Sunlight greenhouse tomato stalk low-temperature fermentation method

Abstract

The application discloses a kind of solar greenhouse tomato straw low-temperature fermentation method of returning to field, it is related to the technical field of vegetable planting, in view of the problems that existing straw returning to field technology relies on high temperature in summer, low-temperature stubble is slow, easy to produce ammonia gas hazard and cannot simultaneously supplement CO2 gas fertilizer, after the last ear of fruit of autumn and winter stubble tomato is harvested, chlorine dioxide aqueous solution and urea aqueous solution are sprayed to plant in turn, after 48 hours, pull seedling and be scattered in ridge ditch after being crushed, spray horseradish element aqueous solution, then close stew shed 2-3 days, after air release, spray ferrous sulfate aqueous solution, then plant early spring stubble tomato;After early spring stubble seedling is pulled, its straw is pressed into the earth in situ with the straw of autumn and winter stubble in ditch that is decomposed and not completely decomposed and returns to field.The application breaks the dependence on high-temperature window period of prior art, can realize about 90 days to complete straw decomposition in low-temperature season, and ammonia gas concentration is always lower than 5 μmol / mol safety threshold, while continuously releasing CO2, to provide gas fertilizer for crop.

Description

Technical Field

[0001] This invention relates to the field of vegetable planting technology, and in particular to a method for returning to the field by low-temperature fermentation of tomato straw in a solar greenhouse. Specifically, it relates to a method for returning to the field in situ tomato straw that ensures timely crop rotation, timely planting of the next crop of vegetables, low-temperature fermentation of straw during the low-temperature period, high safety, and continuous replenishment of carbon dioxide fertilizer. Background Technology

[0002] Tomatoes are a major high-value-added vegetable cultivated in greenhouses in my country, with large-scale planting and a high multiple cropping index. The common practice is a two-crop-a-year high-ridge cultivation model, combining autumn / winter and early spring crops. This compact crop rotation and high land utilization rate make it the mainstream model for efficient greenhouse vegetable production. However, the continuous year-round cultivation of greenhouse tomatoes generates a large amount of straw residue. If discarded haphazardly or piled up in the open, it not only occupies land and increases transportation costs but also easily breeds pathogens, spreads soil-borne diseases and pests, and causes non-point source pollution in farmland, seriously hindering the green and sustainable development of greenhouse vegetables. Returning straw to the field in situ, as a core technology for resource recycling, can effectively improve soil structure, increase soil organic matter, enrich soil fertility, and reduce fertilizer input.

[0003] Currently, most existing technologies for returning straw to the field in greenhouses rely on high-temperature fermentation and decomposition in summer, which is also the industry's recognized mainstream process. Conventional high-temperature straw return technology requires extreme daytime temperatures inside the greenhouse to reach 70-80℃, while maintaining a soil temperature of 40-50℃ in the 0-30cm tillage layer. This high-temperature environment activates microbial activity, rapidly degrades straw, and kills harmful soil bacteria and insects, achieving the dual effects of rapid straw decomposition and soil disinfection. The standardized industry regulation NY / T 3850-2021, "Technical Specification for In-situ Return of Straw to the Field in Greenhouses for Fruit and Vegetable Production," is also primarily designed for the high-temperature window period during summer off-season greenhouses, adapting to high-temperature, long-off-season crop rotation production models.

[0004] However, the year-round two-crop continuous tomato planting model in solar greenhouses has extremely strong agricultural time constraints. Autumn and winter tomatoes are mostly planted in July and August and pulled up in January and February during the low-temperature period. There is no summer high-temperature idle period between the autumn / winter and early spring crops, resulting in short crop intervals and limited available processing time. In the closed environment of solar greenhouses during the low-temperature season, the highest daytime temperature inside the greenhouse can only be maintained at 32-40℃, which is far from the temperature required for rapid high-temperature decomposition of straw. The metabolic activity of soil microorganisms is significantly reduced, the straw decomposition rate is greatly slowed down, and the complete decomposition cycle of straw is long, which cannot meet the connection requirements of short low-temperature cropping. If the next crop is not planted on time and the straw is forcibly returned to the field, the undecomposed straw will continue to ferment anaerobically during the crop's growing season, releasing large amounts of harmful gases such as ammonia and volatile organic acids. This can easily cause physiological damage to crops, such as leaf edge scorching, white spots, and growth inhibition, seriously affecting the yield and quality of early spring tomatoes. Ma Qiangqiang (2009) published a study entitled "Occurrence and Prevention of Harmful Gases in Vegetable Production in Solar Greenhouses in Zhuanglang County" in Gansu Agriculture. The results showed that when the ammonia concentration in the air inside the greenhouse reached 5 ml / m³, the ammonia concentration in the greenhouse was significantly reduced. 3 When this happens, it will damage vegetables to varying degrees. The symptoms of damage are that the leaves become water-soaked, their color fades, gradually turns white and brown, and then withers and dies. Wang Futong (2005) published a study entitled "Identification and Prevention of Gas Damage to Greenhouse Vegetables" in "Agricultural Science and Technology Information", which disclosed research conclusions similar to those of Ma Qiangqiang et al.

[0005] To address the issues of slow straw decomposition and low safety when returning straw to the field during low-temperature seasons, various auxiliary technologies for straw return to the field have been developed, including adjusting the carbon-nitrogen ratio, greenhouse heating through fumigation, material disinfection, and the addition of microbial agents. Conventional urea carbon-nitrogen ratio regulation technology can optimize soil microbial activity under low-temperature conditions and slightly increase the straw decomposition rate, but the low-temperature environment easily leads to nitrogen volatilization and ammonia accumulation, and also results in uneven straw decomposition, leading to insufficient production safety. Winter greenhouse heating only slightly raises the temperature and, limited by the external low temperature, cannot effectively accelerate the straw maturation process. Conventional disinfection methods only provide short-term surface bacterial inhibition and cannot continuously control disease and gas during the long-term low-temperature decomposition of straw. Existing technologies are relatively independent in function and lack systemic synergy, making them difficult to adapt to the production characteristics of short-stubble greenhouse production.

[0006] In summary, current straw return technology is highly dependent on the high temperatures of summer, limiting its applicability. In low-temperature crop rotations, it suffers from slow straw decomposition, easy ammonia accumulation, susceptibility to crop gas damage, and difficulty in adapting to year-round double-cropping. Furthermore, it fails to address the challenges of insufficient carbon dioxide and restricted crop growth in closed greenhouses during winter and spring. Existing technologies struggle to simultaneously meet the multiple needs of rapid low-temperature decomposition, safe gas suppression, crop rotation, and supplemental gas fertilizer, thus hindering the safe application of tomato straw return in low-temperature seasons. Therefore, developing a low-temperature fermentation method for tomato straw return that is suitable for low-temperature environments, safe and stable, and can simultaneously increase carbon dioxide concentration in greenhouses has significant practical value for the green year-round production of greenhouse tomatoes. Summary of the Invention

[0007] To address the shortcomings of existing in-situ vegetable straw return technology, which is subject to strict time constraints, has a narrow applicable window, and cannot guarantee the safety of returning vegetable straw to the field during the low-temperature season after the vegetable vines are pulled up, a low-temperature fermentation method for returning to the field of tomato straw in a solar greenhouse is proposed. This method overcomes the above-mentioned technical defects, does not affect the timely connection of crop rotation, and ensures that the release of ammonia gas is reduced and safety is improved during the straw return process, while also providing sufficient carbon dioxide fertilizer for tomatoes.

[0008] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A method for low-temperature fermentation and returning of tomato straw to the field in a solar greenhouse is applied to year-round continuous cropping of tomatoes in a solar greenhouse, using high-ridge cultivation, including continuous planting in autumn-winter and early-spring crops. Among them, autumn-winter tomatoes are planted in July-August and harvested in January-February of the following year; early spring tomatoes are planted after the autumn-winter tomatoes are harvested and harvested in June-July of the same year. After the last cluster of tomatoes in the autumn / winter crop has been harvested, process them in the following order: (1) Spray the tomato plants with a chlorine dioxide solution; (2) Within 24 hours after spraying chlorine dioxide solution, spray urea solution on tomato plants; (3) 48 hours after spraying urea solution, pull up the seedlings and crush the tomato stalks, then spread them evenly in the furrows; (4) After the straw is spread, spray horseradish solution into the ditch and close the ventilation opening of the greenhouse to seal it. (5) After the shed is sealed, ventilate for 2-3 days; (6) After ventilating and exhausting the air, spray a ferrous sulfate solution into the ditch; (7) After spraying with ferrous sulfate solution, plant early spring tomatoes; after the early spring tomatoes are harvested, crush their straw and return it to the field in situ, and turn the well-rotted and incompletely decomposed autumn and winter tomato straw in the ditch into the soil.

[0009] The height of the raised beds in the above-mentioned raised bed cultivation is 20-25cm, the width of the top surface of the raised bed is 50-70cm, and the width of the bottom of the furrow is equal to the width of the top surface of the raised bed; In step (1), the concentration of the chlorine dioxide aqueous solution is 7.5-10 μg / kg, per 667m³. 2 The amount of chlorine dioxide aqueous solution sprayed per planting area is 30-40 kg. In step (2), the concentration of the urea aqueous solution is 2-2.5%, per 667m³. 2 The amount of urea solution sprayed per planting area is 50-60 kg. In step (3), the tomato straw crushing is to chop the roots, stems, leaves, flowers and fruits that have no commercial value generated during the tomato production process, and the length of the chopped straw is no more than 4cm. In step (4), the horseradish aqueous solution is prepared by spraying a 20% horseradish aqueous solution diluted with water per 667m³. 2 For 20% of the planting area, the dosage of horseradish aqueous solution is 4-5L, which is diluted with water to 100-120kg for spraying. In step (4), the suffocation time is 2-3 days in a sealed greenhouse, with the indoor daytime temperature maintained at 32-40℃; In step (6), the ferrous sulfate aqueous solution is obtained by spraying ferrous sulfate diluted with water at a concentration of 667m³. 2 The dosage of ferrous sulfate per planting area is 2.5-3 kg, diluted with water to 100-120 kg for spraying; In step (7), the in-situ return of straw after crushing is carried out in accordance with the provisions of NY / T 3850-2021 "Technical Specification for In-situ Return of Straw to Facility Fruit and Vegetable Fields".

[0010] The present invention adopts the above technical solution and has the following advantages compared with the prior art: 1. This invention overcomes the dependence of existing straw return technology on the high-temperature window period in summer by using synergistic treatment of chlorine dioxide spraying, urea spraying, horseradish fumigation and ferrous sulfate spraying. Under the low temperature season (greenhouse temperature 32-40℃), the decomposition of autumn and winter tomato straw can be completed in about 90 days (weight loss rate greater than 75%), ensuring timely connection between autumn and winter crops and early spring crops.

[0011] 2. While achieving low-temperature composting, this invention can effectively suppress the release of ammonia during the straw decomposition process, maintaining the ammonia concentration in the greenhouse at a low range of 2.11-2.62 μmol / mol, thus avoiding damage to subsequent crops from ammonia and significantly improving the safety of straw return to the field during the low-temperature season.

[0012] 3. This invention utilizes the CO2 release characteristic of straw decomposition to continuously supplement carbon dioxide in a closed greenhouse. Experiments show that the CO2 concentration during the early spring tomato growing season is maintained at 461-736 μmol / mol, matching the crop's photosynthetic requirements, thus acting as an artificial supplement of gaseous fertilizer and promoting tomato growth. The function of straw return to the field has been expanded from soil fertility improvement to the synergistic regulation of soil fertility improvement and greenhouse photosynthetic environment, achieving process coupling and synergistic effects. Detailed Implementation

[0013] The following examples are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention.

[0014] It should be noted that in the following examples and comparative examples, the crop rotation arrangement is based on the following example: "Autumn-winter tomatoes are planted in July and pulled up in January of the following year; early-spring tomatoes are planted after the autumn-winter crop is pulled up and pulled up in June of the same year." In actual production, the planting time for autumn-winter crops can be adjusted between July and August according to the climate conditions of the planting area and the temperature changes of the year, and the pulling up time can be adjusted accordingly between January and February of the following year; the pulling up time for early-spring tomatoes can be adjusted accordingly between June and July of the same year, after the autumn-winter crop is pulled up.

[0015] Example 1 Low-temperature fermentation and returning of tomato straw to the field in solar greenhouses In this embodiment, the year-round continuous planting of tomatoes in the solar greenhouse adopts high-ridge cultivation, with a ridge height of 20cm, a ridge top width of 50cm, and a furrow bottom width equal to the ridge top width.

[0016] Autumn-winter tomatoes are planted in July and harvested in January of the following year; early spring tomatoes are planted after the autumn-winter crop is harvested and harvested in June of the same year.

[0017] After the last cluster of tomatoes in the autumn / winter crop has been harvested, proceed with the following processing steps: (1) Treatment of tomato plants with chlorine dioxide aqueous solution: Foliar spraying with chlorine dioxide aqueous solution at a concentration of 7.5 μg / kg per 667m² 2 The amount of liquid sprayed per planting area is 40 kg. (2) Within 24 hours after treatment with chlorine dioxide solution, spray the tomato plants with urea solution: per 667m³ 2 Apply 60 kg of a 2% urea solution evenly to the planting area. (3) After spraying the tomato plants with urea solution for 48 hours, pull up the plants, chop the tomato stalks, and the length of the chopped stalks should not exceed 4cm. Then, spread the crushed stalks evenly in the furrows. The tomato stalks are the roots, stems, leaves, flowers and fruits that have no commercial value produced during the tomato production process. (4) After spreading the crushed tomato straw, spray horseradish extract solution into the furrow: per 667m 2 For the planting area, use 4L of 20% horseradish extract solution, diluted with water to 100kg for spraying; after spraying, close the ventilation openings of the greenhouse and seal it for 2 days, maintaining the indoor daytime temperature at 32-40℃. (5) After the shed is sealed, ventilate for 2 days; (6) After ventilation and exhaust, spray ferrous sulfate solution into the ditch: per 667m 2 The dosage of ferrous sulfate per planting area is 2.5 kg, diluted with water to 100 kg for spraying; (7) After spraying with ferrous sulfate solution, plant early spring tomatoes; pull up the early spring tomatoes in June of the same year of planting, and after pulling up the plants, return the early spring tomato straw to the field in situ in accordance with the provisions of NY / T 3850-2021 "Technical Specification for In-situ Return of Straw to the Field of Facility Fruits and Vegetables", and turn the well-rotted and incompletely decomposed autumn and winter tomato straw in the ditch into the soil together.

[0018] Example 2 Low-temperature fermentation and returning of tomato straw to the field in solar greenhouses In this embodiment, the year-round continuous planting of tomatoes in the solar greenhouse adopts high-ridge cultivation, with a ridge height of 22.5cm, a ridge top width of 60cm, and a furrow bottom width equal to the ridge top width.

[0019] Autumn-winter tomatoes are planted in July and harvested in January of the following year; early spring tomatoes are planted after the autumn-winter crop is harvested and harvested in June of the same year.

[0020] After the last cluster of tomatoes in the autumn / winter crop has been harvested, proceed with the following processing steps: (1) Treatment of tomato plants with chlorine dioxide aqueous solution: Foliar spraying with chlorine dioxide aqueous solution at a concentration of 9 μg / kg per 667m² 2 The amount of liquid sprayed per plant area is 35 kg. (2) Within 24 hours after treatment with chlorine dioxide solution, spray the tomato plants with urea solution: per 667m³ 2 Apply 55 kg of a 2.25% urea solution evenly over the planting area. (3) After spraying the tomato plants with urea solution for 48 hours, pull up the plants, chop the tomato stalks, and the length of the chopped stalks should not exceed 4cm. Then, spread the crushed stalks evenly in the furrows. The tomato stalks are the roots, stems, leaves, flowers and fruits that have no commercial value produced during the tomato production process. (4) After spreading the crushed tomato straw, spray horseradish extract solution into the furrow: per 667m 2 For the planting area, use 4.5L of 20% horseradish extract aqueous solution, diluted with water to 110kg for spraying; after spraying, close the ventilation openings of the greenhouse and seal it for 3 days, maintaining the indoor daytime temperature at 32-40℃. (5) After the shed is sealed, ventilate for 3 days; (6) After ventilation and exhaust, spray ferrous sulfate solution into the ditch: per 667m 2 The amount of ferrous sulfate used per planting area is 2.75 kg, which is diluted with water to 110 kg for spraying. (7) After spraying with ferrous sulfate solution, plant early spring tomatoes; pull up the early spring tomatoes in June of the same year of planting, and after pulling up the plants, return the early spring tomato straw to the field in situ in accordance with the provisions of NY / T 3850-2021 "Technical Specification for In-situ Return of Straw to the Field of Facility Fruits and Vegetables", and turn the well-rotted and incompletely decomposed autumn and winter tomato straw in the ditch into the soil together.

[0021] Example 3 Low-temperature fermentation and returning of tomato straw to the field in solar greenhouses In this embodiment, the year-round continuous planting of tomatoes in the solar greenhouse adopts high-ridge cultivation, with a ridge height of 25cm, a ridge top width of 70cm, and a furrow bottom width equal to the ridge top width.

[0022] Autumn-winter tomatoes are planted in July and harvested in January of the following year; early spring tomatoes are planted after the autumn-winter crop is harvested and harvested in June of the same year.

[0023] After the last cluster of tomatoes in the autumn / winter crop has been harvested, proceed with the following processing steps: (1) Treatment of tomato plants with chlorine dioxide aqueous solution: Foliar spray with chlorine dioxide aqueous solution at a concentration of 10 μg / kg per 667m² 2 The amount of liquid sprayed per planting area is 30 kg. (2) Within 24 hours after treatment with chlorine dioxide solution, spray the tomato plants with urea solution: per 667m³ 2 Apply 50 kg of a 2.5% urea solution evenly over the planting area. (3) After spraying the tomato plants with urea solution for 48 hours, pull up the plants, chop the tomato stalks, and the length of the chopped stalks should not exceed 4cm. Then, spread the crushed stalks evenly in the furrows. The tomato stalks are the roots, stems, leaves, flowers and fruits that have no commercial value produced during the tomato production process. (4) After spreading the crushed tomato straw, spray horseradish extract solution into the furrow: per 667m 2 For the planting area, use 5L of 20% horseradish extract aqueous solution, dilute with water to 120kg and spray; after spraying, close the ventilation openings of the greenhouse and seal it for 3 days, maintaining the indoor daytime temperature at 32-40℃. (5) After the shed is sealed, ventilate for 3 days; (6) After ventilation and exhaust, spray ferrous sulfate solution into the ditch: per 667m 2 The dosage of ferrous sulfate per planting area is 3.0 kg, diluted with water to 120 kg for spraying; (7) After spraying with ferrous sulfate solution, plant early spring tomatoes; pull up the early spring tomatoes in June of the same year of planting, and after pulling up the plants, return the early spring tomato straw to the field in situ in accordance with the provisions of NY / T 3850-2021 "Technical Specification for In-situ Return of Straw to the Field of Facility Fruits and Vegetables", and turn the well-rotted and incompletely decomposed autumn and winter tomato straw in the ditch into the soil together.

[0024] Comparative Example 1 Comparative Example 1 adopted the low-temperature fermentation and return of tomato straw in a solar greenhouse method of Example 2, replacing the chlorine dioxide aqueous solution sprayed in step (1) with an equal amount of water, and the remaining steps and process parameters were the same as in Example 2.

[0025] Comparative Example 2 Comparative Example 2 adopted the low-temperature fermentation and return of tomato straw in a solar greenhouse method of Example 2, replacing the urea solution sprayed in step (2) with an equal amount of water, and the remaining steps and process parameters were the same as in Example 2.

[0026] Comparative Example 3 Comparative Example 3 adopted the low-temperature fermentation and return of tomato straw in a solar greenhouse method of Example 2, replacing the horseradish aqueous solution sprayed in step (4) with an equal amount of water, and the remaining steps and process parameters were the same as in Example 2.

[0027] Comparative Example 4 Comparative Example 4 adopted the low-temperature fermentation and return of tomato straw in a solar greenhouse method of Example 2, replacing the ferrous sulfate aqueous solution sprayed in step (6) with an equal amount of water, and the remaining steps and process parameters were the same as in Example 2.

[0028] Comparative Example 5 In this comparative example, the year-round continuous planting of tomatoes in the solar greenhouse adopts high-ridge cultivation, with a ridge height of 22.5cm, a ridge top width of 60cm, and a furrow bottom width equal to the ridge top width. Autumn and winter tomatoes are planted in July and pulled up in January of the following year. After the last cluster of tomatoes is harvested, all tomato stalks are removed outdoors, and early spring tomatoes are planted at the same time as in Example 2, pulling up in June of the same year. After pulling up, the early spring tomato stalks are returned to the field in situ according to the provisions of NY / T 3850-2021 "Technical Specification for In-situ Return of Straw to the Field of Facility Fruits and Vegetables".

[0029] Experimental Example 1 In a vegetable production base in Shouguang City, tomatoes were grown according to Examples 1-3 and Comparative Examples 1-5, for a total of 8 treatments. These were conducted in 8 identical greenhouses, with the same length and span. Except for the technical features described, all other management measures were identical during the cultivation process.

[0030] The tested variety was the strawberry tomato "Yu Linglong". The tomatoes were planted and managed according to the requirements of Examples 1-3 and Comparative Examples 1-5. The autumn-winter crop tomatoes were planted on July 5, 2024 and harvested on January 10, 2025. The early spring crop tomatoes were planted on January 22, 2025 and harvested on June 30, 2025.

[0031] On the day of transplanting early spring tomatoes, the levels of ammonia and carbon dioxide in the greenhouse were measured, and then measured every 20 days for a total of 6 times. Each measurement was taken at the middle of the greenhouse, at the intersection of the middle of the greenhouse's length and the middle of its span.

[0032] Ammonia determination: A portable electrochemical ammonia detector was used. The detector was required to be equipped with a pump-type electrochemical NH3 sensor; the range was 0-50 μmol / mol. For the first test, the probe was placed 30 cm above the ridge surface; for subsequent tests, the probe was placed 30 cm above the tomato canopy, away from the soil surface.

[0033] Carbon dioxide detection: A portable non-dispersive infrared (NDIR) CO2 detector was used. Detector requirements: range 0-5000 μmol / mol; accuracy ≤ ±50 μmol / mol; waterproof, dustproof, and moisture-proof; pump-suction type. The detection point and ammonia sampling point were kept at the same location. No nitrogen-containing fertilizers were applied for 5 days before and after each detection.

[0034] Straw weight loss rate test: The weight loss rate represents the degree of decomposition of straw at a certain time. The straw weight loss rate is tested according to the test method of NY / T 2722-2015.

[0035] Ammonia and carbon dioxide levels were measured in the early morning before ventilation on January 22, February 13, March 6, March 27, April 17, and May 8. All tests were conducted with the greenhouse under normal ventilation the day before the tests.

[0036] Samples were taken on February 20, March 22, April 21, May 21, and June 20 to test the weight loss rate of tomato stalks in the ditch. When the weight loss rate of the stalks was greater than 75%, the stalks had basically completed decomposition, and no further testing was conducted.

[0037] The test results are shown in Tables 1, 2 and 3.

[0038] Table 1. Detection results of ammonia concentration in air

[0039] Ma Qiangqiang (2009) published a study entitled "Occurrence and Prevention of Harmful Gases in Vegetable Production in Solar Greenhouses in Zhuanglang County" in Gansu Agriculture. The results showed that when the ammonia concentration in the air inside the greenhouse reached 5 ml / m³, the ammonia concentration in the greenhouse was significantly reduced. 3At this time, it will damage vegetables to varying degrees. Symptoms include water-soaked leaves, pale color, gradually turning white and then brown, eventually leading to withering and death. Therefore, 5ml / m 3 (5 μmol / mol) can be used as the safety warning threshold for ammonia in tomato growth.

[0040] As shown in Table 1, during the straw decomposition process, the ammonia concentration in the air of Examples 1-3 and Comparative Examples 1-4 initially increased from low to high, reached a certain peak, and then gradually decreased, while Comparative Example 5 showed no obvious peak. The indoor ammonia concentration in Examples 1-3 and Comparative Example 5 remained within the safety warning threshold; the test results of Comparative Examples 1 and 3 on March 6 were close to the safety warning threshold, indicating a potential stress risk, which could easily lead to ammonia gas damage if not properly managed. The results indicate that Comparative Example 1 (without chlorine dioxide) and Comparative Example 3 (without horseradish extract) were not effective in reducing ammonia release. Comparative Example 2, without the addition of exogenous nitrogen fertilizer, resulted in slow straw decomposition, delayed peak ammonia release, and a lower overall concentration, but it was still higher than Comparative Example 5 (without straw), posing a risk of low-temperature cumulative gas damage. Comparative Example 4 (without ferrous sulfate) showed test results above the safety warning threshold from February 13 to March 27, which could easily cause ammonia damage in a short period of time, indicating that the use of ferrous sulfate is crucial for effectively reducing ammonia release.

[0041] From March 1st to 3rd, Shouguang City experienced continuous rain and snow. To avoid excessively low temperatures inside the greenhouse, ventilation was limited and the duration of ventilation was short. An investigation on March 5th revealed that some plants in Comparative Examples 1, 3, and 4 showed symptoms of ammonia damage on their lower leaves. Affected leaves exhibited pale yellowish-brown, water-soaked chlorotic spots along the leaf margins. In Comparative Example 4, the damage had spread to the middle leaves, significantly more severe than in Comparative Examples 1 and 3. No ammonia damage was observed in Comparative Examples 2 and 5. This further demonstrates that Comparative Examples 1 (without chlorine dioxide) and 3 (without horseradish extract) are prone to ammonia accumulation and gas damage under continuous rainy and snowy weather conditions with insufficient greenhouse ventilation. Throughout the entire implementation process, Examples 1-3 did not experience ammonia damage or damage from nitrous oxide or other harmful gases; the tomatoes maintained healthy growth throughout.

[0042] Table 2. Detection results of carbon dioxide concentration in the air

[0043] Solar greenhouses are enclosed facilities with limited ventilation during cold seasons. During the vigorous growth period of vegetables, photosynthesis continuously consumes carbon dioxide inside the greenhouse. Two to four hours after sunrise, the CO2 concentration inside the greenhouse will rapidly drop to 60-150 μmol / mol, which is far lower than the normal atmospheric concentration of 330-380 μmol / mol, resulting in a carbon dioxide deficit. Artificial CO2 supplementation is a key technology for improving the quality and efficiency of greenhouse vegetables.

[0044] As shown in Table 2, during the decomposition of straw, the carbon dioxide concentration in the air in Examples 1-3 and Comparative Examples 1-4 all showed a pattern of increasing from low to high, reaching a certain peak, and then gradually decreasing, while Comparative Example 5 showed no obvious peak. The test results of Examples 1-3 were greater than those of Comparative Example 5, and the differences were significant, indicating that applying straw during the low-temperature season is beneficial to increasing the carbon dioxide concentration in the greenhouse, and is an effective method for artificially supplementing CO2 fertilizer. The test results of Comparative Examples 1-3 were all less than those of Examples 1-3, indicating that Comparative Example 1 (without chlorine dioxide), Comparative Example 2 (without urea), and Comparative Example 3 (without horseradish extract) were not conducive to effectively increasing CO2 release. Among them, the test results of Comparative Example 2 (without urea) were significantly less than those of Comparative Examples 1 and 3, indicating that insufficient nitrogen slowed down the decomposition rate of straw organic matter and reduced the rate of organic matter oxidation to CO2. The test results of Comparative Example 4 (without ferrous sulfate) were no different from those of Examples 1-3, indicating that the presence or absence of ferrous sulfate did not affect CO2 release.

[0045] Table 3 Results of straw weight loss rate test

[0046] As shown in Table 3, the straw weight loss rate of Examples 1-3 was greater than 75% on April 21, indicating that the low-temperature fermentation of Examples 1-3 basically completed the decomposition in about 90 days. The results of Comparative Example 4 were similar to those of Examples 1-3, indicating that ferrous sulfate did not affect the straw decomposition rate. In Comparative Example 1, the straw weight loss rate was greater than 75% on June 20, indicating that the low-temperature fermentation of Comparative Example 1 basically completed the decomposition in about 150 days, and the straw decomposition rate was slow without the application of chlorine dioxide. In Comparative Example 2, the straw weight loss rate was still less than 75% on June 20, and the straw decomposition was not completed after 150 days of low-temperature fermentation, indicating that in Comparative Example 2, without the addition of exogenous nitrogen fertilizer, the decomposition period was significantly prolonged and the decomposition was incomplete. In Comparative Example 3, the straw weight loss rate was greater than 75% on May 21, indicating that the low-temperature fermentation of Comparative Example 3 basically completed the decomposition in about 120 days, and the absence of horseradish extract was not conducive to effectively improving the straw decomposition rate.

[0047] Based on the results in Tables 1, 2 and 3, Examples 1-3 overcome the dependence on crop rotation and temperature, and can achieve full decomposition of straw during non-summer off-seasons. Low-temperature fermentation can basically complete decomposition in about 90 days, which is suitable for the in-situ straw return to the field in low-temperature seasons.

[0048] In Examples 1-3, the ammonia concentration in the greenhouse remained below 5 μmol / mol throughout the low-temperature fermentation process of the straw, which was within the safety warning threshold for tomato growth. At the same time, no other harmful gases were detected, and the tomatoes maintained a healthy growth state.

[0049] Examples 1-3 show that throughout the low-temperature fermentation process of straw, the carbon dioxide concentration in the greenhouse remains at a high level, which is beneficial for "carbon supplementation" of tomatoes. This expands the effect of straw return to the field from "soil fertilization and improvement" to "greenhouse photosynthetic environment regulation". The carbon dioxide release rate is perfectly matched with the growth of early spring tomatoes, making it an effective method for artificially supplementing CO2 fertilizer.

Claims

1. A method for returning to the field via low-temperature fermentation of tomato straw in a solar greenhouse, characterized in that: This method is applied to year-round continuous cropping of tomatoes in greenhouses, using raised-ridge cultivation, including two consecutive seasons: autumn / winter and early spring. Autumn / winter tomatoes are transplanted in July-August and harvested in January-February of the following year; early spring tomatoes are transplanted after the autumn / winter harvest and harvested in June-July of the same year. After the last cluster of fruits in the autumn / winter crop is harvested, the tomatoes are processed in the following order: (1) Spray the tomato plants with a chlorine dioxide solution; (2) Within 24 hours after spraying chlorine dioxide solution, spray urea solution on tomato plants; (3) 48 hours after spraying urea solution, pull up the seedlings and crush the tomato stalks, then spread them evenly in the furrows; (4) After the straw is spread, spray horseradish solution into the ditch and close the ventilation opening of the greenhouse to seal it. (5) After the shed is sealed, ventilate for 2-3 days; (6) After ventilating and exhausting the air, spray a ferrous sulfate solution into the ditch; (7) After spraying with ferrous sulfate solution, plant early spring tomatoes; after the early spring tomatoes are harvested, crush their straw and return it to the field in situ, and turn the well-rotted and incompletely decomposed autumn and winter tomato straw in the ditch into the soil.

2. The method for low-temperature fermentation and returning of tomato straw to the field in a solar greenhouse according to claim 1, characterized in that, The raised bed cultivation method has a ridge height of 20-25cm, a ridge top width of 50-70cm, and a furrow bottom width equal to the ridge top width.

3. The method for returning to the field after low-temperature fermentation of tomato straw in a solar greenhouse according to claim 1, characterized in that, In step (1), the concentration of the chlorine dioxide aqueous solution is 7.5-10 μg / kg, per 667m³. 2 The amount of chlorine dioxide aqueous solution sprayed per planting area is 30-40 kg.

4. The method for returning to the field by low-temperature fermentation of tomato straw in a solar greenhouse according to claim 1, characterized in that, In step (2), the concentration of the urea aqueous solution is 2-2.5%, per 667m³. 2 The amount of urea solution sprayed per planting area is 50-60 kg.

5. The method for low-temperature fermentation and returning of tomato straw to the field in a solar greenhouse according to claim 1, characterized in that, In step (3), the tomato straw crushing is to chop the roots, stems, leaves, flowers and fruits that have no commercial value generated during the tomato production process, and the length of the chopped straw is no more than 4cm.

6. The method for low-temperature fermentation and returning of tomato straw to the field in a solar greenhouse according to claim 1, characterized in that, In step (4), the horseradish aqueous solution is prepared by spraying a 20% horseradish aqueous solution diluted with water per 667m³. 2 For 20% of the planting area, the dosage of horseradish extract is 4-5L, which should be diluted with water to 100-120kg for spraying.

7. The method for returning to the field after low-temperature fermentation of tomato straw in a solar greenhouse according to claim 1, characterized in that, In step (4), the suffocation time is 2-3 days in a sealed greenhouse, and the indoor daytime temperature is maintained at 32-40℃.

8. The method for returning to the field by low-temperature fermentation of tomato straw in a solar greenhouse according to claim 1, characterized in that, In step (6), the ferrous sulfate aqueous solution is obtained by spraying ferrous sulfate diluted with water at a concentration of 667m³. 2 The dosage of ferrous sulfate per planting area is 2.5-3 kg, diluted with water to 100-120 kg for spraying.

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