Sweet potato soilless tuber production system and method

Abstract

The application discloses a sweet potato soilless tuberization cultivation system and method. In view of the fact that existing sweet potato production cannot get rid of solid substrates such as soil, and is restricted by upgrading of cultivation technology and product value positioning, the sweet potato soilless tuberization cultivation technology of the application adjusts the number and single weight of tubers by controlling environmental air pressure conditions. The cultivation system comprises a culture box and a regulation system, the culture box is divided into a nutrient bin and a tuberization bin, the tuberization bin is provided with seedling holes and has an airtight structure, and the regulation system monitors and regulates the culture conditions in the culture box. The culture method is a stage regulation culture technology, and the continuous long-term tuberization production can be realized through the tuberization period regulation culture. The application solves the key technical problem that all existing soilless cultivation technologies of sweet potato need to use solid substrates to press vines to induce tuber enlargement to realize tuberization, is a completely soilless cultivation technology of sweet potato, introduces the sweet potato cultivation technology into a new stage, and provides a scientific basis and production control means for stable small-scale sweet potato production.

Description

Technical Field

[0001] This invention relates to an agricultural planting technology, and in particular to a soilless cultivation system and method for sweet potatoes that enables continuous harvesting, belonging to the fields of agricultural machinery and agricultural planting technology. Background Technology

[0002] conventional sweet potatoes ( Ipomoea batatas (L.) Lam. Compared to greenhouse agriculture, sweet potato cultivation is a more extensive production method, mainly manifested in two aspects: Firstly, the planting method is "coarse." During sweet potato cultivation, both the tubers and nutrient-absorbing roots grow underground. At harvest, the vines are cut off and the tubers are dug up. This destructive harvesting method constitutes the largest labor and soil cost in sweet potato production. Secondly, the value proposition is "coarse." Sweet potato is my country's seventh largest grain crop. When used for processing as both food and feed, its cultivation techniques focus more on improving tuber yield, quality, and disease and stress resistance—that is, emphasizing enhancing its value as a primary agricultural product or a coarsely processed product—while neglecting the significance of improving the tuber's appearance for enhancing its overall value as a "fashionable commodity."

[0003] With changing nutritional concepts and dietary habits, the nutritional value of sweet potatoes has been re-recognized and widely valued, leading to a year-on-year increase in the consumption of fresh sweet potatoes. Market demand has placed new requirements on sweet potato production technology, such as: First, a year-round continuous supply of fresh sweet potatoes, breaking through the previous technical limitations of supplying fresh sweet potatoes during the harvest season and storing them outside the harvest season. Second, reducing the average weight of tubers; mini / small fresh sweet potatoes (80g-150g per tuber) are more popular and command higher prices per unit weight. Third, improving the appearance of tubers, such as regular shape and smooth surface, can further enhance their marketability. In addition to the above market demands, hydroponics is, to some extent, a development direction in agricultural planting technology. Hydroponics eliminates the dependence of agriculture on arable land, saving land use and allowing production bases to be built closer to cities in the suburbs, shortening the distance from farm to table, accelerating regional economic production cycles, and meeting the market's demand for "fresh supply." Therefore, in order to break free from the constraints of traditional planting methods and increase the production value of sweet potatoes, it is necessary to develop new sweet potato cultivation techniques.

[0004] In terms of species attributes, the sweet potato vine's inherent ability to produce multiple tubers is a key factor. Traditional planting methods employ destructive harvesting because both the storage roots and nutrient-absorbing roots grow underground and their functions overlap to some extent, thus limiting the scientific and efficient utilization of the vine's continuous tuber-producing characteristic. Patent application ZL2010101367043 discloses a grafting method that spatially separates the nutrient-absorbing roots and tubers, providing a basis for year-round growth and continuous harvesting, increasing yield and extending the viewing period. However, this technology is a soil-based cultivation technique. Patent application CN2009100775748 discloses a sweet potato atomization cultivation method, achieving continuous production, but this technology has certain limitations: First, although the sweet potato plants are planted in a soilless cultivation system, the most crucial tuber-forming stage is "inducing tuber formation by burying the lateral vines in a solid substrate," not a completely soilless process. Since the solid substrate used for vine burying is generally a mixture of vermiculite, sand, or soil, this technology is not truly soilless cultivation. Secondly, in this technology, because "adventitious roots of conventional sweet potato varieties do not easily develop into tubers under nutrient solution aeroponic conditions," even with substrate-based vine training to induce tuber formation, this technology still requires the selection of "sweet potato varieties that easily expand into tubers, such as Xushu 22," to achieve sweet potato production. Thirdly, the yield, quantity, and shape of the tubers harvested using this technology are greatly affected by varietal characteristics, typically producing tubers with an average weight of about 800 grams each. This is not suitable for the fresh sweet potato market and therefore hinders the increase in price per unit weight. Furthermore, continuous harvesting of small tubers requires repeated disruption of root expansion and growth conditions, significantly impacting yield and limiting production efficiency.

[0005] Looking at existing sweet potato cultivation techniques, regardless of whether they incorporate soilless cultivation methods, they all share a common characteristic: during the planting process, the artificial manipulation of vine training using solid substrates is required to induce the adventitious roots at the tuber-forming points to swell and develop into tubers underground. Essentially, sweet potato production remains inseparable from solid substrates such as soil, and marketable traits such as tuber shape are greatly influenced by cultivation conditions or the vine training substrate. Its "value proposition" is a reluctant choice made under the constraints of traditional production methods. The introduction of artificial vine training to induce tuber formation has become a significant obstacle to the improvement and refinement of sweet potato production technology: First, it increases the complexity of the planting process and raises labor costs (vine training and post-training management require substantial manual input); second, and more importantly, it increases the time required for coordination between the plant's growth period and the manual training period, limiting the development of fully automated control and large-scale planting technologies; third, the tuber-forming process remains underground, making it difficult to observe the overall growth of the tubers (only individual samples can be dug up for observation). Finally, apart from controlling the average tuber size (volume or weight) through repeated vine pressing to disperse nutrients and high-density planting, there are no effective cultivation conditions to control the average tuber size, thus making it impossible to controllably increase the economic value per unit weight and improve the overall efficiency of sweet potato production. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a hydroponic sweet potato cultivation technology, including a system and method. This technology enables continuous tuber production of sweet potatoes year-round under completely soilless conditions, while controlling the average weight and appearance of the tubers.

[0007] To achieve the above objectives, the present invention first provides a soilless sweet potato tuber-forming cultivation system, the technical solution of which is as follows:

[0008] A soilless sweet potato tuber-forming cultivation system, characterized in that it includes an incubator and a control system;

[0009] The incubator is divided into a nutrient chamber and a tuber formation chamber by an internal partition. The tuber formation chamber has seedling holes on its top / wall and / or partition. The tuber formation chamber has an airtight structure.

[0010] The control system includes a liquid supply component, a monitoring component, an adjustment component, and a power supply circuit component, all of which are connected to the control unit.

[0011] The liquid supply component sprays nutrient solution into the incubator;

[0012] The monitoring component monitors environmental factors in the incubator through sensors, including a pressure sensor that monitors the pressure in the tuber-forming chamber.

[0013] The regulating components include a pressure regulating component for regulating the pressure in the tuber-forming bin;

[0014] The control unit controls and adjusts the working state of the component according to preset time conditions and / or feedback data from the monitoring component.

[0015] The rootstock of the grafted sweet potato plant extends into the nutrient chamber through the seedling hole in the partition, and the tuber vine of the scion extends into the tuber-forming chamber. The terminal vine extends out of the cultivation box from the seedling hole in the top / wall of the tuber-forming chamber. The grafted sweet potato plant is a plant that achieves functional separation of the sweet potato root system through grafting.

[0016] Under preferred conditions, the above cultivation system can be optimized as follows. Each of the following optimizations can be implemented separately, but the optimal situation is to implement them simultaneously.

[0017] Optimization 1: To regulate the air conditions inside the cultivation chamber, an oxygen concentration sensor is added to the monitoring component to monitor the oxygen concentration in the nutrient chamber and the tuber forming chamber respectively; at the same time, an oxygen regulating component is added to the regulating component to regulate the oxygen content in the nutrient chamber.

[0018] Optimization 2: To effectively regulate the temperature and humidity conditions inside the cultivation chamber, the monitoring components are equipped with a humidity sensor to monitor the humidity inside the tuber forming chamber and a temperature sensor to monitor the temperature inside the nutrient chamber and the tuber forming chamber respectively; the adjustment components are equipped with a temperature control component.

[0019] Optimization 3: To improve the utilization efficiency of nutrient solution, the nutrient solution is sprayed into the incubator from the storage tank of the nutrient solution supply component; the monitoring component is equipped with level sensors to monitor the liquid levels in the storage tank and the nutrient chamber respectively; the regulating component is equipped with a water pump to collect excess nutrient solution collected in the incubator and return it to the storage tank; at the same time, the control unit controls the working status of the water pump according to the liquid level data in the nutrient chamber.

[0020] The present invention also provides a method for soilless tuber cultivation of sweet potatoes using the above-mentioned soilless tuber cultivation system, the technical solution of which is as follows.

[0021] A method for soilless sweet potato tuber formation cultivation using the aforementioned soilless sweet potato tuber formation cultivation system is characterized by: obtaining grafted sweet potato plants, wherein the grafted sweet potato plants are grafted seedlings using a hydroponically tolerant, perennial sweet potato-related plant with a non-bulging root system as rootstock, and short-vine and / or extra-short-vine sweet potato varieties with good tuber formation habits as scions; when the tuber-forming vines of the grafted sweet potato scions have grown to 3-8 stem nodes, they are transferred into a culture box, the box lid is closed, and the grafted sweet potato plants are passed through the seedling holes and the seedling holes are sealed with modeling clay; nutrient solution is injected into the storage tank of the nutrient supply component, and the start time is set. T 1. Begin tuber formation cycle regulation culture, including;

[0022] Phase 1: Inside the nutrient chamber, maintain a temperature of 22℃~26℃. Spray nutrient solution mist for 15s~20s every 10min~15min. Every 5d~7d, ventilate using an oxygen regulating device for 60s~120s at an airflow rate of 1m³. 3 / min; Inside the tuber forming chamber, the humidity of the air inside the chamber is controlled at 95% to 100% by spraying nutrient solution, the temperature inside the chamber is regulated at 26℃ to 32℃ by the constant temperature component, and the pressure inside the chamber is controlled at natural atmospheric pressure by the air pressure regulating component, where ΔP = 200 Pa to 800 Pa; After 14 days of cultivation, the second stage begins.

[0023] Phase 2: In the nutrient chamber, the cultivation conditions are the same as in the previous phase; in the tuber forming chamber, the temperature is 20℃~22℃, the air humidity is 70%~75%, and the chamber pressure is the same as in the previous phase; after 35 days of cultivation, proceed to Phase 3.

[0024] Phase 3: In the nutrient chamber, the cultivation conditions are the same as in the previous phase; in the tuber-forming chamber, the temperature and humidity control conditions are the same as in the previous phase, and the chamber pressure is controlled as follows: if the cultivation goal is to increase the number of tubers and limit the average weight of tubers, the chamber pressure is the same as in the previous phase; if the cultivation goal is to limit the number of tubers and increase the average weight of tubers, the chamber pressure is adjusted to increase the pressure by ΔP from natural atmospheric pressure, where ΔP = 0 Pa to 200 Pa; the sweet potatoes continue to grow, and all tuber-forming sites on the tuber-forming vines gradually swell and form tubers. After tuber harvesting is completed, the tuber-forming cycle regulation cultivation ends, and the termination time is marked. T 2.

[0025] The above-described soilless sweet potato tuber-forming cultivation method allows for the inspection of vine growth at the outer end of the cultivation chamber after one round of tuber-forming cycle regulation. Well-developed vines at tuber-forming sites are selected and pulled back from the rootstock end into the tuber-forming chamber to become new tuber-forming vines, thus initiating a new round of tuber-forming cycle regulation. This results in continuous tuber formation throughout the entire plant.

[0026] The above-mentioned soilless tuber formation cultivation method for sweet potatoes can be optimized under preferred conditions as follows: artificially control the light conditions outside the cultivation box, use LED modulated light source with a red-blue-green light ratio of 4:3:3 for the vines outside the cultivation box, and set an appropriate day-night cycle.

[0027] Compared with the prior art, the beneficial effects of the present invention are: (1) The soilless tuber formation technology of sweet potato of the present invention solves the key technical problem that all existing soilless cultivation technologies of sweet potato require solid substrate pressing operations to induce tuber enlargement and achieve tuber formation. It is a completely soilless cultivation technology of sweet potato, which introduces sweet potato cultivation technology into a new stage. (2) Existing research shows that many diseases and damages of tuber crops originate from soil microbial invasion or soil pollution. Tubers carrying diseases / contamination are more prone to deterioration and rot during storage. The completely soilless cultivation technology of sweet potato provided by the present invention avoids the aforementioned threats from the source of sweet potato production and improves the overall level of sweet potato production. (3) Existing technologies can only induce tuber enlargement in soil or solid substrate, so it is impossible to effectively control the individual weight of tubers. To meet market demand, small sweet potatoes are mostly obtained by artificial screening or increasing the number of tuber formation points, and the quality and quantity are not very stable. This invention employs a completely different technical concept from existing technologies, enabling the adjustment of the number and weight of tubers by controlling environmental air pressure conditions, thus providing a scientific basis and production control method for stable small-scale sweet potato production. Compared with underground tuber formation in existing technologies, this invention enables sweet potatoes to form tubers in visible space, providing a cost-effective means for studying the development mechanism of sweet potato tubers and for observing and recording tuber growth at any time during sweet potato production, and even collecting tuber data. (4) This invention specifically solves the problem in existing sweet potato aeroponic technology that "adventitious roots of conventional sweet potato varieties do not easily develop into tubers under nutrient solution aeroponic conditions." When selecting cultivation varieties, it is not necessary to specifically "select sweet potato varieties that are easy to expand into tubers," but only to consider the length of the sweet potato vines (the purpose is to improve the space utilization efficiency of the tuber formation chamber), thereby broadening the applicability of sweet potato aeroponic technology. (5) The tubers obtained by this invention are uniform in size, have smooth and clean skin, and have a superior overall appearance. They are better able to meet the needs of modern dietary consumption and have a higher market value. (6) Since the high-cost manual vine pressing operation in the existing sweet potato cultivation technology is eliminated, the soilless tuber formation cultivation technology of the present invention can achieve full automatic control; further, with the addition of continuous tuber formation throughout the year, the technology of the present invention provides a technical basis for the large-scale and intensive production of commercial sweet potatoes with higher unit weight value. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a soilless tuber cultivation system for sweet potatoes. Figure I .

[0029] Figure 2 This is a schematic diagram of a soilless tuber cultivation system for sweet potatoes. Figure II .

[0030] Figure 3 This is a block diagram of the control system structure in Example 1.

[0031] Figure 4a , Figure 4b , Figure 4c , Figure 4d These are schematic diagrams of the external structure of the lids of several incubators (dashed arrows indicate the direction in which the lids open).

[0032] Figure 5 This is a block diagram of the control system structure in Example 2.

[0033] Figure 6 This is a schematic diagram of a multi-layer incubator structure.

[0034] The numbers in the attached diagram are labeled as follows:

[0035] 1. Incubator 11. Nutrient Chamber 12. Tuber Forming Chamber 12.1 Airtight Structure 13. Partition 14. Seedling Placement Hole 15. Chamber Body 16. Chamber Lid 2. Control System 21. Control Unit 22. Liquid Supply Component 23. Monitoring Component 23.1 Pressure Sensor 23.2 Oxygen Concentration Sensor 23.3 Humidity Sensor 23.4 Temperature Sensor 23.5 Liquid Level Sensor 24. Adjustment Component 24.1 Pressure Adjustment Component 24.1.1 Air Pump 24.1.2 Pressure Reducing Valve 24.2 Oxygen Adjustment Component 24.3 Temperature Control Component 24.3.1 Heating Component 24.3.2 Constant Temperature Component 24.4 Water Pump 3. Grafted Sweet Potato Plants 31. Rootstock 32. Tuber Forming Vines 33. Terminal Shoot Vines 4. Artificial Lighting Implementation

[0036] The preferred embodiments of the present invention will now be further described with reference to the accompanying drawings. Example 1

[0037] like Figures 1 to 4d As shown, a soilless sweet potato tuber cultivation system is fabricated.

[0038] Figure 1 , Figure 2 These are schematic diagrams of a soilless tuber cultivation system for sweet potatoes. Figure I , indication Figure II ; Figure 3 This is a block diagram of the control system structure in Example 1; Figure 4a , Figure 4b , Figure 4c , Figure 4d These are schematic diagrams of the external structure of the lids of several incubators (dashed arrows indicate the direction in which the lids open).

[0039] The soilless sweet potato tuber formation cultivation system includes an incubator 1 and a control system 2. The incubator 1 is divided into a nutrient chamber 11 and a tuber formation chamber 12 by an internal partition 13. Seedling holes 14 are opened in the top / walls and / or partition 13 of the tuber formation chamber 12, which has an airtight structure 121. In this embodiment, the incubator 1 is a rectangular box, with the nutrient chamber 11 and tuber formation chamber 12 separated left and right by the partition 13. The incubator 1 includes a box body 15 and two lids 16. The lids 16 are L-shaped bent plates, hinged to or detached from the box body 15. The two lids 16 can be opened and closed independently, facilitating operation in the left and right chambers respectively.

[0040] The rectangular shape of the cultivation box 1, with the nutrient chamber 11 and tuber-forming chamber 12 arranged side-by-side, allows the terminal vines 33 of the sweet potato plants to emerge from the seedling holes 14 and creep along the top surface of the cultivation box 1, saving space and accommodating the natural growth posture of the vines. The airtight structure 121 of the tuber-forming chamber 12 includes a sealing ring / strip at the connection between the side chamber 15 and the lid 16, fasteners, and modeling clay used in conjunction with the seedling holes 14. The slope of the bottom plate of the nutrient chamber 11 is its optimized structure.

[0041] The control system 2 includes a liquid supply assembly 22, a monitoring assembly 23, an adjustment assembly 24, and a power supply circuit assembly, all connected to the control unit 21. Among them—

[0042] The nutrient solution in the storage tank of the liquid supply component 22 is sprayed into the incubator 1.

[0043] The monitoring component 23 monitors environmental factors in the incubator 1 through sensors, including a pressure sensor 231 that monitors the pressure in the tuber forming chamber 12. The sensitive element of the monitoring component 22 is on the same side as the nutrient solution spray nozzle to avoid the sensitive element being affected by the spray water vapor.

[0044] The regulating component 24 includes a pressure regulating component 241 for regulating the pressure of the tuber forming chamber 12; the control unit 21 controls the working state of the regulating component 24 according to preset time conditions and / or feedback data from the monitoring component 23. In this embodiment, the pressure regulating component 241 includes an air pump 2411 for pumping gas into the tuber forming chamber 12 to increase the chamber pressure and a pressure reducing valve 2412.

[0045] In this example, the gas pumped into the tuber-forming chamber 12 is uncontaminated conventional air.

[0046] Figure 2 The diagram shows the structure of a hydroponics sweet potato cultivation system. Figure II In the middle, the seedling hole 14 is opened on the top / wall of the tuber forming bin 12.

[0047] Example 2

[0048] like Figure 5 As shown, a soilless sweet potato tuber cultivation system was fabricated, with optimized design based on the product of Example 1.

[0049] Figure 5 This is a block diagram of the control system structure in Example 2.

[0050] The system adds an oxygen content regulation function to the incubator 1. Specifically, the regulation component 24 includes an oxygen regulation component 242 for regulating the oxygen content in the nutrient chamber 11. In this embodiment, to save costs, the oxygen regulation component 242 configured in the nutrient chamber 11 uses a ventilator and / or an exhaust fan. The control unit 21 starts the ventilator and / or exhaust fan according to a preset working time to introduce fresh air into the chamber. Further, the monitoring component 23 can be equipped with an oxygen concentration sensor 232 to monitor the oxygen concentration in the nutrient chamber 11. When the control unit 21 detects that the oxygen concentration in the nutrient chamber 11 is too low, it starts the ventilator and / or exhaust fan. The monitoring component 23 can also be equipped with an oxygen concentration sensor 232 to monitor the oxygen concentration in the tuber forming chamber 12. When the control unit 21 detects that the oxygen concentration in the tuber forming chamber 12 is too low, it starts the air pressure regulation component 241 to supplement fresh air or oxygen.

[0051] The system adds a humidity control function inside the tuber forming chamber 12. The humidity sensor 233 monitors the humidity inside the tuber forming chamber 12. The control unit 21 starts or stops the liquid supply component 22 to increase the humidity inside the chamber based on the humidity monitoring data inside the tuber forming chamber 12 and the preset humidity control limit, or starts or stops the air pressure regulating component 241 to reduce the temperature by refreshing the air inside the chamber.

[0052] The system adds a temperature control function to the incubator 1. The sensors include temperature sensors 234 that monitor the temperatures of the nutrient chamber 11 and the tuber-forming chamber 12 respectively. The adjustment component 24 includes temperature control components 243 connected to both chambers. In this embodiment, the temperature control component 243 connected to the tuber-forming chamber 12 uses a constant temperature component 2432 to achieve temperature regulation within the chamber; to save costs, the temperature control component 243 connected to the nutrient chamber 11 uses a heating component 2431, and the control unit 21 uses the heating component 2431 in conjunction with a ventilator and / or exhaust fan to achieve temperature regulation within the chamber.

[0053] The system enriches the functions of the liquid supply component 22. The monitoring component 23 includes level sensors 235 that monitor the liquid levels in the storage tank and the nutrient tank 11 respectively; the regulating component 24 includes a water pump 244, and the control unit 21 controls the working status of the water pump 244 according to the level sensors 235 to recover excess nutrient solution collected in the nutrient tank 11 and return it to the storage tank. The control unit 21 sends signals to increase or decrease the amount of nutrient solution stored in the storage tank based on the data from the level sensors 235.

[0054] A transparent window is added to one wall of the incubator 1. The transparent window is covered with a black light-blocking material. After the black light-blocking material is removed, the transparent window can be used as an observation window for the nutrient chamber 11 and the tuber forming chamber 12, respectively.

[0055] Example 3

[0056] Soilless sweet potato tuber cultivation was carried out using the soilless tuber cultivation system processed in Example 2. The cultivation experiment was divided into conditional groups (large tuber cultivation group and small tuber cultivation group), with replicates for each group. The following text is simplified, omitting descriptions of the experimental procedures for grouping and replication, and only describing the groupings where necessary.

[0057] 1. Material preparation

[0058] 1.1 Rootstock 31 Materials

[0059] The rootstock should be a closely related plant to sweet potato that is tolerant of hydroponics, can be perennial, and has a non-bulging root system. Since the rootstock needs to be inserted horizontally through the seedling holes 13 and 14 of the partition, the stems of the selected rootstock material should not be too thin or soft; a stem diameter of 3 mm to 4 mm is preferable. Water spinach (Water spinach) is generally a suitable choice. Ipomoea aquatica Local varieties of water hyacinth and purple-flowered perennial morning glory ( Ipomoea indica ), Morning glory ( Ipomoea nil Varieties such as Blue Crown, Pink and White Edge, and Suining Big Red Flower are included.

[0060] In this embodiment, Suining hibiscus morning glory was selected as the rootstock material. The seeds of Suining hibiscus morning glory were cut off with a nail clipper, soaked in water for 6 hours, and then sown in the substrate. After germination, the seedlings were raised to a height of about 10 cm to 15 cm and then used as the rootstock material.

[0061] 1.2 Scion Material

[0062] The sweet potato plant used as a scion can be selected based on the cultivation goals. However, to reduce the space occupied by the tuber vines 32 in the tuber-forming box 12 and to improve nutrient utilization and photosynthetic conversion efficiency, short-vine or extra-short-vine sweet potato varieties can be selected as scions. Short-vine varieties include Xinxiang (red skin and yellow flesh) and T82-2 (purple skin and purple flesh), while extra-short-vine varieties include Bread Potato (high starch).

[0063] In this embodiment, the sweet potato variety Xinxiang was selected as the scion. When the sweet potato shoots at the top grew to 20 cm to 25 cm in length, they were cut off and used as scion material.

[0064] 1.3 Obtained 3 grafted sweet potato plants

[0065] Grafting of sweet potato seedlings onto rootstock and scion materials according to method ZL2010101367043 indicates successful grafting if the scion does not wilt and new leaves emerge, signifying that the plant has achieved functional separation of the sweet potato root system. Grafted sweet potato plants can be used for hydroponics when the tuber vines have grown to 3-8 nodes.

[0066] 1.4 Preparation for Cultivation

[0067] Wash away the substrate from the roots of the grafted sweet potato plants (3), and transfer them into culture box 1. Insert the rootstock (31) through the seedling hole (14) on the partition (13) into the nutrient chamber (11). Insert the tuber-forming vine (32) of the scion into the tuber-forming chamber (12). The terminal vine (33) extends from the seedling hole (14) on the top / wall of the tuber-forming chamber (12) out of the culture box 1. Seal the seedling hole (14) with modeling clay. Close the box lid (16) and tighten the fasteners to ensure the tuber-forming chamber (12) is airtight.

[0068] Nutrient solution is injected into the storage tank of the nutrient supply assembly 22. The nutrient solution used is MS culture medium at a concentration of 1 / 3.

[0069] Set the control conditions for control unit 21, begin the tuber formation cycle regulation culture process, and mark the start time. T 1.

[0070] 2. Tuber formation cycle regulation culture process

[0071] 2.1 Phase 1

[0072] Inside nutrient chamber 11, the temperature was maintained at 22℃~26℃. Conventional aeroponic spray flow rates were used, with nutrient solution mist sprayed for 15s~20s every 10-15 minutes. Every 5-7 days, oxygen regulator 242 was used for ventilation for 60s~120s at an airflow rate of 1m³ / h. 3 / min.

[0073] Inside the tuber forming chamber 12, a humidity sensor 233 monitors the humidity. Nutrient solution is sprayed to maintain the humidity between 95% and 100%. The purpose of spraying the nutrient solution mist inside the tuber forming chamber 12 is to ensure humidity; therefore, the spray flow rate is not a critical factor. The temperature is regulated between 26℃ and 32℃ by a temperature control component 2432; the pressure is controlled by a pressure regulating component 241 to maintain the pressure at atmospheric pressure by an increase of ΔP, where ΔP = 200 Pa to 800 Pa.

[0074] After 14 days of cultivation (day 1 to day 14), the second stage begins.

[0075] 2.2 Phase 2

[0076] In nutrient chamber 11, the cultivation conditions are the same as in the previous stage;

[0077] Inside the tuber-forming storage 12, the storage temperature is regulated at 20℃~22℃, the air humidity inside the storage is regulated at 70%~75%, and the storage pressure is the same as the previous stage.

[0078] After 35 days of cultivation (from day 15 to day 50), the third stage begins.

[0079] 2.3 Phase 3

[0080] In nutrient chamber 11, the cultivation conditions are the same as in the previous stage;

[0081] Inside tuber forming bin 12, the temperature and humidity control conditions are the same as in the previous stage. The bin pressure control is as follows: if the cultivation goal is to increase the number of tubers and limit the average weight of tubers, the bin pressure conditions are the same as in the previous stage; if the cultivation goal is to limit the number of tubers and increase the average weight of tubers, stop pressurizing tuber forming bin 12 and adjust the bin pressure to natural atmospheric pressure ΔP, ΔP = 0 Pa ~ 200 Pa.

[0082] In this embodiment, a total of 4 sets of silo pressure control conditions are set, as shown in Table 1.

[0083] Table 1. Grouping of tuber storage pressure in stage 3

[0084] Small potato chunks (increase the number of potato chunks, limit the weight of each chunk) Large potato chunk group (limit the number of potato chunks, increase the weight of each chunk) Group S1: Pressure boost ΔP = 800 Pa Group b1: Pressure boost ΔP = 200Pa Group S2: Pressure boost ΔP = 500 Pa Group B2: Natural Atmospheric Pressure

[0085] Sweet potatoes continue to grow, and all tuber-forming sites on the tuber-forming vine (32) gradually swell and form tubers. Once all tuber-forming sites have been harvested (determined based on actual cultivation costs and profits), it indicates the end of one tuber-forming cycle regulation and cultivation process, and the termination time is marked. T 2.

[0086] This stage of cultivation begins on day 51 and continues until... T The time frame typically lasts 55 days, ending on day 105. Table 2 summarizes the environmental conditions for the tuber formation cycle regulation culture process.

[0087] Table 2 Environmental conditions for the three stages of tuber formation cycle regulation culture process

[0088]

[0089] 3. Continuous cultivation of plants to produce tubers

[0090] Check the growth of the terminal vines 31 outside the incubator 1, select vines with well-developed tuber-forming sites, pull them back from the rootstock end into the tuber-forming chamber 12 to become new tuber-forming vines 32, and start a new tuber-forming cycle regulation culture process. T 1~ T 2). For old vines (i.e. tuber vines 32 from the previous tuber formation cycle) or vines that cannot develop tuber formation sites, they can be pruned as needed, or used as wrapping and binding filling material to fix new tuber vines 32, thereby reducing unnecessary loss of plant nutrients.

[0091] 4. Growth and Harvest Status / Data

[0092] Table 3. Growth status and data of sweet potatoes at different stages

[0093]

[0094] The harvested tubers are uniform in size, with smooth skin, no obvious scars, and are generally clean. Example 4

[0095] like Figure 6 As shown, the soilless sweet potato tuber cultivation system and method in this embodiment are basically the same as those in Embodiment 3. The difference lies in the artificial control of the external light conditions of the incubator.

[0096] The outer tip vines of incubator 1 were illuminated by artificial light 4, using an LED modulated light source with a red-blue-green light ratio of 4:3:3. The light-dark cycle was 100 μmol / m². 2 • 1 hour of light exposure, 200 μmol / m 2 • 1 hour of light exposure, 500 ± 100 μmol / m 2 • Irradiation for 10-12 hours, 200 μmol / m 2 • 1 hour of light exposure, 100 μmol / m 2 • Illuminate for 1 hour, then turn off the light source for 8 to 10 hours.

[0097] The sweet potato growth and tuber formation data were superior to those of Example 3. The advantage of using artificially controlled external light conditions in the cultivation chambers is that the soilless sweet potato tuber formation system can be moved indoors, and one system comprises multiple cultivation chambers. A nutrient solution supply component 22 supplies nutrient solution to multiple cultivation chambers 1, and a control unit 21 regulates the operation of the monitoring component 23 and the regulating component 24 connected to each cultivation chamber 1. The cultivation chambers 1 are placed on multi-layer cultivation racks, making full use of vertical space and saving floor space; the entire system enables fully intensive cultivation.

[0098] Figure 6 This is a schematic diagram of a multi-layer incubator structure.

[0099] Comparative Example 1

[0100] The scion variety Short-Vine Heart Fragrance (red skin, yellow flesh) used in Example 3 was cultivated using conventional soil cultivation. The cultivation site was the applicant's experimental site, and the transplanting took place on June 4, 2021, with harvesting on November 16.

[0101] Fourteen days after transplanting, an average of 9.6 adventitious roots ≥5cm in length were induced per plant. After another 35 days of cultivation, an average of 11 enlarged roots ≥3mm were induced per tuber-bearing vine per plant, of which 3.4 were ≥5mm in diameter, with a maximum diameter of 15mm. At the end of the cultivation period (approximately 160 days in total), the tuber production data were as follows: 1.81 kg of tubers per plant. Among them, 4.73 tubers weighed more than 150g each, with an average weight of 0.266 kg each; 5.07 tubers weighed between 50g and 150g each, with an average weight of 0.099 kg each; and 1.8 tubers weighed less than 50g each, with an average weight of 0.027 kg each.

Claims

1. A soilless sweet potato tuber-forming cultivation system, characterized by: Includes an incubator (1) and a control system (2); The incubator (1) is divided into a nutrient chamber (11) and a tuber forming chamber (12) by an internal partition (13). The tuber forming chamber (12) has seedling holes (14) on its top / wall and partition (13). The tuber forming chamber (12) has an airtight structure (121). The control system (2) includes a liquid supply assembly (22), a monitoring assembly (23), an adjustment assembly (24), and a power supply circuit assembly, all of which are connected to the control unit (21). The liquid supply component (22) sprays nutrient solution into the incubator (1); The monitoring component (23) monitors environmental factor indicators inside the incubator (1) through sensors, including a barometer (231) for monitoring the pressure of the tuber-forming chamber (12). The regulating component (24) includes a pressure regulating component (241) for regulating the pressure of the tuber silo (12). The control unit (21) controls the working state of the adjustment component (24) according to the preset time conditions and / or the feedback data from the monitoring component (23); The rootstock (31) of the grafted sweet potato plant (3) passes through the seedling hole (14) of the partition (13) and extends into the nutrient box (11). The tuber vine (32) of the scion extends into the tuber box (12). The terminal vine (33) extends out of the seedling hole (14) on the top / wall of the tuber box (12) and out of the culture box (1). The grafted sweet potato plant (3) is a plant that has achieved the separation of sweet potato root functions through grafting.

2. The cultivation system according to claim 1, characterized in that: The pressure regulating assembly (241) includes an air pump (2411) for pumping gas into the tuber hopper (12) and a pressure reducing valve (2412).

3. The cultivation system according to claim 2, characterized in that: The monitoring component (23) further includes oxygen concentration sensors (232) for monitoring the nutrient bin (11) and the tuber forming bin (12) respectively. The regulating component (24) further includes an oxygen regulating component (242) for regulating the oxygen content in the nutrient bin (11) and the tuber forming bin (12) respectively. The oxygen regulating component (242) includes a ventilator and / or ventilation fan connected to the nutrient bin (11).

4. The cultivation system according to claim 3, characterized in that: The sensors also include a humidity sensor (233) for monitoring the humidity inside the tuber-forming chamber (12) and a temperature sensor (234) for monitoring the temperature of the nutrient chamber (11) and the tuber-forming chamber (12) respectively; the adjustment component (24) also includes a temperature control component (243); the temperature control component (243) includes a heating component (2431) connected to the nutrient chamber (11) and a constant temperature component (2432) connected to the tuber-forming chamber (12).

5. The cultivation system according to claim 4, characterized in that: The nutrient solution in the storage tank of the liquid supply component (22) is sprayed into the incubator (1); the monitoring component (23) also includes a liquid level sensor (235) that monitors the liquid level in the storage tank and the liquid level in the nutrient tank (11) respectively; the regulating component (24) uses a water pump (244) to recover excess nutrient solution collected in the incubator (1) and return it to the storage tank; the control unit (21) controls the working status of the water pump (244) according to the data of the liquid level sensor (235) in the nutrient tank (11).

6. The cultivation system according to claim 5, characterized in that: The culture box (1) is a rectangular box, with the nutrient chamber (11) and the tuber forming chamber (12) separated on the left and right. The culture box (1) includes a box body (15) and two box covers (16). The box cover (16) is an L-shaped bent plate that is hinged to or separated from the box body (15). The airtight structure (121) includes a sealing ring / strip, fasteners, and modeling clay used in conjunction with the seedling hole (14) at the connection between the box body (15) and the box cover (16) on the tuber forming chamber (12) side. The terminal vines (33) creep along the top surface of the incubator (1); The sensitive element of the monitoring component (23) is on the same side as the nutrient solution spray nozzle.

7. The cultivation system according to claim 6, characterized in that: The sweet potato soilless tuber cultivation system is provided with nutrient solution by a nutrient supply component (22) to at least two culture boxes (1), and the working status of the monitoring component (23) and the regulating component (24) connected to each culture box (1) is regulated by a control unit (21); the culture box (1) is placed on a multi-layer culture rack.

8. A method for soilless sweet potato tuber cultivation using the soilless sweet potato tuber cultivation system described in claim 6 or 7, characterized in that: Obtain grafted sweet potato plants (3). The grafted sweet potato plants (3) are successfully grafted seedlings with a sweet potato close relative that is tolerant to hydroponics, can be perennial, and has a non-bulging root system as the rootstock and a short-vine and / or extra-short-vine sweet potato variety with good tuber formation habit as the scion. When the tuber-forming vines (32) of the grafted sweet potato plants (3) have grown to 3 to 8 stem nodes, they are transferred into the culture box (1). The box cover (16) is closed. After the grafted sweet potato plants (3) pass through the seedling hole (14), the seedling hole (14) is sealed with clay. Nutrient solution is injected into the storage tank of the liquid supply component (22), and the start time is set. T 1. Begin tuber formation cycle regulation culture, including; Phase 1: Inside the nutrient chamber (11), the temperature is 22℃~26℃. Nutrient solution mist is sprayed for 15s~20s every 10min~15min. Every 5d~7d, the oxygen regulating component (242) is used for ventilation for 60s~120s with an airflow of 1 m³ / s. 3 / min; Inside the tuber-forming storage (12), the humidity of the air inside the storage is controlled at 95% to 100% by spraying nutrient solution, the storage temperature is adjusted at 26℃ to 32℃ by the constant temperature component (2432), and the storage pressure is controlled at natural atmospheric pressure by the air pressure regulating component (241), where ΔP = 200 Pa to 800 Pa. After 14 days of cultivation, the second stage begins. Phase 2: Inside the nutrient chamber (11), the cultivation conditions are the same as in the previous stage; Inside the tuber storage (12), the storage temperature is 20℃~22℃, the air humidity is 70%~75%, and the storage pressure is the same as the previous stage; After 35 days of cultivation, the third stage begins. Phase 3: Inside the nutrient chamber (11), the cultivation conditions are the same as in the previous stage; Inside the tuber storage (12), the temperature and humidity control conditions are the same as in the previous stage, and the storage pressure is controlled as follows: if the cultivation goal is to increase the number of tubers and limit the average weight of tubers, the storage pressure is the same as in the previous stage; if the cultivation goal is to limit the number of tubers and increase the average weight of tubers, the storage pressure is adjusted to increase the pressure by ΔP at the natural atmospheric pressure, where ΔP = 0 Pa ~ 200 Pa. Sweet potatoes continue to grow, and all tuber-forming sites on the tuber-forming vines (32) gradually enlarge and form tubers. Once tuber formation is completed and harvested, the tuber-forming cycle regulation culture is terminated, and the termination time is marked. T 2.

9. The cultivation method according to claim 8, characterized in that: exist T After 2 hours, check the growth of the terminal vines (33) outside the incubator (1), select vines with well-developed tuber-forming sites, pull them back from the rootstock end into the tuber-forming chamber (12) to become new tuber-forming vines (32), and start a new round of tuber-forming cycle regulation culture.

10. The cultivation method according to claim 8 or 9, characterized in that: The outer end vines (33) of the incubator (1) are illuminated by artificial light (4). The ratio of red, blue and green light in the LED modulated light source of the artificial light source is 4:3:3, and the day-night cycle of the light is 100 μmol / m 2 • 1 hour of light exposure, 200 μmol / m 2 • 1 hour of light exposure, 500 ± 100 μmol / m 2 • Irradiation for 10-12 hours, 200 μmol / m 2 • 1 hour of light exposure, 100 μmol / m 2 • Illuminate for 1 hour, then turn off the light source for 8 to 10 hours.

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