Additives for hydroponic cultivation
Bamboo-derived earthworm compost additives address disease suppression in hydroponics by using a solid culture medium, improving plant growth and yield in hydroponic systems.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- PUBLIC UNIVERSITY CORPORATION OSAKA CITY UNIVERSITY
- Filing Date
- 2022-03-17
- Publication Date
- 2026-06-02
AI Technical Summary
Hydroponic cultivation of vegetables like spinach is limited due to susceptibility to water-borne diseases and the prohibition of pesticide use in nutrient solutions, leading to plant diseases and high costs with synthetic compounds.
A hydroponic additive containing bamboo-derived earthworm compost, which can be used in a solid culture medium to suppress diseases, including heat-treated forms for enhanced efficacy.
The additive effectively suppresses diseases caused by pathogens such as Pythium and Olpidium fungi, enhancing plant growth and yield in hydroponic systems.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to additives for hydroponics and the like.
Background Art
[0002] Most of the hydroponic cultivation of vegetables in plant factories is limited to the Asteraceae family (such as lettuce) and the Brassicaceae family (such as Komatsuna). Although vegetables such as the Urticaceae family (spinach) and the Aizoaceae family (ice plant) are expensive, they have not spread as crops for hydroponic cultivation. This is because crops such as spinach, which are vulnerable to water-borne diseases, are shunned. In addition, the application of pesticides to nutrient solutions is prohibited, and the lack of effective solutions is also a major factor. Although plant factories are closed facilities and it seems that there is no room for plant pathogens to enter, in reality, nutrient solution-borne plant diseases occur constantly.
[0003] Patent Document 1 describes a disease control agent containing a substituted pyridine compound having a specific structure as an active ingredient. Since the active ingredient in Patent Document 1 is a synthetic compound, considering the large-scale cultivation of plants, cost problems may arise in the technology of Patent Document 1. In addition, in Patent Document 1, the effects in hydroponic cultivation have not been evaluated.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] An object of the present disclosure is to provide a disease suppression technique in hydroponic cultivation.
Means for Solving the Problems
[0006] In view of the above problems, the inventors have diligently conducted research and have found that a hydroponic cultivation additive containing bamboo-derived earthworm compost can solve the above problems. That is, this disclosure encompasses the following aspects.
[0007] Item 1. A nutrient solution additive for hydroponics containing bamboo-derived earthworm compost.
[0008] Item 2. A hydroponic cultivation additive as described in Item 1, for use by being retained in a solid culture medium for hydroponic cultivation.
[0009] Item 3. The hydroponic additive according to Item 2, wherein the material of the solid growing medium for hydroponics includes at least one selected from the group consisting of rock wool, urethane, sand, gravel, perlite, peat moss, coconut fiber, vermiculite, leaf mold, bark, bark compost, rice straw, rice straw compost, sawdust, sawdust compost, wood pellets, charcoal, and bamboo charcoal.
[0010] Item 4. A hydroponic cultivation additive according to item 2 or 3, for use in such a way that 0.001 to 5 g of the bamboo-derived earthworm compost is retained in the solid culture medium for hydroponic cultivation for one plant.
[0011] Item 5. A hydroponic cultivation additive described in any of Items 1 to 4, for use in suppressing diseases in hydroponic cultivation.
[0012] Item 6. The additive for hydroponic cultivation according to any one of items 1 to 5, wherein the bamboo-derived earthworm compost is a heat-treated product of bamboo-derived earthworm compost.
[0013] Item 7. A solid growing medium for hydroponics that holds any of the hydroponic additives described in items 1 to 6.
[0014] Item 8. A solid culture medium for hydroponic cultivation as described in Item 7, for use in disease control.
[0015] Item 9. A method for producing plants, comprising growing plants hydroponically in a solid growing medium for hydroponics as described in Item 7 or 8. [Effects of the Invention]
[0016] This disclosure provides a technology for suppressing diseases in hydroponic cultivation. [Modes for carrying out the invention]
[0017] In this specification, the terms “contains” and “includes” include the concepts of “contains,” “includes,” “substantially consist of,” and “consist solely of.”
[0018] 1. Additives for hydroponic cultivation This disclosure relates, in one aspect, to an additive for hydroponic cultivation (which may also be referred to as "the additive of this disclosure" in this specification) containing bamboo-derived earthworm compost. This is described below.
[0019] Vermicompost is compost produced by earthworms consuming organic matter and excreting it. The bamboo-derived vermicompost used in the additives of this disclosure is vermicompost produced using bamboo as organic matter, and is not particularly limited to that extent.
[0020] The term "bamboo" broadly refers to bamboo, including herbaceous plants like dwarf bamboo that do not grow into wood. The specific type of bamboo used is not restricted, but it is preferable to use bamboo in the narrow sense, which is classified as a woody plant. Examples of bamboo in the narrow sense include Phyllostachys bambusoides, Phyllostachys heterocycla pubescence, Phyllostachys nigra, and Phyllostachys aurea. Examples of dwarf bamboo include Pseudosasa japonica and Pleioblastus simonii. Furthermore, the bamboo can be edible bamboo shoots, young bamboo (bamboo shoots that have grown beyond the stage of being edible and before branching), or mature bamboo (young bamboo that has grown and hardened). The bamboo species that earthworms feed on can be a single species or a combination of two or more species.
[0021] The shape of the mushrooms fed to the earthworms is not particularly limited. The mushrooms are preferably crushed or ground materials so that the earthworms can easily ingest them. Specifically, the mushrooms are preferably crushed materials (powders) of a size that can pass through a sieve with a mesh size of 1 to 2 mm, for example.
[0022] The mushrooms are preferably brought into contact with water for a certain time or period before being fed to the earthworms. This can remove the growth inhibitory components for the earthworms and more efficiently produce earthworm-derived earthworm compost. As a method of bringing the mushrooms into contact with water, specifically, for example, a method of immersing the mushrooms in water can be mentioned. In this method, the temperature of the water can be, for example, 1 to 50°C, the immersion time can be, for example, 1 to 48 hours, preferably 24 to 48 hours, and the amount of water can be, for example, 3 to 500 times the amount of the mushrooms, preferably 5 to 20 times the amount. After immersion, it is preferable to separate the mushrooms and the water. As another method of bringing the mushrooms into contact with water, specifically, for example, a method of leaving the mushrooms outdoors can be mentioned. In this method, since natural rainfall is allowed to contact and penetrate the mushrooms, it is preferable to leave the mushrooms outdoors for a period sufficient to obtain sufficient rainfall, for example, 1 to 6 months.
[0023] The method of feeding the mushrooms to the earthworms is not particularly limited. Typically, the earthworms can ingest the mushrooms by putting the mushrooms and the earthworms into a container. The earthworms are not particularly limited, and examples include the zebra worm, the grease worm, the giant worm, etc. Among these, the zebra worm that mainly feeds on organic decaying substances is preferably used as the earthworms. The input amount of the earthworms is appropriately determined, but is, for example, about 0.1 to 20% by mass, preferably 1 to 10% by mass, based on 100% by mass of the mushrooms.
[0024] Containers containing bamboo and earthworms can be left for about 1 to 6 months, preferably about 2 to 3 months, although it also varies depending on the amount of earthworms introduced. The environment for leaving them can be any environment where earthworms can grow, for example, a dark place at about 15 to 30°C. Also, during the leaving period, it is preferable to supply water appropriately to prevent excessive drying.
[0025] As the organic matter for earthworms to feed on, other plants can be used together with bamboo. As long as the earthworms are not killed, the types of other plants are not restricted. As other plants, plants with a high nitrogen content are preferably used. Since the carbon content of bamboo is high, by using plants with a high nitrogen content as other plants, it is possible to make the content ratio of carbon and nitrogen (C / N ratio) in the obtained compost fall within a more suitable range. Plants with a high nitrogen content are preferably plants with a nitrogen amount of 3% or more, preferably 5% or more, and desirably 8% or more relative to the carbon amount in the plant. Specifically, leguminous plants are exemplified. As leguminous plants, kudzu, Kawarakezumei, locust bean, Ebi sugusa, senna, hakamakazura, hanazou, tamarind, acacia, arabic gum tree, ojigisou, nemunoki, chickpea, rooibos, kingwood, hamasoybean, sweet pea, hirame, pea, yahazu pea, broad bean, lotus, wisteria, natamame, soybean, fujimame, kidney bean, adzuki bean, enju, purple gromwell, white gromwell, crow pea, rice pea, miyakogusa, vine bean, aretinus bitohaagi, hairy betchi, clitoria, sesbania are exemplified. The plants used can be any of these edible parts, or parts not suitable for eating such as leaves and stems, or even so-called food waste after eating. When using other plants, the usage amount of other plants can be, for example, 30% by mass or less, 20% by mass or less, 10% by mass or less, 5% by mass or less, or 1% by mass or less with respect to 100% by mass of bamboo.
[0026] The obtained bamboo-derived earthworm compost can be used as is or after other processing as an additive of this disclosure. Other processing includes, for example, heat treatment. Heat treatment can further enhance the disease-suppressing effect of the bamboo-derived earthworm compost. For this reason, the bamboo-derived earthworm compost contained in the additive of this disclosure is preferably a heat-treated product of bamboo-derived earthworm compost. The temperature of the heat treatment is, for example, 50 to 150°C, preferably 55 to 130°C, more preferably 60 to 100°C, even more preferably 60 to 90°C, and even more preferably 65 to 80°C. The time of the heat treatment is, for example, 30 minutes to 5 hours, preferably 30 minutes to 2 hours.
[0027] The additives of this disclosure may consist solely of bamboo-derived earthworm compost, or they may contain bamboo-derived earthworm compost in addition to various other components depending on the dosage form, application method, etc., as described later. The proportion of bamboo-derived earthworm compost in the additives of this disclosure can be appropriately determined depending on the properties, application method, etc., as described later, but for example it may be 1-100% by mass, 5-100% by mass, 10-100% by mass, 20-100% by mass, 40-100% by mass, 60-100% by mass, 80-100% by mass, or 90-100% by mass. Other components include, for example, carriers, binders, dispersants, and auxiliary agents. Examples of carriers include solid carriers such as talc, bentonite, clay, kaolin, diatomaceous earth, white carbon, vermiculite, and silica sand; and liquid carriers such as water-soluble polymer compounds (polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, etc.), water, vegetable oil, and liquid animal oil. Examples of binders include casein, gelatin, gum arabic, and alginic acid. Examples of dispersants include alcohol sulfate esters and polyoxyethylene glycol ether. Examples of auxiliary agents include carboxymethylcellulose, starch, and lactose. The above carriers, binders, dispersants, and auxiliary agents can be used individually or in appropriate combinations depending on the purpose.
[0028] The properties of the additives of this disclosure are not particularly limited. The additives of this disclosure may be, for example, solid, plaster-like, gel-like, sol-like, or liquid.
[0029] The additives described herein are intended for use in hydroponic cultivation of plants.
[0030] The plants to which the additives described herein can be applied are not particularly limited, as long as they are plants that can be grown hydroponically. For example, they can be broadly applied to angiosperms (dicotyledonous plants, monocotyledonous plants, etc.). Specific examples include tomatoes, bell peppers, chili peppers, eggplants, cucumbers, pumpkins, melons, watermelons, and other gourds, cabbage, broccoli, Chinese cabbage and other leafy greens, celery, parsley, lettuce and other raw or spicy vegetables, leeks, onions, garlic and other alliums, soybeans, peanuts, green beans, peas, adzuki beans and other legumes, strawberries and other fruit vegetables, taproots such as radishes, turnips, carrots, and burdock, tubers such as taro, cassava, potatoes, sweet potatoes, and yams, asparagus, spinach, komatsuna, shirona, mizuna, ice plant, mitsuba, tsurumurasaki, and shiitake. Examples of target plants include soft vegetables such as sorghum, flowers such as lisianthus, stock, carnation, and chrysanthemum, grains such as rice, wheat, barley, oats, corn, and quinoa, grasses such as bentgrass and Korean lawn grass, oil crops such as rapeseed and peanuts, sugar crops such as sugarcane and sugar beet, fiber crops such as cotton and rush, fodder crops such as clover, sorghum, and dent corn, deciduous fruit trees such as apples, pears, grapes, and peaches, citrus fruits such as Satsuma mandarins, lemons, and grapefruits, root vegetables such as ginger, taro, and sweet potatoes, and flowering trees such as roses and hydrangeas. From the viewpoint of being susceptible to waterborne diseases, spinach, ice plant, perilla, quinoa, and strawberries are preferred as target plants.
[0031] Hydroponics is a cultivation method that uses a solution of fertilizer dissolved in water (nutrient solution) to grow crops without soil. There are several methods of hydroponics, including "hydroponics" in which roots grow in or on the surface of the nutrient solution without using a growing medium, "solid medium cultivation" in which crops are planted in various solid growing media instead of soil, and "spray cultivation" in which the nutrient solution is sprayed onto the roots in a mist. The additives disclosed herein can be applied to any of these methods. Depending on the method, the additives disclosed herein can be used in an appropriate manner that allows the plants (especially the roots or stems) to come into contact with the bamboo-derived earthworm compost.
[0032] The additives of this disclosure are preferably used in a solid culture medium for hydroponic cultivation, from the viewpoint of being able to exert a disease-suppressing effect more effectively. The solid culture medium for hydroponic cultivation is not particularly limited in that it maintains a stable shape, can hold a part of the plant (usually a part or all of the roots or stem) so that the plant does not fall over, and can permeate the supplied nutrient solution so that it comes into contact with the plant's roots or stem and is absorbed by the plant.
[0033] The materials for the solid growing medium for hydroponics are not particularly limited and include, for example, rock wool, urethane, sand, gravel, perlite, peat moss, coconut fiber, vermiculite, leaf mold, bark, bark compost, rice straw, rice straw compost, sawdust, sawdust compost, wood pellets, charcoal, bamboo charcoal, etc. Among these, inorganic materials, especially rock wool, are preferred from the viewpoint of enabling stable germination. The shape of the material for the solid growing medium for hydroponics is preferably fibrous from the viewpoint of water permeability, etc.
[0034] From the viewpoint of more effectively exhibiting disease suppression effects, the solid growing medium for hydroponics is particularly preferably an aggregate of fibrous materials (preferably inorganic materials, and especially preferably rock wool). The shape of the solid growing medium for hydroponics is not particularly limited, but it can be, for example, a cube or a rectangular prism. Furthermore, it is preferable that the solid growing medium for hydroponics is divided into portions for one plant, or that it is used after being divided into portions for one plant.
[0035] The manner in which the additive of this disclosure is retained in a solid culture medium for hydroponics is not particularly limited, as long as the additive does not immediately wash away due to the permeation of the nutrient solution and the plant (especially the roots or stems) can come into contact with the bamboo-derived earthworm compost. From the viewpoint of simplicity, cost, etc., it is preferable to place the additive of this disclosure on the surface of the solid culture medium for hydroponics around the stems or roots of the plants, or at the site where sowing is planned. The supplied nutrient solution continues to permeate the solid culture medium for hydroponics and the bamboo-derived earthworm compost retained therein during hydroponics.
[0036] The amount of the additive of this disclosure to be retained in the solid culture medium for hydroponics is not particularly limited. From the viewpoint of more effectively exhibiting the disease suppression effect, it is preferable to use such a method that 0.001 to 5 g of bamboo-derived earthworm compost is retained per plant in the solid culture medium for hydroponics. The retained amount can be more preferably 0.002 to 2 g, even more preferably 0.005 to 1 g, even more preferably 0.01 to 0.5 g, and particularly preferably 0.01 to 0.1 g. Although the above retained amount is applicable regardless of the plant's growth stage, from the viewpoint of more effectively exhibiting the disease suppression effect, it is particularly preferable that it be the retained amount per plant in the solid culture medium for hydroponics during the sowing to seedling stage (preferably the seedling stage).
[0037] The additives of this disclosure have a disease-suppressing effect in hydroponic cultivation. For this reason, the additives of this disclosure can be used to suppress diseases in hydroponic cultivation. Diseases include, for example, a decrease in yield due to infection by pathogenic fungi. Pathogens are not particularly limited, but examples include Pythium aphanidermatum and other Pythium fungi, Olpidium fungi, Late blight fungi, Downy mildew fungi, Aphanomyces fungi, Fusarium fungi, Soft rot fungi, Bacterial wilt fungi, etc.
[0038] 2. Solid growing medium for hydroponics In one aspect, this disclosure relates to a solid culture medium for hydroponics (which may also be referred to herein as "the culture medium of this disclosure") that holds the additives of this disclosure.
[0039] The culture medium disclosed herein is intended for use in hydroponic cultivation of plants. The culture medium disclosed herein can preferably be used for disease control in hydroponic cultivation.
[0040] The additives, storage methods, hydroponic cultivation, solid media for hydroponic cultivation, target plants, disease suppression, etc. of the culture medium disclosed herein are as described in "1. Additives for Hydroponic Cultivation" above.
[0041] 3. Plant manufacturing methods This disclosure relates, in one aspect, to a method for producing plants (which may be referred to herein as the "production method of this disclosure") that includes growing plants hydroponically in a solid culture medium for hydroponics provided herein.
[0042] The solid culture medium for hydroponics, target plants, and hydroponics methods described herein are as explained in "1. Additives for Hydroponics" and "2. Solid Culture Medium for Hydroponics" above.
[0043] In the manufacturing method of the present disclosure, the timing of using the solid medium for hydroponic cultivation of the present disclosure is not particularly limited. Cultivation can be started by sowing seeds in the solid medium for hydroponic cultivation of the present disclosure, or cultivation can be started by sowing seeds in the solid medium for hydroponic cultivation and cultivating for a certain period of time, after which the additive of the present disclosure can be retained in the solid medium for hydroponic cultivation (i.e., plants can be grown hydroponically in the solid medium for hydroponic cultivation of the present disclosure). In one preferred embodiment of the present invention, it is preferable to retain the additive of the present disclosure in the solid medium for hydroponic cultivation in which seedling plants are growing.
[0044] The nutrient solution used in hydroponics is a solution in which the nutrients (essential elements) necessary for plant growth are dissolved in water at a concentration suitable for absorption, and it is a liquid that is continuously supplied to the plants.
[0045] Nutrients include macronutrients such as nitrogen (nitrate form; NO3-N and ammonia form; NH4-N, etc.), phosphorus (phosphate form; PO4-P, etc.), potassium, calcium, magnesium, and sulfur (sulfate form; SO4-S, etc.), as well as trace elements such as iron, manganese, boron, copper, zinc, molybdenum, silicon, chlorine, aluminum, sodium, and nickel. Carbon, oxygen, and hydrogen can be supplied mainly in the form of carbon dioxide from the air and water absorbed by the roots.
[0046] The composition of the nutrient solution, nutrient solution management, temperature, humidity, light conditions, and other conditions for hydroponic cultivation can be appropriately set according to the type of crop being cultivated and the desired quality of the harvested product. These conditions can be set by referring to resources such as the "New Manual for Hydroponic Cultivation" (edited by the Japan Greenhouse Horticulture Association, Seibundo Shinkosha, July 2002).
[0047] The manufacturing method disclosed herein makes it possible to produce plants while suppressing diseases. According to the manufacturing method disclosed herein, higher yields can be obtained even in the presence of pathogenic fungi. [Examples]
[0048] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.
[0049] Manufacturing Example 1: Production of bamboo-derived earthworm compost Bamboo shoots (from Kawachinagano City, Osaka Prefecture) were processed into a powder with a maximum diameter of approximately 2 mm. Approximately 10 times the volume of water was added to this bamboo powder, and after being left at room temperature (approximately 25°C) for 24 hours, the supernatant was removed to obtain bamboo powder soaked in water. Alternatively, bamboo powder was obtained by leaving it piled up outdoors and exposed to rain for more than 3 weeks. 10 kg of bamboo powder (moisture content 80%) was placed in a plastic container, and 100 g of earthworms (Eisenia foetida) were added. The container was covered and left in a room at 28°C ± 2°C for 2 months. During this time, water was sprayed on the surface approximately once every two days to maintain the moisture content of the composted material at approximately 80%. The obtained compost showed granulation due to the feeding action of the earthworms, and a homogeneous granular structure was observed. The obtained compost was used as bamboo-derived earthworm compost in the following test examples.
[0050] Test Example 1. Evaluation test of disease caused by Pythium aphanidermatum fungus. A simple hydroponic system was constructed using a plastic case (22 cm long x 14 cm wide x 4 cm deep) filled with hydroponic nutrient solution (manufactured by Otsuka House, product name: a mixture of Otsuka House fertilizer No. 1, S1, and No. 2). Rock wool cubes (23 mm long x 23 mm wide x 28 mm high) (manufactured by Grodan, product name: Grodan Taco Plug) were placed inside. The amount of hydroponic nutrient solution was enough to submerge the lower part of the rock wool cubes. Spinach (variety: Mirage) seeds were sown in the central depression on the top surface of the rock wool cubes and grown for 17 days in a plant growing device with a daytime temperature of 23°C and a nighttime temperature of 20°C (11h photoperiod). After 17 days of growth (seedling stage), the plants were divided into three test groups as described below (1) to (3). The presence or absence of treatment and the details of the treatment for each test group are as follows. (1) Untreated: Rock wool cubes only. (2) Vermiculite treatment (hereinafter referred to as "Vermiculite treatment" in Table 1, etc.): 0.2 g of vermiculite (Vermiculite GS30L poly bag, manufactured by Nittai Co., Ltd.) was placed in the center of the top surface of the rockwool cube (around the base of the spinach stem). (3) hVB treatment: 0.1 g of a mixture obtained by heat-treating bamboo-derived earthworm compost at 70°C for 1 hour with vermiculite in a ratio of 1:4 (bamboo-derived earthworm compost: vermiculite) was placed in the center of the top surface of the rock wool cube (around the base of the spinach stem).
[0051] For the test plots described in (1) to (3) above, after the treatments described in (2) to (3) above, the plants were grown for 9 days under artificial lighting at 25°C (12h photoperiod), and Pythium aphanidermatum was inoculated at the base of the spinach plants. Subsequently, the plants were grown for 7 days under artificial lighting at 25°C (12h photoperiod), and the fresh weight of the above-ground and below-ground parts was measured.
[0052] The results are shown in Table 1. * indicates a statistically significant difference compared to the "untreated" group using Student's t-test (5% level). N = 3.
[0053] [Table 1]
[0054] It was found that treatment with bamboo-derived earthworm compost suppressed the inhibition of above-ground and root growth. Furthermore, observation of the root appearance revealed that the degree of root browning was significantly lower in the test plots treated with bamboo-derived earthworm compost compared to the other test plots.
[0055] Test Example 2. Evaluation Test of Disease Caused by Orpidium Fungi A simple hydroponic system was constructed using a plastic case (28 cm long x 16 cm wide x 10 cm deep). Hydroponic nutrient solution (manufactured by Kyowa Co., Ltd., product name: Hyponica Liquid Fertilizer) was placed inside, and individual rockwool cubes (23 mm long x 23 mm wide x 28 mm high) (manufactured by Grodan, product name: Grodan Taco Plug) were placed inside. The amount of hydroponic nutrient solution was enough to submerge the lower part of the rockwool cubes. Spinach (variety: Mirage) seeds were sown in the central depression on the top surface of the rockwool cubes, and the plants were grown for 17 days in a plant growing device with a daytime temperature of 23°C and a nighttime temperature of 20°C (11h photoperiod). After 17 days of growth (seedling stage), the plants were divided into four test groups (A) to (D) below. The presence or absence of treatment and the details of the treatment for each test group are as follows. (A) Untreated: Rock wool cubes only. (B) Treatment: 0.2 g of vermiculite was placed in the center of the top surface of the rockwool cube (around the base of the spinach stem). (C) VB treatment: 0.1 g of a mixture obtained by mixing unheated bamboo-derived earthworm compost and vermiculite in a ratio of 1:4 (bamboo-derived earthworm compost: vermiculite) was placed in the center of the top surface of the rockwool cube (around the base of the spinach stem). (D) hVB treatment: Bamboo-derived earthworm compost, heat-treated at 70°C for 1 hour, and vermiculite were mixed in a ratio of 1:4 (bamboo-derived earthworm compost: vermiculite). 0.1g of this mixture was placed in the center of the top surface of the rockwool cube (around the base of the spinach stem).
[0056] For the test plots (A) to (D) described above, after the treatments described in (B) to (D), Orpidium bacteria were inoculated into the hydroponic nutrient solution of spinach. Subsequently, the plants were grown for 11 days in a growth chamber at a daytime temperature of 23°C and a nighttime temperature of 20°C (11h photoperiod), and the fresh weight of the above-ground and underground parts was measured.
[0057] The results are shown in Table 2. * indicates a statistically significant difference compared to the "untreated" group using Student's t-test (5% level). N = 7.
[0058] [Table 2]
[0059] It was found that treating plants with bamboo-derived earthworm compost suppressed the inhibition of above-ground and root growth. Furthermore, it was found that the inhibitory effect was enhanced by heat treatment of the bamboo-derived earthworm compost.
Claims
1. A nutrient-rich additive for hydroponic cultivation, containing bamboo-derived earthworm compost and intended to be retained in a solid growing medium for hydroponics.
2. The additive for hydroponic cultivation according to claim 1, wherein the material of the solid growing medium for hydroponic cultivation includes at least one selected from the group consisting of rock wool, urethane, sand, gravel, perlite, peat moss, coconut fiber, vermiculite, leaf mold, bark, bark compost, rice straw, rice straw compost, sawdust, sawdust compost, wood pellets, charcoal, and bamboo charcoal.
3. A hydroponic cultivation additive according to claim 1 or 2, for use in such a way that 0.001 to 5 g of the bamboo-derived earthworm compost is held in the solid culture medium for hydroponic cultivation for one plant.
4. A hydroponic cultivation additive according to any one of claims 1 to 3, for use in suppressing diseases in hydroponic cultivation.
5. The additive for hydroponic cultivation according to any one of claims 1 to 4, wherein the bamboo-derived earthworm compost is a heat-treated product of bamboo-derived earthworm compost.
6. A solid culture medium for hydroponic cultivation that holds the additive for hydroponic cultivation described in any one of claims 1 to 5.
7. A solid culture medium for hydroponic cultivation according to claim 6, for use in suppressing diseases.
8. A method for producing plants, comprising growing plants hydroponically using a solid growing medium for hydroponic cultivation described in claim 6 or 7.