Nutrition regulation and control method suitable for growth of hydroponic alfalfa in different periods

Abstract

The invention relates to the technical field of nutrient regulation of hydroponic plants, in particular to a nutrient regulation method suitable for growth of hydroponic alfalfa in different periods, which comprises the following steps: dividing the growth period of hydroponic alfalfa into a seedling period, a vegetative growth period, a squaring period and a flowering period, and dynamically adjusting nutrient solution components and environmental parameters for each period. The method specifically comprises the steps of promoting root development through low-concentration nitrogen and naphthylacetic acid in the seedling stage, optimizing the nitrogen-phosphorus ratio and conductivity in the vegetative growth stage, increasing potassium and boric acid in the squaring stage to prevent flower buds from falling off, reducing nitrogen in the flowering stage and supplementing 6-benayl aminopurine to delay senescence, and cooperatively regulating and controlling illumination and pH value in the squaring stage. The method can significantly improve the yield and crude protein content of hydroponic alfalfa, shorten the growth cycle, reduce the production cost, and meet the efficient and accurate requirements of modern agriculture.

Description

Technical Field

[0001] This invention belongs to the field of hydroponic plant nutrient regulation technology, specifically a nutrient regulation method suitable for hydroponic alfalfa growth at different stages. Background Technology

[0002] With the rapid development of modern agriculture, hydroponics has become increasingly widely used in crop production due to its high efficiency, environmental friendliness, and strong controllability. Hydroponically grown alfalfa (Medicago sativa L.) has become an important research subject in hydroponics due to its short growth cycle, high yield, and excellent quality. However, existing hydroponic alfalfa nutrient regulation techniques still have significant shortcomings in dynamically adjusting for different growth stages, making it difficult to further improve its growth efficiency and quality, thus limiting the full potential of hydroponic alfalfa in actual production.

[0003] A search revealed that patent document CN112471352B discloses a compound feed additive and its feed for preventing goose wing flapping disease. This technology involves mixing feed enzymes, methionine, antioxidant vitamins, white-feathered lentil powder, alfalfa meal, and wheat bran to improve animal feather production performance and prevent related diseases. However, this technology primarily focuses on animal feed and does not address plant nutrient regulation, particularly lacking dynamic nutrient solution formulation design for different growth stages of hydroponic alfalfa. Furthermore, this solution does not delve into the adjustment of the proportions of macro- and micro-elements and growth regulators required for plant growth, failing to meet the needs of optimizing the growth environment for hydroponic alfalfa at different stages.

[0004] Further research revealed that no patent literature directly related to the dynamic regulation of nutrient solutions in hydroponic alfalfa has been found in the existing technology. Therefore, while the technical solution based on CN112471352B has some innovation in the field of feed additives, its applicability to plant nutrition regulation is limited, especially in terms of phased dynamic adjustment of nutrient solution composition and synergistic environmental parameter regulation. These issues indicate that there is currently no systematic solution for the dynamic regulation of nutrient solutions, the division of growth stages, and the synergistic optimization of the environment during the growth of hydroponic alfalfa.

[0005] In summary, in order to overcome the limitations of existing technologies, it is urgent to develop a nutrient regulation method suitable for hydroponic alfalfa growth at different stages. By adjusting the nutrient solution composition and environmental parameters in stages, the growth environment of hydroponic alfalfa can be optimized, thereby increasing yield and quality, shortening the growth cycle and reducing production costs, so as to meet the needs of modern agriculture for efficient and precise hydroponic technology. Summary of the Invention

[0006] The purpose of this invention is to provide a nutrient regulation method suitable for the growth of hydroponic alfalfa at different stages. To achieve the above-mentioned objective, the nutrient regulation method of this invention, suitable for the growth of hydroponic alfalfa at different stages, includes the following steps: S1, Stage division: Dividing the growth cycle of hydroponic alfalfa into seedling stage, vegetative growth stage, budding stage, and flowering stage, and formulating corresponding nutrient solution formulas for each stage; S2, Seedling stage regulation: Using low concentration nitrogen and adding an appropriate amount of naphthaleneacetic acid to promote root development during the seedling stage; S3, Vegetative growth stage regulation: Increasing the nitrogen-phosphorus ratio in the nutrient solution and controlling the electrical conductivity (EC value) within a suitable range; S4, Budding stage regulation: Increasing potassium content and supplementing boric acid solution to prevent bud drop; S5, Flowering stage regulation: Reducing nitrogen supply and supplementing with 6-benzylaminopurine to prolong the functional period of leaves; S6, Environmental synergistic regulation: Adjusting the light duration and red-blue light ratio during the budding stage, and raising the pH value of the nutrient solution to a slightly alkaline range.

[0007] As an improvement to the nutrient regulation method for hydroponic alfalfa growth at different stages of the present invention, in the seedling stage, a nutrient solution with a nitrate nitrogen concentration below 80 mg / L is used, and 0.1-0.3 mg / L of naphthaleneacetic acid is added to promote root development. In the vegetative growth stage, the nitrogen-phosphorus ratio of the nutrient solution is adjusted to 3:1-4:1, and the electrical conductivity (EC value) is controlled between 1.8-2.2 mS / cm. In the budding stage, the potassium concentration is increased to 200-250 mg / L, and 0.05% boric acid solution is added to reduce bud drop. In the flowering stage, the nitrate nitrogen concentration is reduced to half of the initial level, and 0.1-0.2 mg / L of 6-benzylaminopurine is supplemented to delay leaf senescence. In the coordinated environmental regulation, the light duration during the budding stage was extended from 10 hours to 12 hours, and 2 hours of red light with a wavelength of 660nm were added daily on the basis of the original red-blue light ratio (8:2). At the same time, the pH value of the nutrient solution was adjusted to 7.5-8.0.

[0008] Compared with the prior art, the beneficial effects of the present invention are: the nutrient regulation method of the present invention for hydroponic alfalfa growth at different stages significantly optimizes the growth environment of hydroponic alfalfa by dynamically adjusting the nutrient solution composition and environmental parameters at different growth stages, which not only increases the yield and crude protein content, but also shortens the growth cycle and reduces the production cost, thereby meeting the needs of modern agriculture for efficient and precise hydroponic technology. Detailed Implementation

[0009] This invention provides a nutrient regulation method suitable for hydroponic alfalfa growth at different stages, the specific implementation of which is as follows. First, the entire growth cycle of hydroponic alfalfa is divided into four stages: seedling stage, vegetative growth stage, budding stage, and flowering stage. Specific nutrient solution formulations and environmental parameter control schemes are developed for each stage. During the seedling stage, a low-concentration nitrate nitrogen nutrient solution is used, with the nitrate nitrogen concentration controlled below 80 mg / L to avoid inhibiting the seedling root system. Simultaneously, an appropriate amount of naphthaleneacetic acid (NAA) is added to promote root development. The concentration range of NAA is 0.1-0.3 mg / L, which effectively induces root tip cell division and enhances root absorption capacity. In practice, commercially available NAA solution can be diluted to the above concentration and added to the nutrient solution, ensuring uniform distribution.

[0010] Once the plant enters the vegetative growth stage, the nitrogen-to-phosphorus ratio in the nutrient solution needs to be increased to between 3:1 and 4:1 to meet the macronutrient requirements for rapid plant growth. At this stage, electrical conductivity (EC value) is a crucial indicator of ion concentration in the nutrient solution and should be strictly controlled within the range of 1.8-2.2 mS / cm. If the EC value is too high, it may lead to salt accumulation and inhibit plant growth; if it is too low, it will not provide sufficient nutrient support. Therefore, when preparing the nutrient solution, the nitrogen-to-phosphorus ratio can be adjusted by gradually adding fertilizers such as potassium nitrate and potassium dihydrogen phosphate, while using an electrical conductivity meter to monitor the EC value in real time to ensure it remains within the appropriate range. Furthermore, to ensure the stability of the nutrient solution composition, it is recommended to change the nutrient solution every 3 days and regularly test and fine-tune the pH value to maintain it between 6.5 and 7.0.

[0011] When alfalfa enters the budding stage, the potassium content needs to be increased to promote flower bud differentiation and formation. At this stage, the potassium concentration should be increased to 200-250 mg / L, and an additional 0.05% boric acid solution should be added to reduce bud drop. Boric acid promotes pollen tube elongation and fertilization, thereby increasing the seed set rate. The specific method is to dissolve boric acid in a small amount of distilled water, then slowly add it to the main nutrient solution and stir well before use. Simultaneously, light conditions need to be adjusted to meet the plant's physiological needs. The light duration should be extended from 10 hours to 12 hours, and 2 hours of 660nm red light should be added daily to the existing red-blue light ratio (8:2). Studies have shown that 660nm red light can significantly promote plant photosynthetic efficiency, especially for alfalfa in the budding stage, resulting in a significant yield increase. Furthermore, the pH of the nutrient solution during the budding stage should be appropriately increased to a slightly alkaline range, i.e., 7.5-8.0, to improve the plant's potassium absorption efficiency.

[0012] The flowering period is a critical stage in alfalfa growth. During this time, nitrogen supply needs to be reduced to avoid excessive vegetative growth that could inhibit reproductive growth. Specifically, the nitrate nitrogen concentration should be reduced to half of its initial level, for example, from 80 mg / L to about 40 mg / L. Simultaneously, 0.1-0.2 mg / L of 6-benzylaminopurine should be added to the nutrient solution to delay leaf senescence and extend its functional period. 6-Benzylaminopurine is a commonly used plant growth regulator that maintains leaf greenness by inhibiting the activity of chlorophyll-degrading enzymes, thereby improving photosynthetic efficiency. In practical applications, 6-benzylaminopurine can be dissolved in a small amount of alcohol and then added dropwise to the nutrient solution, mixing thoroughly. It is important to note that the amount of 6-benzylaminopurine added must strictly adhere to the recommended concentration to avoid phytotoxicity due to excessive concentration.

[0013] Besides the dynamic adjustment of nutrient solution composition, the coordinated regulation of environmental parameters is equally crucial. For example, during the budding and flowering stages, temperature and humidity control must match the light conditions. Typically, the suitable temperature for the budding stage is 20-25℃, and the relative humidity is 60%-70%; while during the flowering stage, the temperature needs to be slightly lowered to 18-22℃, and the humidity controlled between 50%-60%. Optimizing these environmental parameters can be achieved through an intelligent greenhouse system, utilizing sensors to collect data in real time and adjusting it through an automatic control system. Furthermore, to further improve the operating efficiency of the hydroponic system, a circulating nutrient solution mode can be introduced. This involves using a water pump to transport the nutrient solution from the storage tank to the cultivation tank, and then returning it to the storage tank for filtration and reuse after use. This mode not only saves water resources but also avoids nutrient solution stratification or sedimentation problems caused by prolonged static storage.

[0014] In actual production, the specific implementation of this invention can be flexibly adjusted according to the climate characteristics and cultivation facility conditions of different regions. For example, in cold northern regions, special attention needs to be paid to heat preservation measures during winter cultivation, which can be achieved by installing underfloor heating or air heating devices to maintain a suitable growth temperature. In hot and humid southern regions, ventilation needs to be strengthened to prevent disease. In addition, for large-scale commercial hydroponic farms, a modular cultivation system can be adopted, with each module independently controlling nutrient solution and environmental parameters to achieve precise management. For example, a standard module can accommodate 100 alfalfa plants, and each module is equipped with independent nutrient solution circulation pipes, light strips, and temperature and humidity sensors. All data is uploaded to the central control system for unified analysis and control.

[0015] In summary, this invention achieves highly efficient and precise cultivation by dynamically controlling the nutrient solution composition and environmental parameters at different growth stages of hydroponically grown alfalfa. From both theoretical research and practical application perspectives, this method has high promotional value and can be widely applied in modern agricultural production, providing technical support for meeting market demand for high-quality forage. Furthermore, this invention provides a useful reference for the development of hydroponic technologies for other crops, possessing significant scientific and economic value.

Claims

1. A nutrient regulation method suitable for hydroponic alfalfa growth at different stages, characterized in that, The method includes the following steps: S1. Stage Division: The growth cycle of hydroponic alfalfa is divided into seedling stage, vegetative growth stage, budding stage and flowering stage, and corresponding nutrient solution formulas are formulated for each stage. S2. Seedling stage management: Use a nutrient solution with a nitrate nitrogen concentration of less than 80 mg / L during the seedling stage, and add 0.1-0.3 mg / L of naphthaleneacetic acid; S3. Regulation during the vegetative growth period: Adjust the nitrogen-phosphorus ratio in the nutrient solution to 3:1 to 4:1, and control the electrical conductivity within the range of 1.8-2.2 mS / cm; S4. Bud formation stage regulation: Increase potassium concentration to 200-250 mg / L and supplement with 0.05% boric acid solution; S5. Flowering period regulation: Reduce the nitrate nitrogen concentration to half of the initial level and supplement with 0.1-0.2 mg / L of 6-benzylaminopurine; S6. Environmental Coordination and Regulation: During the budding stage, extend the light duration from 10 hours to 12 hours, and supplement the original red and blue light ratio with 2 hours of red light with a wavelength of 660nm per day. At the same time, adjust the pH value of the nutrient solution to 7.5-8.

0. In the coordinated environmental regulation, the temperature during the budding stage is controlled at 20-25℃ and the relative humidity is controlled at 60%-70%, while the temperature during the flowering stage is controlled at 18-22℃ and the relative humidity is controlled at 50%-60%.

2. The nutrient regulation method for hydroponic alfalfa growth at different stages according to claim 1, characterized in that, In seedling stage management, the nutrient solution with a nitrate nitrogen concentration of less than 80 mg / L is prepared by adding potassium nitrate or calcium nitrate.

3. The nutrient regulation method for hydroponic alfalfa growth at different stages according to claim 1, characterized in that, During the vegetative growth period, the nitrogen-to-phosphorus ratio is adjusted by adding potassium nitrate and potassium dihydrogen phosphate.

4. The nutrient regulation method for hydroponic alfalfa growth at different stages according to claim 1, characterized in that, In the regulation of the budding stage, the boric acid solution is prepared by dissolving boric acid in distilled water and added to the main nutrient solution dropwise.

5. The nutrient regulation method for hydroponic alfalfa growth at different stages according to claim 1, characterized in that, In the regulation of flowering period, the 6-benzylaminopurine is dissolved in a small amount of alcohol and added dropwise to the nutrient solution.

6. The nutrient regulation method for hydroponic alfalfa growth at different stages according to claim 1, characterized in that, In the coordinated environmental control, the red and blue light ratio is 8:2, and red light with a wavelength of 660nm is provided by an LED light source.

7. The nutrient regulation method for hydroponic alfalfa growth at different stages according to claim 1, characterized in that, During the vegetative growth period, the nutrient solution should be changed every 3 days, and the pH value should be tested regularly to maintain it within the range of 6.5-7.

0.

8. The nutrient regulation method for hydroponic alfalfa growth at different stages according to claim 1, characterized in that, In the regulation of the budding stage, the potassium concentration is adjusted by adding potassium sulfate or potassium chloride.

9. The nutrient regulation method for hydroponic alfalfa growth at different stages according to claim 1, characterized in that, During flowering period regulation, the nitrate nitrogen concentration was reduced to 40 mg / L.