Greenhouse tomato water-saving and quality-improving planting method based on cooperation of shallow-buried drip irrigation and biochar

Abstract

The invention discloses a greenhouse tomato water-saving and quality-improving planting method with cooperation of shallow-buried drip irrigation and biochar, and the method comprises the following steps: detecting greenhouse tomato planting soil, and conditioning the soil texture according to a detection result; laying a drip irrigation system on the conditioned soil, and laying a soil monitoring network; based on the established dropper system and the soil detection network, tomato seedlings are planted, and initial moisture management is carried out on the tomato seedlings after planting; after the tomatoes survive after field planting, performing staged irrigation and water and fertilizer integrated management according to the requirements of the tomatoes in different growth stages; performing charcoal rhizosphere activation and function regulation on the tomatoes in the growth period; real-time data of a greenhouse environment and a soil monitoring network are integrated, an intelligent irrigation decision model is established and operated, and a dynamic optimization irrigation scheme is implemented; and carrying out oxidation and ecological improvement on the soil after tomato harvesting. The tomato planting quality can be improved, and the soil health condition can be improved.

Description

Technical Field

[0001] This application belongs to the field of greenhouse tomato water-saving and quality-improving cultivation technology, specifically involving a method for greenhouse tomato water-saving and quality-improving cultivation that combines shallow-buried drip irrigation with biochar. Background Technology

[0002] Currently, greenhouse tomato cultivation generally faces problems such as water waste, low fertilizer utilization, soil degradation, and unstable fruit quality. Traditional drip irrigation methods mostly use surface drip irrigation, resulting in significant water evaporation losses, shallow root distribution, and poor stress resistance. In addition, although biochar has been used for soil improvement, its spatiotemporal synergy mechanism with irrigation systems is still unclear, and there is a lack of an integrated water-biochar-root synergistic regulation system. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this application is to provide a water-saving and quality-improving greenhouse tomato cultivation method that combines shallow-buried drip irrigation with biochar. This application constructs an integrated synergistic control system of "shallow-buried drip irrigation - biochar activation - intelligent decision-making," which enables efficient synergy of water, fertilizer, biochar, and roots during greenhouse tomato cultivation, thereby improving tomato quality and soil health.

[0004] To achieve the above objectives, this application provides the following technical solution: A method for water-saving and quality-improving greenhouse tomato cultivation using shallow-buried drip irrigation and biochar synergy, comprising: testing the greenhouse tomato planting soil and conditioning the soil based on the test results, wherein the testing includes soil pH, organic matter content, bulk density, available phosphorus content, available potassium content, electrical conductivity, and field capacity; laying a drip irrigation system on the conditioned soil and establishing a soil monitoring network; transplanting tomato seedlings based on the established drip irrigation system and soil monitoring network, and managing the initial water supply to the transplanted seedlings; after the seedlings have established themselves, implementing phased irrigation and integrated water and fertilizer management according to the needs of different tomato growth stages; activating and regulating the rhizosphere of the tomatoes during their growth period using biochar; integrating real-time data from the greenhouse environment and soil monitoring network to establish and operate an intelligent irrigation decision model and implement dynamically optimized irrigation schemes; and oxidizing and ecologically improving the soil after tomato harvest.

[0005] Optionally, the detection of the greenhouse tomato planting soil includes: obtaining a soil extract; selecting and pretreating a biochar probe; and performing an adsorption reaction of the pretreated biochar probe on the soil extract to obtain a detection signal, the detection signal including the percentage change in conductivity, etc. The absolute value of the change and the amount of turbidity change are measured; based on the detection signal, a root zone adsorption fingerprint index is constructed to determine the soil condition.

[0006] Optionally, the soil conditioning based on the test results includes: comparing the root zone adsorption fingerprint index to determine the problems existing in the soil; determining the amount and method of biochar application based on the existing soil problems; supplementing basic nutrients and organic matter; improving soil structure; and regulating moisture.

[0007] Optionally, the installation of the drip irrigation system on the conditioned soil and the deployment of the monitoring network include: laying trenches on the conditioned soil; using embedded drip irrigation tape to lay at the bottom of the narrow trenches; and installing soil moisture sensors in the tomato root zone.

[0008] Optionally, the process of transplanting tomatoes and managing them in the initial stage includes: preparing for transplanting; selecting and treating tomato seedlings; and transplanting and managing the initial water supply for the treated tomato seedlings.

[0009] Optionally, the transplanting and initial water management of the treated tomato seedlings includes: gently placing the root-dipping tomato seedlings into the planting hole, with the planting depth such that the cotyledons of the seedlings are slightly higher than the ground surface; covering the roots with a small amount of nutrient soil or seedling substrate after transplanting to stabilize the plants; and slowly watering the base of each seedling with water.

[0010] Optionally, the staged irrigation and fertigation management of tomatoes after initial water management includes: staged dynamic irrigation of tomatoes after initial water management; and targeted fertigation management during the staged dynamic irrigation process.

[0011] Optionally, the biochar activation and rhizosphere regulation of tomatoes during their growth period includes: biochar rhizosphere activation of tomatoes during their growth period; dynamic regulation of the rhizosphere environment based on data from deployed soil sensors; synergistic regulation of the rhizosphere microbial community; and assessment and adjustment of the biochar functional status during the middle and late stages of tomato growth.

[0012] Optionally, the integration of greenhouse environment and soil moisture data to establish a multi-factor irrigation decision model and realize dynamic optimization of irrigation strategies includes: real-time integration of multi-source data and calculation of crop water requirements; construction of an intelligent irrigation decision model to analyze the collected multi-source data and output an optimized irrigation plan; execution of the optimized irrigation plan and monitoring of irrigation effects.

[0013] Optionally, the oxidation and continuous improvement of soil after tomato harvesting includes: removing plant residues from the soil after harvesting and performing shallow tillage; oxidizing, activating, and regenerating the biochar in the soil after harvesting; and adding organic materials to the biochar-activated soil to perform ecological restoration of the soil.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: This application constructs an integrated collaborative control system of "shallow-buried drip irrigation - biochar activation - intelligent decision-making," which enables efficient synergy of water, fertilizer, biochar, and roots during greenhouse tomato cultivation. While reducing irrigation water consumption (reducing evaporation and deep seepage), it can improve the soil structure and buffering capacity in the root zone, activate the continuous water and fertilizer retention and adsorption functions of biochar, and achieve precise on-demand supply of water and fertilizer based on a multi-source data fusion intelligent irrigation model. Ultimately, it achieves comprehensive technical effects such as water saving (approximately 20%-30%), improved fruit quality (e.g., sugar content, VC content), stable yield increase (approximately 10%-15%), improved soil health, and relief of continuous cropping obstacles. Attached Figure Description

[0015] Figure 1 This is a schematic flowchart of a method for water-saving and quality-improving greenhouse tomato cultivation that combines shallow-buried drip irrigation with biochar, provided in one embodiment of this application. Detailed Implementation

[0016] Specific embodiments of this application will now be described in detail with reference to the accompanying drawings. While specific embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0017] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0018] To facilitate understanding of the embodiments of this application, the following will provide further explanation and description with reference to the accompanying drawings and specific embodiments, and the accompanying drawings do not constitute a limitation on the embodiments of this application.

[0019] Figure 1 This is a schematic flowchart illustrating a method for water-saving and quality-improving greenhouse tomato cultivation using shallow-buried drip irrigation and biochar synergy, as provided in one embodiment of this application. Figure 1 As shown, the method includes the following steps: S1: Test the soil for greenhouse tomato cultivation, including soil pH, organic matter content, bulk density, available phosphorus content, available potassium content, electrical conductivity and field water holding capacity, and adjust the soil quality according to the test results; S2: Lay a drip irrigation system on the conditioned soil and set up a soil monitoring network; S3: Based on the established drip irrigation system and soil testing network, transplant tomato seedlings and manage the initial water supply for the transplanted tomato seedlings. S4: After the seedlings have survived, implement phased irrigation and integrated water and fertilizer management according to the needs of different growth stages of tomatoes; S5: Biochar rhizosphere activation and functional regulation of tomatoes during their growth period; S6: Integrate real-time data from greenhouse environment and soil monitoring networks, establish and run intelligent irrigation decision-making models, and implement dynamically optimized irrigation schemes; S7: Oxidize and ecologically improve the soil after tomato harvesting.

[0020] This embodiment achieves precise, intelligent, and sustainable management of greenhouse tomato cultivation through systematic technological integration. Specifically, it involves: establishing a suitable soil foundation for root growth based on initial soil testing and conditioning; providing hardware support for precise water and fertilizer management through the installation of drip irrigation and monitoring networks; implementing phased integrated water and fertilizer management at transplanting and each growth stage to significantly improve water and fertilizer utilization efficiency; optimizing the root zone microenvironment using biochar rhizosphere activation technology to enhance nutrient availability and plant stress resistance; relying on real-time monitoring data to drive an intelligent irrigation model, achieving dynamic optimization and automated control of irrigation schemes; and conducting soil oxidation and ecological improvement after harvest to effectively alleviate continuous cropping obstacles and maintain soil health and long-term productivity. The above-described technical solutions form a closed-loop management system from pre-planting preparation to post-harvest restoration, ensuring tomato yield and quality while achieving efficient resource utilization and sustainable soil production.

[0021] In another exemplary embodiment, step S1, the testing of the greenhouse tomato growing soil, includes the following steps: S11: Obtain soil extract; In this step, before transplanting greenhouse tomatoes, soil stratification sampling is carried out at the root zone of the tomato planting row, and multiple mixed samples are preferably taken at two depths of 0 to 10 cm and 10 to 20 cm to characterize the difference between the soil surface layer and the potential taproot distribution layer.

[0022] Next, after removing plant debris and gravel from the collected soil samples, they were mixed with deionized water at a mass-to-volume ratio of 1:5 and shaken thoroughly to ensure that soluble salts, dissolved organic matter, and exchangeable ions in the soil were fully dissolved in the deionized water. Subsequently, soil extracts were obtained through natural sedimentation or filtration through filter paper for subsequent testing and analysis.

[0023] S12: Select biochar probes and pretreat them; In this step, agricultural straw from the same source as that used in subsequent soil conditioning is pyrolyzed to generate biochar, which is then used as an adsorption probe material for detection. Furthermore, to reduce the impact of physicochemical differences between different batches of biochar on the detection results, this embodiment pre-treats the biochar, specifically including: First, the biochar is initially screened and washed and dried. Specifically, the biochar is sieved and biochar particles with a diameter of 1 mm to 2 mm are selected. The sieved biochar particles are repeatedly washed with deionized water until the conductivity of the eluent is stable (e.g., ≤50µS / cm) to remove free ash and soluble salts. After draining the water, the biochar is placed in a ventilated place to air dry naturally or dried at a low temperature of 40℃ to 50℃ until constant weight is achieved.

[0024] Secondly, the dried biochar granules are activated, specifically by mixing the dried biochar granules with a 5% humic acid solution (mass ratio 1:10) and soaking them for a certain period of time (e.g., 24 hours); after draining off the excess solution, a 1% potassium dihydrogen phosphate solution (based on the dry weight of the biochar) is added, sprayed evenly and stirred; the biochar treated in the above manner is piled up for 48 hours, during which it is turned over 2 to 3 times to promote nutrient adsorption and surface activation.

[0025] Secondly, the activated biochar is stabilized, specifically by spreading the activated biochar on a clean surface and exposing it to natural sunlight for 3 to 5 days, turning it over twice a day. After the exposure to sunlight, the moisture content (controlled to ≤10%) and pH value (target range 7.0 to 8.5) of the biochar are tested.

[0026] Finally, the biochar treated as described above is packed into breathable and moisture-proof packaging bags for storage.

[0027] S13: The pretreated biochar probe is adsorbed onto the soil extract to obtain a detection signal; In this step, a certain volume of soil extract (e.g., 20 mL) is placed in a reaction vessel, and a pretreated biochar probe (e.g., 0.5 g) is added. The mixture is gently shaken at room temperature to ensure thorough contact and reaction between the biochar probe and the soil extract for 5 to 8 minutes. Furthermore, the conductivity, pH value, and color or turbidity changes of the extract are measured before and after the reaction. Conductivity and pH can be obtained using portable instruments, while color or turbidity can be semi-quantitatively recorded using a colorimetric card or a simple turbidity tube, thus forming a multidimensional detection signal reflecting changes in the characteristics of the soil solution.

[0028] S14: Construct a root zone adsorption fingerprint index based on the detection signal to determine the soil condition.

[0029] In this step, based on the aforementioned detection signals, the percentage change in conductivity, the magnitude of pH change, and the amount of turbidity change before and after biochar adsorption are calculated. These are then combined to construct the root zone adsorption fingerprint index, which comprehensively characterizes the soluble salt level, dissolved organic matter load, and buffering capacity of the soil. By comparing and analyzing the fingerprint indices of different soil layers, the uniformity of salt distribution in the root zone and the presence of potential salt stress or continuous cropping obstacles are determined. This provides a basis for determining subsequent biochar application rates, rotary tillage depth, and shallow-buried drip irrigation system deployment parameters, achieving quantitative linkage between soil testing results and conditioning measures. Specifically, the root zone adsorption fingerprint index RZAFI is expressed as follows:

[0030] in, , , These are the weight coefficients for each item, for example, values ​​of: , , .

[0031] The percentage change in conductivity is expressed as follows:

[0032] in, Indicates the initial conductivity; This indicates the conductivity after adsorption.

[0033] express The absolute value of the change is expressed as follows:

[0034] in, Indicates the initial , Indicates after adsorption .

[0035] The change in turbidity is expressed as follows:

[0036] in, Indicates the initial turbidity. This indicates the turbidity after adsorption.

[0037] In another exemplary embodiment, step S1, the soil conditioning based on the test results, includes the following steps: S101: Compare the root zone adsorption fingerprint index (including the percentage change in conductivity, the magnitude of pH change, and the amount of turbidity change) to determine the problems existing in the soil. In this step, the soil quality can be adjusted accordingly using the root zone adsorption fingerprint index set as shown in Table 1: Table 1

[0038] Table 1 classifies soil conditions and corresponding control measures based on the root zone adsorption fingerprint index (RZAFI) within different ranges. When the RZAFI is below 15, the soil salinity is low, the buffering capacity is good, and the organic matter is moderate. Conventional management and application of 2–3 tons / hectare of biochar are recommended. An RZAFI in the range of 15–30 indicates mild salt accumulation or decreased buffering capacity. Application of 3–5 tons / hectare of biochar and rotary tillage to a depth of 20 cm are required. An RZAFI in the range of 30–45 indicates significant salt stress or continuous cropping obstacles. Application of 5–8 tons / hectare of biochar and strengthening of organic matter supplementation are recommended. If the RZAFI exceeds 45, the soil salinity is too high or the organic matter is severely insufficient. Application of 8–10 tons / hectare of biochar is required, along with comprehensive improvement through organic fertilizer and structural adjustment.

[0039] S102: Determine the application rate and method of biochar based on existing soil problems; In this step, based on the comprehensive diagnosis of soil testing results and root zone adsorption fingerprint index (RZAFI), the main limiting factors in the soil are identified, and a differentiated biochar application strategy is formulated accordingly. The specific implementation method is as follows: Firstly, when the soil exhibits mild to moderate salt accumulation (e.g., RZAFI in the range of 15–45) or decreased soil buffering capacity (significant pH fluctuations), the recommended biochar application rate is 3–5 t / ha. Application should be done using a combination of furrow application and rotary tillage, including: digging furrows along the intended planting rows, 15–20 cm deep and 20–25 cm wide; evenly spreading the measured biochar at the bottom of the furrows and initially mixing it with the soil; then using a rotary tiller to thoroughly mix the entire layer, ensuring the biochar is concentrated in the 0–20 cm root zone soil layer. This enhances the soil's ability to adsorb and fix salt ions, improves the micro-buffering capacity of the root zone, and thus mitigates the adverse effects of salt stress on tomato roots.

[0040] Secondly, if the soil organic matter content is below 2%, or if the RZAFI indicates insufficient dissolved organic matter load (small change in turbidity), the biochar application rate should be increased to 5-8 t / ha to simultaneously enhance the soil carbon pool and water and fertilizer retention capacity. In this case, the trench application + rotary tillage mixing method should still be used, but the application rate and mixing depth can be appropriately increased (e.g., extending to 20-25 cm). Additionally, the biochar should be pre-mixed with well-rotted organic fertilizer (e.g., 3-5 t / ha) or humic acid granules before application to form an organic-inorganic composite conditioning system, promoting soil aggregate formation and slow nutrient release.

[0041] Thirdly, when the RZAFI exceeds 45, it indicates that the soil salinity is too high or the organic matter is severely lacking, and there is a significant risk of continuous cropping obstacles. At this time, the biochar application rate should be further increased to 8–10 t / ha, and combined with comprehensive improvement measures. The improvement measures can adopt a layered application strategy. For example, 60% of the biochar can be mixed into the 0–20 cm soil layer during rotary tillage, and the remaining 40% can be applied locally in the planting hole to strengthen rhizosphere repair. At the same time, organic fertilizer (5 t / ha to 8 t / ha) can be applied and combined with soil structure improvers (such as coconut coir 2 t / ha to 3 t / ha). Through the synergistic effect of biochar, organic matter and physical improvement, a healthy root zone environment can be rebuilt.

[0042] S103: Replenishes basic nutrients and organic matter; In this step, based on the specific content of available phosphorus and readily available potassium in the soil test, the corresponding fertilizers are precisely supplemented—potassium dihydrogen phosphate is used if both phosphorus and potassium are needed, and potassium sulfate is used if only potassium is needed; at the same time, when the test shows that the soil organic matter content is less than 2%, it is necessary to apply additional well-rotted organic fertilizer (recommended dosage 3–5 tons / hectare) or humic acid granules to enhance the soil carbon pool and fertilizer retention capacity; all supplemented materials should be evenly spread on the surface, and then lightly tilled (to a depth of 10–15 cm) to fully mix them with the topsoil, promoting nutrient integration and rapid utilization in the root zone.

[0043] S104: Improve soil structure and regulate water.

[0044] In this step, the soil bulk density is greater than 1.4 g / cm³. 3 For soils with a compacted structure, the bulk density of the soil can be reduced and the pore structure improved by adding coconut coir or straw fragments (recommended dosage 2–3 tons / hectare). The rotary tillage depth should be dynamically adjusted according to the distribution range of the main tomato root system, usually controlled at 20–25 cm, to ensure thorough mixing of the soil and the amendment material. After the conditioning work is completed, immediately carry out a thorough irrigation of about 20 mm to promote the settling and compaction of soil particles, accelerate the integration of amendment material and nutrients, and create a loose, well-aerated and moisture-balanced soil environment for subsequent root growth.

[0045] In another exemplary embodiment, step S2, which involves laying the drip irrigation system on the conditioned soil and setting up the monitoring network, includes the following steps: S21: Ditches are dug on the conditioned soil. In this step, after soil testing and conditioning, precise furrows are made along the planting direction using a small furrow opener or manual furrowing tools, according to the row spacing design for greenhouse tomatoes. The furrow width should be controlled at 20–25 cm, and the furrow depth at 15–20 cm, ensuring a flat bottom and uniform slope to facilitate subsequent drip irrigation tape installation and even water distribution. Avoid compacted soil areas during furrowing, and maintain consistent furrow spacing. Typically, narrow row spacing is set at 40–50 cm, and wide row spacing at 70–80 cm, balancing ease of operation with space for root development. After furrowing, debris should be cleared from the furrows, and the furrow walls should be lightly trimmed to prevent soil collapse from affecting the installation of the drip irrigation system.

[0046] S22: Use embedded drip irrigation tape to lay at the bottom of narrow furrows; In this step, select an embedded drip irrigation tape that is resistant to clogging and has a uniform flow rate. The recommended dripper spacing is 20–30 cm to suit the root distribution characteristics of tomatoes. When laying the tape, place it straight along the bottom of the narrow furrow, ensuring the drippers are facing upwards to avoid soil clogging. The burial depth of the drip irrigation tape should be strictly controlled within the range of 10–15 cm. Too shallow a burial depth will easily lead to water evaporation loss, while too deep a burial depth will affect the water supply during the seedling stage. Immediately after laying, cover with 2–3 cm of fine topsoil and lightly compact it to reduce soil erosion and drip tape displacement during irrigation, while keeping the surface level for subsequent agricultural operations.

[0047] S23: Install soil moisture sensors in the tomato root zone (e.g., at a distance of 10cm from the plant, at a depth of 10cm and 20cm).

[0048] In this step, to monitor soil moisture dynamics in the root zone in real time, a soil moisture sensor is installed near each tomato plant, 10cm from the base of the stem, at two soil depths: 10cm and 20cm. During installation, a specialized drilling tool is used to drill vertical holes matching the sensor probe diameter. After insertion, ensure the probe is in tight contact with the soil without gaps. The sensor wires should be led out along the trench wall and fixed, connecting to the data acquisition unit or IoT terminal. After installation, calibration and testing are performed to ensure accurate and reliable data, providing a basis for subsequent phased precision irrigation.

[0049] In another exemplary embodiment, step S3, which involves transplanting tomatoes and performing initial management of the transplanted tomatoes, includes the following steps: S31: Prepare for transplanting, specifically including: accurately marking each transplanting point on both sides of the narrow row where soil conditioning and drip irrigation systems have been completed, according to the predetermined plant spacing (35–40cm); then using a special transplanting shovel or hole opener, dig transplanting holes at each marked location, with a depth of, for example, 12–15cm and a diameter of about 10cm; and applying 10–15 grams of well-rotted organic fertilizer or special bio-organic fertilizer as base fertilizer to each hole, and lightly mixing it with the soil at the bottom of the hole to locally enhance the fertility of the root zone, thereby creating a nutrient-rich microenvironment for the early growth of tomato seedlings.

[0050] S32: Select and treat tomato seedlings, specifically including: selecting healthy, robust, and disease-free high-quality tomato seedlings with 4-5 true leaves; and moderately controlling watering and hardening off the seedlings 1-2 days before transplanting to enhance their adaptability and resistance to the external environment; when transplanting, a special root-dipping solution containing rooting agents and beneficial microorganisms can be used to soak the seedling roots for 10-15 minutes to promote rapid root development and microbial colonization after transplanting.

[0051] The above treatment plan, by selecting robust, disease-free seedlings with 4-5 true leaves and combining this with water control and hardening off 1-2 days before transplanting, can enhance the environmental adaptability and stress resistance of tomato seedlings. Furthermore, by using a special root-dipping solution containing rooting agents and beneficial microorganisms for root soaking treatment, it can effectively promote the rapid development of the root system after transplanting and the successful establishment of functional microorganisms in the rhizosphere, laying a good physiological and microecological foundation for seedling recovery and early growth.

[0052] S33: Transplanting and initial water management of treated tomato seedlings, specifically including: First, gently place the root-dipping tomato seedlings into the planting hole, ensuring the seedling roots are naturally spread out without tangling or breakage. The planting depth should be such that the cotyledons are slightly above the soil surface (e.g., 0.5–1 cm) to avoid direct contact between the stem base and moist soil, which could lead to disease, and to ensure the roots are fully buried in the soil to maintain plant stability. After transplanting, a small amount of nutrient soil or seedling substrate can be covered around the roots to stabilize the plant. Subsequently, slowly water each seedling at the base, using approximately 0.5–0.8 liters per plant, to promote close contact between the soil and roots, while activating the adsorption and buffering functions of the root zone biochar, providing a good rhizosphere environment for seedling establishment and initial growth.

[0053] The above transplanting and initial water management plan achieves close contact between the roots and soil by gently placing the seedlings, after root dipping treatment, into the planting hole while keeping the roots spread out and the cotyledons slightly above the soil surface, and covering them with nutrient soil for stability. Subsequently, an appropriate amount of water is poured along the base to settle the roots. This not only effectively promotes the contact between the soil and the roots and the water supply, but also activates the adsorption and buffering function of the pre-applied biochar in the root zone. This creates an excellent rhizosphere microenvironment with coordinated water, air, and fertilizer for the seedlings to recover and grow in the early stages, significantly improving the transplanting survival rate and initial growth vigor.

[0054] In another exemplary embodiment, step S4, which involves phased irrigation and integrated water and fertilizer management of tomatoes after initial water management, includes the following steps: S41: Implement phased dynamic irrigation for tomatoes after initial water management; In this step, dynamic irrigation management needs to be implemented in zones and layers through a shallow-buried drip irrigation system, based on the water requirements of tomatoes at different growth stages. For example: During the seedling stage (within 30 days after transplanting), the focus is on maintaining moisture in the topsoil of the root zone. The target irrigation depth is 10 cm, the single irrigation volume is 5–8 cubic meters per hectare, and the irrigation interval is 5–7 days.

[0055] During the flowering and fruiting period (31–70 days after transplanting), as the roots extend and the moist layer expands to 15–20 cm, the amount of irrigation per application increases to 10–15 cubic meters per hectare, the irrigation interval is shortened to 3–5 days, and topdressing begins in conjunction with irrigation at this stage.

[0056] During the ripening period (71 days after transplanting to harvest), in order to promote the accumulation of sugar in the fruit and improve its quality, moderate water control should be implemented, keeping the soil moisture in the root zone at 60-70% of field capacity, adjusting the single irrigation amount to 8-10 cubic meters per hectare, and extending the irrigation interval to 7-10 days.

[0057] S42: During the phased irrigation process, targeted integrated water and fertilizer management is carried out; In this step, during the phased dynamic irrigation process, based on the nutrient requirements of tomatoes at different growth stages (seedling stage, flowering and fruiting stage, and ripening stage), precise integrated water and fertilizer management is implemented through the drip irrigation system. Specifically, this includes: during the seedling stage, the focus is on promoting root growth and strong seedlings, and high-phosphorus water-soluble fertilizer (such as N-P2O5-K2O ratio of 15-30-15) is applied with each irrigation, at a rate of, for example, 5 kg / ha to 8 kg / ha; during the flowering and fruiting stage, the goal is to balance nutrition and promote fruit setting, so a balanced water-soluble fertilizer (such as 20-20-20) is switched to be used, combined with foliar spraying of micronutrients such as calcium and boron, with a fertilizer application rate of, for example, 10–15 kg / ha per irrigation; during the ripening stage, the focus is on improving quality and controlling water, applying high-potassium water-soluble fertilizer (such as 10-10-30), and appropriately reducing nitrogen fertilizer supply, with a application rate of, for example, 8–10 kg / ha per irrigation.

[0058] It should be noted that all fertilizers are fully dissolved in the irrigation reservoir beforehand, and then evenly mixed with irrigation water using a Venturi fertilizer applicator or fertilizer pump to form an integrated fertigation solution, which is then precisely delivered to the root zone via a shallow-buried drip irrigation system. Simultaneously, the system dynamically adjusts the duration and fertilizer concentration of each irrigation based on real-time data from soil moisture sensors deployed in the root zone, achieving synergistic optimization of water and nutrient control, thereby improving water and fertilizer utilization efficiency and ultimately achieving the cultivation goals of water conservation, quality improvement, and increased yield for tomatoes.

[0059] In another exemplary embodiment, step S5, the biochar activation and rhizosphere regulation of tomatoes during their growth period, includes the following steps: S51: Biochar rhizosphere activation for tomatoes during their growth period; In this step, after the tomatoes enter the flowering and fruiting stage, local biochar activation is performed in the root zone of the plant (within 10-15cm of the stem base). Specifically, a mixture of 0.2% humic acid aqueous solution and 0.1% potassium dihydrogen phosphate solution can be used as the activator. This mixture is applied via drip irrigation during irrigation breaks (150-200ml per plant) to allow the activator to penetrate into the biochar application layer (10-20cm deep). Activation enhances the activity of the functional groups on the biochar surface, promotes its nutrient exchange capacity with the rhizosphere soil, and improves its adsorption and retention of cations such as potassium and calcium.

[0060] S52: Dynamically regulate the rhizosphere environment based on data from deployed soil sensors; In this step, pre-deployed soil moisture, temperature, and conductivity sensors are used to monitor changes in the root zone microenvironment in real time. When the soil conductivity (EC value) is higher than a set threshold (e.g., 1.5 mS / cm) for 48 consecutive hours, the biochar-assisted regulation program is activated. This involves injecting an appropriate amount of low-concentration (0.05-0.1%) humic acid solution through the drip irrigation system to promote the adsorption of salt ions by the biochar. At the same time, the irrigation frequency is adjusted according to soil moisture data to ensure that the root zone remains appropriately moist but not waterlogged, thereby enhancing the slow-release buffering function of the biochar.

[0061] S53: Synergistic regulation of rhizosphere microbial communities; In this step, after biochar activation treatment, functional microbial agents are introduced to construct a synergistic "biochar-microorganism" system. Specifically, this includes selecting compound microbial agents containing Bacillus subtilis, Trichoderma, and other organisms with growth-promoting and stress-resistance functions, diluting them, and applying them with irrigation water through a drip irrigation system (≥1×10^12 CFU of live bacteria per hectare). After application, the root zone humidity is appropriately increased to 75-80% of field capacity and maintained for 3-5 days to create favorable conditions for microbial colonization in the biochar pores, promoting the functional balance and nutrient transformation of the rhizosphere micro-ecosystem.

[0062] S54: During the mid-to-late stages of tomato growth, assess and adjust the functional status of biochar.

[0063] In this step, during the peak fruiting period to maturity of tomatoes, the functional status of biochar is assessed through root zone sampling and rapid testing. Biochar-containing soil samples are collected at different distances (10, 20 cm) and depths (10, 20 cm) from the plant, and their water-holding capacity, cation exchange capacity (CEC), and pH changes are measured. If the biochar's water-holding capacity decreases by more than 20% or the CEC value decreases significantly, a 0.1% potassium humate solution (100-150 ml per plant) is applied during subsequent irrigation to maintain the biochar's continuous regulatory effect during fruit quality formation through functional regeneration.

[0064] In another exemplary embodiment, step S6, which involves integrating greenhouse environment and soil moisture data to establish a multi-factor irrigation decision model and dynamically optimizing irrigation strategies, includes the following steps: S61: Real-time integration of multi-source data and calculation of crop water requirements; In this step, the system will collect multi-dimensional data from greenhouse environmental sensors in real time, including air temperature, relative humidity, light intensity and carbon dioxide concentration, and combine it with soil moisture information obtained from soil moisture and temperature sensors distributed in the tomato root zone.

[0065] The aforementioned data is first synchronously transmitted and preprocessed via IoT nodes to form a multi-source dataset with a unified spatiotemporal benchmark. Based on this, the system uses a Penman-Monteith model corrected for crop coefficients and greenhouse microclimate to dynamically calculate the instantaneous evapotranspiration (ETc) of tomatoes at different growth stages. This calculation process not only considers real-time changes in environmental factors but also incorporates evapotranspiration pattern learning based on historical data to identify water demand characteristics under abnormal climatic conditions. Finally, the system automatically matches the stage-specific water demand coefficients based on the current growth stage of the tomatoes (e.g., seedling stage, flowering and fruit setting stage, maturity stage), generating high-resolution daily or even hourly crop water demand curves, providing dynamic and reliable core input for subsequent precision irrigation decisions.

[0066] S62: Construct an intelligent irrigation decision model, analyze the collected multi-source data, and output an optimized irrigation plan; In this step, this application constructs an intelligent irrigation decision-making model integrating self-learning and adaptive capabilities. This model is driven by real-time calculated crop water requirements, while simultaneously integrating multiple collaborative input factors, including dynamic soil moisture monitoring data, water-holding characteristic curves of the biochar application layer, historical irrigation response records, and plant physiological monitoring information (such as stem flow rate and canopy temperature changes). Based on this, the model introduces a hybrid architecture with a three-layer coupling of "time series-feature-decision" to achieve precise adaptive regulation of water and fertilizer requirements for greenhouse tomatoes. Specifically, in the time series feature extraction layer, this embodiment introduces a dual-channel hybrid network. The long-period memory channel uses a GRU to capture weekly trend changes, while the short-period response channel utilizes a TCN to extract hourly to daily-scale irrigation-response dynamic features. A learnable hysteresis weight matrix is ​​introduced to explicitly model the dynamic delay effect between water stress and irrigation response. In the feature fusion layer, an attention-weighted cross-modal fusion mechanism is proposed. This mechanism first encodes and represents the source data, and then assigns adaptive weights to heterogeneous features such as soil moisture, biochar water-holding characteristics, and plant physiological indicators through a learnable attention module, enhancing the ability to identify key state features such as effective water capacity in the root zone and biochar water-holding contribution. In the decision reasoning and optimization layer, a collaborative optimization strategy generation mechanism is constructed. This mechanism not only outputs preliminary schemes for irrigation time, water volume, and fertilizer-solution ratio based on fused features, but also predicts the potential impact of different strategies on root zone water and fertilizer distribution, nutrient availability, and fruit quality through a built-in soil-crop system simulation module. Furthermore, using a closed-loop reinforcement learning framework and historical strategies as an experience pool, the Proximal Policy Optimization (PPO) algorithm is used to conduct multi-objective self-game and Pareto front search, gradually iterating to generate a dynamic irrigation instruction set that balances water conservation, quality improvement, and yield increase. The model ultimately achieves full-process intelligent management from data perception to strategy generation, supporting precise and adaptive control of water and fertilizer management throughout the entire growth period of greenhouse tomatoes.

[0067] S63: Implement optimized irrigation plans and monitor irrigation results.

[0068] In this step, the system automatically sends the optimized irrigation instructions (including the start and stop times, flow rates, and fertilizer concentrations for each irrigation zone) generated in step S62 to the control terminal of the shallow-buried drip irrigation system. This drives the solenoid valves, water pumps, and fertilization devices to work in tandem, achieving precise integrated water and fertilizer supply. During execution, the system uses a sensor network deployed at different depths and locations in the root zone to monitor the redistribution of soil moisture in the vertical and horizontal directions, water infiltration depth, and irrigation uniformity in real time. Simultaneously, the system uses UAV multispectral imaging or fixed cameras to periodically collect plant canopy images and analyze growth indicators such as the Normalized Difference Vegetation Index (NDVI). After irrigation, the system compares and analyzes the collected "irrigation response data" (such as soil moisture recovery curves and canopy temperature changes) and "crop performance data" against preset targets. Based on this feedback, the system's built-in optimization algorithm calibrates parameters and iterates rules in the decision model constructed in step S62. For example, it adjusts the irrigation duration coefficient for different soil types or optimizes the irrigation initiation threshold under the influence of biochar. Through this continuous "execution-monitoring-learning-adjustment" closed loop, the entire irrigation strategy can continuously evolve itself, gradually adapting to the dynamic needs of crop growth and the long-term changes in the greenhouse environment, ultimately achieving intelligent and lean irrigation management.

[0069] In another exemplary embodiment, step S7, the oxidation and continuous improvement of the soil after tomato harvesting, includes the following steps: S71: Remove plant debris from the soil after harvesting and perform shallow tillage to loosen the soil; In this step, after the tomatoes are harvested, the above-ground plant debris is first removed to cut off the overwintering hosts of pests and diseases and reduce the initial number of pathogens. Then, a shallow tillage of 10-15 cm is carried out to precisely break up the plow pan and surface crust formed by irrigation, trampling, and root growth. This operation increases the ratio of capillary to non-capillary porosity in the soil, promotes gas exchange within the tillage layer, restores soil respiration, and thus creates favorable conditions for aerobic activity of soil microorganisms and decomposition of organic matter, accelerating the oxidative renewal process of rhizosphere biochar.

[0070] S72: Oxidation activation and functional regeneration of biochar in harvested soil; In this step, after a growing season, the pores of biochar in the soil may become clogged by soil organic colloids, microbial metabolites, etc., leading to a decrease in specific surface area and the occupation of adsorption sites. At this time, a low-concentration (0.05%-0.1%) hydrogen peroxide solution can be applied to the root zone soil using a drip irrigation system to slowly release active oxygen into the soil. This active oxygen can gently oxidize and decompose the organic adhering substances clogging the pores, achieving a "chemical cleaning" of the biochar pores and restoring its specific surface area and adsorption capacity. More importantly, this oxidation process introduces or increases oxygen-containing functional groups such as carboxyl, hydroxyl, and phenolic groups on the surface of the biochar. These functional groups are key to enhancing the electrostatic adsorption and complexation capacity of biochar for nutrient ions (such as ammonium nitrogen, potassium ions, and calcium ions), while also improving its hydrophilicity. This simultaneously regenerates the nutrient slow-release function and soil water retention capacity of the biochar, allowing it to continue to play a highly efficient role in the next planting season.

[0071] S73: Add organic materials to the soil after biochar oxidation activation to carry out ecological restoration of the soil.

[0072] This step focuses on the synergistic reconstruction of soil biological and chemical fertility. Specifically, rotary tillage thoroughly mixes organic materials with the soil to replenish it with stable organic carbon sources and various nutrients. Subsequently, a compound functional microbial agent (containing actinomycetes and lignin-decomposing bacteria) is inoculated and precisely introduced into the pre-activated, carbon-rich soil environment. Further, irrigation is used to regulate soil moisture to the optimal range of 70%-80% of field capacity and maintain this level for a period, creating a moist, well-aerated, and nutrient-rich "fermentation" environment for the microorganisms. Under these conditions, functional microorganisms rapidly colonize and reproduce, efficiently decomposing freshly added organic matter into humus, thus improving the quality and content of soil organic matter. Simultaneously, through site competition and the secretion of antibacterial substances, they inhibit soil-borne pathogens, promoting the establishment of a beneficial microbial community and forming a diverse, balanced, and healthy soil microbial community structure, providing biological protection for the root health of the next crop.

[0073] This application compared the method described in this application with traditional methods in four indicators after one tomato growing season: water saving rate, tomato yield increase, fruit sugar content increase, and soil organic matter increase. The specific comparison results are shown in Table 1. Table 1

[0074] The results in Table 1 were obtained through a field comparative experiment lasting one full growing season: Under the same greenhouse environment, an experimental group (using the method described in this application) and a control group (using conventional surface drip irrigation and fertilizer management) were set up. Under the premise of consistent varieties, planting time and basic environmental conditions, the total amount of irrigation water, final harvest yield, fruit sugar content (measured by a handheld refractometer) and changes in soil organic matter content in the root zone before and after planting were systematically recorded. The typical range of data for each group and its relative differences were obtained by statistical calculation.

[0075] As shown in Table 1, compared with the traditional surface drip irrigation model, the planting method based on this application saves 25-30% of irrigation water, increases average yield by 10-15%, increases fruit sugar content by 10-15%, and increases soil organic matter content in the root zone by 15-20%, achieving a synergistic improvement in water conservation, yield increase, quality improvement and soil improvement.

[0076] The above embodiments are only for illustrating the technical concept and features of this application, and are intended to enable those skilled in the art to understand the content of this application and implement it accordingly. They should not be construed as limiting the scope of protection of this application. All equivalent changes or modifications made in accordance with the spirit and essence of this application should be included within the scope of protection of this application.

Claims

1. A method for water-saving and quality-improving greenhouse tomato cultivation using shallow-buried drip irrigation and biochar synergy, characterized in that, The method includes: The soil for greenhouse tomato cultivation was tested, and the soil quality was adjusted based on the test results. The tests included soil pH, organic matter content, bulk density, available phosphorus content, available potassium content, electrical conductivity, and field water holding capacity. Drip irrigation systems were laid on the treated soil, and a soil monitoring network was established. Based on the established drip irrigation system and soil testing network, tomato seedlings were transplanted, and initial water management was carried out on the transplanted tomato seedlings. After the seedlings have established themselves, irrigation and fertigation should be carried out in stages according to the needs of different growth stages of tomatoes. Biochar rhizosphere activation and functional regulation of tomatoes during their growth period; Integrate real-time data from greenhouse environment and soil monitoring networks, establish and operate an intelligent irrigation decision-making model, and implement dynamically optimized irrigation schemes; The soil after tomato harvesting is oxidized and ecologically improved.

2. The method according to claim 1, characterized in that, The testing of the soil for greenhouse tomato cultivation includes: Obtain soil extract; Biochar probes were selected and pretreated. The pretreated biochar probe was used to adsorb onto the soil extract to obtain detection signals, including the percentage change in conductivity. Absolute change and amount of turbidity change; Based on the detection signal, a root zone adsorption fingerprint index is constructed to determine the soil condition.

3. The method according to claim 2, characterized in that, The soil conditioning based on the test results includes: By comparing the root zone adsorption fingerprint index, the problems existing in the soil can be determined; The amount and method of biochar application are determined based on the existing soil problems. Replenish basic nutrients and organic matter; Soil structure is improved and water is regulated.

4. The method according to claim 1, characterized in that, The installation of a drip irrigation system on the conditioned soil and the establishment of a monitoring network include: Ditches were dug in the prepared soil. Embedded drip irrigation tape is used and laid at the bottom of narrow furrows; Soil moisture sensors were installed in the root zone of the tomato plants.

5. The method according to claim 1, characterized in that, The process of transplanting tomatoes and providing initial management after transplanting includes: Prepare for planting; Select and treat tomato seedlings; Transplanting and initial water management were carried out on the treated tomato seedlings.

6. The method according to claim 5, characterized in that, The transplanting and initial water management of the treated tomato seedlings include: After dipping the roots in the tomato seedlings, gently place them in the planting hole, ensuring that the cotyledons of the seedlings are slightly above the ground surface. After transplanting, cover the roots with a small amount of nutrient soil or seedling substrate to stabilize the plant. Slowly water each seedling at the base to help it establish roots.

7. The method according to claim 1, characterized in that, The staged irrigation and fertigation management of tomatoes after initial water management includes: Tomatoes were irrigated in stages following the initial water management; During the phased dynamic irrigation process, targeted integrated water and fertilizer management is carried out.

8. The method according to claim 7, characterized in that, The aforementioned biochar activation and rhizosphere regulation of tomatoes during their growth period includes: Biochar rhizosphere activation was performed on tomatoes during their growth period; Based on data from deployed soil sensors, the rhizosphere environment is dynamically regulated. Synergistic regulation of rhizosphere microbial communities; During the mid-to-late stages of tomato growth, the functional status of biochar is assessed and adjusted.

9. The method according to claim 1, characterized in that, The integrated greenhouse environment and soil moisture data are used to establish a multi-factor irrigation decision model to achieve dynamic optimization of irrigation strategies, including: Real-time integration of multi-source data and calculation of crop water requirements; Construct an intelligent irrigation decision model, analyze the collected multi-source data, and output an optimized irrigation plan; Implement optimized irrigation plans and monitor irrigation results.

10. The method according to claim 1, characterized in that, The oxidation and continuous improvement of soil after tomato harvesting includes: Remove plant debris from the soil after harvesting and perform shallow tillage to loosen the soil; The biochar in the harvested soil is oxidized, activated, and regenerated. Organic materials are added to the soil after it has been activated by biochar oxidation to carry out ecological restoration of the soil.

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