low-concentration ethanol area. Therefore, it was confirmed that an excellent soil reduction effect can be obtained by using the soil reducing disinfectant of the present invention.

[0060] (Test Example 2: Soil reduction disinfection test) A soil reduction disinfection test was carried out using the soil reduction disinfectant produced in Production Example 1, which is an example of the present invention, according to the following test method.

[0061] <Test Method> 1) Location Test location: Fukaya City, Saitama Prefecture Soil: Brown lowland soil (Shinkai style) 2) Test scale Facility (house), 22 ares (a) 3) Test crops cherry tomatoes 4) Test area Soil reduction disinfection with rice bran application (hereinafter referred to as the "control group") The application rate of rice bran is 150 kg / 10a. Soil reduction disinfection using the soil reduction disinfectant produced in Production Example 1 (hereinafter sometimes referred to as the "present invention area"). The application rate of the soil reducing disinfectant produced in Production Example 1 was 1,000 L / 11 a. 5) Processing method Invention Zone Irrigation tubes (Everflow™ 40 diameter) were laid on the soil surface, leveled evenly, at 1 m intervals between planting rows. 1,000 L of the soil reducing disinfectant produced in Production Example 1 was diluted with well water (irrigation water), and 13,800 L / 10 a of the diluted concentrated solution was applied to the entire 11 a area until the soil was in a water-logged state. Four days after the irrigation was completed, the soil surface was covered with transparent vinyl, and the greenhouse was sealed. Control area Rice bran (150 kg / 10a) and soil treatment fermentation agent (S agent) (30 kg / 10a) were applied to the entire layer, and the same amount of groundwater as in the invention plot was irrigated. Four days after the irrigation was completed, the soil surface was covered with transparent vinyl and the greenhouse was sealed. 6) Period of soil reduction disinfection 25 days

[0062] <Result> -Air temperature and soil temperature- Four days after the start of the test (the day the ground surface was covered with clear vinyl), eight days, 14 days, 21 days, and 25 days later, the air temperature inside the greenhouse (20 cm above the ground surface) and the soil temperature (surface layer: 5-10 cm below the ground surface, lower layer: 20-25 cm below the ground surface) were measured. The results are shown in Table 1. Table 1 also shows the daily average temperature (outside temperature) observed by the meteorological observatory in the area where the test was conducted.

[0063] [Table 1]

[0064] As shown in Table 1, the soil temperature in both the control and invention plots was similar, reaching high temperatures, including in the lower layers. The soil temperature in the invention plot, both in the surface and lower layers, was slightly higher by about 1°C than in the control plot.

[0065] -Oxidation-reduction potential- To measure the redox potential of the greenhouse soil, a simple soil Eh meter (FN-702, Fujiwara Seisakusho) was used. The tip of the platinum electrode was inserted into the surface layer (15 cm below the soil surface), and measurements were collected using a data logger on the final day of the test. The measured values ​​of the oxidation-reduction potential in the present invention group were converted into theoretical values, and the results are shown in Figure 4. The theoretical values ​​were calculated using the following formula. Theoretical value = Measured value x 26 + 206

[0066] As shown in FIG. 4, in the present invention group, the actual measured value of the oxidation-reduction potential from the fourth day onwards was converted to a theoretical value of about −200 mV, confirming that a strong reduction state was maintained.

[0067] -Soil pathogens- Soil samples were collected from the surface and subsoil layers before and after soil reduction disinfection. The four soil pathogens tested were those that cause major soil diseases in tomato cultivation: · Ralstonia solanacearum · Tomato wilt fungus (Fusarium oxysporum f. sp. lycopersici) · Tomato root rot wilt fungus (Fusarium oxysporum f. sp. radics-lycopersici) Gray mold fungus (Botrytis cinerea Persoon)

[0068] The laboratory analyzed the bacterial wilt pathogen using the smear plate method on selective media, and the other pathogens using DNA extraction and PCR. The test results are shown in Tables 2 and 3.

[0069] [Table 2]

[0070] [Table 3]

[0071] As shown in Tables 2 and 3, in the soil before soil reduction disinfection, both the surface and lower layers were 10 2 Although bacterial wilt bacteria were detected at 1 cfu / g, after soil reduction disinfection, the number of bacteria decreased to less than 1 cfu / g in both the control and the invention sections. Furthermore, before soil reduction disinfection, tomato wilt bacteria inhabited the surface and subsurface layers, and tomato root rot wilt bacteria inhabited the surface layer. However, after soil reduction disinfection, neither the control nor the concentrated solution sections were detected. Therefore, it was confirmed that the soil reduction disinfectant of the present invention has a control effect against soil pathogens. In addition, the gray mold fungus, which is often a problem in continuous crop greenhouses, was not detected in this test.

[0072] -Soil chemical characteristics before and after soil reduction disinfection- Soil samples were collected from two locations: the surface soil and the subsoil, before and after soil reduction disinfection. General component analysis (nitrate nitrogen, available phosphate) of the collected soil was performed. The results are shown in Table 4.

[0073] [Table 4]

[0074] As shown in Table 4, nitrate nitrogen in the control area decreased significantly after soil reduction disinfection, whereas it remained stable or increased slightly in the invention area after soil reduction disinfection. Available phosphate in the control area decreased slightly after soil reduction disinfection, whereas it increased significantly in the invention area after soil reduction disinfection.

Claims

1. A soil reducing disinfectant made from baker's yeast culture wastewater, The amount of total solids in the culture waste liquid of the baker's yeast is 40 to 55% by mass, and the amount of total sugars is 3 to 10% by mass, The biochemical oxygen demand (BOD) of the culture wastewater of the baker's yeast is 100,000 to 500,000 mg / L, The soil reducing disinfectant does not contain baker's yeast, The amount of the soil reducing disinfectant applied is 1 m of soil. ２ A soil reducing disinfectant characterized by having a volume of 0.1 to 10 L per unit area.

2. A soil reducing disinfectant made from baker's yeast culture wastewater, The amount of total solids in the culture waste liquid of the baker's yeast is 40 to 55% by mass, and the amount of total sugars is 3 to 10% by mass, The biochemical oxygen demand (BOD) of the culture wastewater of the baker's yeast is 100,000 to 500,000 mg / L, The soil reducing disinfectant does not contain baker's yeast, The amount of the soil reducing disinfectant applied is 1 m of soil. ２ The soil reducing disinfectant is characterized in that the carbon amount per unit area is 15 to 1,500 g.

3. 3. The soil reducing disinfectant according to claim 1, wherein the culture wastewater of baker's yeast is a culture solution using blackstrap molasses.

4. 4. The soil reducing disinfectant according to claim 1, wherein the total organic carbon (TOC) in the culture wastewater of the baker's yeast is 50,000 to 300,000 mg / L.

5. The soil reducing disinfectant according to any one of claims 1 to 4, wherein the total amount of nitrogen in the culture wastewater of the baker's yeast is 0.5 to 2% by mass.

6. 5. The soil reducing disinfectant according to claim 1, wherein the viscosity of the baker's yeast culture wastewater at 25° C. is 1 to 100 cP.

7. A soil reduction disinfection method comprising adding the soil reducing disinfectant according to any one of claims 1 to 6 to soil, fermenting it, and disinfecting the soil by bringing it into a reduced state.

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