Reductive disinfectant for soil and reductive disinfection method for soil

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 liquor of baker's yeast and a soil reducing disinfection method using the soil reducing disinfectant. [Background technology]

[0002] It is known that when a single crop is repeatedly cultivated in a field or facility, pathogens in the soil increase, causing poor growth and death, resulting in continuous crop damage. This continuous crop damage can lead to the occurrence of bacterial wilt, tomato wilt, tomato root rot wilt, gray mold, and other diseases caused by soil-derived microorganisms, resulting in significant agricultural losses.

[0003] For the above-mentioned continuous crop damage, soil sterilization is generally performed using chemical pesticides such as chloropicrin or soil fungicides. However, for example, chloropicrin must be handled with care due to its lachrymation and irritation properties, and if it is handled improperly, there is a problem that damage due to its irritating odor occurs.

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

[0005] As the 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 supplied to the soil (for example, see Patent Document 1). However, the proposed method requires the installation of pipes for supplying hot water to the soil, which results in high equipment costs, and the method can only disinfect the soil in the area where the pipes are installed, and cannot disinfect a wide area of ​​soil or soil in any 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 only seen in the surface layer of the soil, and it is difficult to make it effective in the entire plowed soil layer or subsoil, and it is necessary to granulate it as mentioned above, which is time-consuming. The method using molasses has the problem that it is difficult to dilute it around the field due to the high viscosity of molasses, and it cannot be used uniformly. There is also a risk of attracting insects such as ants. Although low-concentration ethanol aqueous solution contains less than 60% ethanol by volume and is not a hazardous material under the Fire Service Act, it is 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, 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, and is not affected by the soil environment, is simple, versatile, and easy to use. [Prior art documents] [Patent documents]

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

[0009] The present invention aims to meet such demands, break through the current situation, solve the above-mentioned conventional problems, and achieve the following objectives: That is, the present invention aims to provide a soil reduction and disinfection material 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 reduction and disinfection method using the same. [Means for solving the problem]

[0010] Means of the Invention The present inventors have conducted extensive research to achieve the above object and have found that culture wastewater of baker's yeast exhibits excellent properties as a soil reducing disinfectant, thereby completing the present invention.

[0011] The present invention is based on the findings of the present inventors, and the means for solving the above problems are as follows. <1> A soil reducing disinfectant containing a culture wastewater of baker's yeast, 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 mass % and the total sugar content is 3 to 10 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> It is a soil reducing disinfectant described in the above. <3> The viscosity of the culture waste liquid of the baker's yeast at 25° C. is 1 to 100 c.P. <1> or <2> It is a soil reducing disinfectant 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> 10. A soil reducing disinfectant according to claim 9, wherein the soil reducing disinfectant is a disinfectant having a pH of 10 or more. <5> The total amount of nitrogen in the culture wastewater of the baker's yeast is 0.5 to 2% by mass. <1> ~ <4> 10. A soil reducing disinfectant according to claim 9, wherein the soil reducing disinfectant is a disinfectant having a pH of 10 or more. <6> The baker's yeast culture wastewater is a culture liquid using blackstrap molasses. <1> ~ <5> 10. A soil reducing disinfectant according to claim 9, wherein the soil reducing disinfectant is a disinfectant having a pH of 10 or more. <7> The above <1> ~ <6> 1. A soil reduction and disinfection method comprising adding the soil reduction and disinfection material according to any one of claims 1 to 5 to soil, fermenting the soil, and disinfecting the soil by bringing it into a reducing state. Effect of the Invention

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

[0013] [Figure 1A] FIG. 1A is a diagram showing an outline of 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. [Diagram 2] FIG. 2 is a diagram showing the results of temperature measurement in Test Example 1. [Diagram 3] FIG. 3 is a graph 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 PREFERRED EMBODIMENTS

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

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

[0016] The physical properties (total solid content, viscosity) of the culture waste liquid are as follows. -Total solids- The amount of the total solid content in the culture waste liquid is not particularly limited so long as it is 40 to 55% by mass, and can be appropriately selected. The method for measuring the total solid content in the culture waste liquid is not particularly limited, and a known method can be appropriately selected, for example, it can be measured by a centrifugation method, a heat drying method, 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 appropriately selected, but is preferably 1 to 100 c.P. (centipoise), and 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 sugar, total nitrogen) contained in the culture wastewater are as follows:

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

[0021] -Total amount of nitrogen- The total amount of nitrogen in the culture waste liquid is not particularly limited and can be appropriately selected, but is preferably 0.5 to 2 mass %. By containing nitrogen in the culture waste liquid, nitrogen can be supplied during soil disinfection. The method for measuring the total amount of nitrogen is not particularly limited, and a known method can be appropriately selected. For example, the total amount of nitrogen can be measured by the Kjeldahl method (Fertilizer Testing Method (2017) - National Institute for Food and Agricultural Materials and Inspection), 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, the ultraviolet absorptiometry method, the hydrazinium sulfate reduction method, the cadmium column reduction method (all of which are factory wastewater test methods for total amount regulation; JIS K 0102), etc.

[0022] Examples of the range of the amount of other components contained in the culture waste liquid include 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) 0.2-0.3 mass% Magnesium: 0.2 to 0.5% by mass Sodium: 0.17 to 0.36 mass% Chlorine: 1.5 to 3.0% by 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 appropriately selected, 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 by 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 may be appropriately selected, but is preferably 100,000 to 500,000 mg / L. Since the culture wastewater has the above-mentioned BOD, it serves as nutrients for anaerobic microorganisms (genus Clostridium) in the soil, causing the anaerobic microorganisms to grow and creating a reducing state. Note that the microorganisms that cause disease are aerobic microorganisms, 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), concentration method, pressure method, or the like.

[0025] The method for preparing the culture waste liquid is not particularly limited, and the culture waste liquid can be prepared by removing the baker's yeast from a culture of baker's yeast 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 is generated during sugar refining and contains components other than sugar. 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 appropriately selected.

[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 in consideration of the total solid content, the total sugar amount, and the like.

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

[0031] <Other ingredients> The other components are not particularly limited and can be appropriately selected as long as they do not impair the effects of the present invention. The contents of the other components in the soil reducing disinfectant are 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 per unit time is preferably 0.1 to 10 L, and more preferably 0.5 to 5 L. If the amount is within the above-mentioned preferred range, it is advantageous in that the soil can be brought into a reducing state more quickly and efficiently while keeping costs required for treatment low.

[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 is preferably 15 to 1,500 g, more preferably 75 to 700 g. This is advantageous in that the soil can be brought into 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 mixed into the soil reducing disinfectant or may be 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 with the above-mentioned soil reduction and disinfection material of the present invention, and may further include other steps as necessary.

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

[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 water level, the surface of the soil is covered with a sheet or the like, and anaerobic fermentation is performed, whereby the soil is brought into a reducing state and disinfected.

[0038] The type of soil to be targeted is not particularly limited and can be selected as appropriate as long as it requires disinfection, and examples include 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, and mixtures thereof, and in terms of pH, may be any of acidic soil, neutral soil, and alkaline soil.

[0039] The targets of disinfection in 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 of such targets 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, it can be 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 of the water 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 as long as it can create anaerobic conditions, and can be appropriately selected. For example, the degree of watering can be such that the soil surface is covered with water.

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

[0044] The period of the 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 appropriately selected 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 place (on-site) where soil originally exists, such as a field, or may be carried out on soil other than the site, such as collected soil or adjusted soil, which has been prepared in advance.

[0048] According to the soil reduction disinfectant and soil reduction disinfection method of the present invention, the effect of reduction disinfection can be obtained in the entire cultivated soil layer, regardless of the surface layer or the subsoil layer. In addition, since the active ingredient is the culture wastewater of baker's yeast, it is safe for human body and safe even if it is accidentally ingested. In addition, there is no risk of fire or unpleasant odor, and it is easy to handle. In addition, the culture wastewater of baker's yeast is a by-process product generated in the yeast manufacturing process, but can be effectively utilized according to the present invention. EXAMPLES

[0049] The present invention will be described below with reference to 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) At the Tokyo factory of Oriental Yeast Co., Ltd., culture waste liquid generated during the production of Oriental Yeast (regular) (using the blackstrap molasses described below as the culture liquid) was used as culture waste liquid 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 easily soluble in water. Its physical properties are shown below. <Physical Properties> pH 4.83 Viscosity: 13c.P. (at 25°C, measured using a Brookfield viscometer) · Specific gravity ··· 1.19 · Total solid content ··· 41.8% by mass

[0053] <Analysis value> Total nitrogen: 1.2% by mass Total phosphorus: 0.05% by mass · Ash content ··· 11% by mass · Crude fat ··· 1% by mass Total sugars: 6% by weight (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] In addition, 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 described 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, and the outline of the test is shown in Figures 1A to 1C. Test soil: Black soil found in Chikusei City that passed through a 5mm mesh. 500g per pot. Culture vessel: Neubauer pot. Treatments were replicated in triplicate. · Covering: Plastic mulch for agricultural use. The soil surface was covered to cut off the 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 study, and on the 2nd, 4th, 6th, 8th, 11th, and 14th days after the start of the study. 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 soil filled in was measured.

[0057] - Setting the amount of materials to be applied and the treatment area - Test area 1: Soil reduction disinfectant (small amount) of Production Example 1 The application rate is 10mL / 100cm 2 (Add about 20% of the carbon amount used for low-concentration ethanol disinfection.) 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) of Production Example 1 The application rate is 25mL / 100cm 2 (Add about 50% of the amount of carbon used for low-concentration ethanol disinfection.) After adding, water until the water level is constant. Test area 3: Soil reduction disinfectant (manufacturing example 1) (multiple) The application rate is 50mL / 100cm 2 (The same amount of carbon as low-concentration ethanol disinfection (780g-C / m 2 After adding, water until the water level is constant. Test group 4: Low concentration ethanol (positive control) The application rate is 15mL / 100cm 2(Use 99.5% ethanol. Apply the net amount of ethanol used in low-concentration ethanol disinfection.) After application, water until the water level is constant. Test area 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) (without irrigation) was not shown in the figure because the Eh value was high (greater than 1,999 mV) in all measurements. In the treatments using the soil reducing disinfectant of Production Example 1, Eh dropped rapidly on the second day from the start of the test in all treatments. In addition, in the treatments using the soil reducing disinfectant of Production Example 1, Eh went negative in fewer days than in the control and low-concentration ethanol treatments. 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 by the following test method using the soil reduction disinfectant produced in Production Example 1, which is an example of the present invention.

[0061] <Test Method> 1) Location Test location: Fukaya City, Saitama Prefecture Soil: Brown lowland soil (Shinkai-tei) 2) Test scale Facility (house), 22 ares (a) 3) Test crops Cherry Tomato 4) Test area - Soil reduction disinfection using rice bran (hereinafter referred to as the "control area") The application rate of rice bran is 150kg / 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 area Irrigation tubes (Everflow TM 40 diameter) were laid on the soil surface, leveled to a level, at 1m intervals between the planting furrows. 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 an irrigation 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 150kg / 10a and soil treatment fermentation agent (S agent) 30kg / 10a were applied to the entire layer, and groundwater was irrigated with approximately the same amount as in the invention plot. Four days after the irrigation, the ground surface was covered with transparent vinyl and the greenhouse was sealed. 6) Period of soil reduction disinfection 25 days

[0062] <Result> -Air temperature / soil temperature- The air temperature (20 cm above the ground surface) inside the greenhouse and the soil temperature (surface layer: 5-10 cm above the ground surface, lower layer: 20-25 cm above the ground surface) were measured 4 days after the start of the test (the day the ground surface was covered with transparent vinyl), 8 days, 14 days, 21 days, and 25 days later. The results are shown in Table 1. Table 1 also shows the daily average temperature (outdoor temperature) observed by the weather station 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 almost the same, reaching high temperatures, including the lower layer. The soil temperature in the invention plot, both in the surface and lower layers, was slightly higher than that in the control plot by about 1°C.

[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 from the ground surface), and the measured value was collected by a data logger on the final day of the test. The results of converting the measured values ​​of the redox potential in the present invention into theoretical values ​​are shown in Figure 4. The theoretical values ​​were calculated from 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 performed analysis of the bacterial wilt pathogen using the smear plate method with selective medium, 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, the surface and lower layers were 10 2 cfu / g of bacterial wilt bacteria was detected, but after soil reduction disinfection, the number of bacteria decreased to less than 1cfu / g in both the control and the invention. In the soil before soil reduction disinfection, tomato wilt bacteria lived in the surface and sub-layers, and tomato root rot wilt bacteria lived in the surface layer, but after soil reduction disinfection, they were not detected in either the control or concentrated solution. 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) was performed on the collected soil. 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 the same or increased slightly in the present invention area after soil reduction disinfection. Available phosphorus in the control area decreased slightly after soil reduction disinfection, whereas it increased significantly in the present invention area after soil reduction disinfection.

Claims

1. A soil reducing disinfectant containing a culture wastewater of baker's yeast, A soil reducing disinfectant characterized in that the total solid content in the culture waste liquid of the baker's yeast is 40 to 55 mass % and the total sugar content is 3 to 10 mass %.

2. 2. 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.

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

4. The soil reducing disinfectant according to any one of claims 1 to 3, wherein the biochemical oxygen demand (BOD) of the culture wastewater of the baker's yeast is 100,000 to 500,000 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 mass%.

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

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

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