JP3452891B2 - Medium for raising rice seedlings and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a paddy rice breeding medium for sowing and raising seedlings of paddy rice, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a medium used for raising rice seedlings for mechanical rice planting, cultivated soil made of natural soil or artificial medium such as rock wool is generally used. These are generally packed in a nursery box as a seed bed, watered from above, and then seeded, covered with soil, and raised. In most cases, natural soil is used for covering soil regardless of the seed bed material. And boxing these seed beds,
A series of work steps of irrigation, sowing, and soil covering are performed by a sowing machine.

However, if the soil for growing rice seedlings is made of natural soil, the weight of the seedling raising box is considerably heavy, and this carrying work is a heavy burden on the operator. In particular, recently, with the aging of agricultural workers, there has been a strong demand for reducing the weight of soil. In addition, the artificial medium used as a lightweight medium for raising rice seedlings had a low penetration rate because the price of the product was high. Furthermore, even when an artificial medium is used, the cover soil cannot use a sufficient weight because it uses natural soil.

Therefore, a method has been considered in which bark, which is lightweight and inexpensive, is used as a material for the artificial medium. A large amount of bark is peeled off from the raw wood when North Sea timber is imported.
For example, it is estimated that the discharge amount of the bark of North American timber in Toyama prefecture is about 50,000 to 60,000 tons per year (dry matter conversion). Recently, this is composted and used as a bark compost for civil engineering, horticultural materials, etc., but there are many that are disposed of at high cost, and the use of bark compost is limited,
Since it is not possible to expect a significant increase in demand, it was necessary to develop an effective usage method with high added value.

Generally, a material having a carbon rate (ratio of total carbon amount (C) to total nitrogen amount (N) contained in the material, also referred to as C / N ratio) of 20 or less like natural soil is used for paddy rice. When the seedlings are raised, the inorganic nitrogen added for the growth of the seedlings is hardly reduced by being taken in by the microorganisms in the material (this is referred to as organizing the inorganic nitrogen).

However, when the bark is used as it is for the medium for raising seedlings, the inorganic nitrogen necessary for the growth of the seedlings is hardly supplied from the bark, and the carbon content of the bark is 1 immediately after the peeling.
Even if it is 20 or more, even if it is piled up in the field, it is extremely high at about 80, so even if inorganic nitrogen is added to the bark, it is usually rapidly organized during the seedling raising period due to the activity of various microorganisms in the bark, and I couldn't grow normally.

Therefore, it was considered to use bark compost obtained by composting bark as a medium for raising seedlings. Here, the bark compost means, for example, bark peeled from raw wood is piled up outdoors in a sedimentation site for about one year and naturally decayed, and then composted (on the bark piled as a secondary material for promoting fermentation). Add livestock manure, etc. and ferment and decompose it) to increase the carbon rate to 25 ~
It was lowered to about 35.

Even in this case, since the carbon content of bark compost is slightly higher than that of natural soil, the organic conversion of inorganic nitrogen is unavoidable during the seedling raising period, and the medium containing inorganic nitrogen before seedling raising is unavoidable. When stored in a warehouse, there was a phenomenon in which inorganic nitrogen was greatly reduced in a few months due to organizing. Therefore, 100% bark compost cannot be used as a medium for raising seedlings, and when bark compost is used as a medium for raising seedlings, it is mixed with natural soil, humus, peat moss or the like to reduce the total carbon content before use. There was a need.

[0009]

In the case of the above-mentioned conventional technique, it takes time (usually more than half a year) to compost the bark, and a wider space is required, so that the cost is rebounded accordingly. Therefore, in order to reduce the manufacturing cost, it has been desired to omit the composting process and ship as early as possible.

Further, in composting, animal excrement of livestock is generally used as an auxiliary material for promoting fermentation, but in this case, the fertilizer components supplied from the auxiliary material used are non-uniform. However, it was difficult to use for raising rice seedlings, which are easily affected by excess and deficiency of fertilizer components.

Further, when bark compost is used as a medium for raising seedlings, it is necessary to mix it with natural soil or the like in order to prevent the material from organizing, which complicates the manufacturing process and causes an increase in cost. There is a problem that the weight becomes heavy due to the mixing of the soil.

The present invention has been made in view of the above conventional problems, and suppresses the organication of inorganic nitrogen due to the use of bark, and provides a lightweight and inexpensive medium for raising rice seedlings and a method for producing the same. The purpose is to provide.

[0013]

According to the present invention, bark crushed into suitable chips is used as a base material and has a pH of about 4.5-5.
It is a medium for growing rice seedlings, which has been adjusted to the following conditions to suppress the activity of microorganisms and keep the content of inorganic nitrogen constant. The bark is ground to an appropriate size (hereinafter particle size of about 4 mm)
Inorganic nitrogen was added to the bark of the bark in the state of decaying and composting.
And other nutrients such as ammonium sulfate, urea, iron sulfate, iron silicate,
Potassium sulfate etc. are added. An acid such as sulfuric acid is added to the bark to set the pH within the above range.

The present invention is also applicable to, for example, an outdoor deposition site.
For about 1 year, the bark was crushed and adjusted to a particle size of about 4 mm or less, and inorganic nitrogen and other nutrients were mixed, and a pH adjusting agent such as sulfuric acid was added to adjust the pH to about 4.5-5.
It is a method for producing a medium for growing rice seedlings, which is adjusted to 1. As the fertilizer, ammonium sulfate, urea, iron sulfate, iron silicate, potassium sulfate, etc. are mixed in a good balance.

The medium for raising rice seedlings according to the present invention has a pH of about
It is adjusted to 4.5 to 5 and the activity of various microorganisms is suppressed. For this reason, the organization of inorganic nitrogen by microorganisms is suppressed, and the content of inorganic nitrogen added as a fertilizer component is maintained constant.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. The medium for growing rice seedlings of this embodiment is obtained by adding a pH adjusting agent to crushed bark and adjusting the pH to 4.5 to 5. Then, fertilizers such as ammonium sulfate, urea, iron sulfate, iron silicate, and potassium sulfate are added as nutrients to the medium for raising rice seedlings. Further, the bark used here is obtained by peeling from imported raw wood such as North Sea timber.

Next, a method for producing the medium for raising rice seedlings of this embodiment will be described. First, bark piled up for about one year is crushed and passed through a sieve of about 4 mm. And p
An H adjuster, for example, an acidic material such as sulfuric acid is added to adjust the pH to 5 or less, preferably 4.5 to 5. The bark that has accumulated in the field for about one year has a pH of about 5.4 to 5.7. Next, fertilizer components lacking nitrogen, iron, potassium, silicic acid, etc. are added to the pH-adjusted bark. The fertilizer to be added can be selected from ammonium sulfate, urea, iron sulfate, iron silicate, potassium sulfate and the like. For example, 2 kg of nitrogen and 3 kg of iron per 2 tons of bark
The above fertilizer is added so that the weight of the fertilizer is 1.5 kg and the weight of potassium is 1.5 kg.
When the pH is changed by the fertilizer added here, the pH adjusting agent is added again to adjust the pH.

The method of using the medium for raising rice seedlings according to this embodiment is to fill a seedling raising box with the medium for raising rice seedlings, irrigate the seedlings from above, and sow the seeds, and cover the soil to raise seedlings. The rice seedlings raised using the medium for raising rice seedlings of this embodiment have substantially the same seedling quality as the seedlings raised in the conventional soil using mountain sand. Then, like the conventional medium for raising seedlings using natural soil containing mountain sand culture soil, sowing work by a seeding machine is possible.

The medium for raising rice seedlings of this embodiment has good air permeability and water retention, and the weight of the seedling raising box is reduced to about half that of the mountain sand culture medium, which facilitates the carrying work. it can.

In addition, the manufacturing method does not require composting, and only adds a pH adjusting agent and a fertilizer to the bark that has been piled up in the field for about one year. Therefore, composting is not necessary and required for composting. It can be supplied at a lower cost without requiring time or a large space. Further, since it is not necessary to mix livestock excrement, which is an auxiliary material required for composting, it is possible to produce a stable quality product without being affected by variations in the components of livestock excrement. .

The medium for raising rice seedlings has a high carbon rate because it is not composted. However, by adjusting the pH to 4.5 to 5 by adding an acidic material such as sulfuric acid, the activity of microorganisms can be suppressed, so that the decrease of inorganic nitrogen can be suppressed and even if the carbon rate is high. , It is possible to always supply products with stable quality. In addition, the medium is generally p
Below H5, many plants such as vegetables will grow poorly,
Paddy rice seedlings are safe because they are not significantly affected even at such a pH.

Further, since the production does not involve complicated work, a general bark compost production plant can produce the medium for raising rice seedlings of this embodiment without a large capital investment. The manufacturing cost is also low, and it can be expected to sell cheaper than conventional artificial media. By the way, when compared with the rockwool-based artificial medium used in Toyama Prefecture, the medium of the present invention is at least 20 times as much as the artificial medium.
It is estimated that it is possible to set a low selling price by 35% or more.

Even when a lightweight artificial medium which is currently used as a medium for raising rice seedlings is used, heavy soil is generally used as the cover soil. However, the medium for raising rice seedlings of this embodiment can be used for covering the artificial medium with soil, and can be used as a lightweight material to replace natural soil. By reducing the weight of the medium for raising rice seedlings, it will reduce the labor required to carry the burden of raising seedling boxes.

In addition, the bark which has not been used until now,
It can be effectively used for high value-added products, and the cost of disposing of bark can reduce the burden on the wood industry. By the way, it is estimated that the total discharge of North American timber bark in Toyama prefecture is about 50,000 to 60,000 tons (dry matter equivalent) per year, but when it is used as a rice cultivation medium for seedling cultivation, about 8,000 tons of bark is used in Toyama prefecture. The required amount will be covered.

The culture medium for raising rice seedlings according to the present invention and the method for producing the same are not limited to the above-described embodiment, but p
Materials for H regulators and fertilizers can be appropriately selected. Also,
The pH of the bark compost obtained by composting bark may be adjusted to obtain a medium for raising rice seedlings.

[0026]

EXAMPLE A first example of the present invention will be described below. First, urea, lime superphosphate, and potassium sulfate were added to the bark as auxiliary materials and composted to produce a bark compost having a carbon ratio of about 35. Then, as fertilizers necessary for raising seedlings, ammonium sulfate, iron sulfate, and potassium sulfate were added so that 2 kg of nitrogen, 3 kg of iron, and 1 kg of potassium were added per 2 tons of this bark compost, respectively, and pH was adjusted.
Not adjusted (pH 5.5) and sulfuric acid to pH
A culture medium for raising rice seedlings adjusted to 4.5 was produced.

Using these two types of rice seedling culture media, 1) immediately after production, 2) after storage in a warehouse for 2 months,
3) After 6 months, 4) 1 year later, the rice seedlings were raised in the respective seedling culture media. Immediately after production and after 1 year of storage, seedlings were raised in a nursery house, and after 2 months and 6 months of storage, seedlings were raised in an artificial climate room (25 ° C during the day, 15 ° C at night).
Further, as a control, rice seedlings were similarly raised using a commercially available soil using natural soil. Then, the growth situation was investigated, and the results are shown in Table 1. Here, the leaf age is the number of leaves counted. The leaf color was measured by placing the center of the expanded first leaf on a leaf plate. Per test zone
About 30 samples were measured and shown as an average value. In addition, the amount of inorganic nitrogen at the start of each seedling was measured and shown in FIG. In addition,
The storage in the warehouse was carried out at room temperature (without temperature adjustment) from April to April of the following year with the product medium packed in a bag.

[0028]

[Table 1] As a result, it can be seen from FIG. 1 that although the medium for raising rice seedlings according to this example was a product satisfying the general maturity criterion for bark compost (carbon ratio of 35 or less), it was added without pH adjustment. It was found that the amount of inorganic nitrogen that had been reduced decreased, and almost no residue remained after 6 months. However, pH 4.5
It was found that the amount of added inorganic nitrogen did not decrease when adjusted to. Further, from Table 1, in the medium of pH 5.5 without pH adjustment, the one immediately after the production had the same growth condition as the medium of pH 4.5 and the control, but the growth was poor in the medium after 2 months or more. , It was found that the plant height was short and the seedlings became yellow (the leaf color became light). From the result of FIG. 1, it is considered that this is due to the decrease of inorganic nitrogen. Therefore, it was found that a pH 5.5 medium without pH adjustment is not suitable as a seedling growth medium.

Next, a second embodiment of the present invention will be described. In this example, on a bark with a carbon content of about 80,
Ammonium sulfate, iron sulfate, and potassium sulfate were added to make 2 kg of nitrogen, 3 kg of iron, and 1 kg of potassium per 2 tons of bark, respectively.
A product adjusted to H4.5 and pH 4.8 was produced.

For this product, rice seedlings were raised using the medium immediately after production and the medium after 6 months storage. Immediately after the production and after 6 months of storage, the seedlings were raised in an artificial climate room (15 ° C during the day, 12 ° C during the night). Further, as a control, rice seedlings were similarly raised using a commercially available soil using natural soil. Then, the growth situation was investigated, and the results are shown in Table 2. In addition, the transition of the amount of inorganic nitrogen is shown in FIG. The product was packed in a bag as in the case of the bark compost and stored in a warehouse (room temperature; no temperature adjustment, May to November).

[0031]

[Table 2] As a result, it was found that even if immature bark, such as open-air bark, has a high carbon content, the pH of the bark is lowered to 5 or less to suppress the organization of inorganic nitrogen. Even after 6 months from the production, about 75% of the added amount of inorganic nitrogen remained, and the seedlings could be grown sufficiently.

Next, a third embodiment of the present invention will be described. First, urea was added to a bark with a carbon content of about 79 so that the amount of nitrogen was 2.5 kg per 2 tons of bark. This is crushed and adjusted to a particle size of about 4 mm or less, and iron sulfate and potassium sulfate are 3 kg of iron and 2 tons of bark and 1 kg of potassium, respectively.
A medium was prepared by adding 2 tons of bark and further adding diluted sulfuric acid so that the pH was 4.5.

This product was stored in a warehouse and seeded with rice after 4 months and after 1 year. After 4 months of storage, the seedlings were raised in a nursery house, and after 1 year of storage, the seedlings were raised in an artificial climate room (daytime 25 ° C, night 15 ° C). Further, as a control, rice seedlings were similarly raised using a commercially available soil using natural soil. Then, the growth situation was investigated, and the result is shown in Table 3.
It was shown to. The product was packed in a bag and stored in a warehouse (room temperature; no temperature adjustment, December to December next year).

[0034]

[Table 3] As a result, even if immature bark with high carbon content such as barley is adjusted to pH 4.5, the decrease of inorganic nitrogen can be suppressed and the medium after 1 year can be sufficiently used for raising rice seedlings. There was found.

Next, the seedlings raised from the bark after storage for 4 months shown in this example were planted in Honda with a rice transplanter. The growth situation after rice transplanting was investigated, and the results are shown in Table 4.

[0036]

[Table 4] As a result, it was found that even in the medium for raising seedlings of this example, rice planting could be performed with high accuracy as in the case of the soil (control) using natural soil, and the growth after rice planting was as good as that of the control.

Next, the weight of the nursery box was measured when the seedlings raised with open-air bark after storage for 4 months shown in this Example were carried out to the nursery house and when rice was planted, and the results were measured. The results are shown in Table 5.

[0038]

[Table 5] As a result, the weight of the nursery box in the medium for raising seedlings of this example was reduced to about half the weight of the culture medium using natural soil.
This can be expected to significantly reduce the labor required for transportation.

[0039]

EFFECTS OF THE INVENTION The culture medium for raising rice seedlings of the present invention has a light weight because it uses bark as a base material, and the medium can be put into a seeding machine and the nursery box can be easily transported. In addition, the medium has good air permeability and water retention, and good quality seedlings can be grown by adding a well-balanced fertilizer as shown in the examples of the present invention. Further, a series of mechanical work using a commercially available seeder or rice transplanter can be performed without any problem.
Further, the bark used as the material is inexpensive, and the manufacturing process of the medium is simple, so that the product can be supplied at low cost. Furthermore, since the pH of the medium is adjusted to approximately 4.5 to 5, the inorganic nitrogen added to the medium is less likely to be organized,
Quality is maintained for about 6 months to 1 year. This makes it possible to manufacture and stock a large amount of seedling culture medium according to the seedling raising period.

[Brief description of drawings]

FIG. 1 is a graph showing the number of months of storage and inorganic nitrogen of a medium for raising rice seedlings using bark compost according to the first embodiment of the present invention.

FIG. 2 is a graph showing the number of months of storage and the inorganic nitrogen of a medium for raising rice seedlings using field-dried bark of the second embodiment of the present invention.

─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshinori Mizuguchi 793 Tanaka, Fukumitsu-cho, Nishitonami-gun, Toyama Prefecture Chumoku Co., Ltd. (56) Reference JP-A-1-285122 (JP, A) Special Table H9-508343 ( (58) Fields surveyed (Int.Cl. ⁷ , DB name) A01G 1/00

Claims (3)

(57) [Claims] 1. A bark crushed into suitable chips is used as a base material, and in the state of decaying and composting this bark, an inorganic nitrogen nutrient necessary for raising seedlings is added, and a pH adjusting agent is added. A medium for growing rice seedlings, characterized in that the pH is adjusted to approximately 4.5 to 5 to suppress the activity of microorganisms, suppress the organication of the added inorganic nitrogen, and maintain the content of the inorganic nitrogen substantially constant. . 2. Decaying bark crushed into suitable chips
In addition to adding the nutrients of inorganic nitrogen required for raising seedlings while maintaining water retention, a pH adjusting agent was added to adjust the pH to approximately 4.5 to 5 to suppress the activity of microorganisms, and then added. A method for producing a medium for raising rice seedlings, which comprises keeping the organic state of inorganic nitrogen suppressed. 3. The crushed bark used is one which has been rotted to a carbon ratio of about 80.
A method for producing a culture medium for growing paddy rice according to the description.