JP6546685B1 - Method of producing soil disinfectant - Google Patents

Abstract

An object of the present invention is to provide a method for producing a soil disinfectant having a high plant-growing effect and nematode-damaging effect in place of chloropicrin, and the soil disinfectant. [Solution] A process of growing a fungus that performs alcohol fermentation with a filter medium mainly composed of humic substances, decomposing starch, which is a main ingredient of sweet potato, into ethanol by the grown fungus that performs alcohol fermentation, and adding citric acid By acidifying the ethanol, a soil disinfecting solution is produced by the step of eluting the fulvic acid contained in the humic substance into the ethanol. 【Selection chart】 None

Description

The present invention relates to the production how soil disinfectant.

  Conventionally, it is known that soil disinfection is carried out using chloropicrin, which is a pesticide, as the last decisive factor when soil diseases spread. This soil disinfection with chloropicrin has an excellent control effect against pathogenic microorganisms.

Japanese Patent Application Laid-Open No. 11-180807

However, soil disinfection with chloropicrin has the following problems.
(A) By promoting the decomposition of soil organic matter, the storage amount of nutrients contained in the soil decreases and the soil becomes hard, so that the growth effect of the plants decreases and the productivity of the plants in the soil is prolonged It is difficult to maintain across.
(B) Soil disinfection with chloropicrin is effective for controlling pathogenic microbes due to its irritability, but the pest nematode (Nematoda) invades the soil after disinfection from the unsanitized surrounding soil It is not effective enough to control nematode damage, because it may grow.
(C) Since soil disinfection with chloropicrin generates an odor, it is difficult to carry out soil disinfection around residential areas.
The present invention has been made by the above-described circumstances, alternative to chloropicrin, and an object thereof is to provide a manufacturing how the control is highly effective soil disinfectant growing effect and nematodes harm plants.

The present invention provides a first step of charging a small amount of sweet potato which is a starch source, a filter medium mainly composed of humic substances, citric acid, and water into a container to make the aqueous solution in the container acidic, and the filter medium. A fungus which causes alcohol fermentation present in the container is grown by the contained humic substance, starch in sweet potato is decomposed into ethanol by the grown alcohol fermented bacterium, and the humic substance is contained in an acidic environment A second step of eluting fulvic acid into an aqueous solution in the container, and a method of producing a soil disinfectant characterized in that the method comprises the steps of:

According to the present invention, alternative to chloropicrin, it is possible to provide a manufacturing how of control effect of growing effect and nematodes harm plant high soil disinfectant.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

(Outline of production method of soil disinfectant)
The soil disinfecting solution in the present embodiment is manufactured as follows. Here, as an example, a method for producing a soil disinfectant of approximately 120 L will be described.

(1) Preparation process Prepare a single 120L capacity kiln and install it outdoors. Into the crucible, 30 sweet potatoes each having a size of about 300 g were cut into a thickness of about 20 mm to 40 mm, 10 kg of a filter medium containing humic substances as main components, and 1 kg of citric acid were charged. Then, after covering the cocoon with a vinyl sheet, if it is tied with a rope so as not to be blown off by wind, preparation is completed. In addition, the pH of the solution in the crucible becomes acidic at about 4.5 to 5.0 when charging is completed by adding citric acid.

  In this manner, bacteria that have normally survived in the natural world (for example, bacilli, yeast, etc.) are present in the cage that has been completely charged. And while this bacteria (hereinafter referred to as alcohol fermenting bacteria) involved in this alcohol fermentation is propagated by the filter medium mainly composed of humic substance, alcohol fermentation is carried out by the alcohol fermenting bacteria in this kiln, and the main component of sweet potato is The component starch is decomposed into ethanol. In addition, the addition of citric acid activates the activity of alcohol-fermenting bacteria and promotes alcohol fermentation.

  Furthermore, as described above, although the main component of the filter medium charged into the crucible is humic substance, humic substance is composed of humin, humic acid and fulvic acid. Moreover, the fulvic acid which comprises humic substance is extracted from humic substance in an acidic environment. The solution in the crucible is acidified to a pH of approximately 4.5 to 5.0 by the addition of citric acid, so that fulvic acid is extracted from humic substances, and the fulvic acid is eluted in the solution in the crucible. It becomes.

  The above-mentioned alcohol fermentation proceeds in the step of decomposing the sweet potato starch into maltose ([C6H10O5] n → nC6H12O6) and the step of decomposing the decomposing maltose into ethanol (C6H12O6 → 2C2H5OH + 2CO2). The decomposition of sweet potato starch into maltose is carried out by Aspergillus among alcohol-fermenting bacteria, but since Bacillus is an aerobic bacterium, oxygen is required for its decomposition into maltose. On the other hand, the decomposition of maltose to ethanol is carried out by the yeast among the alcohol-fermenting bacteria, but since the yeast is an anaerobic bacterium, the decomposition to ethanol does not require oxygen and oxygen In the absence state, decomposition to ethanol is more likely to proceed.

(2) Fermentation process After the preparation is completed as described above, the vinyl sheet is removed and the bottle is opened once every week, and the solution in the bottle is stirred for about 5 minutes. This stirring is carried out using a long stalk or the like so that the entire solution in the vat is well mixed. As a result, oxygen is absorbed in the whole solution, and the activity of Aspergillus oryzae, which is an aerobic bacterium, becomes active, so that the decomposition of sweet potato starch into maltose is promoted.

After stirring is complete, cover the pot with a plastic sheet and tie it with a rope again. As a result, oxygen is not absorbed into the solution from outside the crucible, and if oxygen is used by the activity of the bacilli, the oxygen in the solution gradually decreases and the activity of the anaerobic bacterium, the yeast, becomes active, and the degraded maltose is degraded. Decomposition of ethanol to ethanol will be promoted.
As described above, alcohol fermentation proceeds by repeating the stirring of the solution and the sealing of the crucible by the vinyl sheet.
Stirring may be performed manually as described above, or may be performed automatically using a predetermined stirring device.

  And, as described above, the stirring is performed once a week for at least two months, and when the solution in the pot becomes yellow and alcohol smell like cautery comes out, the soil disinfecting solution in this embodiment It will be completed.

(Characteristics and effects of soil disinfectant)
The soil disinfecting solution produced as described above is acidic at a pH of about 4.5 to 5.0, and fulvic acid is eluted, and the concentration of ethanol is about 0.5% (v / v) to It is a 0.6% (v / v) aqueous solution.

When the soil disinfectant is sprayed on the soil, the ethanol contained in the soil disinfectant is absorbed into the soil. In addition, as above-mentioned, the ethanol concentration of this soil disinfectant is about 0.5% (v / v)-0.6% (v / v), and is low concentration. Here, although the soil microbe is destroyed when the soil disinfectant containing high concentration ethanol is sprayed, when the soil disinfectant according to the present embodiment containing low concentration ethanol is sprayed, Since soil microorganisms are activated by the contained ethanol to activate the soil microbes and respiratory activity is increased, oxygen in the soil is consumed, and the soil is in a state of oxygen deficiency (reduction state). As a result, since the activity of nematode will be limited in the soil lacking oxygen, it is possible to control nematode harm.
In addition, in the oxygen-deficient state, the redox potential of the soil decreases, and iron and manganese originally present in the soil are reduced to release metal ions (cations having a divalent charge). Furthermore, soil microorganisms decompose the organic matter originally present in the soil to produce acetic acid. These metal ions and acetic acid have a high bacteriostatic effect, which also restricts the activity of nematode and further enhances the control effect of nematode damage.
Furthermore, since the above-mentioned soil disinfecting solution is acidic at a pH of approximately 4.5 to 5.0, the soil to which the soil disinfecting solution is sprayed also becomes acidic. And, in an acidic soil environment, the soil becomes more oxygen deficient because soil microorganisms are more activated and respiratory activity is further increased. By this, the control effect of the nematode will be further enhanced.

Furthermore, acidic soil promotes the absorption of manganese contained in the soil into plants. Manganese also has the effect of enhancing the photosynthetic capacity of plants. Therefore, plants planted in the soil to which the soil disinfectant has been sprayed can absorb much manganese contained in the soil in the growth process, and the photosynthetic capacity is enhanced, thereby promoting the growth of the plants. can do.
On the other hand, generally acidic soil makes the phosphoric acid contained in the said soil less soluble, and becomes a factor which inhibits that a phosphoric acid is absorbed by a plant. However, fulvic acid is eluted in this soil disinfectant, and the soil to which this soil disinfectant is sprayed contains fulvic acid. Fulvic acid is effective in promoting the absorption of phosphoric acid into plants. Therefore, a plant planted in the soil to which the soil disinfectant has been applied can absorb a large amount of phosphoric acid contained in the soil during its growth process, and thus can promote the growth of the plant.

  As described above, according to this soil disinfecting solution, an extremely high control effect of nematode can be obtained, and plants can easily absorb both manganese and phosphoric acid, which are opposite in degree of absorption in an acidic soil environment. And can synergistically promote plant growth.

  In addition, as sweet potato to be put in the pot in the preparation process, among the ones harvested before the previous year, non-standard products that do not conform to the shipping standard such as distortion in shape or damage are used. Is desirable. In addition, it is desirable that about 10 to 20 of the sweet potatoes introduced into the pot be completely ripened and processed for sweets.

In addition, although the soil disinfecting solution in the present embodiment can start production from any time throughout the year, the optimum temperature for the activity of Neisseria gonorrhoeae that decomposes starch into maltose is 25 ° C to 28 ° C. It is desirable to start production around March, as the time when the solution inside the kiln can reach that temperature due to the outside air temperature is around April.
For example, if production of a soil disinfectant starts in March, the ethanol concentration of the solution in the weir reaches 0.1% (v / v) in March alone, 0.6% in April Reach (v / v). As described above, in order to control nematode by putting the soil in an oxygen deficient state, it is desirable to set an ethanol concentration of approximately 0.5% (v / v) to 5.0% (v / v), In the two months of March and April, a soil disinfecting solution with an ethanol concentration effective for controlling nematodes as described above can be produced.

(Outline of soil disinfection method by soil disinfectant)
In the target soil, a brow of about 30 cm is raised, and the soil disinfecting solution in the present embodiment is sprayed along the brow. Then, after the spraying is finished, mulch and maintain it for 3 weeks or more. This completes soil disinfection.
The soil disinfecting solution may be sprayed only once before mulching, and it is not necessary to remove the mulching and spray multiple times. Also, with regard to mulching, there is no need to remove the plants until after the application of the soil antiseptic solution and planting of seedlings has been completed, in order to increase soil temperature, maintain weed control and maintain soil oxygen deficiency.
As described above, by performing disinfection with the soil disinfecting solution in the present embodiment, it is possible to control nematode and to make it easy to absorb manganese and phosphoric acid contained in the soil into plants, Growth can be promoted synergistically. In addition, after the soil disinfectant is sprayed as described above and planting of the seedlings is completed, it is prevented that the soil comes in contact with the open air by preventing mulching from being removed until harvest of the plant, and the oxygen deficiency state of the soil Can be further enhanced the control effect of nematode damage.

  The activity of nematode is greatly restricted when the soil temperature rises to 30 ° C or higher, and if the soil disinfectant is sprayed by soil disinfectant in this state, the soil disinfectant can be sufficiently given to nematode. Since it can be done, it is desirable to start soil disinfection at a time when the temperature of the soil is around 25 ° C to 40 ° C. Specifically, in order for the temperature of the soil to reach the above-mentioned range, the maximum daily temperature must be 25 ° C or higher, but from May onwards the maximum daily temperature is 25 ° C or higher It is desirable to apply soil disinfectant during this period and to carry out soil disinfection by maintaining mulching after the end of spraying and maintaining for more than 3 weeks.

  In addition, before spraying the soil disinfectant, chemical fertilizers containing nutrients necessary for the growth of plants such as nitrogen and potassium, and insecticides for controlling scarab beetles and longhorn beetles that are pests other than nematode You may spray etc.

(Evaluation of soil disinfecting solution in the present embodiment)
Next, regarding the effect of the soil disinfecting solution in the present embodiment, the following items were evaluated in comparison with the case where soil disinfection was performed with chloropicrin.

(1) Quantitative value of available phosphoric acid in the soil Soil disinfected with soil disinfectant according to the present embodiment (hereinafter referred to as soil A), and soil disinfected with chloropicrin ( Hereinafter, seedlings of sweet potato are fixedly planted in each of the soils B), and a predetermined amount of soil A and soil B one month after the planting is collected, and the amount of available phosphoric acid contained in 100 g of each soil is It measured with the measuring instrument "ultraviolet visible near-infrared spectrophotometer V-730" of JASCO Corporation. Table 1 below shows the measurement results.

According to this Table 1, 7.2 mg of the available phosphate contained in 100 g of soil A and 12.0 mg of the available phosphate contained in 100 g of soil are contained in soil A. As for the amount, the amount of available phosphoric acid contained in soil B was reduced.
Here, the available phosphoric acid is a phosphoric acid that can be solubilized in soil and absorbed by plants. And phosphoric acid becomes easy to be absorbed by plants by combining with fulvic acid and solubilizing it. In the present embodiment, fulvic acid is eluted in the soil disinfecting solution, and in the soil A subjected to soil disinfection with the soil disinfecting solution, the fulvic acid in which the phosphoric acid contained in the soil is eluted in the soil disinfectant It is thought that more phosphoric acid was absorbed by the planted sweet potato seedlings than in soil B soil-sanitized with chloropicrin because it was combined with the acid. Therefore, as described above, it is considered that the amount of the available phosphoric acid contained in the soil A was that the amount of the available phosphoric acid contained in the soil B was small.
From the above, it is clear that the soil disinfected with the soil disinfecting solution in the present embodiment is more effective in promoting the absorption of phosphoric acid to plants than the soil disinfected with chloropicrin. It became.

(2) Quantitative value of exchangeable manganese in soil Settled seedlings of sweet potato in each of soil A and soil B, collect a predetermined amount of soil A and soil B one month after planting, and include in each soil The amount of exchangeable manganese, which indicates the amount of solubilized manganese, was measured with a measuring instrument “atomic absorption spectrophotometer SPCA-6210” manufactured by Shimadzu Corporation. Table 2 below shows the measurement results.

According to Table 2, the amount of exchangeable manganese contained in soil A1 kg is 0.7 mg, the amount of exchangeable manganese contained in soil B1 kg is 1.6 mg, and the amount of exchangeable manganese contained in soil A is And about 56% less than the amount of exchangeable manganese contained in soil B.
Here, exchangeable manganese is manganese which is solubilized in soil and absorbable by plants. And while manganese plays an important role in generation of oxygen in photosynthesis of plants, it is an important element (element which enhances photosynthetic ability) involved in formation of chlorophyll, chlorophyll body and structure maintenance, and solubilization in an acidic environment Promote absorption into plants. Since the soil A subjected to soil disinfection with the soil disinfecting solution according to the present embodiment is acidic as described above, in this soil A, sweet potato which has been planted is planted more than the soil B subjected to soil disinfection with chloropicrin. It is considered that a large amount of manganese was absorbed by the seedlings. Therefore, as described above, the amount of exchangeable manganese contained in the soil A is considered to be smaller than the amount of exchangeable manganese contained in the soil B.
From the above, it is clear that the soil disinfected with the soil disinfecting solution in the present embodiment is more effective in promoting the absorption of manganese to plants than the soil disinfected with chloropicrin. became.

(3) Length and number of sweet potato leaves planted Sweet potato seedlings are planted in soil A and soil B respectively, and the leaf length of the seedlings in soil A and soil B one month after planting (from the tip) The length to the rear end) and the number of teeth were measured. Table 3 below shows the measurement results.
The leaf lengths in Table 3 are values obtained by excluding small leaves, selecting the top 10 large leaves, and calculating the average of the lengths from the front end to the rear end.

According to Table 3, the number of sweet potato leaves planted in soil A is 32 more than the number of sweet potato leaves planted in soil B. In addition, the length of sweet potato leaves planted in soil A is 1 cm smaller than the length of sweet potato leaves planted in soil B. That is, the sweet potato seedlings planted in soil A have many small leaves as compared to the seedlings of sweet potato planted in soil B. The fact that there are many small leaves means that there are many leaves that have not grown sufficiently. From this result, the sweet potato seedlings planted in soil A are younger than the seedlings of sweet potato planted in soil B. It became clear that there were many.
Here, since the function of producing many young leaves is due to manganese, the soil A which has been subjected to soil disinfection with the soil disinfecting solution in the present embodiment is more planted than the soil B which has been subjected to soil disinfection with chloropicrin. It is considered that much manganese was absorbed by the sweet potato seedlings.
From the above, it is clear that the soil disinfected with the soil disinfecting solution in the present embodiment is more effective in promoting the absorption of manganese to plants than the soil disinfected with chloropicrin. became.

  In addition, since young leaves have a higher photosynthetic ability related to the generation of starch than old leaves, the soil subjected to soil disinfection with the soil disinfecting solution in the present embodiment is more than soil disinfected with chloropicrin. However, the effect of promoting plant growth is also high.

(4) The number of nematodes that survive in soil Spraying is performed in each of soil A and soil B, and 1 kg each of soil A and soil B one month and three months after this spraying are collected and included in each soil The number of nematodes was measured with a measuring instrument "Baleman device" of Fujidaira Kogyo Co., Ltd. Here, the number of parasitic nematodes that cause parasitic rot on sweet potato is measured. Table 4 below shows the measurement results.

According to Table 4, in soil B, although the number of parasitic nematodes one month after the application of chloropicrin was 0, the number of parasitic nematodes three months after is 500, which is an increase. It was On the other hand, in the soil A, the number of parasitic nematodes one month after the application of the soil disinfecting solution in the present embodiment is 10, and the number of parasitic nematodes three months after the decrease is zero. Was.
Although chloropicrin shows a high control effect on nematode after spraying, it is considered that its effect did not continue, and parasitic nematode gradually invaded from the undisinfected surrounding soil to the disinfected soil. On the other hand, the soil disinfecting solution according to the present embodiment has the effect of eliminating nematodes and the activity of parasitic nematode is limited by the bacteriostatic effect of ions released from iron, acetic acid and the like in the soil by ethanol contained in the solution As a result, it is considered that parasitic nematodes could be prevented from invading from the unsanitized surrounding soil to the disinfected soil.
From the above, the soil disinfected with the soil disinfecting solution in the present embodiment is more effective in controlling nematode damage than the soil disinfected with chloropicrin, and the sustainability of the effect is high. It became clear.

(5) The number of actinomycetes and general bacteria in the soil Spraying is carried out in each of the soil A and the soil B, and a predetermined amount of soil A and soil B one month and three months after this spraying are respectively collected The number of actinomycetes and general bacteria contained in was measured by dilution plate method with soil exudates agar medium. Table 5 below shows the measurement results.

According to this Table 5, in soil B, the number of actinomycetes three months after spraying chloropicrin was greater than the number of actinomycetes after one month, but the number of general bacteria after three months Was reduced from the number of general bacteria after one month. On the other hand, in the soil A, the number of actinomycetes three months after the application of the soil disinfecting solution in the present embodiment is smaller than the number of actinomycetes after one month, and three months after the general bacteria The number was also lower than the number of common bacteria after one month. Thus, the phenomenon in which both the number of actinomycetes and the number of general bacteria decrease is often seen when the soil is acidic. That is, it is considered that the soil A subjected to soil disinfection with the soil disinfecting solution in the present embodiment is acidic, and the control effect of the nematode is further enhanced.
From the above, it has become clear that the soil treated with the soil disinfecting solution according to the present embodiment has a higher control effect of the nematode than the soil subjected to soil disinfection with chloropicrin.

(6) Size and number of crops Based on the seedlings planted in each soil as described above, 1,168 sweet potatoes are harvested from soil A in autumn (October) and 1,324 from soil B. The sweet potatoes were harvested to determine the size and number of these crops. Table 6 below shows the measurement results.
In addition, in Table 6, "L standard" indicates a sweet potato whose weight is 100 g or more and 700 g or less and there is no deformation, disease, injury or the like, and "S" is a sweet potato whose weight is less than 100 g. Is an indicator of Moreover, "B" is what shows a sweet potato which has a deformation | transformation, a disease, a wound, etc. although it is L specification (what is called a defect product).

According to Table 6, the average weight of L standard in soil A is 345.0 g, the average weight of L standard in soil B is 254.7 g, and the average weight of L standard in soil A is L standard in soil B It weighed 91 g more than the average weight.
In soil A, absorption of manganese in plants is promoted compared to soil B, so that many young leaves are formed and photosynthetic ability is improved. Furthermore, absorption of phosphoric acid by fulvic acid contained in soil It is thought that the growth rate per crop increased and the average weight of the L standard became heavier.
According to Table 6, with regard to the number of harvests of L standard, soil B is more than soil A, but in soil A, nutrients are utilized for leaf growth due to the improvement of photosynthetic capacity, and landing It is thought that the result was stagnant. On the other hand, considering the total harvest weight of L standard determined by the product of the number of harvests of L standard and the average weight of L standard, it is about 281 kg (= 345.0 g x 816) in soil A and about 241 kg in soil B. = 254.7 g x 946), and as a whole of the L standard sweet potato, soil A was able to accumulate more nutrients than soil B.
From the above, in the soil subjected to soil disinfection with the soil disinfecting solution in the present embodiment, phosphoric acid and manganese are more easily absorbed by plants than in soil subjected to soil disinfection with chloropicrin, and plant growth is promoted. It became clear that

Further, according to Table 6, the proportion of the B product in the soil A is 3.0%, the proportion of the B product in the soil B is 6.0%, and the proportion of the B product in the soil A is the B product in the soil B The rate of was low.
As described above, the product B is a sweet potato with disease and the like, and in the soil A, it is considered that nematode damage can be controlled over the period from planting to harvesting rather than the soil B.
From the above, it has become clear that the soil disinfected with the soil disinfecting solution in the present embodiment has a higher effect of continuously controlling nematode damage than the soil disinfected with chloropicrin. .

Claims (1)

A first step of charging a small amount of sweet potato which is a starch source, a filter material mainly composed of humic substances, citric acid, and water into a container to make the aqueous solution in the container acidic ;
The humic substance contained in the filter medium is allowed to grow the bacteria that performs alcohol fermentation present in the container, and the grown alcohol fermentation is used to decompose starch in sweet potato to ethanol, and the humic material in an acidic environment A second step of eluting the fulvic acid contained in the solution into the aqueous solution in the container ;
A method of producing a soil disinfectant characterized in that it comprises