JP7123324B2 - Novel organic soil, method for producing the same, and method for cultivating plants using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel organic soil, a method for producing the same, and a method for cultivating plants using the organic soil.

Agricultural products cultivated in organic soil do not accumulate nitrates, etc., and the demand for organic agricultural products is growing rapidly in Europe and the United States. Organic soil is essential for organic farming. In particular, high-quality organic soil is required for greenhouse cultivation and cultivation in a plant factory.

In Japan, some products are commercially available in the form of organic soil and potting soil. On the other hand, in chemical soil where chemical fertilizer is added, inorganic substances N, P, and K are added separately, so it is possible to create uniform and reproducible soil, and many types of chemical soil are manufactured and sold. . However, there is a problem that nitrates tend to accumulate in agricultural products (there is a risk of carcinogenesis if taken in large amounts).

In addition, since microorganisms are constantly active in organic soil, the organic fertilizer contained therein is likely to change, making it difficult to provide a uniform product. Concerning the uniformity of organic soil, there are problems in the reproducibility of the types of microorganisms and the heterogeneity of input organic matter changing to inorganic matter. On the other hand, chemical soil contains inorganic substances as fertilizer components and does not change unless it is washed away by water or the like. Therefore, the fertilizer component of chemical soil is stable.

The demand for high-quality potting soil is increasing year by year. In particular, the demand for potting soil in home gardening and greenhouse agriculture is very high. Top-dressing of chemical soil compost that has hitherto been commercially available has been established through previous studies, and can be performed by adding a predetermined amount of nitrogen, phosphoric acid, or potassium. However, chemical soil culture soil, which pursues lightness, deteriorates rapidly, and it is very difficult to reuse it because it cannot be restored just by adding fertilizer. Thus, soil treatment after use is a troublesome problem, and development of a solution method is desired.

As means for solving such problems, Patent Documents 1 to 3 report methods for diagnosing and preparing soil suitable for cultivating crops by organic farming or natural farming.

In addition, lightweight potting soil made from plant fibers, such as pulverized coconut shells, is often used in agriculture, gardening, and the like. Cultivation soil made from such plant fibers is not only lightweight, but also has the advantage of being able to increase the porosity during cultivation due to its fiber content, and has excellent water retention and water permeability.

However, such plant fibers contain polyphenol components (mixtures such as tannins that produce polyhydric phenolic acids such as gallic acid by hydrolysis), which poses the problem of inhibiting plant growth. Therefore, when these plant fibers are used as potting soil, a method has been proposed in which tannins are reacted with iron ions to be inactivated.

Patent Documents 4 and 5 report that tannin can be effectively inactivated by acting ammonium ferric citrate on wood fragments, and inhibition of plant growth can be prevented. there is

WO 2010/107121 Japanese Patent Application Laid-Open No. 2011-182747 Japanese Patent Application Laid-Open No. 2011-184267 Japanese Patent Application Publication No. 2018-117589 Japanese Patent Application Laid-Open No. 2018-117590

Patent Documents 1 to 3 relate to methods for diagnosing and preparing soil suitable for cultivating crops by organic farming or natural farming, but there is room for further improvement.

The present invention is characterized by the use of novel organic soil that has high air permeability, water permeability and water retention, is lightweight, and has improved microbial diversity and total bacterial count, a method for producing the same, and the use of the organic soil. It aims at providing the cultivation method of the plant which carries out.

As a result of intensive studies to achieve the above object, the present inventors have found that organic soil can be prepared by combining a woody medium composed of woody fragments of conifers with inactivated tannins with organic materials and compost. In addition, it has high water permeability and water retention and is lightweight, and it has been found that the diversity of microorganisms and the total number of bacteria can be increased. In addition, by preparing organic soil that does not contain moisture, it is possible to suppress the activity of microorganisms (put them in a dormant state), make the microorganisms in the organic soil constant (it is possible to control microbial activity), and uniform It was discovered that organic soil can be produced.

The present invention was completed through further studies based on these findings, and provides the following organic soil, a method for producing organic soil, and a method for cultivating plants.

Section 1. A dry organic soil containing dry woody medium, dry organic material and dry compost,
The woody medium is composed of coniferous wood fragments, and the size of the wood fragments is such that they can pass through a mesh of 10 mm or less,
Dry organic soil containing 10 to 90% by volume of the woody medium.
Section 2. Item 2. The dry organic soil according to Item 1, wherein the wood chips are blackened by contact with iron salts and contained in the dry organic soil at 30 to 90% by volume.
Item 3. The total carbon content is 12,000-35,000 mg/kg, the total nitrogen content is 900-1,800 mg/kg, the total phosphorus content is 800-1,600 mg/kg, the total potassium content is 900 mg/kg or more, and the C/N ratio is 10. 3. The dry organic soil according to item 1 or 2, which is ~25.
Section 4. 4. Dry organic soil according to any one of items 1 to 3, wherein the wood chips contain a surfactant.
Item 5. Item 5. The dry organic soil according to any one of items 1 to 4, further comprising dry soil.
Item 6. A method for producing dry organic soil containing dry woody medium, dry organic material and dry compost, comprising the steps of:
(A) preparing a dry woody medium;
(B) preparing a dry organic material;
(C) preparing dry compost;
(D) measuring the total carbon content, the total nitrogen content, the total phosphorus content, and the total potassium content in each of the woody medium, the organic material, and the compost;
(E) adding the woody medium so that the total carbon content, the total nitrogen content, the total phosphorus content, the total potassium content, and the C/N ratio are predetermined values, and the woody medium contains 10 to 90% by volume of the woody medium; Mixing the organic material and the compost.
Item 7. The step A includes a step of pulverizing coniferous wood to a size that passes through a mesh of 10 mm or less, and a step of contacting the obtained woody fragments with an iron salt aqueous solution to turn black. 7. The manufacturing method according to item 6.
Item 8. The predetermined values in step E are 12,000 to 35,000 mg/kg for total carbon, 900 to 1,800 mg/kg for total nitrogen, 800 to 1,600 mg/kg for total phosphorus, and 900 mg/kg for total potassium. Item 8. The production method according to item 6 or 7, wherein the wood medium has a C/N ratio of 10 to 25 and is mixed so as to contain 30 to 90% by volume of the woody medium.
Item 9. Item 6. A method for cultivating a plant, comprising using the dry organic soil according to any one of Items 1 to 5.

The dry organic soil of the present invention has excellent properties such as high air permeability, water permeability and water retention, light weight, and remarkably improved microbial diversity and total bacterial count. .

The dry organic soil of the present invention suppresses the activity of microorganisms and stabilizes the microorganisms in the organic soil, thereby suppressing the change of organic matter to inorganic matter and having excellent uniformity. In addition, since it is possible to mix dry woody medium, organic materials, compost, soil, etc., and adjust the component content (total carbon content, total nitrogen content, C/N ratio, etc.), there is no difference between lots. It has excellent manufacturing reproducibility.

Furthermore, by analyzing dehydrated compost and organic materials in the dry organic soil of the present invention, and preparing and adding them according to the analytical values, an effective additional fertilization effect can be exhibited. Also, by using this technique, it is possible to reuse the soil after use.

1 is a photograph showing an untreated cedar material and a cedar material that has turned black due to contact with an iron salt. 10 is a photograph showing the results of bacterial flora analysis by PCR-DGGE in Test Example 5. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.

As used herein, the term "comprise" includes both the meaning of "essentially consisting of" and the meaning of "consisting only of."

Definitions of terms used in this specification are provided below.

The term "soil" is conceptual and means a material constituting a base for cultivating plants, and does not necessarily include soil.

"Soil" or "dry soil" refers to coarse-grained or fine-grained minerals (primary minerals) and finely divided colloidal minerals (clay minerals or secondary minerals) produced by the weathering of rocks.

“Chemical soil” is a culture soil in which the fertilizer components necessary for plant growth are added with chemical fertilizers composed of inorganic N, P, K, etc. as main components, and nutrients are added in advance in a form that can be absorbed by plants. Because it is added, it refers to soil that aims to grow plants without necessarily borrowing the action of microorganisms.

"Organic soil" means mixing fermented or unfermented bulky organic matter or humus with soil, and decomposing these bulky organic matter aerobicly with the action of microorganisms to obtain the nutrients necessary for plant growth. Soil intended for Although we do not deny the use of chemical fertilizers as a supplement, the soil is characterized by containing a large amount of various microorganisms.

"Culture soil" is conceptual and means a material constituting a base for cultivating plants, and does not necessarily include soil.

"Total carbon" (also referred to herein as TC) means the sum of organic carbon and inorganic carbon in soil. Total carbon can be measured with a total organic carbon meter (TOC-V, Shimadzu Corporation), a solid sample combustion apparatus (SSM-5000A, Shimadzu Corporation), and the like.

"Total nitrogen" (also referred to herein as TN) means the sum of organic nitrogen and inorganic nitrogen in soil. Total nitrogen can be measured by the Kjeldahl method-indophenol blue method or the like.

"C/N ratio" means the mass ratio of total carbon/total nitrogen (TC/TN).

"Total phosphorus" (also referred to herein as TP) means the sum of inorganic and organic phosphorus in soil. Total phosphorus can be measured by Kjeldahl method-molybdenum blue spectrophotometry or the like.

"Total potassium" (also referred to herein as TK) means the sum of water-soluble, exchangeable and fixed potassium in soil. Total potassium can be measured by the Kjeldahl method-atomic absorption spectrophotometry or the like.

By "dry" is meant that the average water content/bone dry weight of the sample is 20% or less, preferably 10% or less.

The dry organic soil of the present invention contains a dry woody medium, a dry organic material and a dry compost, the woody medium is composed of coniferous wood chips, and the wood chips pass through a mesh of 10 mm or less. It ranges in size and is characterized by containing 10-90% by volume of said woody medium. The dry organic soil of the present invention can further contain soil and the like in addition to the woody medium and the organic material.

The method for producing dry organic soil containing dry woody medium, dry organic material and dry compost according to the present invention is characterized by including the following steps.
(A) preparing a dry woody medium;
(B) preparing a dry organic material;
(C) preparing dry compost;
(D) measuring the total carbon content, the total nitrogen content, the total phosphorus content, and the total potassium content in each of the woody medium, the organic material, and the compost;
(E) adding the woody medium so that the total carbon content, the total nitrogen content, the total phosphorus content, the total potassium content, and the C/N ratio are predetermined values, and the woody medium contains 10 to 90% by volume of the woody medium; Mixing the organic material and the compost.

The woody medium consists of uncomposted fine shavings of wood, the main source of which is coniferous wood. Here, "not composted" also means that the polysaccharides constituting the wood are not biodegraded by fermentation. Although the wood chips are finely divided, the fiber component of the wood whose main skeleton is cellulose remains inside. Since the fiber component of wood is difficult to biodegrade, as will be described later, by crushing wood and forming wood chips of a predetermined shape with different water retention and water permeability, cultivation conditions suitable for the plant to be cultivated can be obtained. can be obtained for a long period of time. It is desirable that the woody medium is non-compostable.

Japanese conifers such as Japanese cedar, Japanese red pine, Japanese cypress, and Sakhalin fir are suitable raw materials for the woody medium. Broad-leaved trees not only contain more unstable organic components such as polysaccharides than conifers, but also contain less polyphenol components that suppress the action of microorganisms, so they rot easily and lack stability in quality compared to conifers. Coniferous trees do not rot easily, so they can maintain an appropriate and stable pF value (an index representing the wetness of soil) and a three-phase distribution (solid phase, liquid phase, gas phase) over a long period of time.

Furthermore, Japanese coniferous trees are widely used for building materials, wood processing materials, and the like, and a large amount of offcuts (excessive scraps of wood) are generated during their production. The offcuts can be used as a raw material for woody medium. Therefore, raw materials for conifers such as cedar, Japanese red pine, Japanese cypress, and Sakhalin fir can be stably secured.

Polyphenolic components are abundant in the wood part, especially in the bark, but also in the inner sapwood (the peripheral part of the tree) and the heartwood (the central part of the tree). Heartwood tends to have a higher content of polyphenol components than sapwood. Therefore, it is preferable to use more sapwood than heartwood as a raw material. Specifically, it is preferable to set the ratio of raw material wood so that the ratio of sapwood to heartwood is in the range of 1:0 to 1:1.

A large amount of sapwood offcuts are generated when plywood and laminated wood are manufactured. In the manufacture of plywood and laminated materials, there is a process of peeling a log, which has been cut into a predetermined size, in a predetermined thickness in the circumferential direction from the outer periphery toward the center in order to form a thin plate. The sapwood obtained at the beginning of the process is the sapwood. In addition, the scrap material consisting of the central part of the log, called the stripped core, which remains at the end, is the core material. By adjusting the ratio of thin plates obtained from each step in this way, the ratio of heartwood and sapwood can be adjusted.

The woody medium is composed of fine sawdust-like wood fragments, and is set in a form according to the plant to be cultivated. Specifically, the extent to which the fiber components of the wood are dissolved is set according to the specifications. The more the fiber content is dissolved, the higher the water retention and water absorbency, and the more the wood structure remains, the higher the water permeability (drainage).

Methods for crushing the raw material wood include, for example, a method of cutting wood finely with a cutting crusher such as a rotary saw or a cutter mill (cutting crusher), or a method of crushing wood by impact with an impact crusher such as a hammer mill or pin mill. (Impact pulverization), and a method of grinding wood with a pulverizer such as an extruder or ball mill (grinding pulverization). Among these methods, biaxial grinding and crushing are the easiest to dissolve the fiber content, so that crushing the wood by grinding and crushing can increase the water retention and water absorbency. Among them, the pulverized shape shown in Patent Document 5 is most preferable.

The wood chips are preferably sized to pass through a mesh of 10 mm or less. Large pieces of wood that do not pass through a mesh of 10 mm or less tend to block root extensions and inhibit their growth. Moreover, there is also a problem that it is difficult to fill a small plastic container generally used for cell raising. By adjusting the size to pass through a mesh of 10 mm or less, an appropriate particle size distribution can be obtained, and appropriate water retentivity and water permeability can be obtained. Also, it is preferable to adjust the size to pass through a mesh of 3 mm or more. A decrease in classification efficiency can be prevented by using a mesh of 3 mm or more.

The expression that the woody medium is composed of coniferous wood fragments includes both the state of being composed only of coniferous wood fragments and the state of containing components other than coniferous wood fragments, and is composed only of coniferous wood fragments. preferably

Furthermore, the wood chips are preferably blackened by contact with the iron salt. The blackening inactivates the tannin component and inactivates the antibacterial function against microorganisms. In addition, it is preferable that the dry organic soil contains 30 to 90% by volume of wood chips that have turned black due to contact with iron salts.

Blackening of wood chips was caused by treatment with iron sulfate, which was intended to inactivate the polyphenolic components (e.g., tannins) contained in the wood, and citric acid, which was added to chelate the iron sulfate. It is desirable to be In addition, the wood chips optionally contain surfactants and pH modifiers to improve the quality of the wood chips.

Iron sulfate and citric acid are not added to wood fragments individually, but are mixed with a water-based chemical solution (improving chemical solution) and added to the woody medium by spraying the wood fragments. As a result, the iron sulfate is chelated, and the wood fragments can be stably blackened.

As the iron salt, iron sulfate is most preferred. Iron sulfate not only has the highest blackening effect on conifers, but is also a safe chemical designated as a food additive. Iron sulfate, specifically ferrous sulfate and the like, has high reactivity with polyphenol components, and is most effective for blackening (deactivating) by binding to polyphenol components. However, when a large amount of iron sulfate is present in the soil, as shown in Patent Document 4, it causes root development failure, so it is necessary to take care not to add an excessive amount when turning wood chips black. In addition, the presence of excessive iron salts in the medium causes inhibition of plant growth. Therefore, it is preferable to adjust the concentration of iron sulfate to 0.15% by mass or more and 0.35% by mass or less with respect to the absolute dry weight of the wood chips. In particular, an excellent modification effect can be obtained for Japanese cedar, Japanese red pine, Japanese cypress, and Sakhalin fir. Within this range, the growth of plants is not inhibited. The term “iron sulfate” used herein mainly means ferrous sulfate (FeSO ₄ .7H ₂ O). As iron salts, other divalent iron salts such as iron chloride, ammonium iron(II) sulfate, and trivalent iron salts such as ferric sulfate and ferric ammonium citrate can also be used. For example, in the case of ferric sulfate, the content ratio may be converted based on the mass excluding water of hydration.

Iron sulfate has the problem of forming a precipitate in a relatively short time when it is made into an aqueous solution, but by adding citric acid, iron sulfate can be chelated, and it forms a precipitate for a long time in the chemical solution. can be stabilized without The content ratio of the mass of citric acid to the mass of iron sulfate in the reforming chemical (content of citric acid/content of iron sulfate, hereinafter referred to as "citric acid/iron sulfate ratio") is adjusted to 0.05 or more. is preferable, and adjusting to 0.1 or more is more preferable. Also, the citric acid/iron sulfate ratio of the reforming chemical is preferably adjusted to 0.3 or less. Within this range, an appropriate quality as a modifying chemical can be stably ensured over a long period of time, and an excellent modifying effect on wood fragments can be expected.

As the iron salt, it is also possible to use, for example, iron chloride, which binds to the polyphenol component and causes blackening. When using tree species other than the above cedar, Japanese red pine, cypress, and Sakhalin fir, the amount of iron salt may be adjusted according to the amount of the polyphenol component contained. In any case, it suffices that the coniferous tree is brought into contact with the iron salt, and the coniferous tree is blackened (inactivated). is desirably chelated by the addition of citric acid.

Wood chips become water repellent by drying. If the wooden medium is made up of water-repellent wood fragments, the water repellency creates a water path called a water path, resulting in uneven water distribution and possibly inhibiting the growth of plants. On the other hand, by adding a surfactant to wood chips, water permeates uniformly throughout the woody medium, and not only does it suppress plant growth inhibition, but it also has the effect of promoting plant growth (Patent document 4). Therefore, surfactants may be added to the wood chips as a supplementary ingredient. As another method, as disclosed in Japanese Patent Application Laid-Open No. 2005-341898, a method of impregnating clay minerals and drying them to improve water repellency may be employed.

Furthermore, many plants generally prefer weakly acidic to neutral pH, and each has a suitable pH. Therefore, a pH adjuster suitable for the plant to be cultivated may be added to the wood chips as an auxiliary raw material. For example, calcium carbonate as an alkalinity adjuster, peat moss as an acidity adjuster, etc. may be added to wood chips according to specifications. In particular, when blackened wood chips are used, the pH should be adjusted to about 4 to 9, preferably about 5 to 8, since strong acidity such as a pH of 2 to 3 or less is not preferable. is desirable.

Even after the production of the above-described woody medium, that is, after the wooden fragments are mixed with the modifying chemical solution, the inactivation of the polyphenol components by the bonding between the polyphenol components and iron sulfate progresses gradually. Therefore, it is preferable to leave (curing) the woody medium for at least a certain period of time instead of using it immediately after producing the woody medium. For example, it is preferable to secure a curing period of about one week, preferably about two weeks. By providing such a curing period after manufacturing the woody medium, a higher quality woody medium can be obtained.

The dry organic soil contains 10 to 90% by volume of woody medium, preferably 30 to 60% by volume. By containing 10% by volume or more of the woody medium, excellent water permeability can be obtained, and by containing 30% by volume or more, excellent lightness can be obtained. In addition, since coniferous wood chips inherently exhibit antibacterial properties against microorganisms, wood chips made of untreated coniferous trees may be used in the case of 10 to 30% by volume, but if the addition exceeds 30% by volume For quantities, it is preferred to use wood chips that have been blackened by contact with iron salts. In addition, the dry organic soil preferably contains 50% by volume or more or 60% by volume or more of woody medium from the viewpoint of weight reduction when carrying pot cultivation for raising seedlings, potted flowers, etc. In this case, iron Particular preference is given to using wood chips which have been blackened by contact with salt.

The organic material is not particularly limited as long as it is not fermented (unfermented material), and examples of such unfermented material include soybean meal, oil cake, rice husk, fish meal, rice bran, and bean curd refuse. , coconut fiber, peat moss, rice straw, water moss, aquatic plants, straw, fallen leaves, grass clippings, bark, bone meal, peptides, chlorella, and bamboo chips. The organic materials can be used singly or in combination of two or more.

The compost is not particularly limited, and various known composts can be used. For example, plant compost such as bark compost, horse manure compost, chicken manure compost, cow manure compost, livestock compost such as pig manure compost, seaweed compost, kitchen waste compost, Leaf mulch etc. are mentioned. Compost can be used singly or in combination of two or more. By adding dried compost to the woody medium, it is possible to supply a large amount of dormant microorganisms. Therefore, when drying compost, air drying at 60° C. or less, preferably 40° C. or less, or sun drying is preferable, instead of drying at high temperatures at which sterilization and sterilization proceed.

The soil is not particularly limited and various known soils can be used. For example, black soil, red soil, mountain soil, vermiculite, natural zeolite, Kanuma soil, sand, masago soil, etc. can be used. As the treated inorganic material, for example, Akadama soil, refined zeolite, perlite, etc. can be used. The soil can be used singly or in combination of two or more.

Components other than woody media, organic materials, compost and soil can also be added to the dry organic soil of the present invention, such components including, for example, microorganisms and minerals.

The dry organic soil of the present invention is characterized by being in a dry state, and the water content is usually about 0 to 25% by mass, preferably about 5 to 20% by mass, more preferably about 5 to 10% by mass. be. The dry organic soil of the present invention can be prepared by mixing materials in a dry state (woody medium, organic materials, compost, soil, etc.), or can be prepared by mixing materials in a dry state (woody medium, organic materials, etc.). , compost, soil, etc.) can also be prepared by drying. Methods for drying organic soils and materials include, for example, air drying, natural drying such as sun drying, and mechanical forced drying using heated air.

Soil microorganisms are organisms, living and active in soil. On the other hand, microorganisms have a stage of dormancy, and the activity of microorganisms can be controlled by utilizing this dormancy state by drying. As a result, uniform organic soil can be obtained.

As used herein, the term "fixed number of microorganisms" means that the number of microorganisms is kept constant without causing them to proliferate in a dormant state.

In addition, by drying the organic soil in this way, it is possible to reduce the weight and reduce transportation costs. It can also reduce pathogens and weeds.

The dry organic soil of the present invention has an appropriate component content (for example, the total carbon content, total nitrogen content, C/N ratio, total phosphorus content, and total potassium content are within the ranges described later. ), dry woody medium, organic material, compost, soil, etc. can be blended in an appropriate mixing ratio. Formulating with dry ingredients allows for precise control of ingredient content. Drying can also be performed after blending the undried materials here. In addition, before blending the material, the component content of the material such as woody medium, organic material, compost, soil (e.g. total carbon content, total nitrogen content, C/N ratio, total phosphorus content, total potassium content, etc.) By performing the measurement, it is possible to obtain an appropriate mixing ratio.

The dry organic soil of the present invention desirably has the following component contents (especially optimum values).

Content of each component per dry weight Total carbon content (TC): 12,000-35,000 mg/kg, optimal value: 18,000-30,000 mg/kg
● Total nitrogen (TN): 900-1,800 mg/kg, optimal value: 1,000-1,500 mg/kg
-C/N: 10-25 (preferably 16-20)
● Total phosphorus (TP): 800-1,600 mg/kg, optimal value: 900-1,400 mg/kg
●Total potassium (TK): 900 mg/kg or more, optimal value: 1,000 to 5,000 mg/kg

The total carbon content and the total carbon content when determining the C/N ratio here include only carbon that can be used by microorganisms, and excludes carbon that cannot be used by microorganisms. The total amount of carbon that can be used by such microorganisms can be obtained by measuring the mineralization rate (the rate at which carbon can be decomposed).

The above ingredient content is the biologically, chemically and physically balanced ingredient content determined based on the SOFIX™ database of over 5,000 specimens. SOFIX here is a diagnostic index that quantifies the amount and balance of soil components that are desirable for material recycling agriculture, including organic farming, and measures the components related to plant growth and the components related to material circulation. (See, for example, WO2010/107121).

By accurately blending materials using such component content as an index, it is possible to produce soil with high reproducibility without lot-to-lot differences. By using the organic soil, it is possible to maintain a high number of bacteria and reproduce a uniform flora in the soil. As a result, high plant yields can be obtained reproducibly.

Since the dry organic soil of the present invention is in a dry state, water is added and the soil is left for about 3 to 10 days before cultivating plants. The amount of water added is about 10 to 40% by volume of the maximum water retention capacity, or about 10 to 40% by mass of water content. In this way, by adding water and leaving it as it is, the microorganisms can be recovered from their dormant state, and it is also possible for the microorganisms to proliferate.

Moreover, the method for cultivating a plant of the present invention is characterized by using the dry organic soil. The plant cultivation method of the present invention can include, for example, a step of adding water to dry organic soil and allowing it to stand, and a step of planting plants in the organic soil after leaving. The term "planting" here also includes the meaning of sowing plant seeds.

Plants that can be cultivated using the dry organic soil of the present invention are not particularly limited as long as they can grow in the dry organic soil of the present invention, and examples thereof include the following. Leafy vegetables (e.g. Chinese cabbage, spinach, cabbage, lettuce, Japanese mustard spinach, mizuna, chrysanthemum, green onion, onion, broccoli, asparagus), root vegetables (e.g. carrot, Japanese radish, burdock root, taro, Chinese yam, lotus root, turnip), fruit vegetables ( Vegetables such as tomatoes, mini tomatoes, eggplants, green peppers, cucumbers, watermelons, strawberries, pumpkins, melons, sweet corn); fruit trees such as apples, pears, grapes, persimmons and blueberries; soybeans, green soybeans, adzuki beans, fava beans, peanuts Beans such as green beans; Tea; Tobacco; Cotton; Wheat such as barley, wheat, oats, and rye; , alstroemeria, lily, tulip, cyclamen, gladiolus, freesia, primula, dendrobium, begonia, cymbidium, poinsettia, phalaenopsis, viola, daisy, scobaria, calibrachoa; succulents such as cacti; Mention may be made of greening plants.

Cultivation of the above plants using the dry organic soil of the present invention can be carried out according to known methods.

The dry organic soil of the present invention can be used, for example, for home gardens, greenhouse cultivation, planter cultivation, pot cultivation, plant factories, rooftop greening, wall greening, and the like. Here, the plant factory is a facility for cultivating plants in a closed or semi-closed space while artificially adjusting and controlling temperature, humidity, light, and the like.

Reproduction of microorganisms in organic soil becomes possible by stabilizing and homogenizing the bacterial flora in the soil. The activities of microorganisms differ according to three factors such as "temperature", "humidity", "organic matter content" and "pH", which are biological, chemical and physical. With the organic soil developed in the present invention, it is possible to suppress the activity of microorganisms (put them in a dormant state) and keep the number of microorganisms in the organic soil constant by preparing organic soil that does not contain moisture.

The dry organic soil of the present invention has high air permeability, water permeability, and water retention, is lightweight, and has improved microbial diversity and total bacterial count. Moreover, according to the dry organic soil of the present invention, by suppressing the activity of microorganisms and making the microorganisms in the organic soil constant, the change of organic matter to inorganic matter is suppressed, and the uniformity is excellent. In addition, it can be produced by adjusting the content of ingredients by mixing dry woody medium, organic materials, compost, soil, etc., so it has excellent production reproducibility without lot-to-lot differences. In addition, it is also possible to adjust the ingredients on a custom-made basis for each agricultural product. Furthermore, by analyzing dehydrated compost and organic materials in the dry organic soil of the present invention, and preparing and adding them according to the analytical values, an effective additional fertilization effect can be exhibited. By using this method, it is possible to reuse the soil after use, and it is economically and environmentally superior. According to the dry organic soil of the present invention, a high yield can be obtained with reproducibility, and even when it is discarded, it can be handled as an incinerated material because it contains a woody medium.

In addition, according to the dry organic soil of the present invention, it is also possible to improve the material cycle (nitrogen cycle and phosphorus cycle) through the contribution of proliferated microorganisms.

Examples are given below to describe the present invention in more detail. However, the present invention is by no means limited to these examples.

Reagents and Equipment Experimental reagents used were purchased from Nacalai Tesque Co., Ltd. (Kyoto) and FUJIFILM Wako Pure Chemical Co., Ltd. (Osaka). Table 1 shows the equipment used.

Manufacturing example /Manufacturing method of modified wood 1
Cedar wood was used as wood chips. Uncomposted cedar wood cut into chips was cut and pulverized with a rotary cutter mill, and the chips were sized to pass through a 4 mm mesh.

Next, a modifying chemical solution was prepared so that the predetermined citric acid/iron sulfate ratio was 0.1 and the concentration of the iron sulfate aqueous solution was 1% by mass. Ferrous sulfate used was ferrous sulfate (FeSO ₄ .7H ₂ O). The modified chemical solution was sprayed onto the wood chips so that the iron sulfate concentration was 0.15% by mass with respect to the absolute dry weight of the wood chips.

Furthermore, a nonionic surfactant (manufactured by Takemoto Yushi Co., Ltd.) was added to the solution so that the concentration of the aqueous solution was 2.0% by mass to prepare a secondary reforming chemical solution. After spraying the wood chips with the secondary modifier solution so that the surfactant is 0.3% by mass relative to the absolute dry weight of the wood chips, add a pH adjuster so that the pH is 6.5. Nurtured for days. Then, the modified wood 1 was obtained by drying in the sun so that the water content was 15% by mass.

・Manufacturing method of modified wood 2
Cedar wood was used as wood chips. Uncomposted cedar wood that has been cut into chips is fiberized using a biaxial grinder (manufactured by Mori Machinery Co., Ltd.), then cut and pulverized with a rotary cutter mill to a size that passes through a 4 mm mesh. (see Japanese Patent Application Laid-Open No. 2018-117590).

Next, a modifying chemical solution was prepared so that the predetermined citric acid/iron sulfate ratio was 0.1 and the concentration of iron sulfate was 1% by mass. Ferrous sulfate used was ferrous sulfate (FeSO ₄ .7H ₂ O). The modified chemical solution was sprayed onto the wood chips so that the iron sulfate concentration was 0.15% by mass with respect to the absolute dry weight of the wood chips.

Furthermore, a nonionic surfactant (manufactured by Takemoto Yushi Co., Ltd.) was added to the solution so that the concentration of the aqueous solution was 2.0% by mass to prepare a secondary reforming chemical solution. After spraying the wood chips with the secondary modifier solution so that the surfactant is 0.3% by mass relative to the absolute dry weight of the wood chips, add a pH adjuster so that the pH is 6.5. Nurtured for days. After that, the modified wood 2 was obtained by drying in the sun until the water content was 15% by mass.

A photograph of the modified wood thus obtained is shown in FIG.

The following shows the results of component analysis of soil in which a part of the composition of the SOFIX standard culture medium was replaced with woody medium.

Test Example 1: Component Analysis of Soil
Regarding the soil in which a part of the composition of the SOFIX standard soil was replaced with woody medium (modified woody material 2: mountain soil: black soil = 6:3:1 (v/v), hereinafter referred to as modified woody material 2-60%), Total carbon concentration (TC), total nitrogen concentration (TN), total phosphorus concentration (TP) and total potassium concentration (TK) were analyzed.

(1) Measurement of Total Carbon Concentration (TC) An appropriate amount of soil was weighed on a sample board and set in a solid sample combustion apparatus SSM-5000A (Shimadzu Corporation, Kyoto). Heated to 900°C, the organic matter in the forest biomass was thermally decomposed and converted to carbon dioxide. The amount of carbon dioxide concentration produced was measured with a total organic carbon meter TOC-V CPH (Shimadzu Corporation, Kyoto), the total organic carbon content (%) per 1.0 g was measured, and the total carbon concentration (TC ). Oxygen was used as the carrier gas, and the total organic carbon gas flow rate was adjusted to 40 mL/min, and the gas flow rate to the solid sample combustion apparatus was adjusted to 500 mL/min.

(2) Total decomposition extraction by the Kjeldahl method Organic matter was decomposed using the Kjeldahl method, and a total decomposition extract was obtained from the soil. 0.5 g of sample powder and 0.5 g of copper (II) sulfate pentahydrate were added to a Kjeldahl test tube. Additional sulfuric acid and 5.0 mL of hydrogen peroxide were added. A Kjeldahl test tube was set in a Kjeldahl digester Kjelderm (Gerhardt Japan Co., Ltd., Tokyo) and heated at 420° C. for 1.5 hours. After standing to cool for 30 minutes, distilled water was added to dilute appropriately. This diluted solution was filtered into a 100 mL Erlenmeyer flask, and distilled water was added to make up to 100 mL. The solution thus obtained was used as a fully decomposed extract to measure the total nitrogen concentration, total phosphorus concentration and total potassium concentration.

(3) Measurement of Total Nitrogen Concentration (TN) Ammonium ion concentration in all-component decomposition extract prepared by the Kjeldahl method was determined by the indophenol blue method. 1.0 mL of fully decomposed extract and 1.0 mL of distilled water (blank) were added to separate test tubes. 400 μL of phenol nitroprusside solution (Tables 2 and 3) and 600 μL of sodium hypochlorite solution (Table 4) were added to each test tube and allowed to stand (room temperature, 45 min). The absorbance at 635 nm was measured with a spectrophotometer U-1900 (Hitachi High-Technologies Corporation, Tokyo) after adjusting to 0 with a blank. The total carbon concentration (TN) was determined by substituting into the calibration curve. A calibration curve was prepared from ammonium dilution series (0, 0.1, 0.2, 0.4, 0.8, 1.6 mg/L) adjusted from ammonium sulfate.

(4) Measurement of Total Phosphorus Concentration (TP) Phosphate ion concentration in all component decomposed extract prepared by Kjeldahl method was quantified by ammonium molybdate method. 1.0 mL of fully decomposed extract and 1.0 mL of distilled water (blank) were added to separate test tubes. Ammonium molybdate solution (Table 5) and ascorbic acid solution (Table 6) were mixed in each test tube at a ratio of 5:1, and 100 μL of the mixed solution was added and allowed to stand (30° C., 30 min). The absorbance at 710 nm was measured with a U-1900 spectrophotometer after zero adjustment with a blank. The total phosphorus concentration (TP) was determined by substituting into the standard curve.

(5) Measurement of total potassium concentration (TK) Using a fully decomposed extract prepared by the Kjeldahl method as a sample, the total potassium concentration (TK) contained in the fully decomposed extract was measured using an atomic absorption photometer Z-2300 (stock It was measured by the company Hitachi High-Tech Science, Tokyo).

Table 7 below summarizes the results for the component amounts of modified wood 2-60%.

(6) Mineralization rate analysis of modified wood
Water was added to the SOFIX standard soil so that the moisture content was 30%, and the soil was left at room temperature for 1 week (water content was adjusted daily). After confirming that the number of bacteria reached 6×10 ⁸ cells/g or more, the total carbon content (TC) was measured and used as the initial TC. After that, 1% (w / w) of modified wood, compost or organic material was added, TC was measured every week (initial TC + TC of each material), and the remaining TC of the input material was obtained (Table 8 ). From this result, it became clear that the modified wood hardly decomposes. Therefore, in the present invention, the carbon content of the modified wood is not included as a soil-analyzed component.

Test Example 2: Improvement of soil properties by mixing modified wood
2.1 Experimental method
SOFIX standard soil is vermiculite (hereafter "V"), mountain soil (hereafter "M"), peat moss (hereafter "P"), and black soil (hereafter "B") at a ratio of 5:3:1:1. A required amount of an organic material was mixed with the mixture. Here, we evaluated the effect of improving soil physical properties when some components of SOFIX standard soil were replaced with modified wood.

Specifically, when the entire amount of vermiculite was replaced with the modified wood, and when the entire amount of vermiculite and peat moss were replaced with the modified wood, the modified wood 1 and the modified wood 2 were evaluated (details are shown in Table 9).

SOFIX standard compost and soil in which a part of the SOFIX standard compost was replaced with two types of modified wood were mixed, and organic materials were fertilized to prepare soil (Table 9). Organic fertilizer components were added to the prepared soil such that 5% cow manure compost, 0.25% oil cake and soybean meal, and 0.05% (w/w) bone meal. Maximum water holding capacity and density were measured for each prepared soil.

(1) Measurement of maximum water retention capacity A soil sample was dried for one day in a dry heat sterilizer SH400 (Yamato Scientific Co., Ltd., Tokyo) at 60°C to prepare dry soil. A well-wet filter paper was set in a funnel, 10.0 g of dry soil was placed on the filter paper, and the funnel was set in a weighed conical beaker (A). 30 mL of distilled water was added to the soil, the funnel was removed after the distilled water had run off from the funnel and the filter paper, and the weight of the conical beaker containing water was measured (B). Maximum water retention capacity (mL/kg)=[30-((B)-(A))]/10×100 was used to calculate the maximum water retention capacity.

(2) Measurement of Density The volume of the air-dried soil was added to 100 mL in a weighed 100 mL graduated cylinder, and the weight was measured.

2.2 Results Table 9 below summarizes the maximum water holding capacity and density of the soil. By mixing the modified wood, the maximum water-holding capacity was increased, the density was decreased, and the weight was reduced compared to vermiculite.

Test Example 3: Improvement of microbial content
3.1 Experimental method After allowing the prepared soil to stand for one week, changes in the total number of bacteria were observed for seven days. Total bacterial counts in soil were quantified by eDNA method.

(1) Extraction of environmental DNA (eDNA)
Into a 50 mL falcon tube, 1.0 g of soil was weighed and 8.0 mL of DNA extraction buffer (Table 10) and 20% sodium dodecyl sulfate (SDS) solution were added. The Falcon tube was set in a microbial DNA extraction pretreatment device IMC-1001 (Imoto Seisakusho, Kyoto) and stirred (1,500 rpm, 20 min). 1.5 mL of the resulting mixture was dispensed into a 2.0 mL microtube and centrifuged (8,000 rpm, 20°C, 10 min). 700 μL of the aqueous layer was placed in an organic solvent-resistant microtube, 700 μL of chloroform/isoamyl alcohol (24:1, v/v) was added and mixed, and then centrifuged (14,000 rpm, 20° C., 20 min). 500 μL of the aqueous layer was placed in a 1.5 mL microtube, 300 μL of 2-propanol was added and mixed, and then centrifuged (14,000 rpm, 20° C., 20 min). After removing the aqueous layer, 1.0 mL of 70% (v/v) ethanol was added and centrifuged (14,000 rpm, 20°C, 5 min). After removing the aqueous layer, it was naturally dried (room temperature, 1 day). To this, 50 μL of 10:1 TE buffer (Table 11) was added and well suspended to obtain an eDNA solution.

(2) Agarose gel electrophoresis Agarose 2.0 and 4.0 mL of 50×TAE buffer (pH 8.0) (Table 12) were added to distilled water to make 200 mL, and dissolved by heating to prepare a 1.0% agarose gel. A solution prepared by mixing 10 μL of eDNA extraction solution with 2 μL of loading dye (bromophenol blue) and 1.5 μL of Smart Ladder containing a known amount of DNA were applied to wells of an agarose gel. Agarose gel electrophoresis (100 V, 30 min) was performed with an electrophoresis apparatus Mupid (trademark)-exU (Advance Co., Ltd., Tokyo) using 1×TAE buffer as an electrophoresis buffer. The agarose gel was soaked in an ethidium bromide solution for 15 minutes for staining and then soaked in distilled water for 10 minutes for washing.

(3) Quantification of Total Bacteria in Soil The agarose gel was irradiated with UV using a gel imager WSE-5200 Printgraph 2M (Ato Co., Ltd., Tokyo), and a DNA band labeled with ethidium bromide was confirmed. The fluorescence intensity of the DNA band was measured using KODAK 1D Image Analysis software (KODAK, Tokyo). A calibration curve of the amount of DNA versus the fluorescence intensity of the DNA band of Smart Ladder was prepared, the amount of DNA was obtained from the fluorescence intensity of the DNA band of each soil eDNA solution, and the total number of bacteria per 1.0 g of soil was calculated. The total bacterial count in soil was obtained from a calibration curve that converts the amount of eDNA to the total bacterial count by DAPI staining. Using the relational expression Y = 1.7 × 10 ⁸ X (R ² = 0.96) [Y: total bacteria count in soil (cells/g-soil), X: amount of eDNA (μg/g-soil)] Soil total bacterial count was calculated.

3.2 Results Table 13 shows the results of the total soil bacterial count. The total number of bacteria on day 0 was 2.81 to 3.63 times higher in soil prepared using modified wood than in soil prepared using vermiculite. By using the modified wood, the total bacterial count in soil was remarkably improved.

Test Example 4: Improvement of plant growth
4.1 Experimental Method A cultivation experiment of Japanese mustard spinach was conducted using the soil prepared above and the rate of increase in the total number of bacteria.

Komatsuna seeds were sown in a 36-hole cell tray using Hanachan potting soil (Hanagokoro Co., Ltd., Aichi) as a commercially available chemical soil, and grown for 7 days to produce seedlings. A polypot for raising seedlings containing 150 g of each prepared soil was prepared, and three seedlings were planted. Experiments were performed in triplicate. Cultivation was carried out in a plant factory (12 hours: light, 12 hours: dark, 23°C) for 4 weeks and compared. 20 to 100 g of the plant body was taken and 5 times the amount of water was added. Then, after pulverizing with a mixer for 1 minute, it was centrifuged at 20,000 g for 10 minutes, and the supernatant was used as a sample.

The nitrate ion concentration was measured by the bricine/4-aminobenzenesulfone method, and the concentration per 1 kg (wet weight) was calculated. 100 μL of brucine/4-aminobenzenesulfonic acid solution (Table 14) was added to 200 μL of the extract obtained from the plant and mixed. 1.0 ml of sulfuric acid (water:concentrated sulfuric acid=3:20) was added thereto, stirred, and allowed to stand (in a cool, dark place for 10 minutes). After adding 1.0 mL of water, stirring and allowing to stand (in a cool dark place for 30 minutes), absorbance at 410 nm was measured to quantify nitrate nitrogen. A calibration curve was prepared from nitrate ion dilution series (0, 1, 5, 10, 25, 50 mg/L) prepared from potassium nitrate. The obtained nitrate nitrogen content was converted to nitrate ion content (mg/kg).

4.2 Results Table 15 shows the above-ground part weight, yield and nitrate ion content of Komatsuna cultivated in each soil. When the yield under the vermiculite condition was taken as 100%, a remarkable increase in yield was observed when the modified wood was used. In addition, nitrate ions showed low values, especially those using modified wood showed even lower values. Nitrate ion concentration of Komatsuna was 1,177 mg/kg-FW when chemical fertilizer soil (Hanachan potting soil) was used at the same time.

Similar results were also confirmed with mizuna, cabbage, strawberry, broccoli, spinach, grape, melon and blueberry.

Test Example 5: Bacterial flora analysis
5.1 Experimental method
The eDNA extract was appropriately diluted, and the 16S rRNA gene was amplified by PCR under the composition (Tables 16 and 17) and conditions (Table 18) shown in the table.

PCR-DGGE analysis was performed using the DCode System (Bio-Rad, CA).

40% acrylamide (Table 19), urea, formamide, and 50×TAE buffer were used to prepare acrylamide gels (Table 20) with a denaturant concentration gradient of 27.5% to 67.5%. After putting 1×TAE buffer into the acrylamide wells, a mixed solution of 23 μL of the above PCR product and 10 μL of Loading Dye (Toyobo Co., Ltd., Osaka) was applied. 5 μL of DGGE Marker II (Nippon Gene Co., Ltd., Tokyo) was applied to each end of the gel in order to compare the bands between gel distortions and different electrophoresis. 7.0 L of 1×TAE buffer was added to the electrophoresis tank and covered with an electrophoresis temperature control module (Bio-Rad, CA) to bring the water temperature to 60°C.

The sandwich core unit with the acrylamide gel set was placed in an electrophoresis tank (Bio-Rad, CA) and subjected to electrophoresis (60 °C, 15 hr) with a power supplier (Power Pac, Bio-Rad, CA). , 70V). After electrophoresis, the acrylamide gel was soaked in distilled water for 30 minutes and the denaturant was eluted in distilled water. Then, after staining with ethidium bromide diluted 5,000 times with distilled water (30 min), UV irradiation was performed using a transilluminator WSE-5200 Printgraph 2M (Ato Co., Ltd.) to confirm the DNA band.

5.2 Results
The results of PCR-DGGE analysis are shown in FIG. As a result, when the modified wood was used, the number of bands increased remarkably, indicating that the bacterial flora increased.

Claims (9)

A dry organic soil containing dry woody medium, dry organic material and dry compost,
The compost is dried to the extent that the microorganisms are dormant, and contains dormant microorganisms due to the drying,
The organic material has a composition that can be decomposed aerobically by microorganisms and is dried to the extent that decomposition by microorganisms does not progress,
The woody medium is composed of coniferous wood fragments, and the size of the wood fragments is such that they can pass through a mesh of 10 mm or less,
Dry organic soil containing 10 to 90% by volume of the woody medium. 2. The dry organic soil according to claim 1, wherein the wood chips are blackened by contact with iron salts and contained in the dry organic soil in an amount of 30 to 90% by volume. The total carbon content is 12,000-35,000 mg/kg, the total nitrogen content is 900-1,800 mg/kg, the total phosphorus content is 800-1,600 mg/kg, the total potassium content is 900 mg/kg or more, and the C/N ratio is 10. 3. The dry organic soil according to claim 1 or 2, wherein the dry organic soil is ∼25. Dry organic soil according to any one of claims 1 to 3, wherein said wood chips contain a surfactant. Dry organic soil according to any one of claims 1 to 4, further comprising dry soil. A method for producing dry organic soil containing dry woody medium, dry organic material and dry compost, comprising the steps of:
(A) preparing a woody medium composed of dry coniferous wood chips ;
(B) a step of preparing a dried organic material by drying an organic material composed of aerobicly degradable composition for the growth of microorganisms to such an extent that decomposition by microorganisms does not proceed;
(C) preparing a dry compost by drying the compost to such an extent that the microorganisms are dormant and making a large amount of the microorganisms contained in the compost dormant;
(D) measuring the total carbon content, the total nitrogen content, the total phosphorus content, and the total potassium content in each of the woody medium, the organic material, and the compost;
(E) adding the woody medium so that the total carbon content, the total nitrogen content, the total phosphorus content, the total potassium content, and the C/N ratio are predetermined values, and the woody medium contains 10 to 90% by volume of the woody medium; Mixing the organic material and the compost. The step A includes a step of pulverizing coniferous wood to a size that passes through a mesh of 10 mm or less, and a step of contacting the obtained woody fragments with an iron salt aqueous solution to turn black. The manufacturing method according to claim 6. The predetermined values in step E are 12,000 to 35,000 mg/kg for total carbon, 900 to 1,800 mg/kg for total nitrogen, 800 to 1,600 mg/kg for total phosphorus, and 900 mg/kg for total potassium. 8. The production method according to claim 6 or 7, wherein the mixture has a C/N ratio of 10 to 25 and contains 30 to 90% by volume of the woody medium. A method of cultivating a plant, characterized by using the dry organic soil according to any one of claims 1 to 5.

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