JP2002125455A - Medium for raising seedling of paddy rice and method for producing the medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide lightweight and inexpensive medium for raising seedlings of paddy rice, inhibiting inorganic nitrogen from being organized due to using bark, and to provide a method for producing the medium for raising seedlings of paddy rice. SOLUTION: This medium for raising seedlings of paddy rice is obtained by the following process: using bark crushed into proper sized tips as a base material and adjusted pH to 4.5-5 so as to maintain the content of inorganic nitrogen at a constant level by suppressing the activity of microorganisms. In this process, the bark is crushed into proper sized tips, and nourishments such as ammonium sulfate, urea, iron sulfate, silicic acid iron, and potassium sulfate are added to the bark.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a medium for raising rice seedlings for sowing and raising rice seedlings 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 using natural soil as a raw material or an artificial medium such as rock wool is generally used. These are generally packed in a nursery box as a sowing bed, irrigated from above, sowed, covered with soil and raised. In most cases, natural soil is used for covering soil regardless of the material of the seedbed. And packing these seeding floors,
A series of work steps of irrigation, seeding, and soil covering are performed by a seeding machine.

[0003] However, when cultivated soil using natural soil as a raw material is used for raising rice seedlings, the weight of the nursery box becomes considerably heavy, and this transporting operation places a heavy burden on workers. In particular, the aging of agricultural workers has recently been increasing, and the demand for lighter soil cultivation has increased. Also, the artificial medium used as a lightweight medium for raising rice seedlings has a low penetration rate due to the high price of the product. Further, even when an artificial medium is used, the covering soil cannot be sufficiently reduced in weight because natural soil is used.

[0004] Therefore, a method of using light and inexpensive bark as a material for the artificial medium has been considered. The bark is peeled off from the log when importing northern timber, etc., and is generated in large quantities.
For example, it is estimated that the amount of northern bark emission in Toyama Prefecture is about 50,000 to 60,000 tons (dry matter equivalent) per year. Recently, it has been composted and used as civil engineering and horticultural materials as bark compost.However, many of them are disposed of at high cost, and the use of bark compost is limited.
Since a significant increase in demand cannot be expected, there has been a demand for the development of high value-added and effective usage methods.

[0005] Generally, paddy rice is produced using a material having a carbon ratio (a ratio of the total carbon amount (C) to the total nitrogen amount (N) contained in the material, also referred to as C / N ratio) of 20 or less, such as natural soil. In the case of raising seedlings, the inorganic nitrogen added for the growth of the seedlings is hardly reduced by being taken up by microorganisms in the material (this is called organic conversion of inorganic nitrogen).

However, when the bark is used as it is in the medium for raising seedlings, almost no inorganic nitrogen necessary for the growth of the seedling is supplied from the bark, and the carbon ratio of the bark is 1 immediately after peeling.
More than 20, even those that have been piled up are extremely high, about 80, so even if inorganic nitrogen is added to the bark, the organic matter usually advances rapidly during the seedling raising period due to the activities of various microorganisms in the bark. I couldn't grow properly.

[0007] Therefore, it has been studied to use bark compost obtained by composting bark as a culture medium for raising seedlings. Here, bark compost means, for example, bark peeled from raw wood is piled up in an outdoor dumping site for about one year, then naturally decayed, and then composted (as bark as an auxiliary material to promote fermentation) Add livestock manure and fermentation to decompose)
It is reduced to about 35.

[0008] Even in this case, since the carbon ratio of bark compost is slightly higher than that of natural soil, the organic nitrogenization of inorganic nitrogen during the seedling raising period is inevitable. When stored in a warehouse, there was a phenomenon that inorganic nitrogen was greatly reduced in a few months due to organic conversion and the like. For this reason, 100% bark compost cannot be used as a medium for raising seedlings. When bark compost is used as a medium for raising seedlings, it is mixed with natural soil, mulch, peat moss and the like to reduce the overall carbon ratio. Needed.

[0009]

In the case of the above-mentioned prior art, the composting of bark takes time (usually more than half a year) and requires a larger space, so that the cost has rebounded. Therefore, it has been desired that the composting process be omitted in order to reduce the production cost, and the shipment be carried out as early as possible.

In composting, livestock manure is generally used as an auxiliary material to promote fermentation. In this case, however, the fertilizer component supplied from the auxiliary material used is not uniform. However, it was difficult to use rice seedlings that are susceptible to excess or deficiency of fertilizer components.

When bark compost is used as a medium for raising seedlings, it must be mixed with natural soil or the like in order to suppress the material from being organically organized, which complicates the production process and increases the cost. There is a problem that the weight increases due to the mixing of the soil.

The present invention has been made in view of the above-mentioned conventional problems. It is an object of the present invention to provide a light-weight and inexpensive medium for raising rice seedlings, which suppresses the organicization of inorganic nitrogen by using bark, and a method for producing the same. The purpose is to provide.

[0013]

According to the present invention, a bark ground into appropriate chips is used as a base material, and the pH of the bark is about 4.5 to 5.
This is a medium for raising rice seedlings, which is adjusted to a low concentration, suppresses the activity of microorganisms, and keeps the content of inorganic nitrogen constant. The bark is pulverized to an appropriate size (a particle size of about 4 mm or less), and nutrients as fertilizer components such as ammonium sulfate, urea, iron sulfate, iron silicate, and potassium sulfate are added to the bark. In the above bark,
The pH is set to the above range by adding an acid such as sulfuric acid.

The present invention is also applicable to, for example, an outdoor deposition site.
The bark, which has been piled up for about a year, is pulverized and adjusted to a particle size of about 4 mm or less, while mixing nutrients and adding a pH adjuster such as sulfuric acid to adjust the pH to about 4.5 to 5. This is a method for producing a culture medium for raising rice seedlings. As fertilizer, ammonium sulfate, urea, iron sulfate, iron silicate, potassium sulfate, etc. are mixed in a well-balanced manner.

The medium for raising rice seedlings of the present invention has a pH
It is adjusted to 4.5 to 5, and the activities of various microorganisms are 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 kept constant.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. The medium for raising rice seedlings of this embodiment is prepared by adding a pH adjuster to crushed bark to adjust the pH to 4.5 to 5. Fertilizers such as ammonium sulfate, urea, iron sulfate, iron silicate, and potassium sulfate are added to the culture medium for rice seedlings as nutrients. The bark used here is obtained by peeling bark from imported northern wood or the like.

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 pulverized and passed through a sieve of about 4 mm. And p
The pH is adjusted to 5 or less, preferably to 4.5 to 5 by adding an H adjuster, for example, an acidic material such as sulfuric acid. In addition, the bark that has been piled up for about one year has a pH of about 5.4 to 5.7. Next, fertilizer components, such as nitrogen, iron, potash, and silicic acid, which are deficient, are added to the pH-adjusted bark. Some fertilizers can be added, such as ammonium sulfate, urea, iron sulfate, iron silicate and potassium sulfate. For example, 2 kg of nitrogen per 2 tons of bark and 3 iron
kg and potassium 1.5 kg.
If the pH changes due to the fertilizer added here, the pH is adjusted again by adding a pH adjuster.

In the method of using the medium for raising rice seedlings of this embodiment, a seedling box is filled with the medium for raising rice seedlings, irrigated from above, seeded, and covered with the medium to grow the seedlings. Rice seedlings raised using the medium for raising rice seedlings of this embodiment have almost the same seedling quality as seedlings raised by cultivation using conventional mountain sand. The seeding operation using a seeding machine is possible as in the case of the conventional seedling culture medium using natural soil including mountain sand culture soil.

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 one using mountain sand cultivation soil, making it easy to carry. it can.

Further, in the production method, no composting is performed, and only a pH adjuster and a fertilizer are added to the bark that has been piled up for about one year, so that composting is unnecessary and required for composting. Supplying at lower cost is possible without requiring time and a large space. Furthermore, since there is no need to mix livestock manure, which is an auxiliary material required for composting, it is possible to produce a stable quality product without being affected by component variations in livestock manure. .

The medium for raising rice seedlings has a high carbon content 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 ratio is high, The product can always be supplied with stable quality. In general, the medium is p
Below H5, many plants such as vegetables will grow poorly,
Rice seedlings are safe even at such a pH, because they are not significantly affected.

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

Even when a lightweight artificial medium that is currently used as a medium for raising rice seedlings is used, it is common to use heavy natural soil for covering soil. However, the medium for raising rice seedlings of this embodiment can also be used for covering soil of these artificial media, and can be used as a lightweight material in place of natural soil. By reducing the weight of the medium for raising rice seedlings, it is possible to reduce the labor of transporting the seedling box, which requires a large burden.

In addition, bark that has not been conventionally used is
It can be effectively used for high value-added ones, and the burden on the wood industry can be reduced by using the bark that has been disposed of at a high cost. By the way, the total amount of bark of northern wood in Toyama prefecture is estimated to be about 50,000 to 60,000 tons (dry matter equivalent) per year. The required amount is a calculation that can be covered.

The culture medium for raising rice seedlings and the method for producing the same according to the present invention are not limited to the above embodiment.
Materials for the H regulator and fertilizer can be appropriately selected. Also,
The bark compost obtained by composting the bark may be subjected to the above pH adjustment to prepare a medium for raising rice seedlings.

[0026]

Next, a first embodiment of the present invention will be described. First, urea, lime perphosphate, and potassium sulfate were added to bark as auxiliary materials, and the bark was composted to produce a bark compost having a carbon ratio of about 35. Then, ammonium sulfate, iron sulfate, and potassium sulfate were added as fertilizers necessary for raising seedlings so that 2 kg of nitrogen, 3 kg of iron, and 1 kg of potassium were contained per 2 tons of this bark compost.
Is not particularly adjusted (pH 5.5), and the pH is adjusted with sulfuric acid.
A medium for raising rice seedlings adjusted to 4.5 was produced.

Using the two types of products, which are mediums for raising rice seedlings, 1) immediately after production, 2) two months after storage in a warehouse,
3) After 6 months, 4) In each of the seedling culture media in a state after one year, rice was grown. The seedlings immediately after production and one year after storage were raised in a nursery house, and those stored two and six months after storage were raised in an artificial weather chamber (25 ° C in the day and 15 ° C at night).
As a control, seedlings of paddy rice were similarly grown using commercially available soil using natural soil. Then, the growth status was investigated, and the results are shown in Table 1. Here, the leaf age is the number of leaves. The leaf color was measured by placing the central part of the developed first leaf on a leaf color plate. Per test plot,
About 30 samples were measured and shown as an average value. In addition, the amount of inorganic nitrogen at the start of each seedling raising was measured and is 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 medium as a product packed in a bag.

[0028]

[Table 1] As a result, from FIG. 1, it can be seen from FIG. 1 that the medium for raising rice seedlings according to this example was added without pH adjustment even though it was a product satisfying the standard for judging ripeness of bark compost (carbon ratio: 35 or less). It was found that the amount of the inorganic nitrogen decreased, and hardly remained after 6 months. However, pH 4.5
, It was found that the inorganic nitrogen added hardly decreased. Also, from Table 1, in the pH 5.5 medium without pH adjustment, the growth state immediately after production was the same as that of the pH 4.5 medium and the control, but the growth became poor in the medium after 2 months or more. It was found that the plant height was short and the seedlings turned yellow (leaf color became lighter). This is considered to be due to the decrease in inorganic nitrogen from the results in FIG. Therefore, it was found that a pH 5.5 medium without pH adjustment was not suitable as a seedling culture medium.

Next, a second embodiment of the present invention will be described. In this example, on a bark with a carbon ratio of about 80,
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 ton of bark, and p was added with sulfuric acid.
A product adjusted to H4.5 and pH 4.8 was produced.

For this product, a rice plant was raised using a medium immediately after production and a medium after 6 months of storage in a warehouse. Immediately after production and 6 months after storage, the seedlings were raised in an artificial weather chamber (15 ° C. in the day and 12 ° C. at night). As a control, seedlings of paddy rice were similarly grown using commercially available soil using natural soil. The growth status was investigated, and the results are shown in Table 2. FIG. 2 shows changes in the amount of inorganic nitrogen. The product was stored in a warehouse (room temperature; no temperature adjustment, from May to November) in a bag as in the case of the above-mentioned bark compost.

[0031]

[Table 2] As a result, it has been found that even in the case of immature ones having a high carbon content, such as bark of the field, the pH is reduced to 5 or less, whereby the organicization of inorganic nitrogen is suppressed. Even after 6 months from the production, about 75% of the added amount of the inorganic nitrogen remained, and the seedlings could be sufficiently grown.

Next, a third embodiment of the present invention will be described. First, urea was added to a bark having a carbon ratio of about 79 so that 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. Then, iron sulfate and potassium sulfate are respectively 3 kg / bark 2 tons with iron and 1 kg / kg with potassium.
A medium was prepared by adding 2 tons of bark and further adding diluted sulfuric acid so as to have a pH of 4.5.

This product was stored in a warehouse, and rice seedlings were raised four months later and one year later, respectively. After 4 months of storage, the seedlings were raised in a nursery house, and after 1 year of storage, they were raised in an artificial weather chamber (25 ° C in the day and 15 ° C at night). As a control, seedlings of paddy rice were similarly grown using commercially available soil using natural soil. And the growth situation is investigated and the result is shown in Table 3.
It was shown to. In addition, the product was stored in a warehouse (room temperature; no temperature adjustment, from December to December of the following year) in a bag.

[0034]

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

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

[0036]

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

Next, the weight of the nursery box was measured when the seedlings grown on the field bark 4 months after storage in the warehouse shown in this example were carried out to the nursery house and when planting rice, and the results were measured. The results are shown in Table 5.

[0038]

[Table 5] As a result, the weight of the seedling raising box in the medium for raising seedlings of this example was reduced to about half of that in cultivation using natural soil.
Thereby, it can be expected that the labor of transportation is greatly reduced.

[0039]

As described above, the medium for raising rice seedlings of the present invention is light in weight because it uses bark as a base material, so that the medium can be easily introduced into the seeding machine and the seedling 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 the fertilizer as shown in Examples of the present invention in a well-balanced manner. In addition, a series of mechanical operations using a commercially available sowing machine or rice transplanter can be performed without any problem.
The bark used as the material is inexpensive, and the production process of the culture medium is simple, so that products 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 not easily organized,
The quality is maintained for about six months to one year. This makes it possible to produce and stock a large amount of seedling culture medium at the time of seedling raising.

[Brief description of the drawings]

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

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

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Mizuguchi 793, Tanaka, Fukumitsu-cho, Nishitonami-gun, Toyama F-term (reference) 2B022 AB20 BA14 BB01

Claims (3)

[Claims] 1. A medium for raising rice seedlings, wherein a bark ground into a suitable chip is used as a base material, and a predetermined nutrient is added to adjust the pH to about 4.5 to 5. 2. The medium for raising rice seedlings according to claim 1, wherein an acid is added to the bark to set the pH within the above range. 3. A method in which nutrients necessary for raising seedlings are mixed with a crushed bark to a certain degree of decay, and a pH adjuster is added to adjust the pH to about 4.5 to 5. Method for producing a medium for raising rice seedlings.