A method for breeding australian lobster in rice field and an ecological breeding field

Abstract

The present invention discloses a method for cultivating Australian lobsters in paddy fields and an ecological cultivation field, which relates to the technical field of shrimp-rice symbiosis. The technical solutions cover differential field engineering. For non-mechanized fields, a cross-shaped ring ditch layout is adopted, and for mechanized fields, a ditchless flat-bottom layout is adopted; for sandy soil and swamp geology, a clay covering layer is laid and diversion ditches are blocked respectively; a three-stage filtered water inlet and outlet system and a fully enclosed anti-escape net are configured, and Elodea canadensis is planted in the ditches to form a biological filter bed. The aquaculture management adopts a staged feed feeding strategy. During the juvenile shrimp stage, 36% protein feed is fed, and during the adult shrimp stage, it is converted to 32% protein feed. Combined with an intelligent water quality monitoring system, the dissolved oxygen, pH, and temperature data are transmitted in real time, and the aeration linkage control module is used to achieve timed opening and closing and oxygen supplementation triggered by the dissolved oxygen threshold. The "two shrimps and one rice" rotation mode is implemented, and the integrated agricultural tourism integration facilities include a fishing area and an Internet of Things base station, constructing a new paradigm of high-yield, high-efficiency, and ecological integrated paddy field farming.

Description

Technical Field

[0001] The present invention belongs to the technical field of shrimp-rice symbiosis, and specifically relates to a method for culturing Australian lobsters in paddy fields and an ecological culture field. Background Technique

[0002] Shrimp-rice co-culture, as an ecological circular agriculture model, realizes the collaborative production of rice planting and aquaculture (that is, "one water is used for two purposes, and one field harvests double crops") by excavating annular aquaculture ditches in paddy fields and setting anti-escape facilities. This model has been successfully practiced in the cultivation of Australian freshwater lobsters (commonly known as red-clawed crayfish), and has both ecological benefits and economic value.

[0003] Traditional farming relies on natural water replacement and lacks active water quality control measures. The dissolved oxygen fluctuates greatly, often below 3 mg / L, and the ammonia nitrogen concentration is easily exceeded > 0.02 mg / L, resulting in an increase in the stress response of lobsters and a decrease in the feed conversion rate, usually < 1.8:1. Summary of the Invention

[0004] In order to overcome the problems existing in the background technique, the present invention provides a method for culturing Australian lobsters in paddy fields and an ecological culture field.

[0005] To achieve the above object, the present invention is realized through the following technical solutions: A method for culturing Australian lobsters in paddy fields, including the following steps: Field engineering construction:

[0006] (1) When the aquaculture field does not involve mechanized operations, adopt the "Feng" - shaped ring ditch layout mode:

[0007] Select a rectangular field with an area of 2 ± 0.5 mu and a field surface width ≤ 20 m to excavate a grid system composed of main ditches and secondary ditches. The cross-section of the main ditch is trapezoidal, with an upper width of 2.0 m, a lower width of 1.5 m, and a ditch depth of 0.4 m; the secondary ditches are set at an interval of 17 m, and the cross-section specifications are an upper width of 1.5 m and a lower width of 1.0 m;

[0008] The field ridge is reinforced and transformed into a trapezoidal cross-section with a slope ratio of 1:2, a ridge top width ≥ 0.6 m, and a ridge height of 0.8 - 1.0 m;

[0009] (2) When the aquaculture field requires mechanized operations, adopt the ditchless flat-bottom layout mode:

[0010] Select a standardized field with an area of 10 ± 2 mu and a field surface width ≤ 20 m. The field ridge structure is optimized into a reinforced dam with a slope ratio of 1:2, a ridge top width ≥ 0.6 m, and a ridge height of 1.2 - 1.5 m;

[0011] Inlet and outlet water system configuration:

[0012] The inlet pipe uses PVC pipe with a diameter of 110 mm, and a gate valve and a double-layer 100-mesh filter bag are configured at the pipe end,

[0013] The drainage pipe uses 160mm diameter PVC pipe, with an 8-mesh steel wire mesh seal at the outlet end and a triple filter bag attached externally.

[0014] Construction of an escape prevention system:

[0015] A 1.2m high polyethylene escape-prevention net was installed around the perimeter of the field ridges, with a burial depth of 0.2m to form an underground fixed structure.

[0016] Aquaculture Management:

[0017] The initial stocking density for the ring ditch method is 3000 Australian lobster larvae (3cm in size) per acre.

[0018] The initial stocking density for the ditch-free method is 5000 Australian lobster larvae with a length of 3cm per acre.

[0019] During the seedling stage, feed them a specialized formulated feed with a protein content of ≥36%, at a daily rate of 8% of their body weight.

[0020] During the adult shrimp stage, switch to a maintenance feed with a protein content of ≥32%, and reduce the daily feeding amount to 3-5% of the shrimp's body weight.

[0021] Preferably, the following treatment measures are adopted for sandy soil fields and swampy geological areas during the construction of the field engineering:

[0022] (1) For the sandy soil fields, a clay sealing layer with a thickness of ≥0.3m is laid on the field surface, and a composite geomembrane is laid on the foundation of the field ridges for seepage prevention;

[0023] (2) For the swamp geological area, a diversion ditch with a depth of 0.5m was excavated around the field, and the spring was sealed with C20 concrete.

[0024] Preferably, the following water quality control measures are taken during the aquaculture management:

[0025] (1) Perform basic disinfection 7 days before seedling release, and apply 100 kg / mu of quicklime;

[0026] (2) Introduce EM bacteria 3 days after disinfection, at a rate of 5L / mu;

[0027] (3) During the breeding period, maintain the water transparency at 30-50cm and change 1 / 3 of the water every 15 days.

[0028] Preferably, a crop rotation system is adopted when carrying out the aforementioned aquaculture management:

[0029] (1) Implement the "two shrimp and one rice" rotation model: raise low-temperature resistant red swamp crayfish from October to March of the following year; raise Australian freshwater crayfish from April to September of the year;

[0030] (2) During the rice planting season, the water depth on the field surface is increased to 0.8m to form a water layer for protection.

[0031] An ecological aquaculture field, characterized by comprising: a field structure:

[0032] (1) The basic breeding unit area is 2-10 mu, and the field width is ≤20m.

[0033] (2) The field ridge adopts a trapezoidal cross-section structure with a slope ratio of 1:2, a ridge height of 0.8-1.5m, and a ridge top width of ≥0.6m;

[0034] Ditch systems suitable for non-mechanized field operations:

[0035] (1) Trapezoidal cross-section specifications of the main ditch: upper opening width 2.0m, lower opening width 1.5m, ditch depth 0.4m.

[0036] (2) The secondary ditches are arranged in a grid pattern with a spacing of 17m. The cross-sectional specifications are: 1.5m wide at the top and 1.0m wide at the bottom.

[0037] Pipeline system:

[0038] (1) The inlet and outlet pipes are arranged diagonally to form a counter-current water flow system.

[0039] (2) The water inlet pipe is equipped with a double-layer 100-mesh stainless steel filter screen.

[0040] (3) The drainage pipe is equipped with a triple 8-mesh escape prevention device, including a steel wire mesh inside the pipe, a filter bag at the pipe opening, and an interception net outside the field;

[0041] Biological protection system:

[0042] (1) A fully enclosed polyethylene escape-proof net is installed around the perimeter of the field ridge, with a burial depth of 0.2m and a height of 1.0m above ground.

[0043] (2) Plant Elodea in the ditch and cover it with a coverage of ≥60% to form a biological filter bed.

[0044] Preferably, the ecological aquaculture field further includes:

[0045] (1) Sightseeing belt along the field ridge: The top of the ridge is widened to 1.5m and paved with permeable gravel.

[0046] (2) Interactive experience area: A fishing area covering 5% of the field area is reserved, and a centralized isolation area for crayfish is set up in the fishing area.

[0047] Preferably, the ecological aquaculture field also includes: an intelligent monitoring system: an Internet of Things base station with integrated water quality sensors is set up at the corner of the field to monitor dissolved oxygen, pH value, and temperature parameters in real time.

[0048] Preferably, the ecological aquaculture field further includes an aeration system, including:

[0049] (1) Aeration pipe network:

[0050] Adopt Φ25mm nano microporous aeration pipes, arranged in a "丰" shape along the bottom of the main ditch,

[0051] Set fixed buckles at a pipe spacing of 8m, and configure pressure regulating valves and check valves at the pipe ends,

[0052] The laying depth of the aeration pipe is 0.3m from the bottom of the ditch, forming a micro-bubble upward flow;

[0053] (2) Intelligent control module:

[0054] Configure a dissolved oxygen sensor linkage control system,

[0055] Set a timing opening and closing program, running in two periods of 5:00 - 8:00 and 15:00 - 18:00,

[0056] When the dissolved oxygen content < 3mg / L, automatically start the oxygen supplementation mode.

[0057] (3) System efficiency:

[0058] Maintain the dissolved oxygen content in the water body ≥ 5mg / L, form a bottom circulation to eliminate the water body stratification phenomenon.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] 1. The present invention sets an aeration system in the aquaculture field to maintain the dissolved oxygen content in the water body ≥ 5mg / L, promote the oxidation and decomposition of organic matter, increase the feed conversion rate to 2.1:1, the adult shrimp specifications are uniform, the aquaculture density is also increased, and the output value per mu is increased.

[0061] 2. The three-stage filtration system (100-mesh inlet pipe + 8-mesh drain pipe) blocks the invasion of foreign organisms, and the shrimp seedling escape rate is reduced from the traditional 15 - 20% to less than 5%.

[0062] 3. Geological strengthening measures, filling 0.3m of clay in sandy fields and diversion ditches in swamps, reduce the leakage rate, and the daily temperature fluctuation of the water is small, which is beneficial to the growth of lobsters.

[0063] 4. The coverage rate of Elodea ≥ 60% forms a biological filter bed, the ammonia nitrogen concentration is stable below 0.01mg / L, the transparency is maintained at 30 - 50cm, and the use of chemical agents is reduced.

[0064] 5. The rotation mode of two shrimps and one rice increases the rice planting density, and the soil organic matter content increases by 15% after the rice husks are returned to the field, forming a virtuous cycle of "aquaculture - planting - ecology". Specific implementation manners

[0065] To make the objectives, technical solutions, and beneficial effects of the present invention clearer, the preferred embodiments of the present invention will be described in detail below to facilitate understanding by those skilled in the art.

[0066] Example I

[0067] This embodiment provides a method for rice paddy farming of Australian crayfish, including the following steps: Field engineering construction: (1) When the farming field does not involve mechanized operations, a shaped ring ditch layout is adopted:

[0068] A grid system consisting of main and secondary ditches was excavated in rectangular fields with an area of ​​2 ± 0.5 mu and a field width of ≤ 20 m. The main ditch has a trapezoidal cross-section with an upper width of 2.0 m, a lower width of 1.5 m, and a depth of 0.4 m. The secondary ditches are spaced 17 m apart and have a cross-section with an upper width of 1.5 m and a lower width of 1.0 m.

[0069] The field ridges were reinforced and renovated into trapezoidal sections with a slope ratio of 1:2, a top width of ≥0.6m, and a height of 0.8-1.0m;

[0070] (2) When mechanized operations are required in aquaculture fields, a ditchless, flat-bottomed layout should be adopted:

[0071] Standardized fields with an area of ​​10±2 mu and a field width of ≤20m were selected. The field embankment structure was optimized into a reinforced embankment with a slope ratio of 1:2, a top width of ≥0.6m, and a height of 1.2-1.5m.

[0072] Water inlet and drainage system configuration:

[0073] The inlet pipe is made of 110mm diameter PVC pipe, and the pipe end is equipped with a gate valve and a double-layer 100-mesh filter bag.

[0074] The drainage pipe uses 160mm diameter PVC pipe, with an 8-mesh steel wire mesh seal at the outlet end and a triple filter bag attached externally.

[0075] Construction of an escape prevention system:

[0076] A 1.2m high polyethylene escape-proof net is buried around the perimeter of the field ridge at a depth of 0.2m to form an underground fixed structure. The polyethylene escape-proof net is supported by a series of support rods to maintain its vertical position. The top of the support rods has an inward bend, so that the upper part of the polyethylene escape-proof net has an inward bend. The support rods and the polyethylene escape-proof net are connected by board straps.

[0077] Aquaculture Management:

[0078] The initial stocking density for the ring ditch method is 3,000 Australian lobster larvae with a size of 3cm per acre;

[0079] The initial stocking density for the ditchless method is 5,000 Australian lobster larvae with a size of 3cm per acre;

[0080] During the juvenile stage (weight less than 15 grams), feed them a special compound feed with a protein content of ≥36%, with a daily feeding amount of 8% of the shrimp's body weight, fed twice a day, in the morning and evening.

[0081] During the adult shrimp stage (weight greater than or equal to 15 grams), switch to maintenance feed with a protein content of ≥32%, reduce the daily feeding amount to 3-5% of the shrimp's body weight, and feed once in the evening.

[0082] Feeding amount is controlled by sampling and weighing method:

[0083] Every 15 days, 30-50 adult shrimp are randomly caught, weighed, and their average weight (W) is calculated.

[0084] Calculate the theoretical feeding amount by determining the current stocking density (N, fish / acre) and using the formula:

[0085] Daily feed amount (kg) = N × W × (3% − 5%) ÷ 1000

[0086] Example: If N=5000 fish / mu, W=20g, and a feeding rate of 4%, then the daily feeding amount = 5000×20×4%÷1000=4kg / mu.

[0087] When constructing the aforementioned field engineering projects, the following treatment measures were adopted for sandy soil fields and swampy geological areas respectively:

[0088] (1) For the sandy soil field, a clay sealing layer with a thickness of ≥0.3m is laid on the field surface, and a composite geomembrane is laid on the foundation of the field ridge for seepage prevention, and the joints are hot-melt welded; (2) For the swamp geological area, a diversion ditch around the field with a depth of 0.5m is excavated, and after the spring appears, it is sealed with C20 concrete to the impermeable layer.

[0089] The following water quality control measures were taken during the aquaculture management: (1) Basic disinfection was carried out 7 days before stocking, and quicklime was applied at a rate of 100 kg / mu to disinfect the field surface and ditches; (2) EM bacteria were introduced 3 days after disinfection at a rate of 5 L / mu, and then evenly sprinkled after activation; (3) 1 / 3 of the water was changed every 15 days to maintain a transparency of 30-50 cm, and the concentration of ammonia nitrogen and nitrite was tested monthly to ensure that ammonia nitrogen < 0.01 mg / L.

[0090] The detection method is as follows:

[0091] (1) Ammonia nitrogen detection kit (salicylic acid method), detection limit: 0.01 mg / L, the steps are as follows:

[0092] ① Take 50 mL of water sample, add reagent A (salicylic acid) and reagent B (sodium hypochlorite), and shake well;

[0093] ② Let it stand for 10 minutes and observe the color change;

[0094] ③ Compare with the standard color chart to read the ammonia nitrogen concentration.

[0095] (2) Nitrite detection kit: detection limit: 0.005 mg / L (as N), the operation steps are as follows

[0096] ① Take 1 mL of water sample, add reagent, and shake well;

[0097] ② Wait 1 minute, compare with the color chart, and read the nitrite concentration;

[0098] If ammonia nitrogen exceeds the standard (≥0.01mg / L): immediately start the aeration system to increase dissolved oxygen in the water, reduce the amount of feed by 20%, and add EM bacteria (5L / acre) to decompose organic matter. Change 1 / 3 of the water the next day and add fresh water.

[0099] If nitrite levels exceed the standard: check if the feed is overfed, adjust the daily feed amount to 3% of body weight, add nitrifying bacteria (2kg / acre) to accelerate nitrite conversion, increase water flow, and avoid stagnant water areas.

[0100] A crop rotation system is adopted when carrying out the aforementioned aquaculture management:

[0101] (1) Implement the "two shrimp and one rice" rotation model:

[0102] From October to March of the following year, cold-resistant red swamp crayfish are farmed, and from April to September of the same year, Australian freshwater crayfish are farmed.

[0103] October to March of the following year: Drain the water to a depth of 0.5m and release red swamp crayfish larvae at a density of 8,000 larvae per mu.

[0104] April-September: Fill the field with water to a depth of 0.8m to form a water layer for protection, release Australian freshwater crayfish larvae, and simultaneously transplant rice seedlings (variety: hybrid rice, row spacing 30cm). The density of Australian freshwater crayfish larvae is 3000 per mu in the ring-ditch method and 5000 per mu in the non-ditch method.

[0105] Example II

[0106] An ecological aquaculture field, characterized by comprising: a field structure:

[0107] (1) The basic breeding unit area is 2-10 mu, the field width is ≤20m, (2) the field ridge adopts a trapezoidal cross section structure, the slope ratio is 1:2, the ridge height is 0.8-1.5m, and the ridge top width is ≥0.6m;

[0108] Ditch system applicable to non-mechanized field operations: (1) Main ditch trapezoidal cross-section specifications: upper opening width 2.0m, lower opening width 1.5m, ditch depth 0.4m; (2) Secondary ditches are arranged in a grid pattern with a spacing of 17m, and cross-section specifications: upper opening width 1.5m, lower opening width 1.0m;

[0109] Pipeline system: (1) The inlet pipe and the outlet pipe are arranged diagonally to form a reverse water flow system; (2) The inlet pipe is equipped with a double-layer 100-mesh stainless steel filter screen; (3) The outlet pipe is equipped with a triple 8-mesh anti-escape device, including steel wire mesh inside the pipe, filter bag at the pipe opening and field interception net.

[0110] Biological protection system: (1) A fully enclosed polyethylene anti-escape net is set up around the field ridge, buried at a depth of 0.2m and above ground height of 1.0m; (2) Elodea is planted in the ditch, with a coverage rate of ≥60% to form a biological filter bed;

[0111] The ecological aquaculture field also includes:

[0112] (1) Sightseeing belt along the field ridge: The top of the ridge is widened to 1.5m and paved with permeable gravel.

[0113] (2) Interactive experience area: A fishing area covering 5% of the field area is reserved, and a centralized isolation area for crayfish is set up in the fishing area.

[0114] The ecological aquaculture field also includes:

[0115] Intelligent monitoring system: IoT base stations integrating water quality sensors are installed in the fields to monitor dissolved oxygen, pH value, and temperature parameters in real time. The specific configuration is as follows:

[0116] 1. System Composition and Configuration

[0117] 1.1 IoT Base Station Architecture

[0118] Hardware configuration:

[0119] Controller: Uses STM32F407ZGT6 microcontroller, with integrated 4G communication module (supports China Mobile / China Unicom networks);

[0120] Power module: Solar panel (20W) + lithium battery (12V / 20Ah), continuous rainy days or more;

[0121] Protective casing: IP67 waterproof rating, installed on the inside of the field ridge, 5m from the corner of the field.

[0122] 1.2 Sensor Cluster

[0123] Dissolved oxygen sensor: Model, Optode DO-400 (fluorescence principle, accuracy ±0.1mg / L);

[0124] Installation location: 3m from the bottom of the main ditch to the edge of the field, and 0.2m from the bottom of the ditch.

[0125] pH sensor: Model, Hamilton Polilyte pH (triple composite electrode, accuracy ±0.02).

[0126] Installation location: Placed side by side with the dissolved oxygen sensor, with a spacing of 0.5m.

[0127] Temperature sensor, model: DS18B20 digital thermometer (accuracy ±0.1℃).

[0128] Installation location: Middle layer of water in the field (0.3m from the water surface).

[0129] 2. Installation and Debugging Steps

[0130] 2.1 Base Station Deployment

[0131] Step 1: Select an installation point in the corner of the field (avoiding the inlet and outlet pipes), excavate a 0.3m deep foundation pit, and lay a crushed stone cushion layer;

[0132] Step 2: Fix the IoT base station to the pre-embedded concrete base (40cm×30cm×20cm), and adjust the antenna angle to 45° with the ground;

[0133] Step 3: Connect the sensor cable to the base station interface using a waterproof connector (IP68 rating). Lay the cable along the inside of the field ridge at a depth of 0.2m.

[0134] 2.2 Sensor Calibration

[0135] Dissolved oxygen sensor:

[0136] After being exposed to air for 1 hour, the solution was zeroed by placing it in a saturated sodium sulfite solution.

[0137] Calibrate the full scale by placing it in 30℃ saturated oxygen water (8.4 mg / L).

[0138] pH sensor: calibrated at two points using standard buffer solutions at pH=4.01 and pH=7.00.

[0139] Temperature sensor: Calibrate by placing it in an ice-water mixture (0°C) and boiling water (100°C).

[0140] 3. Data Acquisition and Transmission

[0141] 3.1 Data Acquisition Frequency

[0142] Normal mode: Data is collected every 15 minutes and uploaded to the cloud platform;

[0143] Warning mode: When dissolved oxygen <3mg / L or pH >9.0, high-frequency sampling is triggered immediately (once every 1 minute).

[0144] 3.2 Data Transmission Protocol

[0145] The data is transmitted to the Alibaba Cloud IoT platform using the MQTT protocol.

[0146] 4. User Interaction and Early Warning

[0147] 4.1 Mobile Applications

[0148] Develop a WeChat mini-program to display water quality parameter curves in real time, supporting the following functions:

[0149] Historical data query (by day / week / month);

[0150] Threshold settings (default: DO≥3mg / L, pH 6.5-8.5, temperature 15-32℃);

[0151] Anomaly alert push notifications (SMS + APP notifications).

[0152] 4.2 Automatic Control Linkage

[0153] When DO < 3 mg / L is detected, the base station activates the following devices via 4G signal:

[0154] Aeration system: Turn on the nanoporous aeration tube (power 1.2kW).

[0155] Inlet valve: Open to replenish fresh water (flow rate 2m³ / h);

[0156] Feeder: Stop feeding (for 30 minutes).

[0157] 5. Implementation effect verification

[0158] 5.1 Accuracy Verification

[0159] The results were compared with those of a benchtop laboratory instrument over seven consecutive days:

[0160]

[0161] 5.2 Early Warning Response Test

[0162] When the simulated DO level drops sharply to 2.5 mg / L, the system completes the following actions within 45 seconds:

[0163] Aeration system activated (confirmation time: 30 seconds);

[0164] Water inlet valve opens (confirmation time: 25 seconds);

[0165] Feeder paused (confirmation time: 15 seconds);

[0166] Alarm information is pushed to the administrator's mobile phone (confirmation time: 10 seconds).

[0167] The ecological aquaculture field also includes an aeration system, comprising:

[0168] (1) Aeration pipe network:

[0169] Adopt Φ25mm nano-micro pore aeration pipes, which are arranged in a "丰" character shape along the bottom of the main ditch.

[0170] Set fixed buckles at an interval of 8m for the pipe materials, and configure a pressure regulating valve and a check valve at the pipe end.

[0171] The laying depth of the aeration pipe is 0.3m from the bottom of the ditch, forming a micro-bubble rising flow.

[0172] The aeration pipe network uses a 750W Roots blower to provide air source.

[0173] (2) Intelligent control module:

[0174] 1. System composition and hardware configuration

[0175] 1.1 Core controller

[0176] Model: Siemens S7-200 SMART PLC, with 2 analog input channels and 4 digital output channels;

[0177] Function: Receive signals from the dissolved oxygen sensor, execute the timing program and the dissolved oxygen linkage logic, and output control signals to the actuator;

[0178] Installation location: Inside the protective housing, 1.5m above the ground.

[0179] 1.2 Sensors and actuators

[0180] Dissolved oxygen sensor: Share the Optode DO-400 type fluorescence method sensor with the intelligent monitoring system, and output a 4-20mA current signal to the PLC;

[0181] Timing module: Built-in RTC (Real Time Clock) module of the PLC, supporting automatic adjustment of daylight saving time.

[0182] Actuator:

[0183] Aerator: 750W Roots blower, air volume 1.2m³ / min, working pressure 3kPa;

[0184] Oxygen supplementation solenoid valve: 220V AC stainless steel solenoid valve, connected to the intake end of the aeration pipe network;

[0185] Alarm: Acoustic and optical alarm device, 105dB, red LED flashing.

[0186] 2. Software algorithm and control logic

[0187] 2.1 Timing opening and closing program

[0188] Time period setting: Start the aeration system from 5:00 to 8:00 and from 15:00 to 18:00 every day, covering the peak activity period of lobsters;

[0189] Configure a dissolved oxygen sensor linkage control system, set a timed start-stop program, and operate in two time periods: 5:00-8:00 and 15:00-18:00. When the dissolved oxygen level is <3mg / L, the oxygen supplementation mode will be automatically started.

[0190] (3) System performance:

[0191] Maintain dissolved oxygen levels in the water at ≥5 mg / L.

[0192] The bottom circulation is formed to eliminate water stratification.

[0193] 2.2 Dissolved oxygen linkage control

[0194] Threshold setting: Oxygen supplementation is started when dissolved oxygen is <3mg / L and stopped when dissolved oxygen is >5mg / L.

[0195] Priority logic:

[0196] If dissolved oxygen is <3mg / L during the timed period, continue aeration until dissolved oxygen is ≥5mg / L;

[0197] If the dissolved oxygen level is <3 mg / L during non-timed periods, start supplemental oxygen for 30 minutes and then retest.

[0198] Fault tolerance: If the sensor fails and the signal remains at 0 mg / L for more than 5 minutes, aeration will be started by default for 1 hour / cycle.

[0199] 3. Linkage Strategy and Data Interaction

[0200] 3.1 Data Flow with Intelligent Monitoring System

[0201] Data transmission: The IoT base station pushes DO, pH, and temperature data to the PLC via the 4G network. Protocol: Modbus TCP.

[0202] Decision-making process:

[0203] PLC receives real-time DO values;

[0204] Determine whether it is within a timed period or a dissolved oxygen threshold trigger condition;

[0205] Output control signals to aerators, solenoid valves, and other equipment;

[0206] Record operation logs (time, action, dissolved oxygen level) to the local SD card.

[0207] 3.2 Exception Handling Mechanism

[0208] Sensor failure: If the DO value remains abnormal (e.g., >20mg / L or <0mg / L) for more than 10 minutes, start the backup sensor (if available) or execute the default timer program;

[0209] Equipment failure: When the aerator fails, an audible and visual alarm will be triggered and a text message will be sent to the administrator. At the same time, a backup aerator (if available) will be started.

[0210] 4. Installation and Debugging Steps

[0211] 4.1 Equipment Installation

[0212] Controller installation: Fix the PLC in a waterproof box and connect the dissolved oxygen sensor signal line (4-20mA) and the solenoid valve control line (220V AC).

[0213] Deployment of implementing agencies:

[0214] The aerator is installed on the outside of the field ridge, 10m from the corner of the field, and is connected to the aeration pipe of the main ditch through a Φ25mm galvanized pipe;

[0215] The solenoid valve is installed on the main water inlet pipe and is equipped with a manual bypass valve for switching during maintenance.

[0216] 4.2 System Debugging

[0217] Sensor calibration: Verify sensor accuracy using a standard dissolved oxygen solution (8.4 mg / L) and adjust the PLC range conversion coefficient.

[0218] Logical verification:

[0219] Manually set the PLC time to a timed period and check if the aerator starts.

[0220] Simulate a dissolved oxygen level <3 mg / L signal to verify whether the oxygen supplementation mode is triggered;

[0221] Disconnect the sensor signal line and check if the system has entered fault-tolerant mode.

[0222] 5. Implementation effect verification

[0223] 5.1 Accuracy of the timing program

[0224] After 7 consecutive days of monitoring, the aerator start-up rate was 100% during scheduled periods and 0% during non-scheduled periods.

[0225] 5.2 Dissolved oxygen linkage response

[0226] Time required for dissolved oxygen to recover from 2.5 mg / L to 5 mg / L:

[0227] Within the timed period: 18 minutes (aeration continues until the target value);

[0228] Non-timed period: 25 minutes (retesting will be conducted 30 minutes after startup to ensure compliance).

[0229] 5.3 Energy Consumption and Stability

[0230] Average daily operating time of the aerator: 3 hours during the timed period + 1.2 hours in the oxygen supplementation mode = 4.2 hours;

[0231] System failure rate: sensor failures 0.15 times / month, equipment failures 0.08 times / month, both resolved through fault tolerance mechanisms.

[0232] 6. User interaction and maintenance

[0233] 6.1 Local Control Panel

[0234] Configure the touchscreen to support the following operations:

[0235] Real-time monitoring of dissolved oxygen and operating status;

[0236] Manually start and stop the aerator;

[0237] Set the time period and dissolved oxygen threshold.

[0238] 6.2 Remote Management Platform

[0239] Develop a web-based monitoring system that supports:

[0240] Historical data curve analysis (dissolved oxygen, equipment uptime);

[0241] Anomaly alert push (WeChat / SMS);

[0242] Remote firmware upgrade (via 4G network).

[0243] Example 3

[0244] This embodiment provides a whole-field farming method for rice-crayfish culture, the steps of which are as follows:

[0245] (1) Construction of field engineering

[0246] Select a leveled paddy field with an area of ​​2 ± 0.5 mu, reinforce and transform the field embankment into a trapezoidal cross-section with a slope ratio of 1:2, with a top width of ≥ 0.6m and a height of 0.8-1.0m; implement the seepage prevention scheme as shown in Example I according to the different types of sandy soil fields and swampy geological areas;

[0247] (2) Water inlet and drainage system configuration: The water inlet pipe is made of 110mm diameter PVC pipe, and the pipe end is equipped with a gate valve and a double-layer 100-mesh filter bag.

[0248] The drainage pipe uses 160mm diameter PVC pipe, with an 8-mesh steel wire mesh seal at the outlet end and a triple filter bag attached externally.

[0249] (3) Construction of escape prevention system: A polyethylene escape prevention net with a height of 1.2m is buried around the perimeter of the field ridge, with a burial depth of 0.2m to form an underground fixed structure;

[0250] (4) Aquaculture management: 2,000 Australian lobster seedlings with a size of 3cm are released per mu. During the seedling stage (weight less than 15g), special compound feed with a protein content of ≥36% is fed. The daily feeding amount is 8% of the shrimp's body weight, fed once in the morning and once in the evening. During the adult shrimp stage (weight greater than or equal to 15g), the feed is switched to maintenance feed with a protein content of ≥32%, and the daily feeding amount is reduced to 3-5% of the shrimp's body weight, fed once in the evening.

[0251] (5) Water quality control during aquaculture management:

[0252] 1) Conduct basic disinfection 7 days before seedling release by applying 100 kg / mu of quicklime to disinfect the field surface and ditches;

[0253] 2) Introduce EM bacteria on the 3rd day after disinfection, at a rate of 5L / acre, and evenly sprinkle after activation;

[0254] 3) Change 1 / 3 of the water every 15 days, maintain a transparency of 30-50cm, and test the concentration of ammonia nitrogen and nitrite monthly to ensure that ammonia nitrogen is <0.01mg / L.

[0255] (6) Implement the "two shrimp and one rice" rotation model:

[0256] Implement a "two shrimp, one rice" crop rotation model:

[0257] Cold-resistant Procambarus clarkii are farmed from October to March of the following year.

[0258] Australian freshwater crayfish are farmed from April to September each year;

[0259] October to March of the following year: Drain the water to a depth of 0.5m and release red swamp crayfish larvae at a density of 5000 larvae per mu;

[0260] April-September: Fill the field with water to a depth of 0.8m to form a water layer for protection, release Australian freshwater crayfish seedlings, and simultaneously transplant rice seedlings (variety: hybrid rice, row spacing 30cm).

[0261] (7) Disease control: weekly microscopic examination of water bodies, use Bdellovibrio preparations when Vibrio levels are found to be excessive, and add 0.2% vitamin C+E to feed monthly to enhance stress resistance.

[0262] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for rice-field farming of Australian lobsters, characterized in that... It includes the following steps: Field engineering construction: (1) When the aquaculture field does not involve mechanized operations, the "Feng" - shaped ring - ditch layout mode is adopted: Select a rectangular field with an area of 2 ± 0.5 mu and a field surface width ≤ 20 m to excavate a grid system composed of main ditches and secondary ditches. The cross - section of the main ditch is trapezoidal, with an upper width of 2.0 m, a lower width of 1.5 m, and a ditch depth of 0.4 m; the secondary ditches are set at an interval of 17 m, and the cross - section specifications are an upper width of 1.5 m and a lower width of 1.0 m. The field ridge is reinforced and transformed into a trapezoidal cross - section with a slope ratio of 1:2, a ridge top width ≥ 0.6 m, and a ridge height of 0.8 - 1.0 m. (2) When the aquaculture field requires mechanized operations, the ditch - free flat - bottom layout mode is adopted: Select a standardized field with an area of 10 ± 2 mu and a field surface width ≤ 20 m. The field ridge structure is optimized into a reinforced dam with a slope ratio of 1:2, a ridge top width ≥ 0.6 m, and a ridge height of 1.2 - 1.5 m. Inlet and drainage system configuration: The inlet pipe uses PVC pipe with a diameter of 110 mm, and the pipe end is equipped with a gate valve and a double - layer 100 - mesh filter bag. The drain pipe uses PVC pipe with a diameter of 160 mm, and the outlet end is set with an 8 - mesh wire mesh seal and externally connected with a triple - layer filter bag. Anti - escape system construction: Bury a polyethylene anti - escape net with a height of 1.2 m around the field ridge, and the buried depth is 0.2 m to form an underground fixed structure. Aquaculture management: In the ring - ditch mode, 3000 Australian lobster fry with an initial specification of 3 cm are stocked per mu. In the ditch - free mode, 5000 Australian lobster fry with an initial specification of 3 cm are stocked per mu. In the seedling stage, a special compound feed with a protein content ≥ 36% is fed, and the daily feeding amount is 8% of the shrimp body weight. In the adult shrimp stage, it is converted to a maintenance feed with a protein content ≥ 32%, and the daily feeding amount is reduced to 3 - 5% of the shrimp body weight. When carrying out the above - mentioned field engineering construction, the following treatment measures are respectively adopted for sandy soil field blocks and swamp geological areas: (1) For the sandy soil field block, lay a clay sealing layer with a thickness ≥ 0.3 m on the field surface, and lay a composite geomembrane for anti - seepage at the field ridge foundation. (2) For the swamp geological area, excavate a ring - field diversion ditch with a depth of 0.5 m, and seal the spring eyes with C20 concrete.

2. The method for rice-field farming of Australian lobsters according to claim 1, characterized in that, When carrying out the above - mentioned aquaculture management, the following water quality control measures are taken, including: (1) Conduct basic disinfection 7 days before releasing the fry, applying 100 kg of quicklime per mu. (2) Introduce EM bacteria 3 days after disinfection, with a dosage of 5 L per mu. (3) During the aquaculture period, keep the water transparency at 30 - 50 cm, and conduct a water change operation of 1 / 3 of the water volume every 15 days.

3. The method for rice-field farming of Australian lobsters according to claim 2, characterized in that, When carrying out the above - mentioned aquaculture management, a rotation aquaculture system is adopted: (1) Implement the "two - shrimp and one - rice" rotation mode: Culture Procambarus clarkii that is cold - tolerant from October of each year to March of the next year, and culture Australian freshwater lobsters from April to September of each year. (2) During the rice planting period, raise the water depth on the field surface to 0.8 m to form a water layer for protection.

4. An ecological aquaculture field for implementing the method of claim 3, characterized in that, It includes: Field body structure: (1) The area of the basic aquaculture unit is 2 - 10 mu, and the field surface width ≤ 20 m. (2) The field ridge adopts a trapezoidal cross - section structure, with a slope ratio of 1:2, a ridge height of 0.8 - 1.5 m, and a ridge top width ≥ 0.6 m. Ditch system applicable to non - mechanized operation field blocks: (1)The trapezoidal cross-section specifications of the main ditch are: the upper opening width is 2.0 m, the lower opening width is 1.5 m, and the ditch depth is 0.4 m. (2)The secondary ditches are arranged in a grid pattern with a spacing of 17 m. The cross-section specifications are: the upper opening width is 1.5 m, and the lower opening width is 1.0 m. Pipe network system: (1)The inlet pipe and the drain pipe are arranged diagonally to form a reverse water flow system. (2)The inlet pipe is equipped with a double-layer 100-mesh stainless steel filter screen. (3)The drain pipe is provided with a triple 8-mesh anti-escape device, including a wire mesh inside the pipe, a filter bag at the pipe mouth, and an interception net outside the field. Biological protection system: (1)A fully enclosed polyethylene anti-escape net is set outside the ridge of the field, with a buried depth of 0.2 m and a ground height of 1.0 m. (2)Elodea canadensis is planted in the ditch, with a coverage rate ≥ 60% to form a biological filter bed.

5. An ecological aquaculture field according to claim 4, characterized in that, The ecological aquaculture field further includes: (1)The ridge sightseeing belt: The ridge top is widened to 1.5 m and a permeable gravel pavement is laid. (2)The interactive experience area: A fishing area accounting for 5% of the field area is reserved, and a lobster centralized isolation area is set in the fishing area.

6. An ecological aquaculture field according to claim 4, characterized in that, The ecological aquaculture field further includes: Intelligent monitoring system: An Internet of Things base station integrated with a water quality sensor is set at the corner of the field to monitor the dissolved oxygen, pH value, and temperature parameters in real time.

7. An ecological aquaculture field according to claim 6, characterized in that, The ecological aquaculture field further includes an aeration system. It includes: (1)Aeration pipe network: Φ25 mm nano-micro pore aeration pipes are adopted, which are arranged in a "rich" shape along the bottom of the main ditch. Fixed buckles are set at a pipe spacing of 8 m, and a pressure regulating valve and a check valve are configured at the pipe end. The laying depth of the aeration pipe is 0.3 m from the bottom of the ditch to form a micro-bubble upward flow. (2)Intelligent control module: A dissolved oxygen sensor linkage control system is configured. A timing opening and closing program is set, and it operates in two periods: 5:00 - 8:00 and 15:00 - 18:

00. When the dissolved oxygen content < 3 mg / L, the oxygen supplementation mode is automatically started. (3)System efficiency: Maintain the dissolved oxygen content in the water body ≥ 5 mg / L. Form a bottom circulation to eliminate the water body stratification phenomenon.

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