Tidal flat laver cultivation uses the ebb interval period leaf surface fertilizer and disease removes algae medicine to spray and recovers integrated device

Abstract

This invention discloses an integrated device for spraying and recycling foliar fertilizer and algaecide during the ebb tide interval for laver cultivation in tidal flats. It is designed to address the problems of poor algal growth, decay, and green algae invasion caused by uneven nutrient distribution in marine areas. The device includes: a traction-moving tray system: the tray has casters at the bottom, is 30 cm high, and adapts to hard muddy tidal flats; mechanical traction is provided, with traction holes on both sides and hooked hand levers for manual steering and assisted traction. A fertilizer and pesticide spraying system: the storage tank is connected to a front-end double-row atomizing nozzle assembly via a water pump, spraying from bottom to top onto the raft frame rope net to improve the double-sided pesticide absorption rate of the algae. A residual liquid recycling system: includes a three-stage filtration process: initial filtration with a flocculent filter pad, sedimentation in a cone-bottomed settling tank for sand removal, and a floating filter, recycling the residual liquid to the storage tank. This device effectively implements the spraying and recycling of foliar fertilizer and algaecide, improving control efficiency and reducing environmental risks, achieving both green algae control and increased laver production and income.

Description

Technical Field

[0001] This invention belongs to the field of aquaculture equipment technology, specifically relating to a foliar fertilizer and disease-controlling algae spraying and recovery device for laver cultivation in tidal flats. The device features an adjustable directional design with universal wheels, adapting to the hard muddy terrain of tidal flats and the slightly curved arrangement of raft support poles due to wind influence; bottom-up spraying ensures that the algae are treated on both sides, increasing utilization by over 40%; three-stage filtration (filter pad → sedimentation tank → filter silk) achieves a residual liquid recovery rate of >85%; a mechanical traction mode supplemented by manual traction achieves an operating efficiency of 10 mu / h, five times higher than manual labor. Background Technology

[0002] Existing methods for applying foliar fertilizers and pesticides to intertidal laver cultivation have several drawbacks: First, the short low tide period (usually ≤4 hours) results in low efficiency for manual application; second, uneven nutrient solution penetration leads to one-sided application of the pesticide to the algae, resulting in a utilization rate of less than 40%, and residual liquid polluting the tidal flat ecosystem; third, existing tidal flat machinery is too large to pass under rafts. In the cultivation of *Porphyra yezoensis* and *Porphyra tenera* on radiating sandbars and connected tidal flats, ocean currents and the surrounding sea area cause uneven nutrient distribution, leading to slow laver growth, poor thallus development, easy rotting and shedding, and green algae infestation of nets. Due to the high fluidity of intertidal seawater, pesticides and fertilizers quickly diffuse and run off after being sprayed into the water, making targeted application impossible; manual application after drying is inefficient and excess pesticides and fertilizers have a significant environmental impact. There is an urgent need for a specialized device that can accurately spray pesticides and fertilizers and recover them during the low tide drying period. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, an integrated device for spraying and recycling foliar fertilizer and disease-controlling algae-removing agents during the ebb tide interval for laver cultivation in tidal flats was invented.

[0004] The purpose of this invention is to provide a specialized device for tidal flats that can efficiently spray liquid fertilizer or pesticides during the ebb tide interval and recover the residual liquid. This is achieved through the following technical solution: an integrated device for spraying and recovering foliar fertilizer and disease-controlling algae-removing agents during the ebb tide interval for laver cultivation in tidal flats, as shown in the figure. This system includes:

[0005] The system for moving the pallet is as follows: The bottom of the pallet (101) is equipped with 4 rows of stainless steel casters (102) with 4 to 6 rows of casters (102) each, and the height is 30 cm. The slope of the pallet (101) is 2%. The pallet is provided with traction holes (103) on both sides, and the diameter of the traction holes on both sides of the pallet is 3 to 5 cm. The pallet is moved forward by mechanical traction mode at the front end of a row of rafts, supplemented by manual traction. The hand lever with straight hook (1.2 m in length) hooks the hole (103) to control the direction of travel and assist traction. This device is suitable for the hard muddy environment of the tidal flats.

[0006] The fertilizer and pesticide liquid storage and spraying system (2) is as follows: The liquid storage tank (201) located at the rear of the tray is connected to the pressurized water pump (203) and connected to the atomizing nozzle group (204) at the front of the tray through the water pipe (double row staggered layout, spray angle 60°~75°, atomized particle size ≤150μm). The nozzle height is 30~50 cm from the rope net and the atomization coverage width is 2.5~2.8 m. The capacity range of the liquid storage tank is 100L~300L. The battery (202) is connected to the power switch (205), which is connected to the pressurized water pump (203) and then connected to the battery (202) to form the power supply circuit of the spraying system.

[0007] Excess liquid fertilizer collection and sand removal system (3): The tray surface is covered with a flocculent filter pad (301), which is then connected to a cone-bottom sedimentation tank (302) for sedimentation; the filter pad is cleaned every 30 minutes of operation; a floating filter (303) is installed in the tank, and the suction port of the filter is covered with 80~120 mesh filter silk (304), and the suction port is connected to the residual liquid recovery pump (305) and leads to the storage tank (201). After the spraying is started, the residual liquid recovery pump (305) automatically starts when the residual liquid in the sedimentation tank is ≥20 cm; and the suction port is always 3~5 cm below the liquid surface along with the floating filter (303). The floating filter (303) contains a closed-cell foamed polyethylene float ball, the volume of a single float ball is ≥300 cm³, the density is 0.25 g / cm³, and the net buoyancy is ≥2 N. A cone-shaped sand discharge port (306) is added to the sedimentation tank (302). A manual sand discharge hose (307) is connected to the outside of the cone-shaped sand discharge port. During the sand discharge, the residual liquid recovery pump (305) is forcibly shut down by the power switch (205). The sand discharge port is opened every 2 hours of operation to discharge sand until clear water flows out, and the residual liquid recovery pump is stopped at the same time.

[0008] The construction of this device enables the effective application and integrated recycling of foliar fertilizer and pesticides to seaweed cultured in tidal flats during the ebb tide interval. The development of this device meets the specific requirements of the Ministry of Agriculture and Rural Affairs in the field of "precision and efficient fertilization and integrated fertilizer and pesticide application and other major products and supporting equipment" in the field of farmland quality improvement (the second major key area) of the "National Key Areas of Agricultural Science and Technology Innovation (2024-2028)". Attached Figure Description

[0009] Figure 1 : 3D structural diagram of the device (showing the positional relationship of the atomizing nozzle assembly (204), the round hole (103), the filter pad (301), the power switch (205), and the sand discharge hose (307);

[0010] Figure 2 : Side elevation view of the device (including front elevation view, left elevation view, and rear elevation view, showing the positional relationship of the tray (101), sand discharge hose (307) and caster wheel (102), and showing the height of the caster wheel (102) as 30 cm);

[0011] Figure 3 Top view and plan view of the device (showing the positional relationship of the power switch (205), liquid storage tank (201), battery (202), pressurized water pump (203), and residual liquid recovery pump (305));

[0012] Figure 4 Top view of the device (arrangement of casters, 4 rows, 5 casters / row);

[0013] Figure 5 : Structural diagram of the equipment for storing, spraying, collecting and removing sand from pesticide and fertilizer solution (showing the positional relationship of floating filter (303), storage tank (201), battery (202), pressurized water pump (203), cone bottom sedimentation tank (302), filter silk (304), residual liquid recovery pump (305), float level switch (308), sand discharge port (306), sand discharge hose (307) and details of floating filter);

[0014] Figure 6 : A cross-sectional view of the device (showing the positional relationship of the atomizing nozzle assembly (204), the 2% slope tray (101) base plate, the float level switch (308), the floating filter (303), the filter port covered with filter silk (304), the casters (102), the sand discharge hose (307), and the details of the floating filter).

[0015] Figure 7 Circuit diagram: Residual liquid recovery system circuit connection diagram (battery (202) positive terminal → power switch (205) → float level switch (308) → residual liquid recovery pump (305) → battery (202) negative terminal); fertilizer spraying system circuit connection diagram (battery (202) positive terminal → power switch (205) → pressurized water pump (203) → battery (202) negative terminal); float level switch connection (corrosion resistant material + 20 cm adjustable set point) → side wall installation (avoiding filter) → connected to pump control circuit → regular maintenance). Detailed Implementation

[0016] Operational Procedure: After low tide, use the hand-operated lever hook to engage the round hole for traction → place the device (traction moving tray, 2.0~3.0 m long, 2.5~2.8 m wide) between the raft frames → start the traction device (winch mounted on the tidal flat tractor) → start the spraying system (spraying volume 10 L / min) → when encountering high resistance from silt, use the hook to engage the lever through the round hole for assistance → filter the remaining liquid through the filter pad into the sedimentation tank → start the remaining liquid recovery pump for recovery (automatic start when remaining liquid ≥ 20 cm) → clean the filter pad every 30 minutes of operation (using a double-layer replaceable filter pad, which can be quickly replaced during the work interval) → open the sand discharge port every 2 hours of operation until clear water flows out, simultaneously stop the remaining liquid recovery pump, and control the sand discharge through the manual sand discharge hose connected to the sand discharge port at the bottom of the sedimentation tank.

[0017] Example: Experiments conducted at a seaweed farming enterprise in Hai'an City, Jiangsu Province, using the Jiangjiasha Zhugen Beach mudflats, showed that after using this device, the application of an algae-removing agent effectively removed green algae, solving the problem of green algae invading seaweed nets. When there was a large amount of green algae, spraying began one hour before high tide, using 0.1% hydrogen peroxide for emergency algae removal. When there was less green algae (or for prevention), spraying began at low tide with 0.1%~0.3% sodium percarbonate (a method for removing green algae in seaweed farming, patent number: CN 103518698 A, abstract: "After spraying the algae-removing agent for 3 days, the green algae removal rate was 100%, and it did not affect the growth of seaweed."). By spraying drugs targeting filamentous fungal diseases (such as parasitic filamentous fungi that cause seaweed rot), the spread of filamentous fungi was effectively inhibited, preventing the continuation of rot. For short-term emergency treatment, sodium hypochlorite, an oxidant, was used at a concentration of 2~5 ppm. By spraying to supplement the nutrients lacking in laver cultivation, laver growth is promoted. After the tide recedes, potassium dihydrogen phosphate and urea are sprayed at concentrations of 0.3% potassium dihydrogen phosphate and 1% urea to prevent premature aging of the algae and promote biomass accumulation. The types and concentrations of the agents mentioned are for illustrative purposes only and do not constitute a limitation on the scope of use of the device. All components in contact with the liquid solution, such as the storage tank, pipelines, and filters, are made of chemically resistant materials (such as PP or 316L stainless steel; filter pads and filter silk are made of PTFE).

[0018] This device effectively removes algae, inhibits bacteria, and applies fertilizer. Compared with traditional manual spraying, the device has an operating efficiency of 10 mu / h. Under the agent concentration and operating conditions described in the example, the utilization rate of foliar fertilizer is increased from 40% to 85%, the green algae removal rate is >90%, and the disease control efficiency is increased by 70%. It improves control efficiency and reduces environmental risks, achieving both green algae control and increased production and income of laver.

Claims

1. A device for spraying and recycling foliar fertilizer and disease-controlling algae-removing agents during the ebb tide interval for laver aquaculture in tidal flats, characterized in that... include: Traction-moving pallet system: The pallet (101) is 2.0~3.0 m long and 2.5~2.8 m wide. There are 4 rows of stainless steel casters (102) at the bottom of the pallet, with each row having 4~6 casters (102). The height of the stainless steel casters is 30 cm. The foliar fertilizer and disease control agent spraying and recycling device for laver cultivation during the ebb tide interval is connected to an external mechanical traction device. The mechanical traction mode is supplemented by manual traction to adapt to the hard mud of the tidal flat. Fertilizer and drug liquid storage and spraying system: The storage tank (201) is connected to the atomizing nozzle group (204) at the front of the pallet via a pressurized water pump (203). The nozzle group sprays at a 60°~75° angle from bottom to top, with a double-row staggered layout. Excess liquid fertilizer collection and sand removal system: The surface of the pallet is covered with a flocculent filter pad (301). The flocculent filter pad is a double-layer replaceable filter pad. It is connected to a cone-bottom sedimentation tank (302) for sedimentation. A floating filter (303) is installed in the tank. The suction port of the filter covers 80~120 cm. The filter cloth (304) is connected to the residual liquid recovery pump (305) and filtered through the flocculent filter pad on the tray surface, sedimentation in the cone bottom sedimentation tank, and filtration by the floating filter before reaching the storage tank (201). After the spraying is started, the residual liquid recovery pump (305) automatically starts when the residual liquid in the sedimentation tank (302) is ≥20 cm. The suction port is always 3~5 cm below the liquid surface along with the floating filter (303). The floating filter (303) contains closed-cell foamed polyethylene floats with a volume ≥300 cm³ and a density of 0.25 g / cm³, providing a net buoyancy ≥2 N. A cone bottom sand discharge port (306) is added to the sedimentation tank (302), and the sand discharge is controlled by a manual sand discharge hose (307) connected to the cone bottom sand discharge port of the sedimentation tank.

2. The apparatus as described in claim 1, characterized in that: The atomizing nozzle group (204) has an atomizing particle size of ≤150 μm and is 30~50 cm above the seaweed raft rope net.

3. The apparatus as described in claim 1, characterized in that: The pallet is equipped with traction holes (103) on both sides, which, together with the hand lever with a straight hook, enable directional control and manual traction.

4. The apparatus as claimed in claim 1, characterized in that: The filter pads and filter silk are made of PTFE material.

Images