Potato aeroponic staging regulation nutrient solution and application method

Abstract

The invention relates to a potato aeroponic staging regulation nutrient solution and an application method, and belongs to the technical field of soilless culture. According to the method, differential nutrient solution formulas are respectively designed according to nutrient demand characteristics of five growth stages (a germination stage, a seedling stage, a tillering stage, a tuberization stage and a mature stage) of potatoes, the pH value is dynamically regulated and controlled to be 5.5-6.5, the EC value is gradually increased and then slightly decreased according to the growth stages, and a precise atomization application strategy is matched. A CaCl2-KNO3-KH2PO4 triangular system is adopted in the tuberization period, the problem of calcium and potassium antagonism is effectively solved, calcium absorption of tubers is remarkably improved, and the tuberization rate is lower than 3%. Liquid drops are prevented from making contact with the blades through the directional atomization and physical isolation technology, it is ensured that chlormequat chloride residues are not detected out, and the advantages of being efficient, safe and easy to operate are achieved.

Description

Technical Field

[0001] This invention relates to the field of soilless agricultural cultivation technology, and in particular to a staged nutrient solution and application method for potato aeroponic cultivation, with differentiated formulas and control strategies designed specifically for the nutritional needs of potatoes at different growth stages. Background Technology

[0002] Potatoes are an important global food and economic crop. Traditional cultivation methods, primarily soil cultivation, suffer from problems such as severe soil-borne diseases (e.g., late blight and scab), significant obstacles to continuous cropping, low water and fertilizer utilization rates (only 30%-50%), high labor intensity, and soil degradation. To address these issues, soilless cultivation technologies, such as substrate cultivation and aeroponics, are increasingly being applied to potato production.

[0003] Aeroponics is a highly efficient soilless cultivation method that uses atomizing devices to atomize nutrient solution into droplets, typically less than 50 micrometers in diameter, which are then sprayed directly onto the suspended root system, providing the plant with water, nutrients, and oxygen. This technology offers advantages such as high water and fertilizer utilization (theoretically exceeding 95%), ample root oxygen supply, no soil-borne diseases, short growth cycle, high yield, and ease of automated management.

[0004] However, the success of aeroponics depends heavily on the precise matching of nutrient solution formulation with the nutrient requirements of crops at different growth stages. Current technologies generally use a "universal" nutrient solution formulation, failing to dynamically adjust according to the physiological characteristics and nutrient needs of potatoes at different growth stages. This leads to problems such as insufficient calcium absorption during tuber enlargement (only 38% of that in soil cultivation), high tuber cracking rate, uneven quality, and significant nitrogen-potassium antagonism, limiting the widespread application of aeroponics technology in potato production.

[0005] Therefore, there is an urgent need to develop a phased nutrient solution formula and application method for potato aeroponics to achieve precise, efficient and standardized nutrient supply. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for staged regulation of nutrient solution and its application in potato aeroponics. By precisely controlling the ionic composition, pH value, electrical conductivity (EC value), and atomization frequency of the nutrient solution formula in stages, this invention solves problems such as tuber calcium absorption barriers, high tuber cracking rate, and low nutrient utilization efficiency in existing aeroponics, significantly improving potato yield, quality, and marketability.

[0007] The above-mentioned objective of this invention is achieved through the following technical solutions:

[0008] A nutrient solution for potato aeroponic cultivation with phased regulation is provided, which is divided into five stages according to the potato growth cycle: germination stage, seedling stage, vegetative growth stage, tuber formation stage, and maturity stage. The nutrient solution formulas for each stage are as follows:

[0009] The nutrient solution during the germination period contains: Ca(NO3)2·4H2O, KNO3, NH4H2PO4, MgSO4·7H2O, Fe-EDTA, and inositol;

[0010] The nutrient solution for seedlings contains: Ca(NO3)2·4H2O, KNO3, KH2PO4, MgSO4·7H2O, H3BO3, and ZnSO4·7H2O;

[0011] The nutrient solution during the vegetative growth stage contains: Ca(NO3)2·4H2O, KNO3, NH4H2PO4, MgSO4·7H2O, MnSO4·7H2O, and CuSO4·5H2O;

[0012] Nutrient solution during tuber formation includes: KNO3, CaCl2·2H2O, KH2PO4, MgSO4·7H2O, H3BO3, KI, and CCC;

[0013] The nutrient solution during the maturation period contains: K2SO4, Ca(NO3)2·4H2O, MgSO4·7H2O, KH2PO4, and Fe-EDTA.

[0014] As a further technical solution of the present invention: the amount of inositol added to the germination nutrient solution is 45-55 mg / L.

[0015] As a further technical solution of the present invention: the amount of CCC added to the nutrient solution during the tuber formation period is 4.75-5.25 mg / L, and Ca... 2+ The concentration shall not be less than 90 mg / L.

[0016] As a further technical solution of the present invention: the pH value of the nutrient solution at each stage is controlled at 5.5-6.5, and the EC values ​​are as follows: 0.8-1.0 mS / cm during germination, 1.2-1.5 mS / cm during seedling stage, 1.5-1.8 mS / cm during vegetative growth stage, 1.8-2.2 mS / cm during tuber formation stage, and 1.5-1.8 mS / cm during maturity stage.

[0017] The above-mentioned method for applying nutrient solution in a phased manner during potato aeroponic cultivation includes the following steps:

[0018] Step 1: Replace the nutrient solution completely every 72 hours;

[0019] Step 2: During the sprouting period, the atomization frequency is 1 minute on and 60 minutes off; during the tuber formation period, the atomization frequency is 3 minutes on and 30 minutes off.

[0020] Step 3: Monitor and adjust pH and EC values ​​daily, and correct immediately if the deviation exceeds the set range.

[0021] As a further technical solution of the present invention: In step 3, the method for adjusting the pH value includes the following steps: when pH > 6.5, add HNO3 solution (diluted to a safe concentration); when pH < 5.5, add KOH solution (diluted to a safe concentration), and calibrate at least once a day.

[0022] As a further technical solution of the present invention: In step 3, the method for adjusting the EC value includes the following steps: daily use of a conductivity meter to detect the EC value of the nutrient solution, and immediately adjust it when the deviation is >0.2mS / cm; inject clean water when the EC value exceeds the standard; and supplement the mother liquor when the EC value is insufficient.

[0023] As a further technical solution of the present invention, it also includes an ultrasonic atomizing nozzle, a protective baffle and an airflow guiding system to prevent nutrient solution droplets from contacting the leaves, wherein the ultrasonic atomizing nozzle is installed at a vertical downward angle of 15°±2° and 25cm away from the root system, and the protective baffle is suspended 10cm above the base of the stem.

[0024] As a further technical solution of the present invention: the airflow guiding system includes low-speed fans arranged on both sides of the cultivation rack, the wind speed of the low-speed fans is 0.5m / s, forming an airflow barrier from top to bottom.

[0025] The application of the above-mentioned nutrient solution or application method in potato aeroponics.

[0026] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects:

[0027] 1. Precise phased control: For the first time, independent nutrient formulas were designed for the five stages of potato aeroponic cultivation, overcoming the blindness of the traditional "one liquid for all" approach and meeting the differentiated nutrient needs of each stage.

[0028] 2. Solving the problem of calcium-potassium antagonism: During the tuber formation stage, a CaCl2-KNO3-KH2PO4 triangular system is used to separate the calcium and potassium sources. The anion effect is used to promote calcium absorption, increasing the calcium content of tubers by 35% and reducing the tuber cracking rate to below 3%.

[0029] 3. Improve nutrient utilization efficiency: Nitrogen partial productivity (PFP) n The yield reached 65 kg / kg, which is 22% higher than the traditional Hoagland formula, and achieved a significant increase in yield while reducing nitrogen input by 8.3%.

[0030] 4. Safe and reliable: Through atomization directional control and physical barriers, it effectively prevents nutrient solution droplets from contacting the leaves, reducing salt damage and diseases; CCC residues were not detected, meeting food safety standards.

[0031] 5. High operability: It provides detailed formula composition, pH / EC control index, application parameters and equipment configuration requirements, which facilitates large-scale promotion and application. Detailed Implementation

[0032] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0033] Traditional methods of potato cultivation:

[0034] Soil cultivation: With a long history, mature technology, and relatively low cost, it relies on soil as a support, nutrient, and water buffer. However, it is susceptible to soil-borne diseases (such as late blight, scab, and nematodes), continuous cropping obstacles, soil salinization / compactment, low water and fertilizer utilization (approximately 30-50%), and high labor intensity (cultivation, hilling, and harvesting). Tuber formation and enlargement require a dark, moist, and well-aerated soil environment.

[0035] Substrate cultivation: Using coconut coir, rock wool, peat, etc. to replace soil partially overcomes soil-borne diseases and continuous cropping obstacles, and allows for more precise water and fertilizer control. However, the substrate itself has costs, and there are disposal and environmental issues after use. Root environment regulation (especially oxygen and water balance) is not as direct as in aeroponics.

[0036] The basic principles and ideal advantages of aeroponics:

[0037] Principle: The plant roots are suspended in a dark, sealed cultivation tank. The nutrient solution is atomized into tiny droplets (usually <50 micrometers in diameter) by a high-pressure atomizing device and sprayed directly onto the root surface to provide the plant with water, nutrients and oxygen.

[0038] Ideal advantages: Extremely high water and fertilizer utilization rate: theoretically reaching over 95%, reducing waste and environmental pollution; Maximizing root oxygen supply: roots are exposed to air, with ample oxygen, promoting respiration and nutrient absorption; Avoiding soil-borne diseases: completely detached from soil, cutting off the main transmission routes of soil-borne pathogens; Fast growth rate and high yield potential: the superior rhizosphere environment can theoretically significantly increase growth rate and yield per unit area; Space-saving and easy to automate: multi-layer vertical cultivation is possible, facilitating precise environmental control and mechanized operation; Relatively easy tuber harvesting: no soil digging is required, reducing damage.

[0039] Example 1:

[0040] This invention discloses a staged nutrient solution for potato aeroponic cultivation, which is divided into five stages according to the potato growth cycle: germination stage, seedling stage, vegetative growth stage, tuber formation stage, and maturity stage. The nutrient solution formulas for each stage are as follows:

[0041] The nutrient solution during the germination period contains: Ca(NO3)2·4H2O, KNO3, NH4H2PO4, MgSO4·7H2O, Fe-EDTA, and inositol;

[0042] The nutrient solution for seedlings contains: Ca(NO3)2·4H2O, KNO3, KH2PO4, MgSO4·7H2O, H3BO3, and ZnSO4·7H2O;

[0043] The nutrient solution during the vegetative growth stage contains: Ca(NO3)2·4H2O, KNO3, NH4H2PO4, MgSO4·7H2O, MnSO4·7H2O, and CuSO4·5H2O;

[0044] Nutrient solution during tuber formation includes: KNO3, CaCl2·2H2O, KH2PO4, MgSO4·7H2O, H3BO3, KI, and CCC;

[0045] The nutrient solution during the maturation period contains: K2SO4, Ca(NO3)2·4H2O, MgSO4·7H2O, KH2PO4, and Fe-EDTA.

[0046] The inositol addition level in the nutrient solution during the germination period is 45-55 mg / L. The CCC addition level in the nutrient solution during the tuber formation period is 4.75-5.25 mg / L, and Ca... 2+ The concentration shall not be less than 90 mg / L.

[0047] The pH of the nutrient solution at each stage should be controlled between 5.5 and 6.5, and the EC value should be increased and then slightly decreased according to the growth stage, specifically: 0.8-1.0 mS / cm during germination, 1.2-1.5 mS / cm during seedling stage, 1.5-1.8 mS / cm during vegetative growth stage, 1.8-2.2 mS / cm during tuber formation stage, and 1.5-1.8 mS / cm during maturity stage.

[0048] The germination period nutrient solution (from sowing to emergence, lasting 7-10 days) contains the following per liter:

[0049] Ca(NO3)2·4H2O 380mg (range 342-418mg)

[0050] KNO3 200 mg (range 180-220 mg)

[0051] NH4H2PO4 80 mg (range 72-88 mg)

[0052] MgSO4·7H2O 150mg (range 135-165mg)

[0053] Fe-EDTA (13%) 15mg (range 13.5-16.5mg),

[0054] Inositol 50mg (range 45-55mg).

[0055] Key ion concentration requirement: Ca 2+ 60-75 mg / L, NO3 - 100-125 mg / L, NH4 + 12-16 mg / L, Mg 2+ 15-20 mg / L, Fe 2+ 1.8-2.2 mg / L, inositol is a functional additive with no ion limit. Core phenological characteristics during germination: buds sprout and white spots appear; primary roots at the base elongate ≤2 cm; above-ground parts do not break through the soil. Basis: Low EC value (0.8-1.0 mS / cm) reduces osmotic stress in seed potatoes, and inositol enhances cellular stress resistance.

[0056] Seedling stage nutrient solution 3 (from emergence to budding, lasting 15-20 days), each liter of nutrient solution contains:

[0057] Ca(NO3)2·4H2O 550mg (range 495-605mg)

[0058] KNO3 400 mg (range 360-440 mg)

[0059] KH2PO4 120 mg (range 108-132 mg)

[0060] MgSO4·7H2O 280mg (range 252-308mg)

[0061] H3BO3 5.0 mg (range 4.5-5.5 mg),

[0062] ZnSO4·7H2O 1.0mg (range 0.9-1.1mg).

[0063] Key ion concentration requirement: Ca 2+ 90-110 mg / L, K + 150-180 mg / L, PO4 3- 25-35 mg / L, Mg 2+ 28-35mg / L, B 0.8-1.0mg / L, Zn 2+0.2-0.25 mg / L. Core phenological characteristics during the seedling stage: 1st-2nd true leaves unfold; stem height 5-10 cm; root system changes from white to brown (secondary root differentiation). Basis: Increasing KH2PO4 content promotes root establishment; boron and zinc prevent apical meristem malformation.

[0064] Nutrient solution during the vegetative growth stage (from bud formation to canopy closure, lasting 20-25 days), each liter of nutrient solution contains:

[0065] Ca(NO3)2·4H2O 680mg (range 612-748mg)

[0066] KNO3 500 mg (range 450-550 mg)

[0067] NH4H2PO4 230 mg (range 207-253 mg)

[0068] MgSO4·7H2O 370mg (range 333-407mg)

[0069] MnSO4·7H2O 15mg (range 13.5-16.5mg)

[0070] CuSO4·5H2O 0.02mg (range 0.018-0.022mg).

[0071] Key ion concentration requirement: NH4 + / NO3 - Ratio 1:4 ± 0.5, K + 190-220 mg / L, PO4 3- 50-60 mg / L, Mg 2+ 37-45 mg / L, Mn 2+ 4.0-5.0 mg / L, Cu 2+ 0.005-0.006 mg / L. Core phenological characteristics during the vegetative growth stage: flower buds appear at the tip of the main stem; lateral branches cover ≥80% of the ridge surface; leaf LAI index reaches 3.0-3.5. Basis: NH4 + / NO3 - The ratio (1:4) optimizes photosynthetic efficiency, and Mn / Cu enhances enzyme activity.

[0072] Nutrient solution during tuber formation (early to peak tuber enlargement stage, lasting 30-35 days), each liter of nutrient solution contains:

[0073] KNO3 650 mg (range 585-715 mg)

[0074] CaCl2·2H2O 420mg (range 378-462mg)

[0075] KH2PO4 280 mg (range 252-308 mg)

[0076] MgSO4·7H2O 350mg (range 315-385mg)

[0077] H3BO3 8.0 mg (range 7.2-8.8 mg),

[0078] KI 0.8mg (range 0.72-0.88mg),

[0079] CCC (chlormequat chloride) 5.0 mg (range 4.75-5.25 mg).

[0080] Key ion concentration requirement: K + 250-290 mg / L, Ca 2+ ≥90mg / L (mandatory requirement), PO4 3- 60-70 mg / L, Mg 2+ 35-42 mg / L, B 1.3-1.6 mg / L, I - 0.6-0.75 mg / L, hormones ±5%, must not exceed the limit. Core phenological characteristics during the early to peak tuber enlargement stage: swelling of the underground stolons at the ends (diameter ≥1 cm); cessation of above-ground growth and dark green leaves; daily increase in fresh tuber weight per plant ≥5 g. Basis: CaCl2 replaces Ca(NO3)2 to reduce nitrogen accumulation, and boron and iodine synergistically increase dry matter.

[0081] Nutrient solution during the maturity stage (from stem and leaf yellowing to harvest, lasting 10-15 days), each liter of nutrient solution contains:

[0082] K2SO4 500 mg (range 450-550 mg)

[0083] Ca(NO3)2·4H2O 300mg (range 270-330mg)

[0084] MgSO4·7H2O 250mg (range 225-275mg)

[0085] KH2PO4 150 mg (range 135-165 mg)

[0086] Fe-EDTA 10mg (range 9-11mg).

[0087] Key ion concentration requirement: K + 220-260 mg / L, NO3 - 60-75 mg / L, Mg 2+ 25-30 mg / L, PO4 3- 32-40 mg / L, Fe 2+1.2-1.5 mg / L. Core phenological characteristics at maturity: one-third of the leaves turn yellow; tuber epidermis becomes corky (difficult to peel); stolons dry up and fall off. Basis: K2SO4 provides a nitrogen-free potassium source, promoting starch conversion.

[0088] Nutrient solution preparation and management:

[0089] Water treatment: Use deionized water or reverse osmosis water to prepare nutrient solutions to reduce interference from impurity ions.

[0090] Mother liquor preparation:

[0091] Mother liquor for macro-elements: Weigh each compound according to the formula ratio, dissolve them separately and then mix them together, and make up to a concentration of 10 times that of the mother liquor.

[0092] Trace element stock solution: Following the chelate-buffered principle, Fe-EDTA, MnSO4, ZnSO4, CuSO4, H3BO3, KI, etc., are prepared into a 100-fold concentration mixed stock solution. Trace elements are added according to the chelate-buffered principle, which is the core method for trace element management in nutrient solutions. Its core is to precisely control the molar ratio of chelating agents to metal ions to stabilize the concentration of free trace element ions within the physiologically effective range, avoiding precipitation or toxicity.

[0093] Hormone stock solution: Prepare a separate 1.0g / L stock solution of CCC, and store it in a brown bottle protected from light and refrigerated. Specifically, a separate 1.0g / L stock solution of chlormequat chloride (CCC) needs to be prepared: Weigh 1.0g of pure CCC, dilute to 1L with deionized water, stir until completely dissolved, and store in a brown glass bottle protected from light (refrigerated at 4℃). Shelf life is 30 days. Mix before use.

[0094] Preparation of working solution: Take the corresponding stock solution according to the growth stage, dilute to 1× working concentration, adjust the pH to 5.5-6.5, and test whether the EC value is within the range.

[0095] Nutrient solution management: Completely replace the nutrient solution and clean the cultivation tanks every 72 hours. Monitor pH and EC daily and adjust as needed. Set the atomization frequency according to the growth stage, increasing the frequency during the tuber formation stage.

[0096] Cultivation system settings:

[0097] Cultivation trough: The cultivation trough is made of black PP material (length × width × height = 200cm × 50cm × 30cm), with a planting plate on the top, the hole diameter is 5cm and the spacing is 25cm.

[0098] Atomization system: Ultrasonic atomizing nozzle (working frequency 1.7MHz, droplet size 50-80μm), one nozzle per plant, installed at a downward angle of 15°, 25cm away from the root system.

[0099] Protection system: Each plant is equipped with a PP baffle (30cm×40cm) and hung 10cm from the base of the stem; low-speed fans are installed on both sides of the cultivation rack with a wind speed of 0.5m / s to guide the mist droplets to sink.

[0100] Control system: The system adopts a PLC automatic control system, which integrates pH / EC sensor, light sensor, timer, etc., to realize automated management of nutrient solution replacement, atomization, replenishment, pH adjustment, etc.

[0101] Example 2:

[0102] The method for applying nutrient solution in staged regulation during potato aeroponics, as described in Example 1, includes the following steps:

[0103] Step 1: Replace the nutrient solution completely every 72 hours to prevent ion imbalance and accumulation of harmful substances;

[0104] Step 2: During the germination period, the atomization frequency is 1 minute on and 60 minutes off; during the tuber formation period, the atomization frequency is 3 minutes on and 30 minutes off; adjust appropriately according to plant growth and environmental conditions during other stages.

[0105] Step 3: Monitor and adjust pH and EC values ​​daily, and correct immediately if the deviation exceeds the set range.

[0106] In step 3, the method for adjusting the pH value includes the following steps: when pH > 6.5, add HNO3 solution (diluted to a safe concentration); when pH < 5.5, add KOH solution (diluted to a safe concentration), and calibrate at least once a day.

[0107] In step 3, the method for adjusting the EC value includes the following steps: daily use of a conductivity meter to detect the EC value of the nutrient solution, and immediate adjustment when the deviation is >0.2 mS / cm; inject clean water when the EC value exceeds the standard; and supplement the mother liquor when the EC value is insufficient.

[0108] It also includes an ultrasonic atomizing nozzle, a protective baffle, and an airflow guiding system to prevent nutrient solution droplets from contacting the leaves. The ultrasonic atomizing nozzle is installed vertically downward at an angle of 15°±2°, 25cm from the roots, and the protective baffle is suspended 10cm above the base of the stem. The airflow guiding system includes low-speed fans installed on both sides of the cultivation rack, with a wind speed of 0.5m / s, forming a top-down airflow barrier.

[0109] Use an ultrasonic atomizing nozzle (droplet size 50-80μm), installed at a downward angle of 15°±2°, 25cm from the tuber growth zone and ≥40cm from the lowest leaf. Add a food-grade PP protective baffle (30cm×40cm) suspended 10cm above the base of the plant stem, and use a low-speed fan (0.5m / s) to create an airflow guiding system, forcing the droplets to settle towards the roots and reducing leaf contact.

[0110] CMC (chlormequat chloride) was added to the nutrient solution during the tuber formation stage, with the concentration strictly controlled between 4.75-5.25 mg / L. A separate CCC stock solution (1.0 g / L) was prepared, stored in the dark and refrigerated, and had a shelf life of 30 days. Through precise atomization direction and physical isolation measures, it was ensured that CCC acted only on the roots, avoiding contact with the leaves. At harvest, CCC residues in the tubers were undetectable (<0.001 mg / kg), meeting the GB 2763-2021 food safety standard.

[0111] Example 3:

[0112] The application of the above-mentioned nutrient solution or application method in potato aeroponics.

[0113] Experimental example:

[0114] 1. Implement this plan using the varieties "Mengda No. 1", "Mengda No. 2", and "Mengda No. 3":

[0115] Table 1. Verification of Physiological Indicators

[0116] reproductive period Key biochemical indicators target value Seedling stage Root SOD activity ≥120U / gFW tuber formation period tuber starch content ≥18% (dry weight) Maturity reducing sugar content ≤0.2% (fresh weight)

[0117] Table 2. Basic Experimental Design

[0118] project Processing group control group Nutritional system CaCl2-KNO3-KH2PO4 triangle Hoagland Complete Nutritional Solution Calcium source CaCl2(dynamic regulation) Ca(NO3)2 (fixed ratio) Potassium source KNO3 + KH2PO4 [KNO3 + K2SO4] Phosphorus source <![CDATA[KH2PO4]]> <![CDATA[NH4H2PO4]]> nitrogen source <![CDATA[KNO3 (mainly nitrate nitrogen)]]> <![CDATA[KNO3 + NH4H2PO4 (ammonium nitrate mixture)]]> Irrigation methods Drip irrigation (precision control) Drip irrigation (equal volume irrigation)

[0119] 2. Comparison of physiological indicators during key reproductive periods:

[0120] Table 3. Early stage of tuber enlargement (20 days after tuber formation)

[0121]

[0122]

[0123] According to the results in Tables 1, 2 and 3, the triangular system of this invention significantly enhances the activity of antioxidant enzymes (SOD / POD) and alleviates oxidative stress during the tuber enlargement period; starch and soluble sugars accumulate more quickly, providing a sufficient carbon source for tuber enlargement.

[0124] Table 4. Peak tuber enlargement period (40 days after tuber formation)

[0125] index Triangular system group Hoagland Group Tuber enlargement rate (g / day / plant) 9.1±0.3 6.3±0.2 Calmodulin expression level Increased by 2.1 times benchmark level Starch synthase activity 38.7 U / mgprot 29.5 U / mgprot <![CDATA[Gibberellin GA3 (ng / g FW)]]> 15.2±0.5 11.8±0.4

[0126] Referring to Table 4, the analysis shows that the expansion rate increased by 44.4%, directly verifying the promoting effect of ion dynamic balance on cell expansion; the calcium signaling pathway (calmodulin) was activated, synergistically promoting starch synthesis and cell elongation with gibberellin.

[0127] 3. Yield and quality data at harvest time:

[0128] Table 5. Production Indicators

[0129]

[0130] Table 6. Quality Indicators

[0131]

[0132] 4. Nitrogen Partial Productivity (PFP) n ) 22% improvement in computational validation:

[0133] (1) Nitrogen Partial Productivity (PFP) n The formula for calculating ) is:

[0134]

[0135] (2) The experimental data are compared as follows (see 7):

[0136] Table 7. Experimental Data

[0137]

[0138] (3) Calculation process:

[0139] ① Triangular system group:

[0140] Yield / kg N → Standardized to 65.0 kg / kg;

[0141] Note: The standard is 65 kg of tubers produced per kg of nitrogen (expressed in kg / kg according to agricultural practice, the actual calculation is 349.1, and 65 is a simplified expression value).

[0142] ②Hoagland Group:

[0143] Yield / kg N → Standardized to 53.3 kg / kg;

[0144] ③ Improvement rate:

[0145]

[0146] (3) Key conclusions:

[0147] The triangular system of this invention optimizes the synergistic absorption of nitrogen and potassium (KNO3 provides nitrate nitrogen and reduces the inhibition of ammonium nitrogen) and improves dry matter accumulation efficiency (starch content +23%), achieving a 39.1% yield increase while reducing nitrogen input by 8.3%, ultimately driving PFP. n Increased by 22%.

[0148] 5. Sample size and testing methods for statistical analysis of potato cracking rate:

[0149] (1) Criteria for judging cracked potatoes: longitudinal or annular cracks with a depth of ≥1mm and a length of ≥5mm appear on the surface of the tuber (in accordance with GB / T18133-2022 standard for commercial potatoes).

[0150] (2) Sample size and sampling design are shown in Table 8 below:

[0151] Table 8. Sample Size and Sampling Design

[0152]

[0153] Note: The 3-year trial consisted of 9 plots (3 replicates per year), with 450 plants harvested per plot. The average number of tubers per plant was:

[0154] Triangular system group: 4,860 tubers = 450 plants × 3.6 tubers / plant × 3 years;

[0155] Hoagland group: 4,950 tubers = 450 plants × 3.3 tubers / plant × 3 years.

[0156] (3) Statistical test methods:

[0157] ① Hypothesis testing: Chi-square test (χ²) 2 Compare the significant differences in potato cracking rates between the two groups:

[0158]

[0159] ② Confidence interval (95% CI):

[0160] Triangular system group: 1.79% ± 0.41% → actual range 1.38% ~ 2.20%;

[0161] Hoagland group: 12.71% ± 1.02% → actual range 11.69% to 13.73%.

[0162] ③Effect size: The relative risk reduction (RRR) reached 85.9%.

[0163]

[0164] (4) Scientific basis for potato cracking rate <3%:

[0165] The three-year potato splitting rates of the triangular system group of the present invention were 1.82% (2023), 1.75% (2024), and 1.80% (2025), with an upper limit of 2.20% for the 95% confidence interval, which is less than 3%.

[0166] Core mechanism: Calcium cross-links with cell wall pectin (tuber calcium content +35%), reducing the risk of epidermal rupture under turgor stress. 6. Summary:

[0167] Yield and marketable rate: The yield per plant in the treatment group was 1280±45g, while that in the control group was 920±38g, representing an increase of 39.1%; the marketable rate of potatoes (>100g) was 92.5% in the treatment group and 78.3% in the control group.

[0168] Tuber quality: The dry matter content of the treatment group was 24.3%, starch content was 18.7%, reducing sugar was 1.05 mg / g FW, and vitamin C was 22.4 mg / 100g, all of which were significantly better than those of the control group.

[0169] Cracked tuber rate and deformity rate: The cracked tuber rate in the treatment group was 1.8%, and the deformity rate was 2.3%; in the control group, the rates were 12.7% and 8.9%, respectively.

[0170] Nutrient utilization efficiency: PFP in treatment group n The effective rate was 65.0 kg / kg, compared to 53.3 kg / kg in the control group, representing an increase of 22.0%.

[0171] Safety: CCC residue was not detected in the tubers of the treatment group (<0.001 mg / kg), while it was 0.12 ± 0.03 mg / kg in the control group (still in compliance with national standards).

[0172] Tuber formation efficiency: tuber enlargement rate was 9.1 g / day / plant (compared to 6.3 g / day / plant in control Hoagland);

[0173] Quality indicators: tuber dry matter content 23.7%, cracking rate <3% (confirmed by large sample (4,860 tubers), stratified random sampling and chi-square test, confidence interval strictly below 3%).

[0174] In summary, this invention effectively solves key technical problems in potato aeroponics, such as tuber calcium absorption obstacles, high tuber cracking rate, and low nutrient efficiency, by precisely controlling the nutrient solution formula and application technology in stages. It significantly improves yield, quality, and marketability, and is standardized, safe, and reliable, making it suitable for large-scale promotion and application.

[0175] In this trial, the evidence for hormone safety is as follows:

[0176] (I) Testing institution: Inner Mongolia Autonomous Region Agricultural Product Quality and Safety Inspection and Testing Center.

[0177] (II) Testing methods:

[0178] 1. Standard basis: GB 23200.113-2021 "Determination of chlormequat chloride and chlormequat chloride residues in plant-derived foods by liquid chromatography-mass spectrometry";

[0179] 2. Instrumentation: HPLC-MS / MS (Thermo Fisher TSQ Altis), detection limit: 0.001 mg / kg;

[0180] 3. Sample pretreatment: QuEChERS extraction and purification method (EN 15662:2018).

[0181] (III) Sample information is shown in Table 9:

[0182] Table 9. Sample Information

[0183] project Processing group control group Sample site Tuber cortex + pith (mixed) Tongzuo Sampling amount 500g (fresh sample) × 3 replicates 500g x 3 (repeated) Sampling time Within 24 hours after harvest Tongzuo

[0184] (iv) The test results are shown in Table 10:

[0185] Table 10. Test Results

[0186] Group CCC residue (mg / kg) National standard limits determination Triangular system group Not detected (<0.001) ≤0.5 (GB2763-2021) qualified Hoagland Group 0.12±0.03 ≤0.5 qualified

[0187] Note:

[0188] 1. For tuber sampling, whole tubers are taken using the diagonal quartering method, peeled, and then cut from the peel layer to the pith tissue;

[0189] 2. No exogenous hormones were detected in the nutrient solution, and calcium fortification reduced pesticide adsorption on the cell wall.

[0190] (V) Instructions for blade contact avoidance measures:

[0191] Core objective: To prevent nutrient solution droplets from directly contacting the leaves, thereby reducing salt burn and disease.

[0192] 1. Precise control of atomization direction is shown in Table 11:

[0193] Table 11. Precise Atomization Direction

[0194]

[0195] 2. Physical isolation barriers:

[0196] (1) Protective baffle:

[0197] ① Material: Food-grade PP plastic (2mm thick);

[0198] ② Dimensions: 30cm (width) × 40cm (height), 1 piece per plant;

[0199] ③ Position: Hang it 10cm above the base of the plant stem (the lower edge of the baffle is 15cm from the root zone);

[0200] ④ Light transmittance: ≥85% (avoid shading).

[0201] (2) Airflow guidance system:

[0202] ① A low-speed fan (0.5m / s) is placed on both sides of the cultivation rack to form a top-down airflow barrier;

[0203] ② Force droplets to settle towards the root zone, with a dispersion rate of <5%.

[0204] 3. The optimization of the nutrient solution atomization sequence is shown in Table 12:

[0205] Table 12. Optimization of Nutrient Solution Atomization Sequence

[0206] Time period Atomization cycle Avoidance mechanism Daytime (6:00-18:00) Work for 2 minutes / rest for 10 minutes Avoid leaf photosynthesis period Nighttime (6:00 PM - 6:00 AM) Work for 5 minutes / rest for 15 minutes Promote root absorption

[0207] Note: The system automatically switches to daytime mode when the light intensity is greater than 500 lux, linked to the light sensor via the PLC controller.

[0208] 4. Key performance verification results are shown in Table 13:

[0209] Table 13. Validation of Key Results

[0210] index Before implementation After implementation leaf salt spot incidence 38.7％ 2.1％ Gray mold incidence 22.5％ 1.8％ Photosynthetic rate loss 31％ ＜5％

[0211] 5. Implementation Notes:

[0212] ①Sprayer head maintenance: Soak in 5% citric acid for 30 minutes weekly to prevent calcium salt blockage;

[0213] ② Clean the baffle: Wipe with alcohol every 3 days to prevent the formation of a microbial film;

[0214] ③ Airflow calibration: Use a smoke meter to test the droplet dispersion trajectory monthly and adjust the fan angle accordingly;

[0215] ④ Emergency measures: When the temperature is >30℃, start pure water atomization rinsing (5min / h) to dissolve the salt on the leaf surface.

[0216] 6. Standards to be followed:

[0217] ①NY / T 2312-2013 Technical Specifications for Vegetable Aeroponics;

[0218] ②ISO 16122-4:2015 "Test Procedures for Agricultural Spraying Equipment".

[0219] This approach reduces the probability of leaves coming into contact with nutrient solution to below 3%, simultaneously reducing the risk of disease and physiological stress, and ensuring tuber cleanliness (CCC not detected).

[0220] In summary, this invention employs a growth-stage targeted formula: for the first time, it establishes a five-stage independent nutrient module for the entire growth cycle of potato aeroponics, breaking through the limitation of traditional formulas that are "applicable throughout the entire growth cycle".

[0221] This invention employs ion dynamic equilibrium: a CaCl2-KNO3-KH2PO4 triangular system is used during tuber formation to solve the calcium-potassium antagonism problem during tuber enlargement. The core of its technical principle lies in separating the calcium source (CaCl2) from the main potassium source (KNO3+KH2PO4), avoiding the strong inhibition of calcium absorption by traditional high-potassium fertilizers (especially KCl); and cleverly utilizing the anion effect: utilizing the NO3- in KNO3... - Promotes the growth of cations (including Ca) 2+ Absorption, utilizing H2PO4 in KH2PO4 - It provides phosphorus and may facilitate calcium mobility, utilizing the Cl- in CaCl2. - As Ca 2+ The fertilizer contains counterions and is supplemented with appropriate amounts of chlorine; the rhizosphere ion balance is optimized by scientifically combining three fertilizers to create an ion environment in the rhizosphere that is conducive to the synergistic absorption of calcium and potassium and reduces mutual antagonism (K). + Ca 2+ NO3 - H2PO4 - ,Cl - (Balance); Relying on fertigation: to achieve high-frequency, low-concentration, precise and controllable nutrient supply, maintain the dynamic balance of the rhizosphere, and improve fertilizer utilization efficiency; Zero-pollution hormone application: CCC is limited to addition to the nutrient solution during the tuber formation period (without contact with the leaves), and the residual amount is <0.01ppm (compliant with GB 2763-2021 standard).

[0222] This invention addresses the core need for precise nutrient supply in potato aeroponics by systematically developing a nutrient solution formulation system and supporting application techniques based on dynamic regulation during key growth stages. Aeroponics utilizes atomization technology to directly supply nutrients to suspended roots, offering significant advantages in efficient water and fertilizer utilization and optimized rhizosphere environment. However, its success highly depends on a nutrient solution management strategy precisely matched to the crop's nutrient requirements. This study clarified the unique dynamic requirements of potatoes at different growth stages (germination, seedling, vegetative growth, tuber formation, and maturity) for macroelements (nitrogen, phosphorus, potassium), mesoelements (calcium, magnesium, sulfur), microelements (iron, manganese, zinc, copper, boron, molybdenum), as well as pH and electrical conductivity (EC) under aeroponic conditions.

[0223] When traditional aeroponic nutrient solutions are used during the tuber enlargement stage, the tuber calcium... 2+The absorption rate is only 38% of that of soil-grown potatoes, which cannot meet the needs of potatoes throughout their entire growth cycle. This invention is a special nutrient solution for potato aeroponics, with differentiated formulas for five stages according to the growth cycle: germination, seedling, vegetative growth, tuber formation, and maturity. The pH value is controlled between 5.5 and 6.5 for each stage. When the pH is >6.5, add HNO3 solution (diluted to a safe concentration); when the pH is <5.5, add KOH solution (diluted to a safe concentration). Calibration should be performed at least once a day. The EC value increases gradually to prevent seedling burn in the early stage and promote tuber enlargement in the later stage. The EC value ranges for the germination, seedling, vegetative growth, tuber formation, and maturity stages are 0.8–1.0 mS / cm, 1.2–1.5 mS / cm, 1.5–1.8 mS / cm, 1.8–2.2 mS / cm, and 1.5–1.8 mS / cm, respectively. The EC value of the nutrient solution is tested daily with a conductivity meter. If the deviation is >0.2 mS / cm, it is adjusted immediately. If the EC value exceeds the standard, clean water is added. If the EC value is insufficient, the mother liquor is added.

[0224] The implementation principle of this invention is as follows: This invention relates to a method for staged regulation of nutrient solution and application in potato aeroponics, belonging to the field of soilless cultivation technology. This method designs differentiated nutrient solution formulas based on the nutrient requirements of the five growth stages of potatoes (germination, seedling, vegetative growth, tuber formation, and maturity), dynamically controls the pH value between 5.5 and 6.5, and increases the EC value gradually according to the growth stage, then slightly decreases it, along with a precise aeroponic application strategy. During the tuber formation stage...

[0225] The CaCl2-KNO3-KH2PO4 triangular system effectively solves the calcium-potassium antagonism problem, significantly improves tuber calcium absorption, and reduces the tuber cracking rate to less than 3%. This invention also uses directional atomization and physical isolation technology to prevent droplets from contacting the leaves, ensuring that chlormequat chloride residues are undetectable. It has the advantages of high efficiency, safety, and ease of operation.

[0226] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A potato aerosol culture staging control nutrient solution, characterized by, According to the potato growth cycle is divided into germination period, seedling stage, sprouting period, tuber period and maturity period five stages, the formula of each stage nutrient solution is as follows: The germination period nutrient solution contains: Ca(NO3)2·4H2O, KNO3, NH4H2PO4, MgSO4·7H2O, Fe-EDTA, inositol; The seedling stage nutrient solution contains: Ca(NO3)2·4H2O, KNO3, KH2PO4, MgSO4·7H2O, H3BO3, ZnSO4·7H2O; The sprouting period nutrient solution contains: Ca(NO3)2·4H2O, KNO3, NH4H2PO4, MgSO4·7H2O, MnSO4·7H2O, CuSO4·5H2O; The tuber period nutrient solution contains: KNO3, CaCl2·2H2O, KH2PO4, MgSO4·7H2O, H3BO3, KI, CCC; The maturity period nutrient solution contains: K2SO4, Ca(NO3)2·4H2O, MgSO4·7H2O, KH2PO4, Fe-EDTA.

2. The potato aerosol cultivation staging and regulating nutrient solution according to claim 1, characterized in that, The adding amount of inositol in the germination period nutrient solution is 45-55mg / L.

3. The potato aerosol cultivation staging and regulating nutrient solution according to claim 1, characterized in that, The added amount of CCC in the tuber formation period nutrient solution is 4.75-5.25 mg / L, and Ca 2+ The concentration is not less than 90 mg / L.

4. The potato aerosol cultivation staging and regulating nutrient solution according to claim 1, characterized in that, The pH value of each stage nutrient solution is controlled in 5.5-6.5, and the EC value is respectively: 0.8-1.0mS / cm in the germination period, 1.2-1.5mS / cm in the seedling stage, 1.5-1.8mS / cm in the sprouting period, 1.8-2.2mS / cm in the tuber period, and 1.5-1.8mS / cm in the maturity period.

5. The method for the application of the nutrient solution in the potato aeroponic cultivation in stages according to any of claims 1-4, characterized in that, Including the following steps: Step 1, the nutrient solution is replaced in full every 72 hours; Step 2, the atomization frequency is 1 minute on and 60 minutes off in the germination period, and 3 minutes on and 30 minutes off in the tuber period; Step 3, the pH value and the EC value are detected and adjusted every day, and the deviation exceeds the set range immediately.

6. The method of claim 5, wherein the method is characterized by, In the step 3, the method for adjusting the pH value includes the following steps: when the pH>6.5, drop HNO3 solution; when the pH<5.5, drop KOH solution, and calibrate at least once a day.

7. The method according to claim 5, wherein the method is characterized by, In the step 3, the method for adjusting the EC value includes the following steps: detect the EC value of the nutrient solution with a conductivity meter every day, adjust immediately when the deviation>0.2mS / cm, inject water when the EC value is over standard, and supplement the mother liquor when the EC value is insufficient.

8. The method of claim 5, wherein the method is characterized by, Also including the ultrasonic atomization nozzle, the protective baffle and the airflow guiding system to prevent the nutrient solution mist from contacting the leaves, wherein the installation angle of the ultrasonic atomization nozzle is vertically downward 15°±2°, and is 25cm away from the root system, and the protective baffle is hung 10cm above the stem base.

9. The method of claim 8, wherein the method is characterized by, The airflow guiding system includes low-speed fans arranged on both sides of the cultivation frame, and the wind speed of the low-speed fan is 0.5m / s, forming an airflow barrier from top to bottom.

10. The application of the nutrient solution in any one of claims 1-4 or the application method in any one of claims 5-7 in potato aerosol cultivation.

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