A "one main two auxiliary" high-density breeding and cultivation circulating system

Abstract

The application discloses a kind of " one main two auxiliary " high-density circulating water aquaculture system, including fish pond, it is characterized by: the fish pond is equipped with three fish breeding tail water circulation routes, is main circulation route, first auxiliary line and second auxiliary line respectively;The main circulation line includes microfilter, fluidized bed, ozone disinfection device and ultraviolet disinfection device connected in sequence, the upper pool surface drain line of the fish pond is connected with microfilter, the outlet pipeline of the ultraviolet disinfection device is connected with fish pond, and the upper pool surface drain of fish pond is filtered after microfilter, into fluidized bed, ammonia nitrogen and nitrite nitrogen are converted into nitrate nitrogen in fluidized bed;Three routes are carried out simultaneously, ensure that the content of nitrate nitrogen in the whole system is less than 500mg / L, ammonia nitrogen is less than 0.5mg / L, and the concentration of nitrite nitrogen is less than 0.2mg / L.Guarantee the quality of vegetable planting, realize high-density fish culture.

Description

TECHNICAL FIELD

[0001] The application relates to a 'one main two auxiliary' high-density circulating water aquaculture system and belongs to the aquaculture field. BACKGROUND

[0002] The fish density in the circulating water is large, and the bait feeding amount is averagely between 1% and 1.2%. A large amount of fecal pollution and residual bait is generated every day. At present, the method of increasing the circulating water amount and increasing the water changing amount is generally used to remove the fecal pollution and residual bait in the fish pond. A large amount of sewage is filtered through a microfilter and then subjected to aerobic treatment. The tail water after treatment is used for vegetable planting or artificial wetland purification, and finally is discharged after reaching the standard.

[0003] Due to the large amount of sewage, the high energy consumption in the treatment process, the large facility capacity, the high construction investment and the large water resource waste, these problems comprehensively affect the healthy development of the circulating water fish culture. Therefore, how to better reduce the energy consumption of the aerobic treatment and reduce the treatment cost becomes a problem to be solved.

[0004] CN 110606643 A discloses a fish pond fish fecal sewage treatment and recycling system. The water outlet of the pool surface discharge port is sequentially returned to the fish pond after passing through a microfilter, an ultraviolet disinfection machine and a boiling type moving bed biological filter. The backwashing water of the microfilter enters a fish fecal collection pool. The sewage in the fish fecal collection pool enters a fish fecal drum thickener for concentration. The clean water from the fish fecal drum thickener enters a backwater pool. The concentrated liquid from the fish fecal drum thickener sequentially enters an anaerobic fermentation tank, a first aerobic tank, a sedimentation tank, a biological filter tank and a tail liquid tank. The water in the tail liquid tank enters a vegetable cultivation system. The vegetable cultivation system comprises a fertilizer water pool, a water and fertilizer integrated system and a vegetable cultivation area. The water in the backwater pool enters a second aerobic tank. The outlet of the second aerobic tank is connected with the ultraviolet disinfection machine. The outlet of the ultraviolet disinfection machine is connected with a filtering device. The water filtered by the filtering device is returned to the fish pond. The fish and vegetable growth environment is controllable, and the disaster risk is effectively reduced. SUMMARY

[0005] In view of the above technical problems, the purpose of the present application is to provide a 'one main two auxiliary' high-density circulating water aquaculture system, which meets the fish pond backwater demand, uses circulating water, has no discharge, and classifies the treatment to ensure the content of nitrate nitrogen in the whole system and ensure the normal growth of vegetables.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows: a 'one main two auxiliary' high-density circulating water aquaculture system, comprising a fish pond, characterized in that the fish pond is provided with three fish breeding tail water circulating routes, namely a main circulating route, a first auxiliary line and a second auxiliary line.

[0007] The main circulation line comprises a microfilter, a fluidized bed, an ozone sterilization device and a UV sterilization device connected in sequence, the upper pool surface drainage pipeline of the fish pond is connected with the microfilter, the outlet pipeline of the UV sterilization device is connected with the fish pond, and the fish pond upper pool surface drainage is filtered by the microfilter, then enters the fluidized bed, ammonia nitrogen and nitrite nitrogen are converted into nitrate nitrogen in the fluidized bed, and then the fish tail water is sterilized by the ozone sterilization device and the UV sterilization device and returned to the fish pond.

[0008] The first auxiliary line comprises a vegetable cultivation system and a filter, a branch pipe is branched from the liquid outlet of the fluidized bed and connected with the vegetable cultivation system, the water outlet of the vegetable cultivation system is connected with the filter, and the water outlet of the filter is connected with the ozone sterilization device, part of the water from the fluidized bed enters the vegetable cultivation system to reduce the content of nitrate nitrogen, the water from the vegetable cultivation system is filtered by the filter, then passes through the ozone sterilization device and the UV sterilization device and returns to the fish pond.

[0009] The second auxiliary line comprises a vertical flow sedimentation device, a fish manure collection tank, a fish manure concentrator, an anaerobic fermentation tank, an aerobic fermentation tank and a bacteria-algae symbiotic system, the fish manure sewage discharge pipeline at the bottom of the fish pond is connected with the vertical flow sedimentation device, the clear liquid outlet pipeline of the vertical flow sedimentation device is connected with the microfilter, the fish manure of the vertical flow sedimentation device and the fish manure filtered by the microfilter enter the fish manure collection tank, a branch pipe is branched from the filtrate outlet pipeline of the microfilter and connected with the fish manure collection tank, the fish manure in the fish manure collection tank is concentrated by the fish manure concentrator, the concentrated fish manure enters the anaerobic fermentation tank for anaerobic fermentation and the aerobic fermentation tank for aerobic fermentation, and the tail water after aerobic fermentation enters the bacteria-algae symbiotic system again, and the water from the bacteria-algae symbiotic system passes through the ozone sterilization device and the UV sterilization device and returns to the fish pond.

[0010] Preferably in the above scheme, the bacteria-algae ratio of the bacteria-algae symbiotic system is 1:4, and the light-dark ratio is 2:1, the bacteria are nitrifying bacteria separated from the fluidized bed, and the algae are Phaeodactylum tricornutum with high efficient light fixation function and as bait for the grouper.

[0011] The bacteria-algae symbiotic system comprises a reactor, the foam generated by the anaerobic fermentation is introduced into the bacteria-algae symbiotic system, slow stirring is performed to make the bubbles uniformly dispersed in the reactor, stirring is stopped, with the continuous light photosynthesis of the microalgae, when the biomass of the microalgae reaches about 0.8-1.0 g / L, the bubbles gradually gather on the surface of the reactor, the bubbles are scraped out by a scraper and broken by ultrasonic vibration, and the algae are recovered, and the algae are put into the fish pond as fish bait.

[0012] In order to realize the efficient growth and rapid separation of bacteria-algae, a large amount of foam produced by anaerobic fermentation of fish manure is introduced into the bacteria-algae pool, the bubbles contain rich nutrients such as nitrogen and phosphorus and have certain viscosity, which can provide nutrients for the growth of bacteria-algae, and on the other hand, the separation of bacteria-algae from the liquid surface can reduce the cost of bacteria-algae recovery (the cost of bacteria-algae recovery generally accounts for more than 20% of the cost of bacteria-algae cultivation). The cultivated bacteria-algae is collected and then put into the fish pool as fish bait.

[0013] In the above scheme: the outlet pipeline of the ultraviolet disinfection device, the outlet pipeline of the fluidized bed, and the filtrate outlet pipeline of the microfiltration machine are respectively provided with an online ammonia nitrogen detector, an online nitrate nitrogen monitor, and an online nitrite monitor.

[0014] In the above scheme: the outlet pipeline of the ultraviolet disinfection device is branched into a branch pipeline connected with the fluidized bed, the content of nitrate nitrogen in the filtrate from the microfiltration machine is monitored according to the online ammonia nitrogen detector, the online nitrate nitrogen monitor, and the online nitrite monitor, and the water quantity of the main circulating route, the first auxiliary line, and the second auxiliary line is adjusted. Under normal circumstances, the main circulating route, the first auxiliary line, and the second auxiliary line are operated at the same time, which not only meets the needs of fish breeding, but also meets the needs of bacteria and vegetable planting, and at the same time, fish manure can be treated. When the content of nitrate nitrogen in the water from the fluidized bed is 500mg / L-1000mg / L, most of the water from the fluidized bed enters the vegetable cultivation system to further remove ammonia nitrogen through vegetable cultivation, so as to ensure that the content of nitrate nitrogen in the water returning to the fish pool is less than 500mg / L, which is suitable for the growth of fish. When the content of nitrate nitrogen is greater than 1000mg / L, part of the water from the microfiltration machine enters the third auxiliary line, and the nitrogen removal is increased through anaerobic reaction, so as to ensure that the content of nitrate nitrogen in the water returning to the fish pool is controlled to be less than 500mg / L, preferably 400-500mg / L, which is suitable for the growth of fish and the growth of vegetables.

[0015] In the above scheme: the ammonia nitrogen in the water returning to the fish pool in the system is less than 0.5mg / L, and the concentration of nitrite nitrogen is less than 0.2mg / L.

[0016] In the above scheme: the solid content after concentration by the fish manure concentrator is 3-5%.

[0017] In the above scheme: the vegetables planted in the vegetable cultivation system are lettuce.

[0018] Beneficial Effects: This invention employs a primary and two auxiliary treatment circuits. The primary circulation circuit utilizes a fluidized bed to convert ammonia nitrogen and nitrite into nitrate nitrogen to meet the needs of plant growth. A portion of the water from the fluidized bed is used for plant growth, while a portion is returned to the fishpond. When feed is introduced or an increase in ammonia nitrogen concentration is detected, most of the water can pass through the secondary auxiliary circuit. Through anaerobic and aerobic biochemical reactions, ammonia nitrogen is converted into nitrate nitrogen, and nitrate nitrogen is simultaneously converted into nitrogen gas, removing nitrogen from the water. All three circuits operate simultaneously, ensuring that the nitrate nitrogen content in the entire system is below 500 mg / L, ammonia nitrogen is less than 0.5 mg / L, and nitrite nitrogen concentration is less than 0.2 mg / L. This ensures the quality of vegetable cultivation and enables high-density aquaculture. Attached Figure Description

[0019] Figure 1 A flowchart of a high-density aquaponics farming system.

[0020] Figure 2 This is a schematic diagram illustrating the removal of ammonia and nitrate nitrogen from fish tank water by lettuce.

[0021] Figure 3 This is a chart showing the growth cycle of lettuce. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0023] like Figure 1 As shown, a high-density aquaculture cycle system includes a fish pond 1, which is equipped with three fish farming tailwater circulation routes, namely the main circulation route, the first auxiliary line, and the second auxiliary line.

[0024] The main circulation line includes a microfilter 2, a fluidized bed 3, an ozone disinfection device 4, and an ultraviolet disinfection device 5 connected in sequence. The upper surface drainage pipe of fish pond 1 is connected to the microfilter 2, and the outlet pipe of the ultraviolet disinfection device 5 is connected to fish pond 1. The upper surface drainage of the fish pond, after being filtered by the microfilter 2, enters the fluidized bed 3, where ammonia nitrogen and nitrite nitrogen are converted into nitrate nitrogen. Part of the water exiting the fluidized bed is disinfected by the ozone disinfection device 4 and the ultraviolet disinfection device before returning to fish pond 1.

[0025] The first auxiliary line includes a vegetable cultivation system 6 and a filter 7. A branch pipe is branched off from the outlet of the fluidized bed 3 and connected to the vegetable cultivation system 6. The outlet of the vegetable cultivation system 6 is connected to the filter 7. The outlet of the filter 7 is connected to the ozone disinfection device 4. Part of the water coming out of the fluidized bed 3 enters the vegetable cultivation system 6 to reduce the nitrate nitrogen content. The water coming out of the vegetable cultivation system is filtered by the filter 7 and then passes through the ozone disinfection device 4 and the ultraviolet disinfection device 5 before returning to the fish pond.

[0026] The second auxiliary line comprises a vertical flow precipitator 8, a fish manure collecting tank 9, a fish manure concentrator 10, an anaerobic fermentation tank 11, an aerobic fermentation tank 12, a bacteria-algae symbiotic system 13, and an ecological regulating tank 14. The fish manure sewage discharge pipeline at the bottom of the fish tank 1 is connected with the vertical flow precipitator 8, the clear liquid outlet pipeline of the vertical flow precipitator 8 is connected with the microfilter 2, the fish manure of the vertical flow precipitator 8 and the fish manure filtered by the microfilter 2 enter the fish manure collecting tank 9, and the filtrate outlet pipeline of the microfilter 2 also branches a branch pipeline connected with the fish manure collecting tank 9. When the ammonia nitrogen content of the pool surface drainage is too high, part of the water is discharged into the fish manure collecting tank 9. The fish manure in the fish manure collecting tank 9 is concentrated by the fish manure concentrator, and then the concentrated fish manure enters the anaerobic fermentation tank 11 and the aerobic fermentation tank 12 for biochemical treatment. The tail water after the biochemical treatment enters the bacteria-algae symbiotic system 13 again. The water from the bacteria-algae symbiotic system 13 is sterilized by the ozone sterilization device 4 and the ultraviolet sterilization device 5 and then returns to the fish tank 1. Valves are arranged on all the connecting pipelines. The outlet pipeline of the ultraviolet sterilization device, the outlet pipeline of the fluidized bed, and the filtrate outlet pipeline of the microfilter are respectively provided with an on-line ammonia nitrogen detector, an on-line nitrate nitrogen monitor, and an on-line nitrite monitor. The outlet pipeline of the ultraviolet sterilization device branches a branch pipeline connected with the fluidized bed. When the ammonia nitrogen detection is unqualified, the water returns to the fluidized bed.

[0027] According to the monitoring of the nitrate nitrogen content of the filtrate from the microfilter by the on-line ammonia nitrogen detector, the on-line nitrate nitrogen monitor, and the on-line nitrite monitor, the water quantity of the main circulation line, the first auxiliary line, and the second auxiliary line is adjusted. Under normal circumstances, the main circulation line, the first auxiliary line, and the second auxiliary line operate at the same time, which not only meets the demand of fish breeding, but also meets the demand of planting of bacteria and vegetables, and at the same time, the fish manure can be treated. When the nitrate nitrogen content of the water from the fluidized bed is 500 mg / L-1000 mg / L, most of the water from the fluidized bed enters the vegetable cultivation system, so as to further remove the ammonia nitrogen through the cultivation of vegetables, so as to ensure that the nitrate nitrogen content of the water returning to the fish tank is less than 500 mg / L, so as to adapt to the growth of fish. When the nitrate nitrogen content is greater than 1000 mg / L, part of the water from the microfilter enters the third auxiliary line, so as to increase the removal of nitrogen. The nitrate nitrogen content of the water returning to the fish tank is controlled to be less than 500 mg / L, preferably 400-500 mg / L, which is suitable for the growth of fish and the growth of vegetables. The ammonia nitrogen of the water returning to the fish tank in the system is less than 0.5 mg / L, and the concentration of nitrite is less than 0.2 mg / L. The solid content of the water concentrated by the fish manure concentrator is 3-5%.

[0028] The bacteria-algae symbiotic system comprises a reactor, the reactor is a racetrack pool, the bacteria-algae ratio of the bacteria-algae symbiotic system is 1:4, and the light-dark ratio is 2:1. The bacteria are nitrifying bacteria separated from the fluidized bed, and the algae are Phaeodactylum tricornutum foams generated by anaerobic fermentation, which are introduced into the bacteria-algae symbiotic system. The algae generated by the bacteria-algae symbiotic system are used as fish bait.

[0029] Foaming is a stable mucilage layer formed by gas bubbles, liquid (wastewater containing surfactants) and solid particles (microorganisms and suspended solids) that is unable to be smoothly discharged from the reactor, forms a dispersion system in the liquid, and eventually accumulates on the liquid surface.

[0030] The characteristics of fish manure, the types of microorganisms it carries, volatile fatty acids (VFAs), and the carbon-nitrogen ratio of raw materials are all foam inducers. In addition to some substrates or intermediate metabolites produced during substrate degradation, the main source of surfactants / biosurfactants in fish manure fermentation systems is extracellular polymeric substances (EPS). EPS can adhere to the cell surface, form a protective barrier, provide resistance to harsh environments, adsorb exogenous organic compounds to store nutrients, and digest exogenous macromolecules to obtain nutrients. Soluble EPS, especially soluble PN, also contributes to foam formation.

[0031] The rapid degradation of organic matter and the efficient accumulation of nitrate nitrogen in fish-vegetable symbiotic systems are key to building a closed-loop system. In previous experiments, it was found that high-concentration fish manure produced a large amount of foam during anaerobic fermentation and aerobic biochemical treatment. The solid materials entrained in the foam caused the stirring device, aeration pipe, and pump to be blocked or even damaged. At the same time, it also caused the reactor to have a reverse profile with high solid concentration at the top and low solid concentration at the bottom, forming a dead zone, reducing the effective volume of the reactor, and seriously affecting the gas-liquid mass transfer efficiency and system stability.

[0032] To achieve efficient growth and rapid separation of bacteria and algae, the large amount of foam produced by fish manure anaerobic fermentation is introduced into the reactor (the foam can be salvaged into the reactor), and is simply and slowly stirred to ensure that the gas bubbles are evenly dispersed in the bacteria-algae symbiotic system and do not break. The gas bubbles contain rich nutrients such as nitrogen, phosphorus, and CO2 and have a certain viscosity (163 mPa·S). On the one hand, they can provide nutrients and carbon dioxide (produced by anaerobic fermentation) for the growth of bacteria and algae, improve the efficiency of photosynthesis, and increase the growth efficiency of microalgae by more than 10%, achieving emission reduction and carbon sequestration. On the other hand, they can achieve the separation of bacteria and algae from the liquid surface, reducing the cost of bacteria and algae recovery. Compared with traditional membrane separation and flocculation sedimentation separation, the cost is reduced by more than 15% (the cost of bacteria and algae recovery generally accounts for more than 20% of the cost of bacteria and algae cultivation). The timely removal of gas bubbles eliminates the inhibition of gas bubbles on the gas-liquid mass transfer efficiency and the stability of the system in the anaerobic fermentation system, increasing the efficiency of anaerobic fermentation by more than 10%. As the photosynthesis of microalgae continues, when the biomass of microalgae reaches about 0.8-1.0 g / L, the gas bubbles gradually accumulate on the surface of the reactor. By scraping the gas bubbles with a scraper and vibrating them with ultrasonic waves, the gas bubbles can be broken and the algae can be recovered. The cultivated bacteria and algae are collected and used as fish bait in the fish pond. The gas bubbles can also be used for the separation of other algae.

[0033] The vegetable cultivation system of this invention can adopt a vegetable hydroponic NFT system or a vegetable hydroponic DFT system. The system's impact on lettuce growth:

[0034] Experiments have shown that lettuce can effectively remove ammonia nitrogen and nitrate nitrogen from wastewater, such as... Figure 2 As shown, we directly used the fish tank tail water (water directly from the fish pond) for hydroponic lettuce cultivation, and its removal of ammonia nitrogen and nitrate nitrogen was as follows: Figure 2 As shown.

[0035] The vegetable cultivation system employed both the NFT (Natural Factorization) and DFT (Digital Factorization) hydroponic systems, along with ordinary tap water, for hydroponics. The resulting growth cycle diagram of lettuce after hydroponics is shown in Figure 3, and the test results of the lettuce are shown in Table 1.

[0036]

[0037] from Figure 3 It can be seen that the above-ground fresh weight of lettuce grown in the NFT (water from the second auxiliary line) of the fish farming system is greater than that of lettuce grown in the DFT (dual-flow) of the fish farming system, which is greater than that grown in the NFT of ordinary tap water.

[0038] As can be seen from the table, fish tail water can appropriately increase the content of soluble sugar, soluble protein and vitamin C in lettuce, significantly reduce the content of nitrate, and improve the quality of lettuce.

[0039] The system's impact on fish growth: It contains abundant trace elements, such as iron and manganese, which act as coenzymes, cofactors, and cofactors in the enzyme system of biochemically reacting microorganisms, promoting intestinal peristalsis and enhancing intestinal microbial activity. The optimal stocking density is 80-100 kg / m². 3

[0040] Compared to replacing the water with fresh water, this system shortens the growth cycle of largemouth bass from 9-10 months to 5-6 months (500g), and reduces the rate of fish diseases by more than 90%.

[0041] This invention is not limited to the above embodiments. Those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this invention. The scope of this invention is defined by the claims and their equivalents.

Claims

1. A "one master two slave" high density recirculating aquaculture system comprising a fish tank, characterized in that: The fish pond is equipped with three fish breeding tail water circulation routes, namely a main circulation route, a first auxiliary route and a second auxiliary route; The main circulation route comprises a microfilter, a fluidized bed, an ozone sterilization device and an ultraviolet sterilization device connected in sequence, the upper pool surface drainage pipeline of the fish pond is connected with the microfilter, the outlet pipeline of the ultraviolet sterilization device is connected with the fish pond, and after the upper pool surface drainage of the fish pond is filtered by the microfilter, the filtered water enters the fluidized bed, ammonia nitrogen and nitrite nitrogen are converted into nitrate nitrogen in the fluidized bed, and then the fish breeding tail water passes through the ozone sterilization device and the ultraviolet sterilization device and returns to the fish pond; The first auxiliary route comprises a vegetable cultivation system and a filter, a branch pipe is connected to the liquid outlet of the fluidized bed and connected with the vegetable cultivation system, the water outlet of the vegetable cultivation system is connected with the filter, and the water outlet of the filter is connected to the ozone sterilization device, part of the water from the fluidized bed enters the vegetable cultivation system to reduce the content of nitrate nitrogen, the water from the vegetable cultivation system is filtered by the filter, then passes through the ozone sterilization device and the ultraviolet sterilization device and returns to the fish pond. The second auxiliary route comprises a vertical flow sedimentation device, a fish manure collecting tank, a fish manure concentrator, an anaerobic fermentation tank, an aerobic fermentation tank and a bacteria-algae symbiotic system; The fish manure sewage discharge pipeline at the bottom of the fish pond is connected with the vertical flow sedimentation device, the clear liquid outlet pipeline of the vertical flow sedimentation device is connected with the microfilter, the fish manure of the vertical flow sedimentation device and the fish manure filtered by the microfilter enter the fish manure collecting tank, a branch pipe is connected to the filtrate outlet pipeline of the microfilter and connected with the fish manure collecting tank, the fish manure in the fish manure collecting tank is concentrated by the fish manure concentrator, the concentrated fish manure enters the anaerobic fermentation tank for anaerobic fermentation and the aerobic fermentation tank for aerobic fermentation, the tail water after aerobic fermentation enters the bacteria-algae symbiotic system again, and the water from the bacteria-algae symbiotic system passes through the ozone sterilization device and the ultraviolet sterilization device and returns to the fish pond. The bacteria-algae symbiotic system comprises a reactor, the foam generated by anaerobic fermentation is introduced into the bacteria-algae symbiotic system, slow stirring is performed, the bubbles are uniformly dispersed in the reactor, stirring is stopped, with the continuous photosynthesis of microalgae, when the biomass of microalgae reaches about 0.8-1.0 g / L, the bubbles gradually accumulate on the surface of the reactor, the bubbles are scraped out by a scraper and broken by ultrasonic vibration, and the algae are recovered, and the algae are put into the fish pond as fish bait.

2. The "one master and two slaves" high density recirculating aquaculture system according to claim 1, characterized in that: The bacteria-algae ratio of the bacteria-algae symbiotic system is 1:4, the light-dark ratio is 2:1, the bacteria are nitrifying bacteria separated from the fluidized bed, and the algae are Phaeodactylum tricornutum which has high efficient light fixation function and can be used as grouper bait.

3. The "one master and two slave" high density recirculating aquaculture system according to claim 1, characterized in that: Online ammonia nitrogen detectors, online nitrate nitrogen monitors and online nitrite monitors are arranged on the water outlet pipeline of the ultraviolet sterilization device, the outlet pipeline of the fluidized bed and the filtrate outlet pipeline of the microfilter respectively.

4. The "one master and two slave" high density recirculating aquaculture system according to claim 3, characterized in that: The ammonia nitrogen in the water returned to the fish pond in the system is less than 0.5 mg / L, and the concentration of nitrite nitrogen is less than 0.2 mg / L.

5. The "one master and two slave" high density recirculating aquaculture system according to claim 4, characterized in that: The solid content of the fish manure concentrated by the fish manure concentrator is 3-5%.

6. The "one master and two slave" high density recirculating aquaculture system according to claim 5, characterized in that: The vegetables planted in the vegetable cultivation system are lettuce.

Images