JPH10273409A - Microbial seed dressing composition - Google Patents

Abstract

(57) [Summary] [Problem] To provide a microbial seed dressing composition excellent in storage stability of live microbial microorganisms. SOLUTION: In a microbe seed dressing composition containing a useful microorganism and a carrier, an organic substance, preferably a sterilized peat moss, which is sterilized by the carrier, is blended at a ratio of 30 to 100% by weight based on the total weight of the dried carrier. I do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dressing composition for microbial seeds, and more particularly to a dressing composition for microbial seeds having excellent storage stability of living microbes.

[0002]

2. Description of the Related Art For the purpose of sterilizing seeds, promoting germination, promoting growth, etc., as a seed dressing agent to be attached to seeds at the time of use or a seed coating agent for pre-coating seeds, chemical synthesis agents have been used. Has been researched and developed and put into practical use. However, there is a concern that the above-mentioned chemically synthesized drug may cause emergence of resistant bacteria to the drug, safety at the time of use, phytotoxicity to plants, and environmental pollution.

[0003] On the other hand, in recent years, microorganisms useful for plants have been included because of their advantages that they have no phytotoxicity to plants, do not remain in crops, and do not adversely affect the environment if they remain in soil. Attempts have been made to improve agricultural productivity using microbial materials. Representative examples of such useful microorganisms include rhizobia, bacteria belonging to the genus Azospirillum and Pseudomonas, photosynthetic bacteria,
Fungi belonging to VA mycorrhizal fungi, genus Gliogradium, and the like are known, and some of them have already been put to practical use.

[0004] However, these useful microorganisms are often mixed with a carrier and used as a microbial material, for example, mixed with a cultivation soil for raising seedlings at the time of raising seedlings of plants, or used in cultivation fields. However, there is a problem with the storage stability of microorganisms, so long-term storage stability is particularly required, and there are few microbial seed dressing materials used for dressing seeds. there were.
In addition, bacteria belonging to the genus Azospirillum, which are expected to be effective due to the above-mentioned problems, have not been used as microbial seed dressing materials.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has as its object to provide a microbial seed dressing composition which is excellent in storage stability of living microbial bacteria.

[0006]

Means for Solving the Problems The present inventor has conducted intensive studies on a carrier used for a microbial seed dressing composition in order to solve the above-mentioned problems, and as a result, by using a sterilized organic substance for the carrier, The present inventors have found that the preservation stability of microorganisms in the microbial seed dressing composition can be ensured, and that a reliable effect can be exhibited even after long-term storage, thereby completing the present invention.

That is, the present invention is a microbial seed dressing composition comprising a useful microorganism and a carrier, wherein the carrier contains a sterilized organic substance.

As the sterilized organic substance contained in the carrier of the microorganism seed dressing composition of the present invention, sterilized peat moss can be preferably mentioned. Specifically, the content of the sterilized peat moss in this case can include a content of about 30 to 100% by weight on a dry weight basis relative to the total weight of the dried carrier.

[0009] The content of useful microorganisms contained in the microbial seed dressing composition of the present invention is, specifically, the carrier 1
The content can be about 10 ³ to 10 ¹¹ individuals per g.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
First, useful microorganisms contained in the microorganism seed dressing composition of the present invention will be described.

(1) Useful Microorganisms The useful microorganisms contained in the microbe seed dressing composition of the present invention are not particularly limited as long as they are microorganisms having a useful effect on plants. As such microorganisms, specifically, genus Azospirillum, genus Azorizobium, genus Pseudomonas, genus Rhizobium, genus Shinorhizobium, genus Photorhizobium, genus Bacillus, genus Brasilizobium, genus Agrobacterium, genus Streptomyces,
Xanthomonas, Lactobacillus, Aeromonas, Anabaena, Frankia, Rhodoseudomonas, Trichoderma, Glomus, Aspergillus,
Microorganisms belonging to the genus Penicillium, Rhizopus, Fusarium, Gliogradium, Gigaspora, Scutrospora, Nostock, Azotobacter, etc.
For each microorganism, for example, "a microorganism belonging to the genus Azospirillum" is abbreviated as "azospirillum bacterium".

In the microorganism seed dressing composition of the present invention, one of these microorganisms may be used, or two or more of these microorganisms may be used in combination. When using a combination of microorganisms, it is preferable to appropriately select a combination and a compounding amount that do not impair the usefulness of each microorganism with respect to the plant.

The useful microorganism is generally a microorganism that inhabits the soil, and can be obtained by screening the soil according to an ordinary method, and can also be obtained from various microorganism depositaries. is there. When using the useful microorganisms in the microorganism seed dressing composition of the present invention,
Usually, the above useful microorganisms are cultured and used. As a medium used for cultivation of useful microorganisms, a medium suitable for the growth of each of these microorganisms is selected and used. As for the culture conditions, conditions suitable for the growth of the microorganism are appropriately selected.

Among the useful microorganisms described above, azospirillum has never been used as a microbial seed dressing composition, and the microbial seed dressing composition containing azospirillum is a novel microorganism. In addition, it is preferable to use Azospirillum as a useful microorganism in the present invention, since the Azospirillum seed dressing composition has an excellent growth promoting effect on applied plants.

Further, in the microbial seed-dressing composition of the present invention, the above-mentioned azospirillum is used as a useful microorganism.
Rhizobium, Sinorhizobium, Photorhizobium, Bradyrhizobium, By using in combination with rhizobia such as Azorhizobium, since the growth promotion effect on the applied plant is improved as compared to the case where each microorganism is used alone, Preferred examples of useful microorganisms used in the present invention include a combination of Azospirillum and rhizobia. Preferred examples of the useful microorganism used in the present invention as described above include a combination of Azospirillum and Trichoderma.

Next, the carrier contained in the microorganism seed dressing composition of the present invention together with the useful microorganisms will be described.

(2) Carrier The carrier contained in the microorganism seed dressing composition of the present invention contains a sterilized organic substance (hereinafter referred to as “sterilized organic substance”). Specific examples of the organic substance to be sterilized include peat moss, charcoal, pulp, oil cake, fish cake, bone meal, blood meal, shell fossil, crab shell, humus, humus, and the like. Peat moss is preferably used in the dressing composition. One of the above organic substances can be used alone or as a mixture of two or more.

The above-mentioned organic substance is sterilized to obtain a sterilized organic substance. A normal sterilization method can be used, and specific sterilization methods include autoclave sterilization, ultraviolet sterilization, radiation sterilization, and the like. Sterilization methods such as sterilization by gas sterilization for sterilization, steam sterilization, and the like can be given. Also, as a more specific example of the above sterilization method, when using peat moss as an organic substance,
Peat moss is autoclaved at 115-125 ° C, 10
Autoclave sterilization is performed for about 80 minutes.

The content of the above-mentioned germicidal organic substance in the carrier contained in the microbial seed dressing composition of the present invention is preferably 30 to 100% by dry weight based on the total weight of the dried carrier. Preferably 40 to 100% by weight
It is. Here, the dry weight used in this specification refers to the weight after the substance is dried at 105 ° C. for one day.

The carrier contained in the microbial seed dressing composition of the present invention can contain, in addition to the above-mentioned sterilized organic substance, an inorganic substance usually used as a microbial material and an unsterilized organic substance. As the inorganic substance contained in such a carrier, specifically, Akadama soil, calcined Akadama soil, Kanuma soil, Kuroboku soil, attapulgite, vermiculite,
Inorganic substances such as montmorillonite, pearlite, zeolite and the like can be mentioned, and as non-sterilized organic substances, the same organic substances as the above-mentioned organic substances to be sterilized can be mentioned. One of these substances alone or a mixture of two or more thereof As a carrier. Here, in the above-mentioned inorganic substance, organic substance, and the like, which are listed as the constituent components of the carrier, the particle shape is not particularly limited, but those having a particle size of about 0.05 mm to 5.0 mm are the present invention. Are preferably used in the microbial seed dressing composition.

The carrier used in the microbial seed dressing composition of the present invention may contain various trace components in addition to the above components, if necessary, in a range that does not impair the effects of the microbial seed dressing composition of the present invention. Can be blended. As such a trace component, specifically, a pH adjuster such as lime, magnesia, calcium carbonate, a fungicide such as metalaxyl, oxadixyl, manzeb, a bactericide such as thiuram, and a molybdenum, cobalt, iron, etc. And the like. Specifically, an appropriate amount of the above-mentioned pH adjuster is an amount for adjusting the pH of the carrier to about 5.0 to 8.0, and an appropriate amount of the above-mentioned fungicide is specifically, the total amount of the carrier. To about 0.001 to 0.2% by weight.

Further, the above-mentioned carrier is added at an appropriate ratio, for example, at a ratio of about 20 to 90% by weight based on the total amount of the carrier.
Moisture can be contained, which is preferable in the microbial seed dressing composition of the present invention.

The microbial seed dressing composition of the present invention containing the useful microorganism and a carrier is described below.

(3) Microbial seed dressing composition of the present invention The microbial seed dressing composition of the present invention is a microbial seed dressing composition containing the above-mentioned useful microorganism and a carrier containing the above-mentioned bactericidal organic substance.

In the microorganism seed dressing composition of the present invention,
Although the preferable content of the useful microorganism depends on the kind of the useful microorganism used, it is generally 1 to 1 g of the carrier.
The 0 ³ 10 ¹¹ individuals of about content, more preferably, can be mentioned content of 10 ⁴ to 10 ^{1 0} individuals about with respect to the support 1g. Here, when the useful microorganism is a mixture of two or more microorganisms, the total number of individuals may be within the above range.

More specifically, when azospirillum is used as the useful microorganism, a preferable content is about 10 ³ to 10 ¹¹ individuals per 1 g of carrier, more preferably 1 g of carrier. 10 ⁴ to 10 ¹⁰
The content of an individual can be mentioned. When rhizobia, specifically Rhizobium, Sinorhizobium, Photorhizobium, Bradyrhizobium, Azorhizobium, or the like is used as the useful microorganism, a preferable content is 10 ³ to 10 ^{1 per 1} g of the carrier. The content of about ¹ individual is more preferably 10 g / g of the carrier.
The content of about ⁴ to 10 ¹⁰ individuals can be mentioned.

For example, when the azospirillum and rhizobial bacteria are used in combination as the useful microorganism, the content of the azospirillum is specifically about 10 ³ to 10 ¹¹ per 1 g of the carrier. Specifically, as the content of rhizobia, specifically, 10 ³ to
The content may be such that the content is less than 10 ¹¹ individuals and the sum of both is 10 ¹¹ or less.

The dosage form of the microorganism seed dressing composition of the present invention is
It is not particularly limited, and can be the same as the dosage form of the seed dressing composition usually used for seeds of cultivated crops. Depending on various dosage forms, the usual microbial seed dressing composition contains In addition, components other than those described above can be arbitrarily contained within a range that does not impair the effects of the microorganism seed dressing composition of the present invention.

The seed to which the microbial seed dressing composition of the present invention is applied is not particularly limited as long as it is a seed of a cultivated crop, and specifically, legumes, brassicaceae, asteraceae,
Crops selected from Solanaceae, Acalyptaceae, Cucurbitaceae, Apiaceae, Lily, Gramineae, and the like. Among these, soybean, adzuki bean, peas, green beans, peanuts, broad beans, clover, alfalfa, vetch (above, legume crops), komatsuna, Chinese cabbage, cabbage, radish,
Turnip, cauliflower (above, cruciferous crop), lettuce, syngiku, burdock (above, asteraceous crop), tomato, eggplant, bell pepper, potato (above, solanaceae crop), spinach (abdoaceae crop), watermelon, cucumber, The present invention relates to seeds of crops such as pumpkin, melon (above, Cucurbitaceae crop), celery, carrot (above, Cucurbitaceae crop), leek, onion, asparagus (above, lily crop), corn (grass crop), etc. And a crop seed having a remarkable effect when cultivated using the microbial seed dressing composition.

The method of dressing the seeds of the above-mentioned crops with the microbial seed-dressing composition of the present invention and the amount to be dressed can be the same as in the case of using the usual microbial seed-dressing composition. For example, when the soybean is dressed with the microbial seed dressing composition and the seed of the present invention,
In a container such as a plastic bag or a PET bottle, soybeans and about 1.5 to 3.0 mg of the microbial seed dressing composition per one soybean are placed and shaken, or soybeans and soybeans are placed on a sheet or tray. It is preferable to put about 2.0 to 8.5 mg of the microbial seed dressing composition per 1 g, and to coat them by mixing them using a spoon or the like.

The seeds thus dressed with the microbial seed dressing composition thus obtained can be sown and cultivated in the same manner as ordinary seeds. Cultivation soil is field soil,
Any of paddy field soil and artificial soil may be used, and may be appropriately set according to the plant to be applied. Sand and artificial soil are preferred.

[0032]

Embodiments of the present invention will be described below. First,
An example of culturing useful microorganisms used in the microorganism seed dressing composition of the example will be described.

[0033]

[Production Example] Culture of Azospirillum and Rhizobium Azospirillum brasiliensis (ATCC29145)
Is a RC medium (DL-malic acid: 5 g / L, KOH:
4.8 g / L, yeast extract: 0.5 g / L, K ₂ HP
O ₄ : 0.5 g / L, MgSO ₄ .7H ₂ O: 0.2 g / L
L, NaCl: 0.1g / L, FeCl 3 · 6H 2 O:
(0.015 g / L, pH 7.0), 100 mL of medium was dispensed into a 500 mL Sakaguchi flask, and then separately liquid-cultured inoculum was inoculated at 10 ⁷ cells per flask, and this was inoculated 180 times per minute. 3 in a shaking incubator
After culturing at 2 ° C. for 24 hours, the cells were collected by centrifugation.

The rhizobial bacteria (B. rhizobium japonicum ATCC 10324) were prepared using a YM medium (manitol: 10%).
g / L, yeast extract: 0.4 g / L, K ₂ HPO ₄ : 0.
_{5g / L, MgSO 4 · 7H} 2 O: 0.2g / L, NaC
1: 0.1 g / L, pH 7.0), and cultured under the same conditions as for Azospirillum, followed by centrifugation.

[0035]

Examples 1 to 11 Rhizobial seed dressing composition Humic soil, peat moss, oil cake (above, organic substance), vermiculite, montmorillonite (above, inorganic substance) were each used as a carrier material in an autoclave.
The solution was sterilized at 15 ° C. for 15 minutes to prepare various sterilized organic or inorganic carrier materials. In addition to these, unsterilized humus, peat moss, and oil cake were prepared.

Table 1 shows the sterilized or unsterilized carrier materials.
Were prepared by mixing at various ratios with the various combinations shown in (1), the water content of these mixtures was adjusted to 70% by weight, the particle size was adjusted to 0.1 mm to 1.0 mm, and lime was added to adjust the pH to 5.5. These were adjusted to 6.0 and used as carriers. Next, the rhizobia obtained in the above production example were uniformly mixed with each of the obtained carriers so that the rhizobia obtained in the above-mentioned production example became 10 ⁹ individuals per 1 g of the carrier, thereby preparing 11 kinds of rhizobia seed dressing compositions. .

Further, for comparison, unsterilized peat moss was used as a carrier using only unsterilized organic substances, and the above-mentioned sterilized vermiculite or montmorillonite was used as a carrier containing no germicidal organic substance. Content 70% by weight, particle size 0.1mm ~
1.0 mm, and what adjusted the pH to 5.5-6.0 by further adding lime was produced. For each of the obtained carriers,
The rhizobial bacteria obtained in the above production example was added to 10 ⁹
Three kinds of rhizobial seed dressing compositions of Comparative Example were prepared by uniformly mixing them so as to become individual.

<Evaluation of the microbial seed dressing composition of the present invention>
The rhizobial seed dressing compositions obtained in each of the above Examples and Comparative Examples were placed at 25 ° C., and the survival rate of rhizobia was measured after 90 days, 180 days, and 360 days. The viability was measured by collecting 1 g of each of the above rhizobial seed dressing compositions and adding 0.1 M Mg
After suspending in 30 mL of SO ₄ and shaking for 1 hour, the suspension was
After diluting 2,000-fold, YM agar medium (mannitol: 10 g /
L, yeast extract: 0.4 g / L, K ₂ HPO ₄ : 0.5 g
_{/ L, MgSO 4 · 7H 2} O: 0.2g / L, NaCl:
0.1 g / L, agar: 20 g / L, pH 7.0), the concentration of viable rhizobia was determined from the number of colonies appearing, and the following concentration was determined from the concentration of viable rhizobia and the initial rhizobia concentration at the time of preparing the composition. The calculation was performed by using a calculation formula. Table 1 shows the results.

[0039]

## EQU1 ## Survival rate (%) = (viable bacterial concentration × initial bacterial concentration) × 100

[0040]

[Table 1]

From these results, it can be seen that the rhizobial seed dressing composition of the example in which the carrier contains a germicidal organic substance is compared to the rhizobial seed dressing composition of the comparative example in which the carrier does not contain a germicidal organic substance. It can be seen that the storage stability is excellent.

[0042]

Examples 12 to 19 Azospirillum seed dressing composition As organic carrier materials, sterilized peat moss, sterilized oil cake and sterilized obtained by sterilizing peat moss, oil cake and humus in autoclave at 121 ° C. for 15 minutes, respectively. Humus soil was prepared. Furthermore, sterilized montmorillonite was prepared by sterilizing montmorillonite, an inorganic substance, in the same manner as described above.

In each of the examples, the mixture obtained by mixing the above-mentioned germicidal organic or germicidal carrier materials in the combinations and mixing ratios shown in Table 2 had a water content of 70% by weight and a particle size of 0.1 mm to 1.0 mm. The carrier was adjusted to 0 mm, and further adjusted to pH 5.5 to 6.0 by adding lime, and used as a carrier. The respective carriers were uniformly mixed with the azospirillum bacterium obtained in the above-mentioned Production Example so as to be 10 ⁸ per gram of the carrier, thereby preparing eight kinds of azospirillum seed dressing material compositions.

<Evaluation of the microbial seed dressing composition of the present invention>
The azospirillum seed dressing composition obtained in each of the above examples was placed at 25 ° C., and the survival rates of the azospirillum bacteria after 90 days, 180 days, and 360 days were measured. In the measurement of the survival rate, in the evaluation of Examples 1 to 11 and Comparative Examples 1 to 3, the YM agar medium was replaced with the RC agar medium (DL-malic acid: 5
g / L, KOH: 4.8 g / L, yeast extract: 0.5 g
_{/ L, K 2 HPO 4:} 0.5g / L, MgSO 4 · 7H
₂ O: 0.2 g / L, NaCl: 0.1 g / L, FeC
_{l 3 · 6H 2 O: 0.015g} / L, agar: 20 g / L,
(pH 7.0), except that the procedure was the same as above. Table 2 shows the results.

[0045]

[Table 2]

From these results, among the azospirillum seed dressing compositions using a carrier containing a germicidal organic substance, among the azospirillum seed dressing compositions containing germicidal peat moss as the germicidal organic substance, the It can be seen that the storage stability is particularly excellent.

[0047]

Examples 20 to 34 Azospirillum + Rhizobium seed dressing composition Peat moss was used as a carrier material in an autoclave.
Sterilized peat moss obtained by sterilizing at 1 ° C. for 15 minutes was prepared.

In each of the examples, the sterilized peat moss was used as a carrier material, the water content was 70% by weight, and the particle size was 0.1 m.
The carrier was adjusted to m to 1.0 mm, and further adjusted to pH 5.5 to 6.0 by adding lime, and used as a carrier. The azospirillum bacterium and / or rhizobia obtained in the above-mentioned Production Example were added to the thus obtained carrier at a cell concentration shown in Table 3, and these were uniformly mixed to obtain 1%.
Five types of microbial seed dressing material compositions were prepared.

<Evaluation of the microbial seed dressing composition of the present invention>
The microbial seed dressing composition obtained in each of the above examples was heated at 25 ° C.
And the survival rate of Azospirillum and / or rhizobia after 180 days was measured. The measurement of the survival rate was performed in the same manner as in the evaluation of Examples 1 to 11, except that the rhizobial colony was measured using the YM agar medium.
The procedure was exactly the same as above, except that the azospirillum colonies were counted using an agar medium. Table 3 shows the results.

[0050]

[Table 3]

From these results, it is understood that the seed dressing composition containing azospirillum and rhizobia alone as useful microorganisms, and the seed dressing composition containing both of them, respectively, contain a bactericidal organic substance according to the present invention. It can be seen that the use of a carrier that provides good storage stability of useful microorganisms.

[0052]

Examples 35 to 43 Seed dressing composition containing Azospirillum and / or rhizobia As a carrier material, peat moss and humus soil were respectively sterilized in an autoclave at 121 ° C. for 15 minutes, and sterilized peat moss and sterilized humus were obtained. I got the soil. In addition, unsterilized humus, montmorillonite was prepared.

In Examples 35 and 37, sterilized peat moss was mixed, in Examples 36 and 38, sterilized humus was mixed, and in Examples 39 and 41, sterilized peat moss and montmorillonite were mixed at a weight ratio of 4: 1. In Example 40, a mixture obtained by mixing sterilized humus and montmorillonite at a weight ratio of 4: 1 was used. In Example 42, a mixture obtained by mixing sterilized peat moss and unsterilized humus at a weight ratio of 3: 2 was used. In Example 43, a mixture of sterilized peat moss, unsterilized humus, and montmorillonite in a weight ratio of 5: 3: 2 was used, each having a water content of 70% by weight and a particle size of 0.1 m.
m to 1.0 mm, and lime was added to adjust the pH to 5.
What was adjusted to 5-6.0 was used as a carrier. To each of these carriers, the azospirillum bacterium and / or rhizobial bacterium obtained in the above Production Example were added at the cell concentrations shown in Table 4, and these were uniformly mixed to obtain nine kinds of microbial seed dressing material compositions. Produced.

<Evaluation of the microbial seed dressing composition of the present invention>
The nine types of microbial seed dressing compositions obtained in each of the above examples were stored at 25 ° C. for 270 days, and then evaluated as seed dressing compositions.

That is, the above-mentioned nine kinds of microbial seed dressing compositions after storage for 270 days were put into plastic bags of an appropriate size, and 40 seeds of edamame (variety: Sapporo midori) were placed in each plastic bag. Seed dressing treatment is carried out by adding and shaking vigorously, and 1.5 ~
The seed dressing composition was applied at a rate of 2.5 mg. In addition, as a control, pH 5.5 to 6.5.
0, a montmorillonite adjusted to a water content of 70% by weight and a particle size of 0.1 mm to 1.0 mm is put into a plastic bag, and 40 seeds of edamame (variety: Sapporo midori) are put into the plastic bag and shaken vigorously. The seed-dressed soybean was obtained.

For cultivation of soybeans, Akadama clay was used as cultivation soil and a black vinyl pot having a diameter of 9 cm was used as a container. Red clay was put into 20 black vinyl pots, leaving a gap of 2 cm at the top, and the microbial seed dressing composition obtained in Example 35 was allowed to adhere to each of the black pots.
Each seed was sown. Such pots were prepared for each of the soybean seeds to which the microbial seed dressing compositions obtained in the remaining examples were adhered and the control soybean seeds, respectively, in 20 pots. These pots were placed in a vinyl greenhouse, irrigated once a day, and maintained at 25 ° C in the day and 15 ° C at night. 1 per pot after seeds germinate
It was thinned out to make a book and grown for one month.

One month after the germination, all the seedlings were pulled out.
After the soil on the roots was washed with water, the aerial part and the root part were separated, the stem length was measured, and the average of 20 plants was determined for each test plot. Then, the aerial part and the root part of the sample were separately separated at 105 ° C for 1 day. After drying, the weight was measured and the average of 20 strains was determined for each test plot. Table 4 shows the results. Here, each numerical value is a relative value with the control value being 100. The T / R ratio is
Aboveground weight / root weight.

[0058]

[Table 4]

From the results, it is clear that the microbial seed-dressing composition of the present invention has an excellent growth-promoting effect on soybeans even after long-term storage. It was confirmed that the product was excellent in storage stability of useful microorganisms.

[0060]

EFFECT OF THE INVENTION The microbial seed dressing composition of the present invention is excellent in storage stability of viable microbial cells.

Claims (4)

[Claims] 1. A dressing composition for microbial seeds comprising a useful microorganism and a carrier, wherein the carrier contains a sterilized organic substance. 2. The dressing composition of claim 1, wherein the organic substance is peat moss. 3. The microbial seed dressing composition according to claim 2, wherein the content of the sterilized peat moss is 30 to 100% by weight on a dry weight basis relative to the total weight of the dried carrier. 4. The microbial seed dressing composition according to claim 1, wherein the content of the useful microorganism is 10 ³ to 10 ¹¹ individuals per 1 g of the carrier.