Chili seedling intelligent cultivation method capable of effectively coping with drought environment

Abstract

The invention belongs to the technical field of agricultural crop cultivation, and discloses an intelligent pepper seedling cultivation method capable of effectively coping with a drought environment, which comprises the following steps: preparing a special seedling cultivation substrate, mixing garden soil, charcoal and halite according to a mass ratio of 3: 1: 1, and adjusting the water content to 35-65% to obtain a basic soil substrate; according to the scheme, the garden soil, the biochar and the halite are mixed according to a specific proportion, and the cursive cursive earthworm cast and the bursomus mosseae fungi are added according to a specified proportion, so that the special seedling culture substrate integrating physical improvement, organic fertilization and biological symbiosis functions is prepared; the drought resistance of the pepper seedlings is systematically constructed in the seedling raising stage in cooperation with moderate water control training with matrix water content control as the core and optimized environment management; experiments prove that by means of the method, the overground fresh weight of the seedlings under drought stress is increased, the net photosynthetic rate is increased, the antioxidant enzyme activity and the osmotic regulation substance content are remarkably enhanced, and the drought resistance and adaptability of the seedlings are comprehensively improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural crop cultivation technology, and in particular to an intelligent cultivation method for chili seedlings that effectively copes with drought environments. Background Technology

[0002] In traditional and existing chili seedling cultivation practices, the conventional process usually includes steps such as substrate preparation, seed treatment, sowing, seedling water and fertilizer management, and environmental control. The seedling substrate used is mostly composed of conventional materials such as peat moss, vermiculite, and perlite mixed in a certain proportion, which aims to provide basic support, water, and some nutrients for seed germination and seedling growth. Seedling management mainly relies on human experience, adjusting irrigation, ventilation, and shading through observation and manual operation to cope with environmental changes. In addition, some studies or technologies apply organic fertilizers (such as ordinary decomposed manure) alone or inoculate a single microbial agent (such as mycorrhizal fungi or rhizobia) in order to promote growth or enhance resistance.

[0003] However, the above-mentioned technical methods have obvious defects and shortcomings in dealing with the increasingly frequent drought stress: (1) Conventional seedling substrates have limited water and fertilizer retention capacity. Under drought and water shortage conditions, they are difficult to maintain a stable rhizosphere water environment, which can easily lead to seedling water stress. (2) Conventional management relies heavily on human experience, has a delayed response, and is difficult to make accurate and timely environmental control in response to the instantaneous changes in drought, which affects the uniformity and reliability of seedling cultivation. (3) Existing technologies often focus on single-aspect improvements (such as improving the substrate or adding a certain type of microbial agent), lacking a systematic approach that integrates physical structure improvement (such as substrate formulation), biological function enhancement (such as inoculation with specific functional microorganisms) and stress physiological induction. As a result, the overall improvement of the root development, photosynthetic function and intrinsic physiological stress resistance (such as antioxidant system and osmotic regulation capacity) of the cultivated seedlings when coping with drought stress is limited, and the survival rate and adaptability after transplanting face challenges.

[0004] Therefore, in response to drought stress, there is an urgent need to develop an integrated new method for chili seedling cultivation. This method not only needs to innovate the composition of the seedling substrate to improve its ability to buffer stress from a physical and biochemical perspective, but also needs to consider how to actively and effectively induce and enhance the comprehensive stress resistance of seedlings during the seedling stage through systematic agronomic design, so as to provide a high-quality seedling foundation for the stable production of chili peppers in harsh environments. Summary of the Invention

[0005] This invention aims to provide an intelligent cultivation method for chili seedlings to effectively cope with drought environments, addressing the problems mentioned in the background art. It involves mixing garden soil, biochar, and perlite in a specific ratio, and adding a prescribed proportion of earthworm castings and *Tetranychus mossae* fungi to prepare a specialized seedling substrate that integrates physical improvement, organic fertilization, and biological symbiosis. Combined with moderate water control and optimized environmental management, focusing on substrate moisture content control, this method systematically builds the drought resistance of chili seedlings during the seedling stage. Experiments have shown that this method increases the aboveground fresh weight of seedlings under drought stress, improves the net photosynthetic rate, and significantly enhances the activity of antioxidant enzymes and the content of osmotic regulators, comprehensively improving the drought resistance and adaptability of seedlings.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An effective intelligent cultivation method for chili seedlings in drought-prone environments includes the following steps: S1, Prepare a special seedling substrate; S1.1, mix garden soil, biochar and perlite in a mass ratio of 3:1:1, and adjust the moisture content to 35%-65% to obtain the basic soil matrix; S1.2, add earthworm castings with a moisture content of 45% to the basic soil matrix obtained in S1.1, and mix evenly so that the mass content of earthworm castings accounts for 10%-20% of the total mass of the mixture obtained in this step; S1.3, Inoculate the propagated arbuscular mycorrhizal fungi inoculant into the mixture obtained in S1.2, and mix evenly to obtain the final special seedling substrate, wherein the mass content of the inoculant accounts for 2%-5% of the total mass of the special seedling substrate; S2, using the special seedling substrate prepared in S1 for chili sowing and seedling raising operations.

[0007] Preferably, the moisture content of the basic soil matrix in S1 is 46%.

[0008] Preferably, the arbuscular mycorrhizal fungus in S1.3 is *M. moses*.

[0009] Preferably, the earthworm castings in S1.2 are produced by *Eriocaulon cristatum*.

[0010] Preferably, the chili pepper variety is the facing-heaven chili.

[0011] Preferably, the arbuscular mycorrhizal fungal inoculant in S1.3 is a mixture containing fungal hyphae, spores, culture medium and host root segments obtained by propagating maize as a host.

[0012] Preferably, the seedling raising operation in S2 includes, after the chili seedlings have grown to a certain stage, moderate water control and hardening-off, controlling the moisture content of the special seedling substrate within the range of 40%-50%.

[0013] Preferably, in the seedling raising operation of S2, after the seedling unfolds its first true leaf, it is placed in an environment with sufficient natural light and good ventilation for cultivation.

[0014] The beneficial effects of this technical solution compared to existing technologies are as follows: (1) By mixing garden soil, biochar and pearl salt in a ratio of 3:1:1, and adding 10-20% of specific earthworm castings and 2-5% of specific arbuscular mycorrhizal fungi, the physical structure improvement, organic nutrient supplementation and obligate microbial symbiosis are creatively combined to build a physical and biochemical basis for seedlings to resist adversity from the substrate level.

[0015] (2) Based on the characteristics of the special substrate, a moderate water control training strategy with controlling the substrate moisture content as the core was proposed. Combined with light and ventilation management, the seedlings were actively and safely induced to start and enhance their drought resistance physiological mechanism during the seedling stage, thus realizing the "pre-training" of stress resistance.

[0016] (3) The chili seedlings cultivated using this method under simulated drought stress showed a 37.4% increase in fresh weight of the aboveground parts, a 20.0% increase in net photosynthetic rate, a 1.78-fold increase in peroxidase activity, and a 21.3% decrease in malondialdehyde content compared to the control. This systematically demonstrated the effectiveness and superiority of this method in cultivating drought-resistant and robust seedlings from multiple perspectives, including growth, photosynthesis, and physiological and biochemical aspects. Attached Figure Description

[0017] Figure 1 This is a flowchart of the chili seedling cultivation method provided by the present invention; Figure 2 This is a schematic diagram of photosynthetic and chlorophyll fluorescence parameters provided by the present invention; Figure 3 This is a schematic diagram of the physiological index measurement results provided by the present invention. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments: like Figure 1-3 As shown, the core of this invention lies in providing a systematic method for chili seedling cultivation. By optimizing the seedling substrate formula and implementing appropriate seedling management, this method effectively builds the inherent ability of chili seedlings to resist drought and combined stress during the seedling stage. The following detailed description, combined with specific implementation steps and effectiveness verification data, further illustrates this method. 1. Preparation of seedling substrate The seedling substrate is the material basis for this method, and its preparation process includes the following three ordered steps: 1.1 Preparation of basic soil substrate Ordinary garden soil, biochar, and perlite are thoroughly mixed in a 3:1:1 mass ratio. The garden soil provides the basic soil environment and some nutrients; the biochar has a porous structure, which can significantly enhance the water retention, fertilizer retention, and ion adsorption capacity of the substrate; the perlite mainly serves to loosen the substrate and improve aeration and permeability. After the three are mixed evenly, the moisture content needs to be adjusted. Generally, the moisture content can be operated within a wide range of 35%-65%. According to the experimental verification of this invention, when the moisture content is adjusted to 46%, the seedlings show the best stress resistance response and growth state under subsequent simulated drought stress. This moisture content not only ensures the initial water supply but also provides a suitable starting point for subsequent water control hardening. The adjustment and monitoring of moisture content can be completed by weighing or using a soil moisture meter.

[0019] 1.2 Addition and mixing of earthworm castings To further improve the substrate from a chemical and biological perspective, earthworm castings of specific conditions and sources need to be added to the aforementioned basic soil substrate. The earthworm castings used should have a moisture content of 45% pre-adjusted. This state facilitates their uniform dispersion and full integration with the substrate. The earthworm castings are added to the basic soil substrate and thoroughly mixed. The amount of earthworm castings added is one of the key parameters, preferably accounting for 10%-20% of the total mass of the final mixture obtained in this step. Preferably, the earthworm castings used in this invention are produced from *Pheretima asiatica*. Adding earthworm castings can significantly enrich the organic matter, humic acid, and beneficial microbial communities in the substrate, effectively improve the substrate's aggregate structure, enhance its water and fertilizer retention capacity, and create a more favorable environment for plant root growth.

[0020] 1.3 Inoculation with arbuscular mycorrhizal fungi This step introduces a key biological symbiotic function, which is one of the core links to improve the drought resistance of seedlings. The pre-propagated arbuscular mycorrhizal fungi inoculant is inoculated into the above-mentioned substrate with added earthworm castings, and then mixed evenly again to finally obtain the special seedling substrate used in this invention. The amount of inoculant added is controlled to account for 2%-5% of the total mass of the special seedling substrate.

[0021] (1) Fungal species: The present invention preferably inoculates with *M. moses*, which can form a highly efficient symbiotic relationship with pepper roots. Through its well-developed extra-root hyphae network, it significantly expands the absorption range of the roots and helps the host plant obtain more water and mineral nutrients (especially phosphorus) from the soil, thereby maintaining the physiological activities of the plant under drought stress.

[0022] (2) Preparation of inoculum: The inoculum is usually propagated and cultured using corn as the host plant. After propagation, a mixture containing active fungal hyphae, spores, original culture medium and infected corn root segments is collected and used as an inoculum. This method can ensure that the inoculum contains a sufficient amount of highly active infection units.

[0023] Thus, a specialized seedling substrate integrating physical structure improvement, organic nutrient supplementation, and specialized microbial symbiosis functions has been prepared.

[0024] 2. Sowing and Seedling Management Chili peppers are sown and raised using the special seedling substrate prepared above. The preferred chili pepper variety is the facing-heaven pepper. Seedling management should fully consider the characteristics of the special substrate and implement management strategies that are adapted to it. The core is to actively induce and train the seedlings to resist stress while ensuring their normal growth.

[0025] 2.1 Water Management Strategy After the chili seedlings have grown to a certain stage (e.g., with 3-4 true leaves), moderate water control can be implemented. Specifically, the moisture content of the substrate is gradually adjusted from the higher level of conventional seedling cultivation (e.g., about 75%) and maintained in the range of 40%-50%. This moisture content range is connected to the preferred starting point (46%) when the substrate was prepared, forming a mild to moderate water stress environment. This controllable water stress will not cause irreversible damage to the seedlings. On the contrary, it can effectively induce the seedlings to initiate a series of drought-resistant physiological and biochemical responses, such as accumulating osmotic regulators (proline, soluble sugars) and enhancing the activity of antioxidant enzyme systems, thereby "pre-adapting" to the future drought environment at the physiological level and improving the survival rate and adaptability after transplanting.

[0026] 2.2 Environmental Condition Control To cultivate robust seedlings, once the first true leaf of the chili seedling unfolds, it should be promptly moved to an environment with ample natural light and good ventilation for continued cultivation. Sufficient light is the foundation for ensuring vigorous photosynthesis and the accumulation of dry matter in the seedlings; good ventilation helps reduce the risk of seedling diseases and promotes thicker stems and firmer tissues, thereby enhancing their physical resistance.

[0027] 3. Verification of technical effectiveness To objectively evaluate the technical effects of this invention, a systematic potted plant comparative experiment was designed. The experiment included four treatment groups: conventional garden soil with normal water supply (CK), special substrate with normal water supply (T), conventional garden soil under drought stress (CKD), and special substrate under drought stress (TD). The substrate moisture content of the normal water supply groups (CK and T) was maintained at approximately 75%, while the substrate moisture content of the drought stress groups (CKD and TD) was controlled to approximately 46% by water restriction. After 50 days of cultivation under their respective conditions, key growth and physiological indicators were measured, and the results are as follows: (1) Effects on plant growth and biomass: Under drought stress, the growth of pepper seedlings treated with conventional garden soil (CKD) was significantly inhibited. In contrast, the TD group treated with the special substrate and treatment method of this invention showed a 37.4% increase in the fresh weight of the aboveground parts and a 29.1% increase in plant height, indicating that this invention can effectively alleviate the inhibitory effect of drought stress on the growth of pepper seedlings (as shown in Table 1).

[0028] Table 1. Effects of adding vermicompost and AM fungi on pepper biomass under drought stress. Note: Different lowercase letters in the table indicate significant differences between treatments. P <0.05); the same applies below.

[0029] (2) Effects on photosynthetic performance: Drought stress leads to a decrease in photosynthetic capacity. The net photosynthetic rate of pepper leaves treated with TD increased by 20.0% compared with those treated with CKD, and stomatal conductance was also significantly improved. In addition, TD treatment can effectively mitigate the damage to the PSII photosystem caused by drought stress, as evidenced by a significant reduction in the decreasing trend of its maximum photochemical efficiency (Fv / Fm) and actual photochemical quantum yield (YII) (e.g. Figure 2 (As shown).

[0030] (3) Effects on physiological and biochemical stress resistance: This invention can systematically enhance the physiological tolerance of seedlings under drought conditions. Specifically, in the leaves of pepper seedlings treated with TD, the peroxidase (POD) activity reached 1.78 times that of those treated with CKD; the catalase (CAT) activity increased by 33.4% compared to CKD; the content of osmotic regulators proline and soluble sugars continued to accumulate; the content of malondialdehyde (MDA), an indicator of cell membrane lipid peroxidation damage, was significantly reduced by 21.3% compared to CKD; at the same time, the root vigor of the seedlings was also significantly improved. These data collectively indicate that this invention, through a special substrate and appropriate management, comprehensively enhances the drought resistance of pepper seedlings from multiple levels, including antioxidant, osmotic regulation, and root function (e.g., Figure 3 (As shown).

[0031] 4. Specific Implementation Examples The following is a specific, non-limiting embodiment example to further understand the present invention: S1, Substrate preparation: Mix garden soil with a water holding capacity of 46% and a pH value of 7.5 with perlite at a mass ratio of 3:1. Take earthworm castings with a water content of 45% and mix them with the above mixed substrate at a mass ratio of 20%. Then, add 5% of the total mass of the final substrate, which is a *Morchella mossicae* inoculant (containing mycelium, spores and root segments) obtained by propagation using corn as the host. After mixing evenly, the special seedling substrate is obtained. S2, Sowing and Management: Sow the chili seeds in pots containing the above-mentioned special substrate. Set up two water treatment groups: one group with normal water supply (maintaining the substrate moisture content at about 75%), and the other group simulating drought stress (maintaining the substrate moisture content at about 46% by controlling watering). After the seedlings unfold their first true leaves, move all pots to an outdoor location with sufficient light and good ventilation for cultivation. For the drought stress group, maintain the target moisture content by precise watering and continue to train water control. S3, Effect Observation: After 50 days of cultivation, the two groups of seedlings under drought stress were compared. The treatment group using the special substrate was significantly better than the control group using conventional garden soil in terms of plant height, fresh weight, leaf photosynthetic rate, chlorophyll fluorescence parameters, and multiple physiological and biochemical resistance indicators, which fully verified the effectiveness of this method in cultivating drought-resistant pepper seedlings.

[0032] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A pepper seedling intelligent cultivation method for effectively coping with a drought environment, characterized in that, The method comprises the following steps: S1, preparing a special seedling substrate; S1.1, mixing garden soil, biochar and pearl salt at a mass ratio of 3:1:1, and adjusting the water content to 35%-65% to obtain a basic soil substrate; S1.2, adding earthworm manure with a water content of 45% to the basic soil substrate obtained in S1.1, and mixing uniformly, so that the mass content of the earthworm manure accounts for 10%-20% of the total mass of the mixture obtained in this step; S1.3, inoculating the mixture obtained in S1.2 with a proliferated arbuscular mycorrhizal fungus inoculum, and mixing uniformly to obtain a final special seedling substrate, wherein the mass content of the inoculum accounts for 2%-5% of the total mass of the special seedling substrate; S2, using the special seedling substrate prepared in S1 to perform pepper sowing and seedling operation.

2. The pepper seedling intelligent cultivation method according to claim 1, characterized in that: The water content of the basic soil substrate in S1 is 46%.

3. The pepper seedling intelligent cultivation method according to claim 1, characterized in that: The arbuscular mycorrhizal fungus in S1.3 is Glomus mosseae.

4. The pepper seedling intelligent cultivation method according to claim 1, characterized in that: The earthworm manure in S1.2 is produced by Amynthas directus.

5. The pepper seedling intelligent cultivation method according to claim 1, characterized in that: The variety of the pepper is Chongtianjiao.

6. The pepper seedling intelligent cultivation method according to claim 1, characterized in that: The proliferated arbuscular mycorrhizal fungus inoculum in S1.3 is a mixture containing fungal hyphae, spores, culture medium and host root segments obtained after proliferation with corn as the host.

7. The pepper seedling intelligent cultivation method according to claim 1, characterized in that: In the seedling operation of S2, after the pepper seedlings grow to a certain stage, moderate water control exercise is performed to control the water content of the special seedling substrate in the range of 40%-50%.

8. The pepper seedling intelligent cultivation method according to claim 1, characterized in that: In the seedling operation of S2, after the first true leaf of the seedling is unfolded, it is placed in an environment with sufficient natural light and good ventilation for cultivation.

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