Novel method for promoting early maturation of large cherries

Abstract

The invention provides a novel method for promoting early maturation of large cherries, and relates to the technical field of fruit tree cultivation. The greenhouse cherry planting device solves the problem that heat is wasted due to the fact that greenhouse cherries planted in a greenhouse do not need to be cooled through ventilation instead of being too high in room temperature. Generally, the room temperature of a greenhouse can reach or exceed 35 DEG C in sunny weather in winter. Ground temperature is increased, rising and falling of the ground temperature and the room temperature tend to be synchronous, rising of the ground temperature in the greenhouse is promoted, and therefore overground and underground physiological synchronization of tree bodies is promoted. The phenomenon that the overground part of the cherries germinates and is high in activity is avoided, and the underground part of the cherries is still in a semi-dormancy and weak-activity state under the limitation of low temperature; and an underground ventilation heating facility is additionally arranged, no extra direct heating facility is needed, energy is saved, and the cost is low. The new facility ensures that no open fire or high-temperature equipment exists in the greenhouse, the operation is safe, and no fire risk exists. And moisture in air in the greenhouse can be condensed in the ventilation pipe, so that the humidity in the greenhouse is reduced, and diseases are reduced.

Description

Technical Field

[0001] This invention relates to the field of fruit tree cultivation technology, and more specifically, to a new method for promoting the early ripening of sweet cherries. Background Technology

[0002] Sweet cherries naturally ripen in June, between spring and summer. Currently, through artificial greenhouse cultivation, the ripening period can be advanced to May. Although imported cherries from South America are available in the winter market, March and April remain a market gap for sweet cherries each year. Even if some South American cherries can be stored until March, their taste and freshness are far inferior to freshly harvested cherries. If the ripening period for domestically produced sweet cherries could be brought forward to March and April, it would greatly satisfy the market demand for fresh sweet cherries.

[0003] In recent years, some regions have been able to advance the ripening period of sweet cherries by leveraging superior hydrothermal conditions or employing additional heating and cooling facilities. However, this has not yet fully filled the market gap, and the additional heating and cooling facilities consume a large amount of energy and electricity, resulting in high cultivation costs. Meanwhile, the application of dormancy-breaking agents provides a theoretical possibility for further advancing the ripening of sweet cherries, but problems such as low winter temperatures, limitations in greenhouse insulation, and low soil temperatures restrict further advancement of the ripening period. Existing greenhouses can improve their insulation performance by increasing height, optimizing lighting angles, and using thick cotton blankets and walls, but low soil temperatures remain a core problem that urgently needs to be addressed.

[0004] The core problems with existing technologies for advancing the ripening of sweet cherries stem from the chilling requirements of sweet cherries themselves and the limitations imposed by external temperatures, as detailed below: (1) Low ground temperature restricts the ripening process: The growth of sweet cherries requires the physiological synchronization of the above-ground and underground parts. Although existing greenhouses can raise the air temperature through various means, the effect of raising the ground temperature is limited. As a result, the above-ground parts sprout quickly and have strong activity, while the underground parts are restricted by low temperature and are in a semi-dormant state with weak activity. It is impossible to achieve physiological synergy between the upper and lower parts of the tree, making it difficult to ripen earlier.

[0005] (2) High energy consumption and high cost: Existing technologies use additional heating facilities to increase greenhouse temperature to promote early maturity, which requires a large amount of electricity or energy to be consumed continuously, greatly increasing cultivation costs and making it unsuitable for large-scale promotion.

[0006] (3) Serious energy waste: In sunny winter weather, the temperature inside the greenhouse can reach or exceed 35°C. Existing technologies usually use ventilation to cool down the temperature, which results in the direct discharge of hot air and the waste of heat, failing to achieve efficient energy utilization.

[0007] (4) Difficulty in balancing heat preservation and humidity control: Existing greenhouse heat preservation measures mainly target air temperature and cannot simultaneously improve ground temperature and control indoor humidity. Excessive humidity in the greenhouse can easily induce cherry diseases, affecting fruit quality and yield. Therefore, a new method to promote early ripening of sweet cherries is proposed. Summary of the Invention

[0008] The purpose of this invention is to address the problems raised in the existing background technology. To achieve the above-mentioned objective, this invention provides the following technical solution: a new method for promoting early ripening of sweet cherries, comprising the following steps: optimizing the basic insulation of the greenhouse; digging an insulation trench with a depth of 1 meter around the greenhouse and filling it with heat insulation material; burying a three-dimensional ventilation and heat conduction device in the soil inside the greenhouse; utilizing the recovered hot air from the upper part of the greenhouse to heat the soil and increase the ground temperature; synergistically regulating the room temperature and ground temperature to synchronize the physiological processes of the tree's upper and lower parts; and combining this with appropriate cultivation management to promote early ripening of sweet cherries.

[0009] As a preferred technical solution of the present invention, the three-dimensional ventilation and heat conduction device includes a main ventilation and heat conduction pipe and a suction fan. The main ventilation and heat conduction pipe is buried in the soil inside the greenhouse to a depth of 50cm and is laid horizontally, with the laying direction consistent with the length direction of the greenhouse.

[0010] As a preferred technical solution of the present invention, the main ventilation heat conduction pipe is made of corrosion-resistant heat conduction pipe with a diameter of 15-25cm. One end of the main ventilation heat conduction pipe extends to the lowest temperature point on both sides of the greenhouse as an air outlet, and the other end extends vertically to the top of the greenhouse as an air inlet. The suction fan is fixedly installed at the air inlet.

[0011] As a preferred technical solution of the present invention, the suction fan is a low-power energy-saving type, equipped with a temperature sensor, and the start-up threshold is set to 25°C. It automatically starts when the temperature in the upper part of the greenhouse reaches 25°C or above.

[0012] As a preferred technical solution of the present invention, the laying density of the main ventilation and heat conduction pipe is determined according to the size and span of the greenhouse and the row spacing of the cherry trees. When the row spacing of the cherry trees is 3m×4m, the laying spacing of the main ventilation and heat conduction pipe is 0.5-0.6 times the row spacing.

[0013] As a preferred technical solution of the present invention, the heat insulation material filled in the heat insulation trench is one of foam board, polystyrene board or rock wool, the width of the heat insulation trench is 0.5-0.8 meters, and the heat insulation material is filled densely without gaps.

[0014] As a preferred technical solution of the present invention, the specific process of hot air recovery and soil heating is as follows: after the suction fan is started, hot air at the top of the greenhouse that has reached the set temperature is drawn into the main ventilation heat conduction pipe. When the hot air flows along the main ventilation heat conduction pipe, it conducts heat to the surrounding soil through the pipe wall, while reducing the air temperature in the upper part of the greenhouse.

[0015] As a preferred technical solution of the present invention, the coordinated regulation of temperature and humidity specifically involves: maintaining the ground temperature at 12-18℃ and the room temperature at 10-26℃; controlling the relative humidity of the room at 60-70% by condensing the moisture in the air through the inner wall of the main ventilation heat conduction pipe; setting the main ventilation heat conduction pipe with a slight slope of 1 degree; and punching holes around the heat conduction pipe and wrapping it with non-woven fabric to facilitate the penetration of moisture and prevent the roots from clogging the drainage holes.

[0016] As a preferred technical solution of the present invention, the supporting cultivation management includes: spraying cyanamide-based dormancy-breaking agents during the dormancy period of sweet cherries, and simultaneously carrying out watering, fertilization, pruning, and integrated pest management in accordance with conventional sweet cherry greenhouse cultivation standards.

[0017] As a preferred technical solution of the present invention, the main ventilation heat conduction pipe is made of PVC anti-corrosion pipe, and the suction fan can be replaced by a solar-powered suction fan.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Achieve significantly earlier ripening of sweet cherries: By increasing soil temperature, coordinating the physiological synchronization of the upper and lower parts of the tree, and combining the application of dormancy-breaking agents, the ripening period of sweet cherries can be advanced by more than half a month, successfully filling part of the sweet cherry market gap, meeting the market demand for fresh sweet cherries, and increasing the added value of the product.

[0019] 2. Energy saving and consumption reduction, reducing cultivation costs: No additional heating facilities are needed. The hot air in the upper part of the greenhouse is recycled to increase the ground temperature, replacing the traditional ventilation cooling, reducing heat waste. At the same time, heat loss is reduced by the external foam board insulation trench, which greatly reduces energy consumption. Each acre can save more than 8,000 yuan in electricity and energy costs per year.

[0020] 3. Enhance cultivation safety and practicality: No open flames or high-temperature equipment are required, avoiding fire risks, ensuring safe operation, and making it suitable for large-scale greenhouse cultivation; at the same time, it achieves coordinated control of temperature and humidity, reducing the incidence of diseases, reducing the amount of pesticides used, and improving fruit quality and safety.

[0021] 4. High adaptability and broad prospects for promotion: It can be adapted to various existing cherry greenhouses, with low modification difficulty, simple construction, low equipment cost, no complicated operation, and can be widely used in the field of cherry facility cultivation, with both economic and social benefits. Attached Figure Description

[0022] Figure 1This is a schematic diagram of the method flow provided by the present invention; Figure 2 A three-dimensional ventilation and heat conduction data block diagram provided for this invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention.

[0024] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] Example 1: A new method to promote early ripening of sweet cherries includes the following steps: optimizing the basic insulation of the greenhouse, digging a 1-meter-deep insulation trench around the greenhouse and filling it with insulation material, burying a three-dimensional ventilation and heat conduction device in the soil inside the greenhouse, using the hot air recovered from the upper part of the greenhouse to heat the soil and increase the ground temperature, coordinating the regulation of room temperature and ground temperature to synchronize the physiological functions of the tree, and promoting early ripening of sweet cherries with supporting cultivation management.

[0026] The three-dimensional ventilation and heat conduction device includes a main ventilation and heat conduction pipe and a suction fan. The main ventilation and heat conduction pipe is buried 50cm deep in the soil inside the greenhouse and is laid horizontally in the same direction as the length of the greenhouse.

[0027] The main ventilation and heat conduction pipe is made of corrosion-resistant heat conduction pipe with a diameter of 15-25cm. One end of the main ventilation and heat conduction pipe extends to the lowest temperature point on both sides of the greenhouse as the air outlet, and the other end extends vertically to the top of the greenhouse as the air inlet. The suction fan is fixedly installed at the air inlet.

[0028] The exhaust fan is a low-power, energy-saving type, equipped with a temperature sensor. The start-up threshold is set to 25℃, and it will automatically start when the temperature in the upper part of the greenhouse reaches 25℃ or above.

[0029] The laying density of the main ventilation and heat conduction pipes is determined according to the size and span of the greenhouse and the spacing between the rows of cherry trees. When the spacing between the rows of cherry trees is 3m×4m, the laying spacing of the main ventilation and heat conduction pipes is 0.5-0.6 times the spacing between the rows of trees.

[0030] The insulation material filling the insulation trench is one of foam board, polystyrene board or rock wool. The width of the insulation trench is 0.5-0.8 meters, and the insulation material is filled densely without gaps.

[0031] The specific process of hot air recovery to heat the soil is as follows: After the suction fan is started, the hot air at the top of the greenhouse is drawn into the main ventilation heat conduction pipe. When the hot air flows along the main ventilation heat conduction pipe, it conducts heat to the surrounding soil through the pipe wall, while reducing the air temperature in the upper part of the greenhouse.

[0032] The specific measures for coordinated temperature and humidity control are as follows: the ground temperature is maintained at 12-18℃ and the room temperature is maintained at 10-26℃. The relative humidity in the room is controlled at 60-70% by condensing the moisture in the air through the inner wall of the main ventilation heat conduction pipe. The main ventilation heat conduction pipe is set with a slight slope of 1 degree. The heat conduction pipe is perforated around its perimeter and wrapped with non-woven fabric to facilitate water penetration and prevent the roots from clogging the drainage holes.

[0033] Supporting cultivation management includes: spraying cyanamide-based dormancy-breaking agents during the dormancy period of sweet cherries, and simultaneously carrying out watering, fertilization, pruning, and integrated pest management according to conventional sweet cherry greenhouse cultivation standards.

[0034] The main ventilation and heat conduction pipe is made of PVC anti-corrosion pipe, and the suction fan can be replaced with a solar-powered suction fan.

[0035] By laying large-diameter main ventilation and heat-conducting pipes 50cm underground in the greenhouse, and combining them with top-mounted exhaust fans, the hot air in the upper part of the greenhouse can be recovered and reused. No additional heating facilities are needed; the greenhouse itself generates its own hot air to heat the soil, solving the problems of low soil temperature and significant energy waste in existing technologies, thus achieving energy conservation and consumption reduction. The technical principle is to use heat conduction and air convection to transfer heat from the upper air to the underground soil, while simultaneously achieving coordinated regulation of indoor and soil temperatures.

[0036] By digging a 1-meter-deep foam board insulation trench around the greenhouse, the heat conduction from the greenhouse to the outdoor soil is blocked, reducing heat loss and helping to improve ground temperature stability. This solves the problem that existing greenhouse insulation only targets air and ground temperature is easily lost. The principle is to use the low thermal conductivity of foam boards to build an underground insulation barrier.

[0037] By recovering hot air through the main ventilation heat pipe, the indoor humidity is reduced by the air condensation effect, which solves the problem of difficulty in balancing heat preservation and humidity control and the easy occurrence of diseases in the existing technology. The principle is to use the difference in air dew point temperature to make the moisture in the air condense on the wall of the heat pipe to achieve humidity control, while avoiding the use of open flames or high-temperature equipment, thus improving the safety of cultivation operations.

[0038] By synchronizing the rise and fall of soil temperature and room temperature, the physiological activities of the above-ground and underground parts of the cherry tree are synchronized, breaking the semi-dormant state of the roots and enhancing root activity. This solves the core problem of asynchronous physiological activity between the upper and lower parts of the tree and restricting early ripening in existing technologies. The principle is to adapt to the temperature and humidity requirements of cherry growth and coordinate the nutrient absorption of the roots with the growth and development rhythm of the above-ground parts.

[0039] The specific implementation steps of this invention are as follows: Step 1. Greenhouse foundation renovation: The existing greenhouse 1 is optimized, retaining the original insulation measures such as increasing height, optimizing light angle, laying thick cotton quilts and reinforcing insulation walls, to further improve the insulation performance of the greenhouse and lay the foundation for subsequent temperature control and hot air recovery.

[0040] Step 2. External insulation treatment: Dig an insulation trench 4 around the outside of greenhouse 1. The depth of the insulation trench 4 is 1 meter, and the width is adapted to the size of the greenhouse (preferably 0.5-0.8 meters). After digging, fill the insulation trench 4 with foam board. The foam board is filled tightly without leaving gaps. Through the heat insulation performance of the foam board, heat inside the greenhouse is prevented from being conducted to the outdoor soil, reducing heat loss and indirectly helping to raise the ground temperature.

[0041] Step 3. Installation of underground ventilation and heat conduction devices: (1) Device selection: Select a large-diameter main ventilation heat conduction pipe 2. The pipe diameter of the main ventilation heat conduction pipe 2 is preferably 15-25cm. The material should be a plastic pipe with excellent thermal conductivity and corrosion resistance (preferably PVC anti-corrosion pipe) to ensure heat conduction efficiency and service life.

[0042] (2) Laying depth and position: The main ventilation and heat conduction pipe 2 is buried in the soil inside the greenhouse 1 at a depth of 50cm. The main ventilation and heat conduction pipe 2 is laid horizontally, and the laying direction is consistent with the length direction of the greenhouse. One end of the main ventilation and heat conduction pipe 2 extends to the lowest temperature point on both sides of the greenhouse 1 (i.e., the edge of the greenhouse near the wall) as an air outlet to facilitate the discharge of low-temperature air cooled by the pipe. The other end extends vertically upward to the top of the greenhouse 1 as an air inlet. A suction fan 3 is fixedly installed at the air inlet. The suction fan 3 is a low-power energy-saving type that can automatically start and stop according to the temperature inside the greenhouse (with a temperature sensor, the start threshold is set to 25℃, and the suction fan 3 starts when the temperature in the upper part of the greenhouse reaches 25℃ or above).

[0043] (3) Determining the laying density: Based on the size and span of greenhouse 1 and the row spacing of cherry trees 5, determine the laying density of the main ventilation and heat conduction pipes 2. Under normal circumstances, the row spacing of cherry trees 5 is 3m×4m, and the laying spacing of the main ventilation and heat conduction pipes 2 is 0.5-0.6 times the row spacing, ensuring that the ground temperature can be raised around each cherry tree through the main ventilation and heat conduction pipes 2, and avoiding uneven local ground temperature.

[0044] Step 4. Temperature and ventilation control: (1) Hot air recovery and utilization: In the sunny weather of winter, the temperature of the air in the upper part of the greenhouse 1 rises due to the influence of sunlight. When the temperature reaches the set temperature, there is no need to use the traditional ventilation cooling method. Instead, the suction fan 3 is started. The suction force of the suction fan 3 draws the hot air at the top of the greenhouse 1 into the air inlet of the main ventilation heat conduction pipe 2. The hot air flows downward along the main ventilation heat conduction pipe 2. During the process, the heat is conducted to the surrounding soil through the pipe wall of the main ventilation heat conduction pipe 2, realizing the reuse of hot air energy. At the same time, it reduces the temperature of the air in the upper part of the greenhouse, replacing the traditional ventilation cooling method and avoiding heat waste.

[0045] (2) Coordinated regulation of soil temperature and room temperature: Through the heat conduction of the main ventilation heat pipe 2, the soil temperature at a depth of 50cm in the greenhouse 1 is gradually increased, so that the rise and fall of soil temperature and room temperature tend to be synchronized. The soil temperature is controlled at 12-18℃ (the suitable temperature for the root activity of sweet cherry) and the room temperature is controlled at 10-26℃. This ensures that the above-ground and underground physiological activities of the sweet cherry plant 5 are synchronized, breaks the limitation of low temperature on root activity, and promotes nutrient absorption and transport.

[0046] (3) Humidity control: When the air in the greenhouse flows in the main ventilation and heat conduction pipe 2, the moisture in the air will condense inside the main ventilation and heat conduction pipe 2 because the pipe wall temperature is lower than the air dew point temperature. The condensed water can seep into the soil through the pre-set drainage holes in the pipe (the main ventilation and heat conduction pipe 2 is set with a slight slope), thereby reducing the air humidity in the greenhouse and controlling the indoor relative humidity at 60-70%, reducing the occurrence of diseases.

[0047] Step 5. Supporting cultivation management: In conjunction with the application of dormancy-breaking agents, spray dormancy-breaking agents (preferably cyanamide-based dormancy-breaking agents) during the dormancy period of sweet cherries. Combined with the soil temperature enhancement and temperature control measures of this invention, the ripening of sweet cherries will be further advanced. At the same time, watering, fertilization, pruning, and integrated pest management will be carried out in accordance with conventional sweet cherry greenhouse cultivation standards to ensure normal plant growth and accelerate the fruit ripening process.

[0048] This invention can replace large-diameter PVC pipes with corrugated pipes of the same diameter, which have better thermal conductivity, stronger corrosion resistance, and can improve heat transfer efficiency, but the cost is slightly higher than that of PVC pipes. It is suitable for scenarios with higher requirements for thermal conductivity.

[0049] This invention can replace low-power energy-saving suction fans with solar-powered suction fans, further reducing energy consumption and adapting to the needs of green and environmentally friendly cultivation. Its working principle is the same as that of the original suction fan, only the power source is different, and it does not affect the effect of hot air recovery and ground temperature improvement.

[0050] This invention can replace the foam board in the insulation trench with polystyrene board or rock wool. Both materials have excellent thermal insulation performance and can achieve the same thermal insulation effect, preventing heat from being conducted to the outside. The only differences are in material cost and construction difficulty.

[0051] Experimental Example: To verify the effectiveness of this invention, a comparative experiment was conducted in three greenhouses. The experimental group adopted the method described in this invention, control group 1 used existing greenhouse technology, and control group 2 used additional heating facilities to raise the soil temperature. The cherry varieties, plant spacing, fertilization, pruning, and other management measures were completely identical in the three groups. The experimental results are as follows: 1. Comparison of ripening period: The ripening period of the sweet cherries in the experimental group was 18 days earlier than that in the control group 1. The ripening period of the experimental group was in late March, while that of the control group 1 was in mid-April. The experimental group successfully filled part of the market gap.

[0052] 2. Energy consumption comparison: The experimental group only consumes low-power electricity required for the operation of the suction fan, with a monthly electricity consumption of 20-30 kWh per acre. The control group 2 requires 800-1000 kWh of electricity for heating facilities per acre per month. The energy consumption of the experimental group is reduced by more than 96%, which greatly saves cultivation costs.

[0053] 3. Comparison of soil temperature and physiological synchronicity: In the experimental group, the soil temperature at a depth of 50cm was maintained at 13-17℃, and the room temperature was maintained at 11-26℃. The soil temperature and room temperature rose and fell synchronously, and the physiological activity of the above-ground and underground parts of the cherry tree was consistent, with the root absorption efficiency increasing by more than 35%. In the control group, the soil temperature was maintained at 8-12℃, and the room temperature was maintained at 8-29℃. The physiological activity of the tree was asynchronous, and the root activity was low.

[0054] 4. Humidity and disease comparison: The relative humidity in the experimental group greenhouse was maintained at 62-68%, and the disease incidence rate (gray mold and anthracnose) was 2.1%; the relative humidity in the control group greenhouse was 75-85%, and the disease incidence rate was 8.7%, with the disease incidence rate in the experimental group being significantly lower.

[0055] 5. Fruit quality comparison: There was no significant difference in the single fruit weight and soluble solids content of the experimental group cherries compared with the control group. The taste and freshness were consistent with freshly picked cherries and superior to imported cherries that were stored, fully meeting the market demand for fresh cherries.

[0056] Experimental results show that the method described in this invention can effectively increase soil temperature, coordinate tree physiological activities, and enable sweet cherries to ripen earlier. At the same time, it can save energy, reduce disease incidence, and improve cultivation efficiency, thus possessing good value for large-scale promotion.

[0057] While some regions have raised ground temperature through additional heating facilities in existing technologies, these methods are costly, risky, and do not allow for energy reuse. This is completely different from the technical approach and solution of this invention. This invention raises ground temperature by recovering and utilizing hot air, eliminating the need for additional heating. It is lower in cost, safer, and can be scaled up. Compared to existing technologies, it can advance the ripening period of cherries by more than half a month, effectively filling the market gap in March and April.

[0058] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A novel method for promoting early ripening of sweet cherries, characterized in that, Includes the following steps: The basic insulation of the greenhouse is optimized by digging a 1-meter-deep insulation trench around the greenhouse and filling it with heat insulation material. A three-dimensional ventilation and heat conduction device is buried in the soil inside the greenhouse. The hot air from the upper part of the greenhouse is recovered to heat the soil and increase the ground temperature. The room temperature and ground temperature are synergistically regulated to synchronize the physiological functions of the tree. Combined with supporting cultivation management, this promotes the early ripening of sweet cherries.

2. The novel method for promoting early ripening of sweet cherries according to claim 1, characterized in that, The three-dimensional ventilation and heat conduction device includes a main ventilation and heat conduction pipe and a suction fan. The main ventilation and heat conduction pipe is buried in the soil inside the greenhouse to a depth of 50cm and is laid horizontally in the same direction as the length of the greenhouse.

3. A novel method for promoting early ripening of sweet cherries according to claim 2, characterized in that, The main ventilation and heat conduction pipe is made of corrosion-resistant heat conduction pipe with a diameter of 15-25cm. One end of the main ventilation and heat conduction pipe extends to the lowest temperature point on both sides of the greenhouse as the air outlet, and the other end extends vertically to the top of the greenhouse as the air inlet. The suction fan is fixedly installed at the air inlet.

4. A novel method for promoting early ripening of sweet cherries according to claim 3, characterized in that, The suction fan is a low-power, energy-saving type, equipped with a temperature sensor, and has a set start threshold of 25°C. It will automatically start when the temperature in the upper part of the greenhouse reaches 25°C or above.

5. A novel method for promoting early ripening of sweet cherries according to claim 2, characterized in that, The laying density of the main ventilation and heat conduction pipes is determined according to the size and span of the greenhouse and the spacing between the rows of cherry trees. When the spacing between the rows of cherry trees is 3m×4m, the laying spacing of the main ventilation and heat conduction pipes is 0.5-0.6 times the spacing between the rows of trees.

6. A novel method for promoting early ripening of sweet cherries according to claim 1, characterized in that, The insulation material filling the insulation trench is one of foam board, polystyrene board or rock wool. The insulation trench is 0.5-0.8 meters wide and 1 meter deep. The insulation material is densely filled without gaps.

7. A novel method for promoting early ripening of sweet cherries according to claim 1, characterized in that, The specific process of hot air recovery and soil heating is as follows: after the suction fan is started, hot air from the top of the greenhouse is drawn into the main ventilation heat conduction pipe. When the hot air flows along the main ventilation heat conduction pipe, it conducts heat to the surrounding soil through the pipe wall, while reducing the air temperature in the upper part of the greenhouse.

8. A novel method for promoting early ripening of sweet cherries according to claim 1, characterized in that, The coordinated regulation of temperature and humidity specifically involves: maintaining the ground temperature at 12-18℃ and the room temperature at 10-26℃; controlling the relative humidity in the room at 60-70% by condensing the moisture in the air through the inner wall of the main ventilation heat conduction pipe; setting the main ventilation heat conduction pipe with a slight slope of 1 degree; and punching holes around the heat conduction pipe and wrapping it with non-woven fabric to facilitate water penetration and prevent the roots from clogging the drainage holes.

9. A novel method for promoting early ripening of sweet cherries according to claim 1, characterized in that, The supporting cultivation management includes: spraying cyanamide-based dormancy-breaking agents during the dormancy period of sweet cherries, and simultaneously carrying out watering, fertilization, pruning, and integrated pest management according to conventional sweet cherry greenhouse cultivation standards.

10. A novel method for promoting early ripening of sweet cherries according to claim 3, characterized in that, The main ventilation and heat conduction pipe is made of PVC anti-corrosion pipe, and the suction fan can be replaced with a solar-powered suction fan.

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