JP7554063B2 - Seedling production method - Google Patents

Description

The present invention relates to a method for producing seedlings.

Container seedlings are seedlings grown in containers that have ribs (vertical protrusions) on the inside of the container and an open bottom to prevent root wrapping. The medium for growing container seedlings is called container soil, and can be a single basic material (such as coco peat) or a mixed soil made by mixing a basic material with a drainage material (such as rice husks or perlite). It is common to add basal fertilizer to the container soil before growing seedlings. Container soil that is already mixed with basic materials, drainage materials, and basal fertilizer is also available for sale (see non-patent literature 1 and 2).

Toshiaki Endo et al., JFA-150 Container Seedling Raising and Planting Manual, March 2009, https://www.rinya.maff.go.jp/j/kanbatu/syubyou/pdf/15-kontenanae_ikubyou_syokusai_manyuaru.pdf Aomori Prefectural Industrial Technology Center Forestry Research Institute, Aomori Prefecture Edition: How to Raise Container Seedlings of Japanese Cedar and Hiba, published January 31, 2019, https://www.aomori-itc.or.jp/_files/00031691/H30sugihibamanyuaru.pdf

However, conventional container soils generally have a poor balance between drainage and water retention, resulting in slow seedling growth. In particular, it can take as long as two years to grow seedlings from seedlings. The object of the present invention is to provide a soil that has a good balance between drainage and water retention and is suitable for the production of container seedlings.

The present invention provides the following:
[1] A method for producing seedlings, comprising the step of growing seedlings using culture soil having a saturated hydraulic conductivity of 1.0 x ^10-5 to 9.9 x ^10-4 m/s and a water retention capacity of 160 to 230 L/ ^m3 and a seedling-raising container.
[2] A combination in which the culture soil contains at least two or more types of artificial soil, or
A combination including at least one type of artificial soil and one or more types of natural soil;
The method according to [1].
[3] The method according to [2], wherein the artificial soil comprises at least one of peat moss and coconut fiber.
[4] The method according to [3], wherein the artificial soil further contains vermiculite.
[5] The method according to any one of [2] to [4], wherein the natural soil comprises at least one of Kanuma soil and Akadama soil.
[6] The method according to any one of [1] to [5], wherein the seedling is a forest seedling.
[7] The method according to any one of [1] to [6], wherein the seedling is a seedling.
[8] A culture soil for seedling production having a saturated hydraulic conductivity of 1.0 x 10 ^-5 to 9.9 x 10 ^-4 m/s and a water retention capacity of 160 to 230 L/m ³ .
[9] A seedling raising kit comprising: a seedling production soil having a saturated hydraulic conductivity of 1.0×10 ⁻⁵ to 9.9×10 ⁻⁴ m/s and a water retention capacity of 160 to 230 L/m ³ ; and a seedling raising container.

The present invention provides a culture soil that has a good balance of drainage and water retention, allowing efficient seedling cultivation, and therefore allows efficient seedling cultivation, resulting in efficient seedling production.

[Soil]
In the present invention, a bed soil having a saturated hydraulic conductivity and water retention capacity within a predetermined range is used.

(Saturated hydraulic conductivity)
The saturated hydraulic conductivity of the culture soil is 1.0×10 ⁻⁵ m/s or more, preferably 1.1×10 ⁻⁵ m/s or more, more preferably 1.2×10 ⁻⁵ m/s or more. The upper limit is 9.9×10 ⁻⁴ m/s or less, preferably 9.8×10 ⁻⁴ m/s or less, more preferably 9.7×10 ⁻⁴ m/s or less. Therefore, the saturated hydraulic conductivity is 1.0×10 ⁻⁵ to 9.9×10 ⁻⁴ m/s, preferably 1.1×10 ⁻⁵ to 9.8×10 ⁻⁴ m/s, more preferably 1.2×10 ⁻⁵ to 9.7×10 ⁻⁴ m/s. This provides adequate drainage, and when the culture soil is placed in a seedling container, water drains well during watering, and water accumulation in the water spot of the seedling container is suppressed. On the other hand, the water retention is moderate, and the rapid escape of water from the bottom of the seedling container after watering is suppressed.
The saturated hydraulic conductivity can be measured by the constant water level method or the variable water level method in Soil Environmental Analysis Method II. 10 (edited by the Japanese Society of Soil Science and Plant Nutrition, edited by the Soil Environmental Analysis Method Editorial Committee).

(Water retention capacity)
The water retention capacity of the culture soil is 160 or more, preferably 165 or more, and more preferably 170 or more. The upper limit is 230 or less, preferably 225 or less, and more preferably 220 or less. Therefore, it is 160 to 230 L/m ³ , preferably 165 to 225 L/m ³ , and more preferably 170 to 220 L/m ³ . This increases the amount of water that can be retained, reducing the frequency of watering and making it easier to retain fertilizer in the culture soil.
The water retention capacity is the available water when the pF is 1.5 to 2.7, and can be measured by the pressure plate method and the centrifuge method in Soil Environmental Analysis Method II.9 (edited by the Japanese Society of Soil Science and Plant Nutrition, edited by the Soil Environmental Analysis Method Editorial Committee).

(Example of soil)
The composition of the culture soil is not particularly limited as long as the saturated hydraulic conductivity and water retention are within the above-mentioned range. For example, natural soil such as sand, soil (e.g., Akadama soil, Kanuma soil), artificial soil such as rice husk charcoal, coconut fiber, vermiculite, perlite, peat moss, glass beads, rice husk, porous molded products such as foamed phenolic resin and rock wool, solidifying agents (e.g., agar or gellan gum), and combinations of two or more of these can be mentioned, and combinations of two or more are preferred, and combinations containing at least two or more types of artificial soil, or combinations containing at least one or more types of artificial soil and one or more types of natural soil are preferred. Coconut fiber is preferably coco peat (coconut husk: fiber obtained from the coconut husk and its residue crushed product).

The culture soil is preferably a combination of at least one of coconut fiber and peat moss and at least one selected from artificial soil and natural soil other than these. The volume of coconut fiber and peat moss (the total when both are included) in the culture soil is usually 10% or more, 20% or more, 30% or more, or 35% or more, preferably 40% or more, more preferably 50% or more, more preferably 55% or more. The upper limit is usually 90% or less or 85% or less, preferably 80% or less, more preferably 75% or less. The artificial soil and natural soil to be combined with coconut fiber and peat moss may be selected from the viewpoint of particle size (e.g., particle size distribution, surface area, void area) or water retention, but it is preferable to use two or more types with different particle sizes or types. The other artificial soil can be appropriately selected from the above examples, but it is preferable to include at least vermiculite, and it is more preferable to include two or more types of vermiculite with different particle size distributions. Combinations of two or more types of vermiculite with different particle size distributions include, for example, a combination of 60% or more of vermiculite with particle sizes less than 2.5 mm and 50% or more of vermiculite with particle sizes of 2.5 mm or more, with the respective ratios being, for example, 55-90:45-10 (preferably 60-80:40-20). Natural soils are preferably Kanuma soil and Akadama soil. Kanuma soil is preferably Kanuma small grain soil. Akadama soil is preferably Akadama small grain soil. Natural soils are preferably combinations of two or more types, more preferably Kanuma soil and Akadama soil, and even more preferably Kanuma small grain soil and Akadama small grain soil. In the combination of Kanuma soil and Akadama soil, the volume ratio of the two (Kanuma soil/Akadama soil) is usually 0.01 to 100, preferably 0.1 to 10, and more preferably 0.5 to 5.

(Other ingredients - base fertilizer, etc.)
The culture soil may contain components other than soil. Examples of other components include base fertilizer and preservatives. The inclusion of base fertilizer can promote the growth of seedlings. The base fertilizer is not particularly limited, and may be a fast-acting fertilizer or a slow-acting fertilizer, and may be any of inorganic fertilizer, organic fertilizer, and chemical fertilizer. The amount of fertilizer applied is not particularly limited, and an amount suitable for the fertilizer used can be selected. Examples of components contained in the base fertilizer include components that can be a source of nutrients for plants, such as inorganic components, silver ions, antioxidants, carbon sources, vitamins, amino acids, and plant hormones. The form of the base fertilizer is not particularly limited, and may be either a solid (e.g., powder, granules) or a liquid (e.g., liquid fertilizer).

Examples of inorganic components include essential elements such as nitrogen, phosphorus, and potassium, and trace elements such as sulfur, calcium, magnesium, iron, manganese, zinc, boron, molybdenum, chlorine, iodine, and cobalt, as well as inorganic salts containing these elements. Examples of inorganic salts include potassium nitrate, ammonium nitrate, ammonium chloride, sodium nitrate, potassium monohydrogen phosphate, sodium dihydrogen phosphate, potassium chloride, potassium sulfate, ammonium sulfate, magnesium sulfate, ferrous sulfate, ferric sulfate, manganese sulfate, zinc sulfate, copper sulfate, sodium sulfate, calcium chloride, magnesium chloride, boric acid, molybdenum trioxide, sodium molybdate, potassium iodide, cobalt chloride, and the like, as well as hydrates thereof. It is preferable that the content of phosphorus or potassium is greater than the content of nitrogen among the essential elements. This allows cuttings with a good rooting rate to be obtained efficiently, regardless of the age of the mother tree from which the cuttings are taken, even if the tree is older. At least one of the weight ratio of the phosphorus content to the nitrogen content and the weight ratio of the potassium content to the nitrogen content (preferably both) is preferably greater than 1, more preferably 1.5 or more, and even more preferably 2.0 or more. The upper limit is usually 4.0 or less, and is not particularly limited.

Examples of antioxidants include ascorbic acid and sulfites, with ascorbic acid being preferred. Ascorbic acid has low residual capacity in culture media, and can therefore prevent environmental pollution.

Carbon sources include, for example, compounds such as carbohydrates and their derivatives, such as sucrose; organic acids, such as fatty acids; and primary alcohols, such as ethanol.

Examples of vitamins include biotin, thiamine (vitamin B1), pyridoxine (vitamin B4), pyridoxal, pyridoxamine, calcium pantothenate, inositol, nicotinic acid, nicotinamide, and riboflavin (vitamin B2).

Examples of amino acids include glycine, alanine, glutamic acid, cysteine, phenylalanine, and lysine.

[Seedling container]
The above-mentioned culture soil can be used for raising seedlings, preferably in combination with a seedling raising container.

The seedling container may be any container with a storage section capable of storing culture soil, and is preferably a container with an opening approximately at the bottom. Examples include containers (e.g., the containers described in JP 2017-079706 A, multi-cavity containers (JFA-150, JFA-300: see Non-Patent Document 1), etc.), cell trays, seedling pots, planters, and trays (box-shaped containers with an opening at the bottom or side, etc.). The container may be a culture container in which one plant is planted in each container, or a seedling container in which two or more plants are planted in each container. There are no particular limitations on the material of the seedling container, and examples include resin, glass, and wood. The size of the container may be selected appropriately depending on the target plant.

[Seedling production method]
The above-mentioned media, preferably together with a culture vessel, can be used for the production of seedlings.

(Target plants)
The target plant may be either a woody plant or a herbaceous plant, with a woody plant being preferred, and a woody plant being more preferred, which generally has a lower rooting ability than a herbaceous plant. Examples of woody plants include plants of the genus Cryptomeria (e.g., Cryptomeria japonica), plants of the genus Chamaecyparis (e.g., Chamaecyparis obtusa), plants of the family Pinaceae (Pinus (Pinus thunbergii)), plants of the genus Larix (Larix kaempferi, Larix gmelinii), and plants of the genus Abies (Abies todomatsu). sachalinensis, etc.), Eucalyptus plants, Prunus plants (cherry blossoms (Prunus spp.), plum blossoms (Prunus mume, Prunus tomentosa, etc.), Mangifera plants (Mangifera indica, etc.), Acacia plants, Myrica plants, Quercus plants (Quercus acutissima, etc.), Vitis plants, Malus plants, Rosa plants, Camellia plants (Camellia Examples of such plants include Jacaranda plants (Jacaranda mimosifolia, etc.), Persea plants (Avocado (Persea americana, etc.)), Pyrus plants (Pyrus serotina Rehder, Pyrus pyrifolia, etc.), and Santalum plants (Sandalwood (Santalum album, etc.)). Among these, cedar, cypress, pine (Japanese black pine, larch, gmelin, todomatsu, etc.), eucalyptus, cherry, mango, avocado, acacia, bayberry, sawtooth oak, grape, apple, rose, camellia, tea, plum, toadflax, jacaranda, among which plants of the genus Cryptomeria japonica, plants of the genus Chamaecyparis obtusifolia, plants of the family Pinaceae (plants of the genus Pinus, larch, fir, etc.), plants of the genus Eucalyptus, plants of the genus Camellia, plants of the genus Mangifera, and plants of the genus Alligator are preferred, and forest seedlings, i.e., plants of the genus Cryptomeria japonica, plants of the genus Pinus, plants of the genus Larch, plants of the genus Fir, and plants of the genus Eucalyptus are more preferred, and plants of the genus Cryptomeria japonica, plants of the genus Cypress, plants of the genus Pinus, plants of the genus Larch, plants of the genus Fir, and plants of the genus Eucalyptus are even more preferred.

(Seedling raising conditions)
The conditions for growing the seedlings may be appropriately set depending on the environmental conditions such as the target plant, the season, the region, the presence or absence of facilities, etc. An example will be described below.

-Planting-
In producing seedlings, usually, first, culture soil is placed in a seedling container, and a target plant is planted (sown or cut). Examples of the form of the target plant to be planted include seeds and cuttings. Of these, seeds are preferred. While container-raising of seedlings from seedlings often requires a long period of time, the present invention allows seedlings to be grown efficiently in a short period of time, making it possible to raise seedlings efficiently in a short period of time. The amount of culture soil to be placed in the seedling container can be determined depending on the container and the target plant, and is usually filled into the entire container. When seeds are sown, seeds that have already germinated before sowing may be included. When commercially available seeds are used, the amount of seeds to be sown may be determined based on the germination rate indicated on the label.

-Fertilization-
After planting, fertilization may be performed as necessary. This can promote the growth of seedlings. As fertilizers, the same specific examples as those described as base fertilizers can be mentioned. Fertilization conditions such as the amount, timing, and method of fertilization are not particularly limited, and a method suitable for the fertilizer to be used can be selected.

-Irrigation-
The irrigation method during the seedling period may be either overhead irrigation or bottom irrigation. Examples of bottom irrigation methods include immersing a seedling container (a seedling container with an opening) in water and irrigating the cuttings through a water-absorbing member. When bottom irrigation is performed through a water-absorbing member, water is usually supplied to the water-absorbing member (e.g., a mat-shaped member), and the water is supplied to the cuttings through the part where the culture soil and the water-absorbing member contact. It is preferable to supply water to the water-absorbing member so that the medium is moistened and/or so that the water-absorbing member is in a state where it absorbs water uniformly. This allows the moisture environment of the medium to be maintained moderately, consistently, and uniformly. The irrigation work may be performed by either hand irrigation or an automatic irrigation device.

- Seedling growing location -
The place where the seedlings are raised may be a closed space (e.g., in a vinyl house, a carbon dioxide gas culture room, a greenhouse, or indoors) or an open space (e.g., outdoors), but a closed space is preferable for the first few months (e.g., up to the second or third month) after the start of seedling raising. This makes it easier to adjust conditions such as temperature and humidity.

- Seedling temperature -
The temperature in the environment for rooting and raising the seedlings is not particularly limited as long as the conditions are such that seedlings can be raised, but a temperature of 20 to 40°C, for example, is preferable.

- Seedling raising period -
The seedlings may be raised in the culture soil until the seedlings are observed, which is usually for 4 months or more, preferably for 6 months or more, and more preferably for 8 months or more. The seedlings are preferably raised until the seedlings reach a height of about 30 cm or more. After the seedlings are observed, the seedlings may be raised in the culture soil and the seedling raising container, or may be moved to another culture soil and continued to be raised.

-others-
When the cutting is inserted, in order to promote rooting until the cutting has rooted to a certain extent, operations such as adjustment of light intensity, adjustment of wavelength components, shading (for example, shading using cheesecloth), adjustment of carbon dioxide concentration, adjustment of humidity, adjustment of temperature, etc. Whether or not these operations are necessary and the operation conditions when they are performed can be appropriately determined depending on the plant species, part, size, and type of additive of the cutting, and it is difficult to specify them in general, but examples are as follows. The light intensity can be adjusted using an irradiation device such as an LED so that the photosynthetically active photon flux density is preferably 10 μmol/m ² /s to 1000 μmol/m ² /s, more preferably 50 μmol/m ² /s to 500 μmol/m ² /s. The wavelength components are preferably adjusted using an agricultural film such as a light quality conversion film so that light containing a wavelength component of 650 nm to 670 nm and a wavelength component of 450 nm to 470 nm is irradiated. The carbon dioxide gas concentration during rooting can be adjusted to usually 300 to 2000 ppm, preferably 800 to 1500 ppm, by placing a culture vessel equipped with a carbon dioxide permeable film in a facility such as an artificial weather chamber. The humidity can be adjusted to usually 60% or more, preferably 80% or more.

[Seedling raising kit]
The culture soil and the seedling container can be provided as a seedling kit. The seedling kit may include other tools as necessary. For example, tools for bottom watering (e.g., immersion container, water-absorbent member), tools for containing the culture soil (e.g., scoop), tools for fixing the culture container (e.g., stand, rack), seeds, fertilizer, and other tools necessary for seedling raising can be included.

Example 1
On March 8, 2018, a 300cc multi-cavity container (manufactured by Sanko Co., Ltd.) was used as a seedling container, and 300cc of peat moss (manufactured by Sun & Hope Co., Ltd.), Kanuma small grain soil (manufactured by Akagi Engei Co., Ltd.), and Akadama small grain soil (manufactured by Yanashima Shoji Co., Ltd.) were mixed in a ratio of 4:1:1 (volume ratio, the same below) and filled as a culture soil. Seven to ten cedar seeds with a germination rate of 20% were directly sown in the container filled with the culture soil and placed in a vinyl greenhouse. After two months, the buds were pruned to one, and the seedlings were placed outside and continued to be grown until November. During the seedling raising period, overhead irrigation was performed, and Hyponex concentrate (manufactured by Hyponex Japan Co., Ltd.) was sprayed once a week at a 500-2000-fold dilution. If the seedlings were alive after the seedling raising period and had a height of 30 cm and a base diameter of 3.5 mm or more, they were judged to have been harvested.

Example 2
The same procedure as in Example 1 was carried out, except that a mixture of Coco Peat Old (manufactured by Top Co., Ltd.), Vermiculite GS (manufactured by Nittai Co., Ltd.) and Vermiculite GL (manufactured by Nittai Co., Ltd.) in a ratio of 4:2:1 was used as the cultivation soil.

Example 3
The same procedure as in Example 1 was carried out, except that a mixture of peat moss, Kanuma small grain soil, and Akadama small grain soil in a ratio of 5:1:1 was used as the cultivation soil.

Comparative Example 1
The same procedure as in Example 1 was carried out, except that only coco peat old was used as the culture soil.

Comparative Example 2
The same procedure as in Example 1 was carried out, except that only peat moss was used as the culture soil.

[Measurement of saturated hydraulic conductivity]
Measurements were performed before filling with the soil using the method described in "Soil Environmental Analysis Method II. 10 Constant Water Level Method or Variable Water Level Method."

[Measurement of water retention capacity]
Measurements were carried out before filling with the culture soil using [Soil Environmental Analysis Method II.9 Pressure Plate Method and Centrifugal Method].

As is clear from Table 1, the seedling yield rate was less than 50% in Comparative Examples 1 and 2, whereas a high seedling yield rate was observed in Examples 1 to 3. Furthermore, the seedling height and base diameter of Examples 1 to 3 were higher than those of Comparative Examples 1 and 2. Examples 1 to 3 were seedling raising tests of seedlings from seedlings, and it is expected that seedlings suitable for shipping can be produced in about one year. These results show that according to the present invention, seedlings can be produced efficiently in a short period of time with typical fertilizer amounts and water management.

Claims (5)

The method includes a step of growing seedlings using a culture soil having a saturated hydraulic conductivity of 1.2 × 10 ^-5 to 9.5 × 10 ^-4 m/s and a water retention capacity of 171 to 219 L/m ³ and a seedling raising container;
The culture soil contains at least one of peat moss and coconut fiber , and vermiculite or a combination of Kanuma soil and Akadama soil ;
The volume of peat moss and coconut fiber (the total volume if both are included) is 40 to 80% by weight of the total culture soil;
The seedling is a forest seedling selected from the group consisting of plants of the genus Cryptomeria japonica, the genus Chamaecyparis obtusa, the genus Pinus serrata, the genus Larch, the genus Abies serrata, and the genus Eucalyptus.
Seedling production methods. 2. The method according to claim 1, wherein the forest seedlings are cedar, cypress, pine, larch, gmelin, or todomatsu. The method according to claim 1 or 2 , wherein the seedling is a seedling. The saturated hydraulic conductivity is 1.2 × 10 ^-5 to 9.5 × 10 ^-4 m / s, and the water retention capacity is 171 to 219 L / m ³ ,
Contains at least one of peat moss and coconut fiber, and vermiculite or a combination of Kanuma soil and Akadama soil ;
The volume of peat moss and coconut fiber (the total volume if both are included) is 40 to 80% by weight of the total culture soil;
The soil for producing forest seedlings is selected from plants of the genus Cedar, Cypress, Pinus, Larch, Abies and Eucalyptus. The saturated hydraulic conductivity is 1.2 × 10 ^-5 to 9.5 × 10 ^-4 m / s, and the water retention capacity is 171 to 219 L / m ³ ,
Contains at least one of peat moss and coconut fiber, and vermiculite or a combination of Kanuma soil and Akadama soil ;
The volume of peat moss and coconut fiber (the total volume if both are included) is 40 to 80% by weight of the total culture soil;
The seedling raising kit includes a seedling raising container and a culture soil for producing forest seedlings of plants selected from the group consisting of plants of the genus Cryptomeria japonica, plants of the genus Chamaecyparis obtusa, plants of the genus Pinus, plants of the genus Larch, plants of the genus Abies japonica, and plants of the genus Eucalyptus.