Hydroponic method and hydroponic device with nutrient solution buffering system

Abstract

The application discloses a hydroponic method and device with a nutrient solution buffer system; the hydroponic method comprises the following steps: placing seeds on the surface of mineral rocks in a planting device, adding water in a nutrient pool, and culturing until the second true leaf of the plant grows; the particle size of the mineral rocks is 1-6 mm; adding a nutrient solution and culturing until the fourth true leaf of the plant grows; adding a culture solution with EC=0.4-0.6 in the first week, adding a culture solution with EC=0.6-0.8 in the second week, adding a culture solution with EC=1.0-1.2 in the third week, and then adding a culture solution with EC=1.4-1.6. The application effectively adjusts and buffers the concentration of nutrient elements in the nutrient solution, achieves accurate control of the concentration of the nutrient solution, creates a competitive relationship between plant growth and green algae reproduction for the nutrient solution, and thus can meet the growth demand of crops and prevent the large-scale reproduction of green algae.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of modern agricultural hydroponic technology and modern agricultural facility construction / equipment manufacturing technology, and particularly relates to a hydroponic method and a hydroponic device with a nutrient solution buffering system. BACKGROUND

[0002] Hydroponic technology is a plant cultivation technology developed in recent decades, which does not use soil to cultivate plants but allows the roots of plants to grow in nutrient solution to provide water, nutrients, air and temperature required by plants throughout the growth cycle.

[0003] Conditions to be met: the seed tank can hold nutrient solution without leakage; the plant can be anchored and the root system can be immersed in the nutrient solution; the nutrient solution and the root system are in the dark; the container holding the nutrient solution needs to be sterilized; the root system needs to obtain sufficient oxygen; the nutrient solution needs to be replaced regularly.

[0004] Types of hydroponic technology: deep liquid flow hydroponic technology, shallow liquid flow hydroponic technology, floating plate and capillary hydroponic technology, and nutrient film technology.

[0005] Hydroponic infrastructure structure: (1) nutrient solution tank. The nutrient solution tank is a device for storing nutrient solution. (2) Cultivation bed. The cultivation bed consists of two parts: bed body and cultivation board. (3) Nutrient solution system. The nutrient solution system includes three parts: liquid adding system, liquid draining system and circulation system.

[0006] The advantages of hydroponic production technology are increasingly valued by people. Hydroponic planting of vegetables has the advantages of short production cycle, high yield and simple operation. Hydroponic technology will be widely used in production.

[0007] In the process of hydroponic experiment or production, no matter what kind of nutrient solution exposed soilless cultivation method, such as hydroponics, fog culture, etc., green algae will grow and reproduce seriously. Green algae are contained in ordinary air and water used to prepare nutrient solution. Since green algae like fertilizer, moisture and light, they will reproduce and expand rapidly in the nutrient solution as soon as they enter the nutrient solution. Moreover, green algae have certain adhesion ability and will adhere to the inner surface of the hydroponic device and the plant roots.

[0008] The massive reproduction and huge increase of green algae will compete with plants for nutrients and dissolved oxygen, affecting the normal growth of plants. At the same time, green algae release some harmful substances to the nutrient solution during their life activities and metabolism, which have adverse effects on the normal growth of plants. Especially when there are more green algae, they will adhere to the surface of plant roots in large quantities, inhibit the life activities of roots, and block the absorption of water and nutrients by plant roots, directly and rapidly leading to the death of plants.

[0009] At present, green algae mainly removes or reduces the concentration of phosphorus and nitrogen by adsorption to inhibit (CN111377495A), but this method has high cost, incomplete removal, low nutrient content, and cannot be used for plant hydroponics; therefore, a green algae inhibition method suitable for plant hydroponics needs to be developed. SUMMARY

[0010] In view of the deficiencies of the prior art, the purpose of the present application is to provide a hydroponic method and device with a nutrient solution buffer system, which can effectively solve the problem of green algae affecting the normal growth of plants in the production process of plant hydroponics, maintain the water body of the hydroponic nutrient solution from being polluted by green algae, and improve the utilization rate of the nutrient solution, promote the pollution-free production of plants, and protect the environment and ecology.

[0011] The purpose of the present application is achieved by the following technical solutions:

[0012] A hydroponic method with a nutrient solution buffer system, comprising the following steps:

[0013] (1) placing seeds on the surface of mineral rocks in the planting device, and adding water in the nutrient pool to cultivate the plants until the second true leaf grows;

[0014] (2) adding nutrient solution to cultivate the plants until the fourth true leaf grows;

[0015] (3) thereafter, adding culture solution with EC=0.4-0.6 to cultivate the plants in the first week, adding culture solution with EC=0.6-0.8 to cultivate the plants in the second week, adding culture solution with EC=1.0-1.2 to cultivate the plants in the third week, and thereafter adding culture solution with EC=1.4-1.6 to cultivate the plants.

[0016] Preferably, the mineral rocks are mineral rocks with good adsorption / release capacity.

[0017] Further preferably, the mineral rocks are 1-3mm montmorillonite and 4-6mm expanded perlite.

[0018] Preferably, in step (1), water is added to the level of the surface of the mineral rocks, and water is added every three days during the cultivation process to keep the water level at the level of the surface of the mineral rocks.

[0019] Preferably, in step (2), the amount of added nutrient solution is: v / 75-v / 95ml of nutrient solution with EC value of 0.8, wherein v is the amount of water added in step (1), i.e. the amount of water added to the level of the surface of the mineral rocks.

[0020] The hydroponic device of the above-mentioned hydroponic method with a nutrient solution buffer system comprises a nutrient pool, a planting rack and mineral rocks; the planting rack comprises a plurality of planting devices fixed on the same panel; the mineral rocks are placed in the planting devices, and the particle size of the mineral rocks is 1-6mm.

[0021] Preferably, the top of the planter is a circular hole with a radius of 1.5-2.5 cm, and the bottom is a hollow bottom with a radius of 1-1.5 cm, and the hollow part is a fence structure with a gap of less than 3 mm.

[0022] Preferably, the height of the mineral rock is 3-5 cm.

[0023] Preferably, the planar specification of the planting frame is a*b, the planting device spacing is 8-12 cm*8-12 cm, the height is 6-8 cm, a=55-75 cm, and b=10-30 cm.

[0024] Further preferably, the specification of the nutrient pool is: the top size (a+2)*(b+8), the bottom size a*(b+6), and the height is 4-6 cm.

[0025] The present application can be applied to vegetable production and general cultivation tests.

[0026] The water culture method based on the present application does not breed / grow green algae, the operation is standardized and simplified, and the modular device is flexible, which is more suitable for indoor production planting.

[0027] The principle of the present application is that the present application effectively adjusts and buffers the nutrient element concentration of the nutrient solution, achieves precise control of the nutrient solution concentration, creates a competitive relationship between plant growth and green algae reproduction for the nutrient solution, so as to meet the growth demand of crops and prevent the large-scale reproduction of green algae at the same time.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] (1) No green algae breeding / reproduction

[0030] The present application can realize scientific and efficient growth of crops in the water culture production process, and prevent the large-scale reproduction of green algae at the same time.

[0031] (2) Improve the utilization rate of nutrient solution

[0032] The water culture method of the present application does not need to be frequently replaced during operation, the plant growth makes full use of the added nutrient solution to the greatest extent, and the loss and residue of nutrient elements are greatly reduced.

[0033] (3) Non-polluting vegetable production

[0034] The dynamic balance of the nutrient element content will not exceed the standard, will not lack nutrients, and will maintain the precise utilization of plants.

[0035] (4) Standardized and simplified operation

[0036] In the production process, the operation steps are reduced, and the operation is simplified.

[0037] (5) Increase capacity, reduce cost

[0038] The device configured by the method has the modularization feature, low manufacturing cost, and greatly reduces the limitation of production place, and is higher in land occupation and space utilization.

[0039] (6) Ecological and environmental protection

[0040] The method uses all environmental protection materials, can be repeatedly used, the nutrient solution is completely closed loop circulation and the residual water discharge is clean and pollution-free. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The figure is a structure diagram of the hydroponic device with the nutrient solution buffer system. DETAILED DESCRIPTION

[0042] In order to make the present application more easily understood, the content of the application will be further described in detail in combination with specific embodiments, but the implementation of the present application is not limited to this.

[0043] The device related to the present application is a combined device, which comprises a nutrient pool, a planting frame and mineral rocks.

[0044] The nutrient pool is used to distribute nutrient solution and place the planting frame, and the specification is: the top size is 67cm*28cm, the bottom size is 65cm*26cm, and the height is 4-6cm.

[0045] The planting frame is formed by fixing a plurality of special planting devices on the same plate, the plane specification is 65cm*20cm, the planting device spacing is 10cm*10cm, and the height is 6-8cm.

[0046] The planting device is used to fill mineral rocks and plant seedlings, the top is a circular hole with a radius of 1.5-2.5cm, the bottom is a hollow bottom with a radius of 1-1.5cm, and the hollow part is a fence structure with a gap less than 3mm.

[0047] The mineral rock is a mineral rock particle with good adsorption / slow release capacity with a particle size of 1-3mm and a particle size of 4-6mm.

[0048] The hydroponic method of the present application is as follows:

[0049] Put the planting frame in the nutrient pool, fill the mineral rock in the planting device to a depth of 3-5 cm, place the seeds on the surface of the mineral rock, add clean water to the nutrient pool until the surface of the mineral rock is level, and replenish water every three days to keep the water surface level with the surface of the mineral rock; when the plant grows the second true leaf, 100 ml of nutrient solution with an EC value of 0.8 needs to be added to the nutrient pool; when the plant grows the fourth true leaf, start using the nutrient solution for cultivation, the first week: EC = 0.4-0.6, the second week: EC = 0.6-0.8, the third week: EC = 1.0-1.2, and the fourth week onwards: EC = 1.4-1.6.

[0050] The seeds used in the examples and comparative examples are: lettuce (fast-growing No. 2);

[0051] The mineral rock used in the examples and comparative examples is: montmorillonite (1-3 mm), expanded perlite (4-6 mm);

[0052] The nutrient solution used in the examples and comparative examples is: A / B type water culture general nutrient solution stock solution.

[0053] Example 1

[0054] The water culture device is as follows:

[0055] Nutrient pool (top size 67 cm*28 cm, bottom size 65 cm*26 cm, height 4 cm), planting frame (plane size 65 cm*20 cm, planting device spacing 10 cm*10 cm, height 6 cm), planting device (top half radius 1.5 cm round hole, bottom center hollow bottom with radius 1 cm, hollow part is a fence structure with 2 mm gap), mineral rock (montmorillonite with particle size 1 mm and expanded perlite with particle size 4 mm, mineral rock particles with good adsorption / slow release capacity).

[0056] The water culture method is as follows:

[0057] Put the planting frame in the nutrient pool, fill the mineral rock in the planting device to a depth of 3 cm, place the seeds on the surface of the mineral rock, add clean water to the nutrient pool until the surface of the mineral rock is level, and replenish water every three days to keep the water surface level with the surface of the mineral rock; when the plant grows the second true leaf, 100 ml of nutrient solution with an EC value of 0.8 needs to be added to the nutrient pool; when the plant grows the fourth true leaf, start using the nutrient solution for cultivation (the nutrient solution is level with the surface of the mineral rock), the first week: EC = 0.4, the second week: EC = 0.6, the third week: EC = 0.8, and the fourth week onwards: EC = 1.0.

[0058] Under this technical solution, the plant grows well after 4 weeks of cultivation, and does not breed / breed green algae.

[0059] Example 2

[0060] The hydroponic device is as follows:

[0061] A nutrient pool (top size 67 cm*28 cm, bottom size 65 cm*26 cm, height 6 cm), a planting frame (plane size 65 cm*20 cm, planting device spacing 10 cm*10 cm, height 8 cm), a planting device (top half radius 2.5 cm circular hole, bottom radius 2 cm center hollow bottom, hollow part is a fence structure with a gap of 2 mm), mineral rock (montmorillonite with a particle size of 3 mm, expanded perlite with a particle size of 6 mm, mineral rock particles with good adsorption / slow release capacity).

[0062] The hydroponic method is as follows:

[0063] The planting frame is placed in the nutrient pool, and the mineral rock is filled in the planting device to a depth of 5 cm, the seeds are placed on the surface of the mineral rock, and the nutrient pool is added with clean water to be flush with the surface of the mineral rock, and the water surface is kept flush with the surface of the mineral rock every three days; when the plant grows out the second true leaf, 100 ml of nutrient solution with an EC value of 0.8 is added to the nutrient pool; when the plant grows out the fourth true leaf, the nutrient solution is used for cultivation, the first week: EC=0.4, the second week: EC=0.6, the third week: EC=0.8, and the fourth week: EC=1.0.

[0064] Under this technical scheme, the plant grows well after 4 weeks of culture, and does not breed / proliferate green algae.

[0065] Example 3

[0066] The hydroponic device is as follows:

[0067] A nutrient pool (top size 67 cm*28 cm, bottom size 65 cm*26 cm, height 4 cm), a planting frame (plane size 65 cm*20 cm, planting device spacing 10 cm*10 cm, height 6 cm), a planting device (top half radius 2.5 cm circular hole, bottom radius 2 cm center hollow bottom, hollow part is a fence structure with a gap of 2 mm), mineral rock (montmorillonite with a particle size of 2 mm, expanded perlite with a particle size of 5 mm, mineral rock particles with good adsorption / slow release capacity).

[0068] The hydroponic method is as follows:

[0069] Put the planting frame in the nutrient pool, fill the mineral rock in the planting device to a depth of 3 cm, put the seeds on the surface of the mineral rock, add clean water to the nutrient pool until the surface of the mineral rock is level, and replenish water every three days to keep the water surface level with the surface of the mineral rock; when the plant grows the second true leaf, add 100 ml of nutrient solution with an EC value of 0.8 to the nutrient pool; when the plant grows the fourth true leaf, start using nutrient solution for cultivation, the first week: EC = 0.6, the second week: EC = 0.8, the third week: EC = 1.0, and the fourth week onwards: EC = 1.2.

[0070] Under this technical solution, the plant grows well after 4 weeks of cultivation, and does not breed / proliferate green algae.

[0071] Comparative Example 1

[0072] The water culture device is as follows:

[0073] Nutrient pool (top size 67 cm*28 cm, bottom size 65 cm*26 cm, height 4 cm), planting frame (plane size 65 cm*20 cm, planting device spacing 10 cm*10 cm, height 6 cm), planting device (top half radius 1.5 cm round hole, bottom center hollow bottom with radius 1 cm, hollow part is a fence structure with gap 2 mm), use sponge or sand instead of mineral rock.

[0074] The water culture method is as follows:

[0075] Put the planting frame in the nutrient pool, fill the sponge or sand in the planting device to a depth of 3 cm, put the seeds on the surface of the sponge or sand, add clean water to the nutrient pool until the surface of the mineral rock is level, and replenish water every three days to keep the water surface level with the surface of the mineral rock; when the plant grows the second true leaf, add 100 ml of nutrient solution with an EC value of 0.8 to the nutrient pool; when the plant grows the fourth true leaf, start using nutrient solution for cultivation, the first week: EC = 0.4, the second week: EC = 0.6, the third week: EC = 0.8, and the fourth week onwards: EC = 1.0.

[0076] Under this technical solution, the plant grows poorly, stops growing, and some plants die; green algae appear at the bottom of the nutrient pool on the third day of cultivation, and a large number of green algae breed and proliferate on the fifth day of cultivation, and the water body is blue-green.

[0077] Comparative Example 2

[0078] The water culture device is as follows:

[0079] Nutrient pool (top size 67cm*28cm, bottom size 65cm*26cm, height 4cm), planting frame (plane size 65cm*20cm, planting device spacing 10cm*10cm, height 6cm), planting device (top radius 1.5cm round hole, bottom radius 1cm center hollow bottom, hollow part is a fence structure with a gap of 2mm), mineral rock (montmorillonite with a particle size of 2mm, expanded perlite with a particle size of 5mm, mineral rock particles with good adsorption / slow release capacity).

[0080] The water culture method is as follows:

[0081] The planting frame is placed in the nutrient pool, and the mineral rock is filled in the planting device to a depth of 3cm, the seeds are placed on the surface of the mineral rock, and clean water is added to the nutrient pool to be flush with the surface of the mineral rock, and the water surface is kept flush with the mineral rock surface every three days; when the plant grows out the second true leaf, 100ml of nutrient solution with an EC value of 0.8 is added to the nutrient pool; when the plant grows out the fourth true leaf, the nutrient solution is used for cultivation, the first week: EC=0.3, the second week: EC=0.4, the third week: EC=0.5, and the fourth week: EC=0.6.

[0082] Under this technical scheme, the plant grows poorly, the growth is hindered, the seedling is thin and weak, and the leaf loses green; on the 7th day of cultivation, green algae appear at the bottom of the nutrient pool, and on the 12th day of cultivation, green algae breed and reproduce in large quantities, and the water body is blue-green.

[0083] Comparative example 3

[0084] The water culture device is as follows:

[0085] Nutrient pool (top size 67cm*28cm, bottom size 65cm*26cm, height 4cm), planting frame (plane size 65cm*20cm, planting device spacing 10cm*10cm, height 6cm), planting device (top radius 1.5cm round hole, bottom radius 1cm center hollow bottom, hollow part is a fence structure with a gap of 2mm), mineral rock (montmorillonite with a particle size of 2mm, expanded perlite with a particle size of 4mm, mineral rock particles with good adsorption / slow release capacity).

[0086] The water culture method is as follows:

[0087] Put the planting frame in the nutrient pool, fill the mineral rock in the planting device to a depth of 3 cm, put the seeds on the surface of the mineral rock, add clean water to the nutrient pool until the surface of the mineral rock is level, and replenish water every three days to keep the water surface level with the surface of the mineral rock; when the plant grows the second true leaf, 100 ml of nutrient solution with an EC value of 0.8 needs to be added to the nutrient pool; when the plant grows the fourth true leaf, start using nutrient solution for cultivation, the first week: EC = 0.8, the second week: EC = 1.0, the third week: EC = 1.2, and the fourth week onwards: EC = 1.5.

[0088] Under this technical solution, the plant grows poorly, stops growing, and part of the plant dies; green algae appears at the bottom of the nutrient pool on the 4th day of cultivation, and on the 5th day of cultivation, green algae proliferates and reproduces in large quantities, and the water body is blue-green.

[0089] Comparative Example 4

[0090] The water culture device is as follows:

[0091] Nutrient pool (top size 67 cm*28 cm, bottom size 65 cm*26 cm, height 4 cm), planting frame (plane size 65 cm*20 cm, planting device spacing 10 cm*10 cm, height 6 cm), planting device (top half radius 1.5 cm round hole, bottom center hollow bottom with radius 1 cm, hollow part is a fence structure with gap less than 3 mm), mineral rock (montmorillonite with particle size 4 mm, expanded perlite with particle size 7 mm, mineral rock particles with good adsorption / slow release capacity).

[0092] The water culture method is as follows:

[0093] Put the planting frame in the nutrient pool, fill the mineral rock in the planting device to a depth of 3 cm, put the seeds on the surface of the mineral rock, add clean water to the nutrient pool until the surface of the mineral rock is level, and replenish water every three days to keep the water surface level with the surface of the mineral rock; when the plant grows the second true leaf, 100 ml of nutrient solution with an EC value of 0.8 needs to be added to the nutrient pool; when the plant grows the fourth true leaf, start using nutrient solution for cultivation, the first week: EC = 0.4, the second week: EC = 0.6, the third week: EC = 0.8, and the fourth week onwards: EC = 1.0.

[0094] Under this technical solution, green algae appears at the bottom of the nutrient pool on the 7th day of cultivation, and on the 10th day of cultivation, green algae proliferates and reproduces in large quantities, and the water body is blue-green.

[0095] Comparative Example 5

[0096] The water culture device is as follows:

[0097] Nutrient pool (top size 67cm*28cm, bottom size 65cm*26cm, height 4cm), planting frame (flat size 65cm*20cm, planting device spacing 10cm*10cm, height 6cm), planting device (top half radius 1.5cm circular hole, bottom radius 1cm center hollow bottom, hollow part is a fence structure with 2mm gap), mineral rock (montmorillonite with particle size 1mm and expanded perlite with particle size 4mm have good adsorption / slow release ability of mineral rock particles).

[0098] The blank control is as follows:

[0099] Place the planting frame in the nutrient pool, fill the mineral rock in the planting device to a depth of 3cm, add clean water to the nutrient pool to the level of the surface of the mineral rock, and replenish water every three days to keep the water surface level with the surface of the mineral rock; add 100ml of nutrient solution with an EC value of 0.8 to the nutrient pool for the first three days; subsequently, first week: EC=0.4, second week: EC=0.6, third week: EC=0.8, fourth week onwards: EC=1.0.

[0100] Under this technical solution, green algae started to grow on the surface of the mineral on the 5th day, and the nutrient solution water body started to become turbid on the 7th day, with a large amount of growth and reproduction of green algae.

[0101] Result analysis:

[0102] Comparison of Example 1 and Comparative Example 1: without the buffering effect, the plants grow poorly and are prone to green algae pollution;

[0103] Comparison of Example 3 and Comparative Example 2: the EC value of the nutrient solution is lower than the reasonable range of the scheme, the plants grow poorly, and green algae also proliferate, affecting the effect.

[0104] Comparison of Example 3 and Comparative Example 3: the EC value of the nutrient solution is higher than the reasonable range of the scheme, the plants grow poorly, and green algae also proliferate, affecting the effect.

[0105] Comparison of Example 1 and Example 2: adjusting the specifications and mineral rock particle size within the reasonable range of the scheme has little effect on the effect;

[0106] Comparison of Example 1 and Comparative Example 4: the mineral rock particle size is not adjusted within the reasonable range of the scheme, which has a greater effect on the effect and loses the green algae inhibition effect;

[0107] Comparison of Example 1 and Comparative Example 5: without transplanting plants, the system is incomplete, and the green algae inhibition effect is poor;

[0108] The above embodiments are preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A hydroponic method with a nutrient solution buffering system, using a hydroponic device, the hydroponic device comprising a nutrient tank, a planting rack, and mineral rocks, the planting rack being fixed to the same flat plate by a plurality of specially designed planters, characterized in that, The method comprises the following steps: Placing seeds on the surface of mineral rocks in the planting device, and adding water in the nutrient pool to culture the plants until the second true leaves grow; the mineral rocks are montmorillonite with a particle size of 1 mm and expanded perlite with a particle size of 4 mm; Placing the planting frame in the nutrient pool, filling the planting device with mineral rocks to a depth of 3 cm, placing seeds on the surface of the mineral rocks, adding clean water to the nutrient pool until the surface of the mineral rocks is level, and replenishing water every three days to keep the water surface level with the surface of the mineral rocks; when the second true leaves grow, 100 ml of nutrient solution with an EC value of 0.8 is added to the nutrient pool; when the fourth true leaves grow, the nutrient solution is used for cultivation, the nutrient solution is level with the surface of the mineral rocks, the first week: EC=0.4, the second week: EC=0.6, the third week: EC=0.8, and the fourth week onwards: EC=1.0; after 4 weeks of culture, the plants grow well and do not breed green algae.

2. A hydroponic method with a nutrient solution buffering system, using a hydroponic device, the hydroponic device comprising a nutrient tank, a planting rack, and mineral rocks, the planting rack being fixed to the same panel by a plurality of specially designed planters, characterized in that, The method comprises the following steps: Placing seeds on the surface of mineral rocks in the planting device, and adding water in the nutrient pool to culture the plants until the second true leaves grow; the mineral rocks are montmorillonite with a particle size of 3 mm and expanded perlite with a particle size of 6 mm; Placing the planting frame in the nutrient pool, filling the planting device with mineral rocks to a depth of 5 cm, placing seeds on the surface of the mineral rocks, adding clean water to the nutrient pool until the surface of the mineral rocks is level, and replenishing water every three days to keep the water surface level with the surface of the mineral rocks; when the second true leaves grow, 100 ml of nutrient solution with an EC value of 0.8 is added to the nutrient pool; when the fourth true leaves grow, the nutrient solution is used for cultivation, the first week: EC=0.4, the second week: EC=0.6, the third week: EC=0.8, and the fourth week onwards: EC=1.0; after 4 weeks of culture, the plants grow well and do not breed green algae.

3. A hydroponic method with a nutrient solution buffering system, using a hydroponic device, the hydroponic device comprising a nutrient tank, a planting rack, and mineral rocks, the planting rack being fixed to the same flat plate by a plurality of specially designed planters, characterized in that, The method comprises the following steps: Placing seeds on the surface of mineral rocks in the planting device, and adding water in the nutrient pool to culture the plants until the second true leaves grow; the mineral rocks are montmorillonite with a particle size of 2 mm and expanded perlite with a particle size of 5 mm; Placing the planting frame in the nutrient pool, filling the planting device with mineral rocks to a depth of 3 cm, placing seeds on the surface of the mineral rocks, adding clean water to the nutrient pool until the surface of the mineral rocks is level, and replenishing water every three days to keep the water surface level with the surface of the mineral rocks; when the second true leaves grow, 100 ml of nutrient solution with an EC value of 0.8 is added to the nutrient pool; when the fourth true leaves grow, the nutrient solution is used for cultivation, the first week: EC=0.6, the second week: EC=0.8, the third week: EC=1.0, and the fourth week onwards: EC=1.2; after 4 weeks of culture, the plants grow well and do not breed green algae.

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