JPH0937652A - Mat for raising seedling of paddy rice - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a mat for raising seedling of paddy-rice plant, by forming vermiculite into a tabular state and supporting a fertilizer of manuring effect control type on the vermiculite, being attached to the fertilizer to a nursery box and used, having improved quality, root rise and root spread, excellent in water retention and shape retention. SOLUTION: Vermiculite is formed into a tabular state. A fertilizer of manuring effect control type in an amount required for culture of paddy rice plant is supported on the vermiculite to give the objective mat for raising seedling of paddy-rice plant, which is attached to a nursery box at the beginning of raising seedling and used. Bentonite as a binder in an amount of 1-10vol.% is added the mat. The mat is preferably mixed with a non-biodegradable fibrous substance such as glass fiber, metal fiber, polyamide fiber, etc., as a reinforcing material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seedling-growing mat for a cultivation method in which an amount of a fertilization-controlling fertilizer required for cultivating paddy rice is carried on a mat at the start of seedling growth and used in a seedling-growing box. More specifically, the present invention relates to a seedling-growing mat, which is formed by forming burned vermiculite into a plate shape.

[0002]

[Prior art and its problems] With the establishment of automatic rice transplanters,
Raise rice seedlings to a certain size (length 28 cm, width 58 cm,
It is widespread nationwide that it is carried out by a nursery box with a depth of 3 cm. Conventionally, in order to obtain the soil to put in the nursery box,
It was necessary for the farmer to individually collect soil, dry it, sieve it to a particle size suitable for bed soil, sterilize it, and add fertilizers and pesticides (mainly bactericides) to the mixture to mix it. In order to save such a series of bed soil adjustment work, artificial nursery bed soil has been developed and partially put into practical use. Further, under the present circumstances, a seedling-raising mat is being developed, which is formed into a shape that can be inserted into a conventional seedling-raising box rather than a powdered or granular artificial floor soil, so as to reduce the labor required for insertion into the seedling-raising box. The functions required of the formed nursery mat are as follows, which are suitable for transplantation by an automatic rice transplanter, reduce the work of adjusting the soil and inserting it into the nursery box, and ensure a healthy seedling growth. It is as follows. It has sufficient strength and shape retention during seedling preparation work such as storage, transportation, and insertion of seedling mats into a nursery box. After seedling raising (after watering), it easily collapses and does not prevent root growth and scraping of seedlings by a rice transplanter during transplantation. Does not retain pathogens. (Less likely to be retained) Does not contain organic matter that feeds pathogenic bacteria. In addition, in recent years, with the improvement of the function of fertilization control type fertilizer represented by resin-coated granular fertilizer, most of the fertilizer required from seedling raising to harvest is applied to the seedling raising box at the start of seedling raising, so-called box fertilizer raising seedling. The law is spreading. With this fertilizer application, around 300g per conventional nursery box up to 2000
In order to apply a large amount of fertilizer control type fertilizer such as g,
It has a drawback that the water retention capacity as a nursery bed is reduced. As a function required for a nursery mat, it also has a large water retention capacity. It has no water repellency and absorbs water smoothly. By providing such a function to the seedling-growing mat, it becomes possible to compensate for the above-mentioned drawbacks of the box fertilization and seedling-raising method, and from this point, it can be said that this is an essential function for the seedling-growing mat in the future. The following techniques have been disclosed so far as techniques related to seedling raising mats for paddy rice and bed soil for raising seedlings. First, Kosho 49-26
In No. 336, after adding fertilizer or the like to powdered or granular perlite, a vegetable fiber material was added as a binder, and then a water-soluble paste material such as starch, dextrin, or polyvinyl alcohol was mixed to adjust the pH. After that, molding and sterilization are performed to obtain a molded nursery bed. In Kai 54-130309,
A molded nursery bed containing gypsum, peat moss, and vermiculite as main components, and further, in Kaihei 1-98421, granular fibrous material and granular mineral material are used as starch, polyvinyl alcohol, synthetic rubber-based or vinyl acetate-based thermosetting polymer. A cover soil for raising seedlings, which is solidified into a plate shape by adding a water-decomposable adhesive such as the above, is disclosed. When these prior arts are compared with the functions required for the above-mentioned seedling raising mat, Kosho 49-2
Glue materials such as starch, which are used as adhesives in No. 6336 and Kaihei 1-98421, are likely to be food for pathogenic bacteria. In this case, if a fungicide is used, there will be no problem with disease, but in recent years, the damage caused by pesticides has been highlighted, and in the cultivation without pesticides or with reduced pesticides, it becomes a major cause of pathogen propagation, which hinders the growth of healthy seedlings. It was. Further, when the thermosetting adhesive used in Kaihei 1-98421 is used, although the strength at the time of molding can be obtained, the strength does not decrease even after the start of seedling growth, and the root growth,
Furthermore, there was a problem with transplanting by rice transplanters. Furthermore,
The peat moss used in Kaisho 54-130309 has strong water repellency and inhibits the compatibility between the nursery bed and water. Therefore, when large water retention is required as in the box fertilizer raising method described above, the number of times of watering is increased. It is difficult to say that it is a material for labor saving.

[0003]

As described above, in the conventional technique, there is no conventional seedling raising method, and there is no seedling raising mat capable of sufficiently satisfying the functions required for the seedling raising mat for box fertilization raising seedlings. The development of seedling raising materials that can achieve both labor saving and healthy seedling growth has been awaited. The present inventors
An intensive study was conducted to solve the above problems. as a result,
By using vermiculite as the main constituent material of the nursery mat, and preferably by adding a small amount of a binder (for example, bentonite) and / or a small amount of non-living fibrous material to this, the above problems are almost completely solved. The present invention has been completed with this knowledge in mind. As is clear from the above description, the purpose of the present invention is to cultivate paddy rice in an automatic rice transplanter, to adapt a conventional conventional seedling raising method, and further to provide a seedling raising mat that can compensate for the drawbacks of the box fertilization raising seedling method. To provide.

[0004]

The present invention has the following configurations (1) to (7). (1) A seedling-growing mat for a cultivation method, which carries a fertilization-controlling fertilizer in an amount necessary for cultivating paddy rice and is used by being attached to a seedling-growing box at the start of seedling growth, and which is formed of vermiculite in a plate shape. Seedling mat for paddy rice. (2) The seedling-growing mat according to (1) above, wherein bentonite is added as a binder. (3) The seedling-growing mat according to (2) above, wherein the amount of bentonite added is 0.5 to 20 Vol%. (4) The seedling-growing mat according to (2) above, wherein the amount of bentonite added is 1 to 10 Vol%. (5) The nursery mat according to any one of (1) to (4) above, wherein a non-biodegradable fibrous substance is added as a reinforcing material. (6) The non-biodegradable fibrous substance is glass fiber, ceramic fiber, silicon fiber, boron fiber, mineral fiber, metal fiber, polyester fiber, polyamide fiber, polyolefin fiber, polyimide fiber, polyacrylate fiber, carbon fiber, polyamide. -The seedling raising mat according to (5) above, which is an imide fiber, a polyether-imide fiber, or a phenolic fiber. (7) The seedling-growing mat according to (1) to (6) above, which contains a fertilizer for raising seedlings.

The structure and effects of the present invention will be described in detail below. The vermiculite used in the present invention is obtained by expanding rough stone by heating or contact treatment with a peroxide to form an accordion. Vermiculite is a hydrous silicate mineral with a crystal structure similar to that of smectite, chlorite, mica, etc. In its structure, there is a large amount of intercalation water between layers, and when it is subjected to rapid high temperature heat treatment, There is a phenomenon in which the layers are spread and expanded in an accordion shape due to the rapid scattering of water. Also, when subjected to contact treatment with peroxide such as hydrogen peroxide, a reaction occurs between the layers, the layers are spread by the generation of gas, and it has the property of expanding like an accordion like heat treatment. ing. Since vermiculite is a mineral and has been heat-treated or treated with peroxide, it is in an aseptic state free of microorganisms such as pathogenic bacteria of paddy rice, and does not contain organic substances that serve as food for pathogenic bacteria. Vermiculite is produced in South Africa, Parabola, North America, Montana, China, Shanghai, China, depending on its origin.
There are types such as those from Tianjin and Fukushima (Japan), and the objects of the present invention can be achieved by using any of them. Vermiculite has a particle size of about 0.1 to 20 mm depending on the particle size expansion method of the raw material, the expansion conditions, the type, etc. Any of these can be used in the present invention, but the particle size is preferably It is in the range of 2 to 4 mm. If the particle size is too small, the structure is not aggregated, so that when water is absorbed, the gas phase (pores) in the mat is small and water permeability is reduced, and oxygen supply to roots is insufficient, which is not preferable. On the other hand, if the particle size is too large, it may hinder the elongation of rooted roots, resulting in poor root growth.

The so-called box fertilization and raising method, in which most of the fertilizer required for raising and harvesting seedlings is used for raising seedlings at the start of raising seedlings, is about 300 g per conventional seedling raising box and a maximum of 20.
Since a large amount of fertilizer control type fertilizer such as about 100 g is used, it has drawbacks such as a decrease in water retention capacity as a nursery bed and excessive elution of fertilizer at the early stage of growth such as seedling raising.
Vermiculite has a water absorption capacity of 4 to 10 times that of the most widely distributed volcanic ash soil in Japan, 600 g / 100.
Since it has a water retention capacity of around g, the speed of water absorption when irrigated (no water repellency), and good ventilation and water permeability,
It is a very effective material when fertilizer is added to the mat.

The method for molding the mat of the seedling-growing mat of the present invention is not particularly limited, but a preferable method is to form a mixture of the above vermiculite and water into a conventional seedling-growing box. Formwork (Vertical 28c
m, width 58 cm, depth 3 cm), press-molding with a compressor or the like, and then drying and solidifying with a forced hot air dryer or the like. Also, after adding and mixing water to vermiculite, put it in a resin bag etc. after filling it in the above mold, compress and mold with a vacuum suction press, etc., remove air and excess water between vermiculite, and then dry. When solidified, good adsorption of fertilizer and the like in the vermiculite gap is obtained, which is the recommended method.

The amount of water added to the vermiculite at the time of molding is 50 to 2 per liter vermiculite.
The range of 50 ml is preferable, and 1 is more preferable.
It is from 00 to 150 ml. If the amount added is less than this, the water is not sufficiently dispersed, and weak portions are partially formed, resulting in a marked loss of strength as a mat. If the amount is too large, it takes energy and time to dry, which is not economical.

The seedling raising mat of the present invention is put in a conventional rice seedling raising box (length 28 cm, width 58 cm, depth 3 cm) for use. The size of this nursery box is basically the same regardless of the manufacturer, but the details are different in shape and design, especially the size of the drainage hole at the bottom part varies considerably. ing.

The seedling-growing mat of the present invention immediately disperses after irrigation and returns to almost the original particle size of vermiculite.
In a nursery box with a large drainage hole at the bottom, vermiculite may spill through the hole. For this reason, it is recommended that a mesh with a grain size of vermiculite or less, a non-woven fabric, or the like be attached to the bottom or bottom and side surfaces of the nursery mat. In this case, the net and the non-woven fabric are not particularly limited, but it is desirable that the seedling is easily disintegrated at the time of transplanting the seedlings into Honda by a transplanter. In other words, biodegradability, so that troubles such as entanglement with the transplanter do not occur during transplantation,
It is desirable to use corrosive or water-soluble materials.

The seedling-growing mat of the present invention has sufficient strength in normal use due to the above-described composition and molding method, but a farmer having a relatively large scale can produce several thousand seedling-raising boxes (nursery-growing mat) per seedling. ) Is used, and at this scale, the nursery box (nursery mat) is moved and seeded,
Since work such as covering with soil may be performed by a machine, stronger one is required. In the present invention, the strength of the mat can be improved by adding a small amount of bentonite to vermiculite. The bentonite used in the present invention is any as long as it exhibits water absorbency, swelling property and disintegration property in a state of being in contact with water, and further exhibits tackiness when dried after absorbing water. Although it can be used as well, for the purpose of the present invention, it is preferable that the swelling property and the tackiness are large. The swelling property and tackiness of bentonite differ depending on the composition and particle size. There are two types of bentonite, sodium-based and calcium-based, and the former has greater swelling and tackiness. Also, bentonite is mainly montmorillonite in clay minerals, and the properties such as swelling and tackiness are peculiar to montmorillonite. . Further, the particle size varies depending on the particle size, and the larger particle size tends to have greater swelling property and tackiness. The bentonite may be added in an amount of 0.5 to 20% by volume, preferably 1 to 10% by volume. If the amount added is less than this range, the strength cannot be improved, and if it is more than this range, it becomes clay-like when absorbing water, which results in poor drainage and air permeability, which is unfavorable to the growth of seedlings. Bentonite is not only effective in improving the strength at the time of molding, but also promotes rapid disintegration of the mat after irrigation due to swelling, and because the main montmorillonite has a strong affinity for water, The improvement of hydrophilicity (reduction of water repellency) is obtained, which makes the present invention more effective.

In the present invention, a non-biodegradable fibrous substance can be added as a means for further increasing the strength of the nursery mat. Non-biodegradability in this case means
It is one that is assimilated by filamentous fungi and bacteria during the cultivation period of paddy rice and does not serve as a nutrient source for growth. The non-biodegradable fibrous substance that can be used in the present invention includes glass fiber, ceramic fiber, silicon fiber, boron fiber, mineral fiber, metal fiber, polyester fiber, polyamide fiber, polyolefin fiber, polyimide fiber, polyacrylate. Examples thereof include fibers, carbon fibers, polyamide / imide fibers, polyether / imide fibers, and phenolic fibers, but are not limited thereto. Although the addition of the non-biodegradable fibrous substance improves the strength of the seedling-growing mat, the disintegration property at the time of watering is impaired accordingly, and therefore it is desirable to use it together with bentonite in order to promote the disintegration. Furthermore, fertilizers and pesticides required during the seedling raising period may be added within a range that does not impair the function of the present invention.

The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

【Example】

Production Example Examples 1-7 were made as follows. A mold for mixing the composition shown in Table 1 (per box for raising seedlings) so that the whole is sufficiently uniform, and then forming three sheets of newspaper in advance into a seedling raising box size laid on the bottom and sides. (Length 28 cm,
(Width 58 cm, depth 3 cm), put the whole form into a polyethylene bag, and use a vacuum suction machine to suck and dehydrate and dewater the filled vermiculite and excess water and air from inside the bag, while compressing 45 g / It was molded by applying a pressure of cm ² .
Then, the thus-formed product was dried and solidified in a hot air dryer controlled at 60 ° C. for 30 hours to obtain a seedling-growing mat of the present invention.

[0014]

[Table 1]

Vermiculite: A vermiculite obtained by subjecting a vermiculite from Parabora, South Africa to a high temperature treatment at 800 ° C. and expanding it into an accordion.
Particle size is 2 to 4 mm using a 2 mm side screen and a 4 mm screen
Was obtained and used as a sample. Bentonite: Wako Pure Chemical Industries, Ltd. Non-biodegradable fibrous substance: 1 cm long polypropylene / polyethylene composite fiber (Chisopolypro Fiber Co., Ltd.)
Product name: Chisso ES fiber) Fertilizer: Sulfurized Rin An 13-13-13

Comparative Example 1 1.8 liters of vermiculite used in Example 1 was mixed with peat moss (Lameque from Canada, apparent specific gravity:
0.10, water content: 35%) 1.8 liters were thoroughly mixed, 500 ml of water was added to this, and the water was mixed until the water was sufficiently distributed throughout the vermiculite. Fill the mold (28 cm in length, 58 cm in width, 3 cm in depth) for molding to the size of the seedling box laid in the box, put the whole mold in a polyethylene bag, and use a vacuum suction machine to fill the vermiculite and excess from inside the bag. 4) by a compressor while sucking and dehydrating various moisture and air
It was molded by applying a pressure of 5 g / cm ² . Then, the thus molded product is heated in a hot air dryer controlled at 60 ° C. for 30 minutes.
After drying and solidifying for a time, a mat for raising seedlings of a comparative example was obtained.

Comparative Example 2 1.2 liters of peat moss used in Comparative Example 1, 1.2 liters of vermiculite used in Example 1, 1.2 liters of β-type hemihydrate gypsum, 200 g of polyvinyl alcohol
Was thoroughly mixed, and 500 ml of water was added to this and mixed until the water content became uniform, and then a form (28 cm in length, 28 cm in length) for forming a seedling box size in which three newspapers were laid on the bottom and sides in advance. 58 cm wide and 3 cm deep)
The entire mold was put in a polyethylene bag, and excess water and air were sucked and dehydrated from the filled vermiculite and the bag with a vacuum suction machine, and while degassing, a pressure of 45 g / cm ² was applied with a compressor to mold. Then, the thus molded product is 60
Dry and solidify for 30 hours in a hot air dryer controlled at ℃,
A mat for raising seedlings of a comparative example was obtained.

Drop Test (Mat Strength) The seedling-growing mats produced in Examples 1 to 7 and Comparative Examples 1 and 2 were dropped onto concrete ground from a height of 0.5 m or 1 m above the ground to determine whether the mat was damaged ( Deformation, and further cracks) were confirmed. Table 2 shows the test results.

Mat hardness after irrigation The seedling mats produced in Examples 1 to 7 and Comparative Examples 1 and 2 were placed in a nursery box, and the hardness of the mat surface immediately after irrigating 6 liters of water was Yamanaka soil hardness tester. It was measured at. However, a large hole at the bottom was used so that the cone of the hardness tester would not hit the bottom of the nursery box (so that the cone would penetrate). Table 3 shows the results.

Water Repellent Situation (Water Absorption) Confirmation Test The seedling raising mats produced in Examples 1 to 7 and Comparative Examples 1 and 2 were placed in a seedling raising box and allowed to absorb water from the bottom surface (water level was kept at 10 mm from the bottom surface of the mat). The time required for reaching the surface of the nursery mat (overall) was measured. Table 4 shows the test results.

Seedling raising test The seedling raising mats produced in Examples 1 to 7 and Comparative Examples 1 and 2 were used as conventional seedling raising boxes for paddy rice (length 28 cm, width 58 c).
m, depth 3 cm), and coated urea (LP manufactured by Chisso Co., Ltd.) having the elution curve (in water at 25 ° C.) shown in FIG. 1 thereon.
SS100, nitrogen component 10wt%) 500g (nitrogen 20
Equivalent to 0 g) is used evenly and 100 g of germinated paddy
/ Grained soil 1 containing 1 g / box each of N, P ₂ O ₅ , and K ₂ O as fertilizer for raising seedlings after seeding / box (variety: Hinohikari)
The soil was covered with kg (excluding Example 5), and seedlings were grown according to the customary seedling management in a glass house (implementation location: Minamata City, Kumamoto Prefecture) where the temperature inside the room can be controlled after watering.
Furthermore, diluvial ash soil with a large water retention capacity (maximum water capacity 120
%, Particle size of 2 mm or less), ammonium sulfate (13-13-1)
3) was mixed in an amount corresponding to 1 g as N per seedling raising box, and used as a control. In addition, during the seedling raising period
3) was applied twice with 0.5 g as N per seedling box. Table 5 shows the results. This test was sown on May 11th and June 1st
Raised seedlings until day 0. Rooted in May 13th, May 18th
Rooting survey was carried out on the day, and the seedlings were cut and measured and analyzed on June 10 other than that.

[0022]

[Table 2]

In Example 1, some deformation was observed when dropped from a height of 0.5 m, but there was no crack, and if this extent, there is no problem in normal use. The strength of the mat was improved by the addition of bentonite and a non-biodegradable fibrous substance, and the strength was further improved by the addition of bentonite and a non-biodegradable fibrous substance.

[0024]

[Table 3]

It can be seen that the mat of the present invention rapidly decreases in hardness after irrigation and is in a state where seed germination and rooting are not affected.

[0026]

[Table 4]

In the comparative example, since the peat moss having an extremely large water repellency was used, the water absorption of the mat was very poor. On the other hand, in each of the examples, water absorption is good, and in examples 2, 4, 6 and 7 using bentonite, the water absorption is faster.

[0028]

[Table 5]

Comparative Examples 1 and 2 contained peat moss having water repellency and had poor water absorption (Table 4).
I had to irrigate about 4 times. Further, in Comparative Example 2, the mat disintegrated slowly after irrigation and had a high surface hardness (Table 3), so that a remarkable rooting phenomenon was observed after sowing. Furthermore, the growth of mildew was recognized on the soil surface of Comparative Example 2, albeit slightly. In Comparative Examples 1 and 2, plant height, fresh foliage weight,
The dry matter foliage weight was smaller than that in the control group. On the other hand, in Examples 1 to 7, since the water absorption was good and the disintegration of the mat after watering was also good, Examples 1, 3, 5,
In No. 6, although very slight root phenomenon was observed, very good growth was obtained. Moreover, in Examples 1 to 7,
No growth or the like of mold on the soil surface as observed in Comparative Example 1 was observed.

[0030]

EFFECTS OF THE INVENTION From the above description, a seedling-growing mat formed of vermiculite in a plate shape, a seedling-raised mat formed by adding bentonite to vermiculite, and a plate shape formed by adding a non-biodegradable fiber substance to them. The seedling-growing mat formed in step 3 is light and has sufficient strength and shape retention during the preparatory work required for paddy rice seedling-raising mats, such as storage, transportation, and insertion into the nursery box. After seedling raising (after watering), it easily collapses and does not prevent root growth and scraping of seedlings by a rice transplanter during transplantation. Does not retain pathogens. (Less likely to be retained) Does not contain organic matter that feeds pathogenic bacteria. Conditions, etc., and the large amount of fertilizer required from seedling raising to harvest is used in the seedling raising box at the start of seedling raising, there is no large water retention capacity necessary to compensate for the drawbacks of the so-called box fertilization raising seedling method. It also has the function of smoothly absorbing water. In particular, the addition of bentonite, which has high hydrophilicity, swelling property, and tackiness, makes it possible to combine mat strength, disintegration after watering, and water absorption at a very high level, and is a very effective additive. is there. If necessary, a non-biodegradable fibrous substance may be added to further improve the mat strength. Thus, the seedling raising mat of the present invention is a seedling raising material that is compatible with transplantation by an automatic rice transplanter, and is capable of achieving both labor saving of seedling management such as floor soil adjustment work and topdressing, and ensuring the growth of healthy seedlings. is there.

Claims (7)

[Claims] 1. A seedling-growing mat for a cultivation method, which carries a fertilization-controlling fertilizer in an amount necessary for cultivating paddy rice and is used by being attached to a seedling-raising box at the start of seedling production, and which is formed into a plate-like vermiculite. Seedling mat for paddy rice. 2. The seedling raising mat according to claim 1, wherein bentonite is added as a binder. 3. The amount of bentonite added is 0.5 to 20 V.
The seedling raising mat according to claim 2, which is ol%. 4. The addition amount of bentonite is 1 to 10 Vol.
% Of the seedling-growing mat according to claim 2. 5. The seedling raising mat according to claim 1, wherein a non-biodegradable fibrous substance is added as a reinforcing material. 6. The non-biodegradable fibrous material is glass fiber, ceramic fiber, silicon fiber, boron fiber, mineral fiber, metal fiber, polyester fiber, polyamide fiber, polyolefin fiber, polyimide fiber, polyacrylate fiber, carbon fiber. The seedling-growing mat according to claim 5, which is a polyamide-imide fiber, a polyether-imide fiber, or a phenol-based fiber. 7. The method according to any one of claims 1 to 6, which contains a fertilizer for raising seedlings.
The nursery mat described in.