JPH08228592A - Sulfur-added and molded culture medium for growing seedling - Google Patents

Abstract

PURPOSE: To obtain a sulfur-added seedling-growing culture medium which is prepared by adding sulfur to a mat-form culture medium made of an inorganic substance, pH of the medium is steadily lowered down to a level suitable for growing seedlings of rice plants without using a mineral acid such as sulfuric acid dangerous to handle, thus is safely used without damage to the formed culture medium. CONSTITUTION: Inorganic and/or organic fibers such as rock wool are formed into a mat as a culture medium after adding sulfur to the formed culture medium, preferably in amount of 10-50g (per 1 unit of the formed culture medium) to give this sulfur-added formed culture medium for growing seedlings. Rice seeds are inoculated into the medium, irrigated, covered with natural soil and moistened at 32 deg.C for 2-3 days or kept at about 25 deg.C for 4-5 days. By these treatments, sulfur-oxidizing bacteria rapidly proliferate to oxidize sulfur into sulfuric acid and the formed culture medium is acidified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to seedling raising of acidophilic plants, especially rice seedlings.

[0002]

2. Description of the Related Art Raising seedlings using rockwool molding medium for rice seedlings will be mainly described below as a typical acidophilic plant. When raising acidophilic plants, especially rice seedlings, an acidic medium is used. In recent years, as box seedlings of rice seedlings have become popular, artificial acid such as rock wool forming medium, pulp forming medium, or synthetic resin forming medium has been used instead of the soil (bed soil) made of acidic natural soil. The medium was developed as a nursery bed. Natural soil (bed soil) is used for covering soil.

Rice seedlings grow healthy in a medium around PH5, especially when densely planted seedlings in a nursery box, but when they are higher than PH6, the risk of causing diseases such as mullet seedlings and dead seedlings is high. Especially in cold years. Therefore, regardless of whether the medium for raising seedlings is natural culture medium or forming medium, PH4.5-5.
Publicly instructed to adjust to 5. (See “Quality of artificial bed soil”, Ministry of Agriculture, Forestry and Silkworm Horticultural Bureau, Agricultural Production Division, Kiyochika Hoshikawa, “Raising rice seedlings”, pp. 28-29). In this case, conventionally, the rockwool molding medium was acidified using "mineral acid and salts thereof and organic acid and salts thereof" and the like and used. (JP-A-58-141731)

[0004]

However, the rockwool molding medium is composed of extremely fine rockwool fibers of 7 micron or less containing 35% or more of lime and is PH7 to PH10. In the prior art, this is treated with a mineral acid or an organic acid or salts thereof as described above.
It is lowered to 4.5 to 5.5.

[0005] For raising rice seedlings, sulfuric acid is generally used as the main ingredient because it can grow well if it is acidified with sulfuric acid in the above acidifying agent. Conventionally, in order to acidify the molding medium, it is common to treat the surface of the molding medium with an acidic substance as described above, especially sulfuric acid. Then, the rockwool fiber reacts with acid to be acidified, but on the other hand, the rockwool fiber is inevitably damaged.

[0006] In raising rice seedlings, the molding medium is inserted into a nursery box as a seed bed, seeded rice is seeded on the surface of the seedlings and watered, and natural soil (bed soil) is covered with the soil and heated. Alternatively, keep the seeds warm and germinate to raise seedlings. Then, the reactant acidified by the irrigation and the unreacted acidifying agent are dissolved, and the pH is adjusted to PH5 initially. Seedlings are on the 7-20
Raise seedlings for days. For medium seedlings, the seedlings are raised for 30 days. By the way,
The seedlings of the 7-day-old seedlings are recently called milk seedlings.

Taking a seedling as an example, a nursery box 28 cm × 58
The seed paddy to be seeded on the molding medium inserted in cm × 3 cm is generally 150 g to 200 g. For example, the variety Nipponbare 15
The seeding number is 5,300 when 0 g is sown, 6,300 when 180 g is sown, and 6,600 when 200 g is sown.
When the seedlings are raised for 20 days, the leaf age becomes 2.0 to 2.4. It's a truly amazing overgrown seedling.

When the seedlings are raised in such an overcrowded state, the seedlings are naturally weak. There is no sunlight at the base. If the seedlings are raised in such a harsh condition, there is a great risk that the seedlings will have wilt disease or will have many mullet seedlings. Therefore, under the present circumstances, rice seedlings are currently cultivated with several kinds of pesticides in order to prevent the above diseases. However, as a result of many seedling raising tests, if the seedling bed PH is constantly maintained at pH 4.5 to 5.5 as described above, the number of dead seedlings and saplings is significantly reduced.

Conventionally used seed beds, especially molding medium, are adjusted so as to maintain PH5 at the beginning of seedling raising, but the acidifying agent is washed away with each irrigation, and from about one week after seeding, the seedling beds are It becomes PH6, and after 15 days, it often becomes close to PH7. Then, as mentioned above, the rice seedlings frequently occur in dead seedlings and saplings. (See Kiyochika Hoshikawa, "Raising Rice Seedlings", pp. 28-29) The present invention aims to eliminate the above-mentioned conventional drawbacks.

[0010]

To achieve the above object, sulfur is used as an acidifying agent in the present invention. Practical use of sulfur flower. To add sulfur to the molding medium. First, a molding medium is formed, and sulfur oxide is sprinkled on the surface of the molding medium. For that purpose, the adhesive is sprayed on the surface of the molding medium in advance, and the sulfur flower is sprayed thereon.
Alternatively, without using an adhesive, the dispersed sulfur flower is pressed into the system of the molding medium. Alternatively, an aqueous solution or suspension or dispersion of sulfur is sprayed and dried. Or while manufacturing rock wool,
A sulfur wool-containing rockwool mat is formed by sprinkling or spraying sulfur rock or an aqueous solution, suspension or dispersion thereof on the produced rockwool. The mat is cut into desired size features to obtain a shaped medium. Incidentally, in order to produce a rockwool mat of a rockwool bundle, an alkaline carboxylic acid resin is generally used as a binder.

[0011] Thus, the required amount of sulfur flower varies depending on the pH of the original culture medium and the desired acidity, but generally PH4.
In order to obtain a rockwool molding medium of 5 to 5.5, 10 g to 50 g of ridges are suitable for one public nursery box, that is, one rockwool molding medium of 28 cm × 58 cm × 2 cm. However, this amount also depends on the type of fertilizer used at the same time (whether it is acidic fertilizer or alkaline fertilizer) and the amount.

As described above, sulfur is added directly or by molding to rock wool fiber, but unlike conventional acidifying agents such as sulfuric acid, there is no danger in handling, and rock wool is damaged. There is no such thing. This is a very good advantage of the present invention. By the way, fertilizers should be applied to the desired amount by the farmers themselves at the time of raising seedlings, but today, many of the ready-made products in which fertilizers are added to the molding medium are used by molding medium manufacturers. There is. In addition to the rockwool molding medium described above, for example, pulp, synthetic fiber, synthetic resin or the like can be used as a molding medium material.

[0013]

The forming medium of the present invention mainly provides a seed bed for raising rice seedlings. Needless to say, it can be used for raising seedlings of acidophilic plants other than rice. As the soil cover, natural soil such as mountain soil, rice field soil, upland soil, or artificial soil (bed soil) obtained by processing them into granules is used. In order to raise rice seedlings with the molding medium of the present invention, according to a conventional method, in a public nursery box,
Inserting the forming medium of the present invention, sowing seed paddy, irrigating to cover the natural soil or the soil consisting of the natural soil, heating or keeping it warm to promote budding, and thereafter seedlings, seedlings, medium Raise seedlings, adult seedlings, etc.

Seed rice is seeded on the sulfur-added forming medium of the present invention, irrigated, covered with natural soil, and heated at 32 ° C. for 2 to 3 days or at 25 ° C. as usual. When kept warm for 4 to 5 days, naturally occurring sulfur-oxidizing bacteria rapidly grow to sulphate sulfur and acidify the forming medium. After that, sulphation gradually progresses at room temperature. As described above, when 10 to 50 g of sulfur is added per molding medium, the PH of the molding medium becomes 4.5 to 5.5. By the way, in the above, without heating or heat retention, 3 ~
At room temperature around April, PH becomes 4.5 to 5.5,
It takes 20 to 30 days. It is not necessary to add sulfur-oxidizing bacteria to most of the natural soils in Japan because they are inhabiting sulfur-oxidizing bacteria.However, when using a cover soil in which sulfur-oxidizing bacteria do not live, sulfur-oxidizing bacteria are not included in the sulfur. However, it is advisable to add it to the forming medium. Even when sulfur-oxidizing bacteria inhabit, addition of sulfur-oxidizing bacteria is preferable from the viewpoint of certainty. It should be noted that the powder of sulfur flower has different particle sizes. Small grains sulphate early and large grains sulphate late. Therefore, if sulfur sulphur, which is a powder having different particle sizes, is used, acidification continues for a long period of time.

[0015]

【Example】

Example 1 Acid-free rock wool molding medium (2 cm × 28 cm × 58 cm) PH8 manufactured by Nitto Boseki Co., Ltd.
40 g of sulfur flower was uniformly sprayed on the surface of No. 0 and press-fitted to obtain a sulfur-added molding medium for raising seedlings of the present invention. (In this case, instead of press-fitting, an adhesive may be previously sprayed on the surface of the molding medium, and sulfur flower may be sprayed thereon.) 180 g of germinated paddy is sown on the molding medium, 2.5 liters of water
And irrigate it with 1.2 l of natural soil (black) PH 6.5.
Soil was covered and heated at 32 ° C. for 2 days for sprouting to obtain a sprouting mat (molding medium) of PH4.5. Ammonium sulfate (5 g), gemstone (6 g), and chloride (1.7 g) were fertilized on the budding mat, and 2
The seedlings were raised for 0 days to obtain 2.4-leaf healthy seedlings. The change in PH is
PH4.5 immediately after heating at 32 ° C. for 2 days, and then PH5.0 on the 7th day after seeding, PH5.0 on the 14th day, 20
PH 5.0 on day one. As a comparative example, commercially available sulfuric acid is used as the main material for acidification treatment, and each of N, P and K is 1.5 g
Using the rockwool molding medium fertilized with the above, seeding, irrigation, soil covering, and heating were carried out in the same manner as in the above-mentioned examples, and seedlings were raised for 20 days in the usual manner to obtain 2.2-leaf seedlings. The change in PH was 5.0 immediately after heating, 5.5 on the 7th day after seeding, 6.5 and 20 days after the seeding.
The day was 7.0. When raising milk seedlings, the seedling raising period should be rounded up to 5 to 9 days.

[0016]

[Example 2] Acid-free rock wool molding medium (2 cm x 28 cm x 58 cm, trade name Chibico Power Mat) manufactured by Nippon Steel Chemical Co., Ltd. PH7.5 surface with 35 g of sulfur flower and ammonium phosphate and nitric acid potassium as elements , P, k were mixed at a ratio of 2 g each and a surfactant was added to 200
The mixture was dispersed and dissolved in cc of water and sprayed as a mixed solution, followed by drying to obtain the sulfur-added molding medium for raising seedlings of the present invention. The molding medium was inserted into an official nursery box, 200 g of seed paddy was germinated and sown on the upper surface, 2.5 l of tap water was irrigated, and 1.2 l of Kureha Chemical's granular soil made from natural soil was covered with 32 A budding mat was obtained by heating at 0 ° C for 2 days, and seedlings were raised for 30 days in the usual manner to obtain 3.3-leaf middle seedlings. The change in PH of the molding medium was PH 4.5 immediately after heating at 32 ° C. for 2 days, and thereafter, 4.8 on the 7th day after seeding, 5.0 on the 14th day, 5.0 on the 20th day after seeding. It was 5.5 on the 30th day. As a comparative example, rice seedlings were raised in the same manner as in the above example using the same acidified trade name Powermat manufactured by Nippon Steel Chemical Co., Ltd. to obtain 3.1 seedlings. Changes in PH were 5.0 immediately after heating at 32 ° C. for 2 days, 5.5 7 days after seeding, and 6 days after seeding.
It was 7.0 after 5, 20 days and 7.0 after 30 days.

[0017]

[Embodiment 3] 1-2 c of rock wool cotton manufactured by Nippon Steel Chemical Co., Ltd.
Sulfur flower (25 g) was added to 300 g of the one cut into m, mixed evenly, polyvinyl alcohol was added as an adhesive, and the mixture was inserted into an official nursery box, compressed and dried, and the sulfur-added nursery of the present invention was added. A molding medium for use was obtained. On the upper surface of the molding medium, seed rice 15 germinated in the shape of a pigeon chest in accordance with a conventional method.
0 g was sown and 1.2 l of paddy soil in the suburbs of Hiratsuka was covered.
2.5 l irrigated water, placed flat in a greenhouse, covered with a poly sheet, kept warm at an average temperature of 25 ° C for 5 days for germination,
After raising the seedlings for 25 days, 2.3 leaf healthy seedlings were obtained. The pH of the forming medium is always 5.0 after the day of removing the coating until the end of the seedling raising.
Kept ~ 5.5. Separately, it took 28 days until the pH of the molding medium that was raised at room temperature without being kept warm was 5.0.

[0018]

Since the present invention is configured as described above, it has the following effects. As described above, the rice seedling-growing medium has the best growth and less disease when the pH is 4.5 to 5.5. Publicly, they are taught that way. That is, the pH of 4.5 to 5.5 is, as it were, an essential condition of the rice seedling culture medium. Conventionally, sulfuric acid was used as the main agent as described above to acidify the medium. Sulfuric acid has the best seedling growth performance than other acids. However, first, handling sulfuric acid is a very dangerous task. Sulfur is an extremely safe substance that crystallizes along the road in hot spring areas.

Secondly, when sulfuric acid is sprinkled onto rock wool and dried, rock wool is extremely fine fibers containing 40% or more of alkali content, and therefore rock wool is damaged in the acidification treatment step. When treated with sulfur, rock is damaged because sulfur is not sulphated and dried by the action of sulfur-oxidizing bacteria in the forming medium and cover soil containing 2-2.5 l of water. There is no.

Thirdly, the sulfur-added forming medium for raising seedlings of the present invention is sown, irrigated, covered with natural soil, and heated at 32 ° C. for 2-3 days for 2 to 3 days according to a conventional method. When the temperature is kept at 25 ° C for 4 to 5 days, sulfur is sulphated by the rapid breeding of naturally-occurring sulfur-oxidizing bacteria, and the P of the forming medium is increased.
H becomes 4.5 to 5.5, and sulfur is gradually sulphated even after it is taken out of the warmer or after removing the heat insulating sheet, and therefore PH4.5 to 5.5 of public guidance is long. Can be held at. Fourthly, when seedlings are raised in the sulfur-containing forming medium for raising seedlings of the present invention, rice seedlings grow healthy and are resistant to wilt disease and mullet seedling disease. As mentioned above, the acidity is adjusted to PH 4.5-5.5.
There is no doubt that it is one of the main reasons that it can be kept at, and in addition to that, the effect due to the bactericidal action of sulfur is also considered.

Claims (1)

[Claims] 1. A sulfur-added seedling-growing forming medium obtained by adding sulfur to an inorganic or / and organic mat-shaped forming medium.