JPH0452730B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a submerged/lowered liquid level/humid root cultivation method that combines submerged cultivation and humid root cultivation. [Conventional technology] Hydroponic cultivation is broadly divided into two types: hydroponic cultivation and solid medium cultivation, each of which has its advantages and disadvantages. Hydroponic cultivation is a method in which the roots of plants grow in a culture solution, and the underwater roots have the triple role of absorbing water and nutrients as well as absorbing dissolved oxygen. Plant roots will suffocate to death without oxygen, so various methods have been devised to supply dissolved oxygen. A typical method is shown in Fig. 2, in which cultivation is carried out by circulating the culture solution a in a sloped cultivation bed b. In other words,
This method obtains dissolved oxygen by moving water. This method has the advantage that the pH and concentration of the culture solution a are uniform, easy to manage, and can be automated. In Figure 2, c is the panel, e is the crop, f is the culture solution tank, g is the topdressing device, h is the liquid supply pump,
i ₁ , i ₂ , i ₃ , and i ₄ are piping such as a liquid supply pipe and a liquid drain pipe, respectively. In solid medium cultivation, plants are rooted in solid materials such as gravel, sand, rock wool, etc., and a culture medium is applied intermittently to cultivate them. Oxygen is supplied from the dissolved oxygen in the culture medium and the aerial roots by intermittent supply of liquid. ing. Therefore, various ideas have been made for culture medium and liquid supply, and liquid supply methods include circulation type and irrigation type. Among these, the circulation type, as shown in Fig. 3, injects the culture solution l into the culture medium n of the cultivation bed m from the inlet p of the supply pipe _o1 , and drains the overflowing culture solution l into the drain pipe. This circulation _system has the same advantages as hydroponic cultivation. In the figure,
o ₃ and o ₄ are pipes, r is a topdressing device, and s is a liquid supply tank. [Problems to be solved by the invention] Hydroponic cultivation, on the other hand, has the disadvantage that once pathogenic bacteria invade, there is a risk that they will spread throughout the plant and wipe it out, and that large-scale equipment is required to obtain dissolved oxygen. Furthermore, among solid medium cultivation methods, the circulating method has the same advantages and disadvantages as hydroponic cultivation, and the irrigated method is relatively safe against diseases, but the moisture content and concentration of each bed varies. Plants originally put down their roots in the soil and dig out the soil.
Soil has adapted and evolved to absorb water and nutrients by grabbing water and nutrients, and soil is divided into a solid phase and pores (more than 60%) by volume, and ideally these pores should be half liquid and half gas. It is said that there must be at least 10% capillary pores (gas phase) where capillary water is not retained. The solid phase supports the expansion of the roots, the liquid phase dissolves nutrients from the solid phase in small amounts, and the gas phase provides oxygen needed by the roots (respiration for the roots to absorb energy,
Provides respiration for new growth and respiration for rhizosphere microorganisms). Of the first two, hydroponic cultivation uses the oxygen in the culture solution in which nutrients are dissolved, while solid medium cultivation uses a specific medium instead of soil. In both cases, it is difficult to control the size of the gas phase in accordance with plant growth. An object of the present invention is to provide a method for submerged, lowered liquid level, and humid root cultivation that eliminates these problems in conventional culture solution cultivation. [Means for solving the problems] The submerged, liquid level lowered, and humid medium root cultivation method of the present invention has the following features:
To achieve this purpose, a double-structured root chamber consisting of an outer multi-hole container on the side and an inner multi-hole container on the side containing the culture medium was placed upright in a semi-underground liquid tank filled with culture medium, and the root chamber was placed in a concentric configuration. A multi-hole planting container with seedlings planted in the medium is placed on top of the multi-hole container so that the bottom part is in contact with the container and the lower half is immersed in the culture solution,
The multi-hole planting container, root chamber, and liquid tank are covered with a light-shielding film, except for the seedling parts exposed to the outside air, and the roots are exposed to atmospheric oxygen as the level of the culture solution in the liquid tank decreases as the crop grows. It is characterized by cultivating until harvest while increasing humidity to encourage root development. [Example] The features of the present invention will be specifically explained below using Examples. For example, in the cultivation of melons, as shown in FIG. 1, a semi-underground liquid tank 1 filled with a culture solution 2,
A multi-hole external container 4 and a culture medium 6 are placed upright in the liquid tank 1.
A cultivation bed consisting of a root chamber 3 consisting of a lateral multi-hole inner container 5 containing a seedling, a multi-hole planting container 7 in which seedlings 8 are planted in a medium 6, and a light-shielding film 9 is used. Among these, the liquid tank 1 is a type of container that is semi-underground to ensure the root zone temperature using geothermal exchange, and is filled with the amount of culture liquid 2 required by the crops. A light-shielding film 9 is placed over the liquid tank 1 to protect the roots by maintaining darkness and humidity. In the embodiment, the light shielding film 9 has a silver mirror film 9a on the outside and a nonwoven fabric 9b on the inside to provide heat insulation properties. The root chamber 3 includes an outer multi-hole container 4 on the side for storing the roots 10, and an inner multi-hole container 5 on the side for storing the culture medium.
It is a double container consisting of. Among these, the multi-hole outer container 4 is made of a root mat pipe having a large number of holes on the side surface, and the outer surface thereof is sequentially wrapped with a spunbond 11 and a root-preventing water-permeable fabric 12 made of a water-permeable nonwoven fabric. Therefore, sufficient humidity is maintained in the root chamber 13, which is a cylindrical space formed between the multi-hole outer container 4 and the inner multi-hole container 5. Further, the multi-hole planting container 7, which is placed with its bottom in contact with the multi-hole inner container 5 on the side surface of the root chamber 3, has a large number of holes on the side surface and the bottom surface and is a container for planting seedlings 8. As the material for the multi-hole transplanting container 7, the multi-hole outer container 4 on the side, and the inner multi-hole container on the side 5, in addition to polyethylene, polypropylene, polystyrene, polyvinyl chloride, etc., foamed plastic materials such as expanded polystyrene can also be used. Moreover, a ceramic unglazed container that can withstand repeated use can also be used. A multi-hole planting container 7 suitable for cultivating melons has a large number of holes provided on the side surface and the bottom surface from above and below. The multi-hole outer container 4 has a large number of holes extending above and below the side surface. Furthermore, the side multi-hole inner container 5 has a diameter of 8, for example.
cm, height 42 cm, and has many holes with diameters of about 5 mm to 15 mm extending over the top and bottom of the sides. The culture medium 6 used in the multi-hole planting container 7 and the multi-hole lateral inner container 5 contains charcoal as a main component. As the carbonized material, carbonized materials such as black ash, which is a waste product from soda pulp production at a paper mill, activated carbon from rice grains, activated carbon from wood chips, etc., are used. A suspension is prepared by adding 5 parts of water to 1 part of these carbides. In this suspension
Add H ₃ PO ₄ and leave for about 24-48 hours to fully adsorb onto the char. This char is separated by filtration and washed with water. The filtered charcoal is immersed in a culture solution suitable for melon cultivation having the following composition for about one week. After each component is adsorbed to the char, the char is filtered off to obtain a medium suitable for sowing, potting, and planting.

〔Effect of the invention〕

As explained above, in the submerged, lowered liquid level, and humid root cultivation method of the present invention, a porous and culture medium is placed in a container having many holes for growing roots of crops and supplying air. This method uses a charcoal-based culture medium impregnated with a charcoal-based medium and fills it with a culture solution to grow crops in a semi-underground cultivation bed. Since the culture solution does not circulate, there is no need for equipment such as pumps, piping, or tanks. Since it is a non-circulating type, even if a disease occurs, it will be localized, making it easy to treat and take safety measures. As the level of the culture medium in the cultivation bed decreases, roots grow in abundance in the humid environment, making the crop durable, and high yields and high quality can be expected. By making the cultivation bed sufficiently large and using a large amount of culture solution, changes in the nutrient ratio are less likely to occur, making it easier to manage the addition of culture solution and nutrient adjustment. In addition, by adjusting the level of the culture solution, the size of the air tank can be adapted to the growth of the plants, allowing for close to ideal management.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing submerged liquid/lowering liquid level/humid root cultivation of the present invention, Fig. 2 is an explanatory diagram showing conventional hydroponic cultivation, and Fig. 3 is an explanatory diagram showing conventional fixed medium cultivation. be. 1: liquid tank, 2: culture solution, 2a, 2b: liquid surface,
3: Root chamber, 4: Side multi-hole outer container, 5:
Side multi-hole inner container, 6: Culture medium, 7: Multi-hole planting container,
8: Seedling, crop, 9: Shading film, 9a: Silver mirror film, 9b: Nonwoven fabric, 10: Root, 1
0a: Underwater roots, 10b: Humid roots, 11: Spunbond, 12: Root-proofing water-permeable fabric, 13: Root pine chamber, 14: Soil, 15: Frame board, 16: Polyethylene film.

Claims (1)

[Claims] 1. In a semi-underground liquid tank filled with culture solution, a double-structured root chamber consisting of an outer multi-hole container on the side and a multi-hole inner container on the side containing the culture medium is installed upright and concentrically, and the culture medium is Place the multi-hole planting container with the seedlings planted on top of the multi-hole inner container so that the bottom part is in contact with the culture solution and the lower half is immersed in the culture solution. The liquid tank is covered with a light-shielding film, and as the level of the culture solution in the liquid tank decreases as the crop grows, the roots are exposed to more oxygen in the air, promoting root development in the humid environment until harvest. A submerged, low-level, and humid root cultivation method characterized by cultivation.