Water and fertilizer combined application system based on fish-farming tail water and combined application method thereof

Abstract

The invention discloses a water and fertilizer combined application system based on fish culture tail water and a combined application method thereof. The combined application system comprises a control module and a pipeline module, the combined application method comprises a primary filling stage and a fertilizer supplementing stage, the primary filling stage is a process of filling the nutrient solution tank for the first time, the fertilizer supplementing stage is a process of supplementing the nutrient solution into the nutrient solution tank while the nutrient solution in the nutrient solution tank is used, and the two stages are used for preparing a standard nutrient solution formula. According to the method, the purpose of preparing a standard nutrient solution formula is achieved, nitrogen in the fish culture tail water serves as a substitution source of nitrogen in the nutrient solution, automatic proportioning of the standard nutrient solution is achieved through the substitution strategy, and the method is remarkably different from a traditional fertilizer preparation method for regulating and controlling the conductivity based on a PID algorithm; the method is an important method for efficiently utilizing the fish-farming tail water.

Description

Technical Field

[0001] The invention relates to the field of efficient utilization of aquaculture tail water, and in particular to a water-fertilizer application system based on fish farming tail water and an application method thereof. Background Art

[0002] In the process of fish farming, a large amount of fish farming tail water is usually produced. Since fish farming tail water contains nitrogen plasma, direct discharge can easily cause pollution to soil or water. However, the existing aquaculture tail water utilization system or equipment can only simply mix fertilizer and water and output them, and adjust the conductivity or pH through the PID algorithm. The water used for fertilizer preparation is mostly conventional water, which is mostly suitable for large fields and substrates, but not suitable for hydroponics. It is impossible to achieve efficient utilization of fish farming tail water, and the degree of intelligence is low, making it difficult to accurately control the fertilization time, fertilizer amount and fertilization speed. For example, the patent publication number is CN 114208470 A, which is an intelligent water and fertilizer control device and method based on PID algorithm. By electrically connecting a data acquisition unit, a data transmission unit, and a water and fertilizer application control unit, and constructing a water and fertilizer ratio model based on fuzzy neural network PID, the water and fertilizer equipment is controlled to complete the water and fertilizer application, and the EC and pH are accurately adjusted, which effectively solves the existing technical problems. However, the water used for fertilizer preparation is mostly conventional water, and the nutrient elements of fish farming tail water cannot be utilized to achieve a win-win situation for the environment and organic.

[0003] The nitrogen in the fish tail water can be used as a substitute for nitrogen fertilizer, but the nitrogen in the fish tail water will fluctuate with factors such as fish farming density and production cycle. When Yamazaki standard nutrient solution is used as the standard nutrient solution formula for fertilization, how to achieve dynamic replacement of nitrogen in the fish tail water has become a technical problem to be solved.

[0004] In summary, there is an urgent need to invent a water-fertilizer application system based on fish farming tail water and an application method thereof. Summary of the invention

[0005] In order to improve or even solve at least one problem in the prior art, the present invention proposes a water-fertilizer application system based on fish farming tail water and an application method thereof.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The first aspect of the present invention provides a water-fertilizer mixing system based on fish farming tail water, the system comprising a control module and a pipeline module, wherein:

[0008] The core components of the control module are the controller and the screen, which are electrically connected to each other for data transmission and display. The pipeline module includes a water pump, a fertilizer absorption channel and a fertilizer bucket. The fertilizer absorption channel is constant to 4 channels, channel A is configured with nitrogen fertilizer, channel B is configured with phosphorus and potassium fertilizers, channel C is configured with trace elements, and channel D is acid adjustment. The water pump is connected to the fertilizer bucket through the fertilizer absorption channel to realize the extraction and transportation of fertilizers.

[0009] The control module is used as a host computer and is responsible for issuing operation commands to the pipeline module. The fertilization channel is equipped with a float flowmeter, a flow regulating valve, a solenoid valve and a Venturi fertilizer applicator in sequence according to the flow direction of the fertilizer;

[0010] The inlet of the venturi fertilizer applicator is connected to the upstream of the main irrigation pipeline, and the outlet is connected to the inlet of the water pump, and the outlet of the water pump is connected to the nutrient solution tank, forming a complete fertilizer distribution link;

[0011] The present invention is further configured as follows: the execution device carrier of the system is a fertilizer spreader.

[0012] The second aspect of the present invention provides a method for applying water and fertilizer based on fish tail water, comprising the following two stages:

[0013] Initial filling stage: According to the standard nutrient solution formula, obtain the nitrogen concentration A1 (mg / L) of the standard nutrient solution, and obtain the nitrogen concentration A2 (mg / L) of the fish tail water by sampling and testing;

[0014] According to the bottom diameter d (cm) of the nutrient solution barrel and the filling limit liquid level h max (cm), find the maximum volume V when the nutrient solution bucket is filled max (cm 3 ), the calculation formula is as follows:

[0015] V max =3.14*d / 2*d / 2*h max ;

[0016] According to the maximum volume V when the nutrient solution barrel is filled max , single channel fertilizer absorption flow q (L / h), nutrient solution concentration ratio e, calculate the time T of the B and C fertilization channels when first filled 1 (s), the calculation formula is as follows:

[0017] T 1 =V max / (q*1000 / 3600) / e, wherein the nutrient solution concentration ratio e is the concentration multiple of the standard nutrient solution formula.

[0018] According to the nitrogen concentration A1 of the standard nutrient solution formula and the nitrogen concentration A2 of the fish tail water, the replacement ratio F is calculated as follows:

[0019] F = A2 / A1;

[0020] According to the time T of the B and C fertilization channels 1 , the time T2 of nitrogen fertilizer channel A is obtained. The substitution algorithm uses the nitrogen in the fish tail water as a nutrient element to replace part of the nitrogen fertilizer. The flow rates of fertilization channels A, B, and C are controlled to be the same, and the time T2 of nitrogen fertilizer channel A is controlled to achieve nitrogen fertilizer substitution. The calculation formula is as follows:

[0021] T 2 =T 1 *(1-F);

[0022] According to the fertilization channel time T 1 , T 2 The fertilizer outlet flow rate Q (L / h) is calculated as follows:

[0023] Q=q 主 +q*3, where q 主 is the water inlet flow rate of the main pipeline (L / h), and the number of fertilization channels of the fertilizer spreader is 3.

[0024] According to the fertilization outlet flow rate Q, the maximum volume V when the nutrient solution tank is filled max， The total fertilization time T(s) is calculated as follows:

[0025] T=V max / 1000 / Q*3600;

[0026] Fertilizer replenishment stage: During the use after the first filling stage, the conductivity value B of the nutrient solution in the nutrient solution tank is monitored in real time by the sensor 1 , the liquid level in the initial filling stage reaches the maximum liquid level h max The conductivity value B and EC deviation rate g at that time are used to determine whether to start the fertilizer supplementation stage. The calculation formula is as follows:

[0027] If (BB 1 ) / B<g, no fertilizer is added. If (BB 1 ) / B≥g, the fertilizer supplementation stage is started, and the conductivity of the nutrient solution is obtained by the liquid level sensor as B 1 Liquid level depth at time h t ;

[0028] According to the liquid level depth h t , the filling limit level h max , calculate the volume V of the nutrient solution 补 , the calculation formula is as follows:

[0029] V 补 =d / 2*d / 2*3.14*(h max -h t );

[0030] According to the volume V when the nutrient solution barrel is filled 补 , single channel fertilizer absorption flow q, nutrient solution concentration e, calculate the initial filling, B, C fertilization channel fertilizer time T 补1 (s), the calculation formula is as follows:

[0031] T 补1 =V 补 / (q*1000 / 3600) / e, wherein the nutrient solution concentration ratio e is the concentration multiple of the standard nutrient solution formula.

[0032] According to the fertilizer replenishment time T of the B and C fertilization channels 补1 , calculate the fertilizer replenishment time T of nitrogen fertilizer channel A 补2 , the calculation formula is as follows:

[0033] T 补2 =T 补1 *(1-F);

[0034] According to the fertilization channel time T 补1 , T 补2 , the fertilizer outlet flow rate Q (L / h) in the supplementary fertilizer stage is obtained, and the calculation formula is as follows:

[0035] Q=q 主 +q*3, where q 主 is the water inlet flow rate of the main pipeline (L / h), and the number of fertilization channels of the fertilizer spreader is 3.

[0036] According to the fertilization outlet flow Q 补 , the maximum volume V when the nutrient solution tank is full 补 , calculate the total fertilizer supplementation time T 补 (s), the calculation formula is as follows:

[0037] T 补 =V 补 / 1000 / Q 补 *3600;

[0038] The present invention is further configured as follows: the irrigation sequence is to irrigate the fish tail water and fertilizer at the same time - then irrigate the fish tail water - the liquid level reaches h max Stop irrigation, and the last fertilization time is T>T 1 >T 2 .

[0039] The present invention is further configured as follows: the flow rate q of the fertilization channel can be manually adjusted according to the fertilization time through the linear valve on the fertilization channel, the fertilizer absorption amount of each channel must be the same, and the fertilizer absorption flow rate setting range is 60-160L / h.

[0040] The present invention is further configured as follows: in the filling stage, the maximum liquid level h is reached. max The default nutrient solution conductivity is the standard conductivity of the standard nutrient solution formula.

[0041] The present invention is further configured as follows: the substitution algorithm fixes the flow rate of each fertilization channel, changes the fertilization time of the nitrogen fertilizer channel, and fully utilizes the nitrogen in the fish tail water. The time ratio of the nitrogen fertilizer fertilization channel A to the fertilization channels B and C of other fertilizers is (1-e):1:1.

[0042] The present invention is further configured as follows: the B and C fertilization channels are opened and closed at the same time.

[0043] The present invention is further configured as follows: in the fertilizer supplementation stage, the conductivity value is quantified by the liquid level, and the maximum liquid level h max The conductivity at 100 °C is the conductivity of the standard nutrient solution formula. t It is the liquid level depth when the deviation rate is less than the conductivity target value EC.

[0044] The present invention is further configured as follows: the A channel, the B channel, and the C channel realize the standard nutrient solution formula by controlling the time, the D channel adopts the position PID algorithm to realize the pH adjustment of the standard nutrient solution, and the standard nutrient solution obtained by fertilizer preparation is stored in a nutrient solution tank, and the nutrient solution tank is equipped with an EC sensor, a pH sensor, and a liquid level sensor.

[0045] Beneficial effect: The present invention proposes and applies a new method for water-fertilizer matching, which is different from the traditional regulation method that uses conductivity as the control target and realizes fertilizer matching for multiple fertilizer absorption channels based on PID algorithm. It uses the standard nutrient solution formula as the matching target, utilizes the nitrogen in the fish tail water, and uses it as an effective alternative source of inorganic nitrogen fertilizer in the fish-vegetable symbiotic system, reduces the use of fertilizers, and achieves a win-win situation for the environment and organic. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0047] Figure 1The present invention shows a flow chart of the filling stage of a method for applying water and fertilizer based on tail water of fish farming.

[0048] Figure 2 The present invention shows a flow chart of the fertilization stage of a method for applying water and fertilizer based on tail water of fish farming.

[0049] Figure 3 The invention shows a connection diagram of a water-fertilizer application control system based on tail water of fish farming.

[0050] Figure 4 A diagram of the liquid level in the nutrient solution tank is shown.

[0051] Among them, 1. irrigation main pipeline; 2. flow control valve; 3. solenoid valve; 4. float flowmeter; 5. venturi fertilizer applicator; 6. fertilizer bucket; 7. water pump; 8. EC sensor; 9. pH sensor; 10. liquid level sensor; 11. nutrient solution tank; 12. control module; h t : Liquid level depth at the current moment; h max : Maximum liquid level depth. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0053] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0054] In the present invention, all embodiments, implementations and features of the present invention can be combined with each other without contradiction or conflict. In the present invention, conventional equipment, devices, components, etc. can be purchased commercially or made according to the contents disclosed in the present invention. In the present invention, in order to highlight the key points of the present invention, some conventional operations and equipment, devices, components are omitted or only briefly described.

[0055] Embodiment 1:

[0056] The purpose of the embodiment of the application is to provide a water-fertilizer mixing system based on fish farming tail water, the system includes a control module and a pipeline module, wherein:

[0057] The control module includes a controller, a screen and supporting electrical components, and the controller is electrically connected to the screen; the pipeline module includes a water pump 7, a fertilizer suction channel and a fertilizer bucket 6, and the water pump is connected to the fertilizer bucket 6 through the fertilizer suction channel;

[0058] The control module, as the upper module of the pipeline module, implements command issuance;

[0059] The fertilizer suction channel is connected with a float flowmeter 4, a solenoid valve 3, a flow regulating valve 2 and a venturi fertilizer applicator 5 in sequence according to the fertilizer suction flow direction;

[0060] The inlet of the venturi fertilizer applicator is connected to the upstream of the irrigation main pipeline 1, and the outlet is connected to the inlet of the water pump. The outlet of the water pump is connected to the nutrient solution tank, forming a complete fertilizer distribution link.

[0061] Embodiment 2:

[0062] The present application example takes the application of standard Yamazaki nutrient solution as an example:

[0063] The Yamazaki nutrient solution was obtained, which was mainly composed of nitrogen fertilizer, phosphorus fertilizer, and potassium fertilizer in a certain ratio. Bucket A was configured with nitrogen fertilizer, bucket B was configured with phosphorus and potassium fertilizer, bucket C was configured with trace elements, and bucket D was configured with acid. The concentration of nitrogen fertilizer, phosphorus and potassium fertilizer, and trace element (Fe) fertilizer stock solution was 8700 mg / L. After 20 times dilution, the concentration of nitrogen, phosphorus and potassium, and trace element (Fe) in the standard nutrient solution was 435 mg / L. The nitrogen concentration of fish tail water was obtained by the fertilizer efficiency evaluation model as 46 mg / L. According to the conservation of nitrogen, part of the nitrogen element in the Yamazaki nutrient solution comes from fish tail water, and part comes from the original solution in bucket A.

[0064] The maximum nutrient solution volume is determined based on the nutrient solution barrel parameters and the maximum watering limit.

[0065] Among them, the diameter of the nutrient solution barrel is selected as 200cm, the fertilizer absorption flow rate can be selected as 80L / h, and the maximum irrigation limit is 30cm;

[0066] The maximum nutrient solution volume Vmax (cm3) is determined based on the nutrient solution barrel parameters and the maximum watering limit. The calculation formula is as follows:

[0067] V max =3.14*d / 2*d / 2*hmax=100*100*3.14*30=942000cm 3 ,

[0068] According to the maximum volume V when the nutrient solution barrel is filled max, single channel fertilizer absorption flow q, nutrient solution concentration ratio e, to obtain the time T1 (s) of other fertilization channels B and C except nitrogen fertilizer when first filled, the calculation formula is as follows:

[0069] T 1 =V max / (q*1000 / 3600) / e=942000 / (80*1000 / 3600) / 20=2140s,

[0070] The nutrient solution concentration ratio in the formula is 20.

[0071] According to the nitrogen concentration A1 of the standard nutrient solution formula and the nitrogen concentration A2 of the fish tail water, the calculation formula for the replacement ratio F is as follows:

[0072] F = A2 / A1 = 46 / 435 = 0.11;

[0073] According to the time T1 of other fertilization channels except nitrogen fertilizer, the time T2 of nitrogen fertilizer channel A is obtained. The calculation formula is as follows:

[0074] T 2 =T 1 *(1-F)=2140*(1-0.11)=1905s;

[0075] According to the fertilization channel time T 1 , T 2 The fertilizer outlet flow rate Q (L / h) is calculated as follows:

[0076] Q=q 主 +q*3=1000+80*3=1240L / h

[0077] In the formula, q 主 is the water inlet flow rate of the main pipeline (L / h), and the number of fertilizer spreader channels is 3.

[0078] According to the fertilization outlet flow rate Q, the maximum volume V when the nutrient solution tank is filled max， The total fertilization time T is calculated as follows:

[0079] T=V max / 1000 / Q*3600=942000 / 1000 / 1240*3600=2734s.

[0080] Embodiment 3:

[0081] Fertilizer replenishment stage: During the use after the first filling stage, the conductivity value B of the nutrient solution in the nutrient solution tank is monitored in real time by the sensor 1 The liquid level in the initial filling stage reaches the maximum level h maxWhen the conductivity value B is between 1.3-1.6 and the set EC deviation rate is 10%, it is determined whether to start the fertilization stage. The calculation formula is as follows;

[0082] (1.35-1.22) / 1.35≥10%, start the fertilizer supplementation stage, in which the conductivity of the nutrient solution obtained by the liquid level sensor is B 1时刻 The liquid level depth h t 26cm;

[0083] According to the liquid level depth h t , fill to limit level h max , calculate the volume V of the nutrient solution 补 , the calculation formula is as follows:

[0084] V 补 =3.14*d / 2*d / 2*(h max -h t )=100*100*3.14*(30-26)=125600cm 3 ;

[0085] According to the volume V when the nutrient solution barrel is filled 补 , single channel fertilizer flow rate q = 80L / h, nutrient solution concentration e is the dilution factor 20, calculate the time T of other fertilization channels except nitrogen fertilizer when first filled 补1 (s), the calculation formula is as follows:

[0086] T 补1 =V 补 / (q*1000 / 3600) / e=125600 / (80*1000 / 3600) / 20=282s;

[0087] According to the time T of other fertilization channels except nitrogen fertilizer 补1 , and obtain the time T of nitrogen fertilizer channel 补2 , the calculation formula is as follows:

[0088] T 补2 =T 补1 *(1-F)=282*(1-0.11)=251s;

[0089] According to the fertilization channel time T 补1 , T 补2 , and obtain the fertilizer outlet flow Q during the supplementary fertilizer stage 补 (L / h), the calculation formula is as follows:

[0090] Q 补 =q 主 +q*n=1000+80*3=1240L / h,

[0091] In the formula, q 主 The water inlet flow rate of the main pipeline is 1000 (L / h), and n is the number of fertilization channels of the fertilizer spreader.

[0092] According to the fertilization outlet flow Q 补 , the maximum volume V when the nutrient solution tank is full 补 , calculate the total fertilizer supplementation time T 补 , the calculation formula is as follows:

[0093] T 补 =V 补 / 1000 / Q 补 *3600=125600 / 1000 / 1240*3600=364s.

[0094] Embodiment 4:

[0095] Another object of an embodiment of the present application is to provide a water-fertilizer application control system based on fish farming tail water, wherein the execution device carrier of the control system is a fertilizer applicator.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A water-fertilizer mixing system and mixing method based on fish tail water, characterized in that: The dispensing system includes: a control module and a pipeline module, wherein: The control module includes a controller and a screen, and the controller and the screen are electrically connected to each other for data transmission and display. The pipeline module includes a water pump, a fertilizer suction channel, a nutrient solution tank and a fertilizer bucket, wherein the water pump is connected to the fertilizer bucket through the fertilizer suction channel to realize the extraction and transportation of fertilizer; The control module, as a host computer, is responsible for issuing operation commands to the pipeline module. The fertilization channel is sequentially installed with a float flowmeter, a flow regulating valve, a solenoid valve and a venturi fertilizer applicator according to the flow direction of the fertilizer. The inlet of the venturi fertilizer applicator is connected to the main irrigation pipeline, and its outlet is connected to the inlet of the water pump; the outlet of the water pump is connected to the nutrient solution tank, forming a complete fertilizer distribution link; The fertilizer absorption channel is composed of four channels, namely channel A, channel B, channel C, and channel D. Channel A is configured with nitrogen fertilizer, channel B is configured with phosphorus and potassium fertilizers, channel C is configured with trace elements, and channel D is configured with acid adjustment; The fertilization method includes: an initial filling stage and a supplementary fertilization stage, wherein the initial filling stage is the process of filling the nutrient solution tank for the first time, and the supplementary fertilization stage is the process of supplementing the nutrient solution tank while the nutrient solution in the nutrient solution tank is being used, and both stages are for achieving the purpose of preparing a standard nutrient solution formula; The steps of the initial filling phase are: S11. According to the standard nutrient solution formula, obtain the nitrogen concentration A1 (mg / L) of the standard nutrient solution, and obtain the nitrogen concentration A2 (mg / L) of the fish tail water in real time through the sensor; S12. According to the bottom diameter d (cm) of the nutrient solution barrel and the filling limit level h max (cm), find the maximum volume V when the nutrient solution bucket is filled max (cm 3 ), the calculation formula is as follows: V max =3.14*d / 2*d / 2*h max ; S13. According to the maximum volume V when the nutrient solution barrel is filled max , single channel fertilizer absorption flow q (L / h) and nutrient solution concentration ratio e, calculate the time T1 (s) of fertilization channels B and C when first filled, and the calculation formula is as follows: T1=V max / (q*1000 / 3600) / e, wherein the nutrient solution concentration ratio e is the concentration multiple of the standard nutrient solution formula; S14. According to the nitrogen concentration A1 of the standard nutrient solution formula and the nitrogen concentration A2 of the fish tail water, the substitution ratio F is obtained. The substitution ratio calculation formula is as follows: F = A2 / A1; S15. According to the time T1 of the fertilization channels B and C, the time T2 of the nitrogen fertilizer channel A is obtained, and the flow rates of the fertilization channels A, B, and C are controlled to be the same, and the time T2 (s) of the nitrogen fertilizer channel A is controlled to achieve nitrogen fertilizer substitution. The calculation formula is as follows: T2 = T1*(1-F); S16. The fertilizer outlet flow rate Q (L / h) is calculated according to the fertilization channel time T1 and T2, and the calculation formula is as follows: Q=q 主 +q*3, where q 主 is the water inlet flow rate of the main pipeline (L / h), and the number of fertilizer application channels of the fertilizer spreader is 3; S17. According to the fertilization outlet flow Q, the maximum volume V when the nutrient solution tank is filled max， The total fertilization time T(s) is calculated as follows: T=V max / 1000 / Q*3600; The steps of the fertilization stage are: S21. According to the conductivity value B1 of the nutrient solution in the nutrient solution tank monitored in real time by the sensor during use after the first filling stage, the liquid level in the first filling stage reaches the maximum liquid level h max The conductivity value B and EC deviation rate g at that time are used to determine whether to start the fertilizer supplementation stage. The calculation formula is as follows: If (B-B1) / B<g, no fertilization is performed. If (B-B1) / B≥g, the fertilization stage is started. The conductivity of the nutrient solution is obtained by the liquid level sensor at the liquid level depth h at the moment B1. t ; S22. According to the liquid level depth h t , the filling limit level h max , calculate the volume V of the nutrient solution 补 , the calculation formula is as follows: V 补 =3.14*d / 2*d / 2*(h max -h t ); S23. According to the volume V when the nutrient solution tank is filled 补 , the fertilizer absorption flow rate q of the single channel, the nutrient solution concentration ratio e, and the fertilizer replenishment time T of the B and C fertilization channels when the initial filling is obtained 补1 (s), the calculation formula is as follows: T 补1 =V 补 / (q*1000 / 3600) / e, where the nutrient solution concentration ratio e is the dilution multiple of the high-concentration nutrient solution; S24. According to the B, C fertilization channel fertilizer time T 补1 , find the fertilizer replenishment time T of the nitrogen fertilizer channel A 补2 , the calculation formula is as follows: T 补2 =T 补1 *(1-F); S25. According to the fertilization channel time T 补1 , T 补2 , the fertilizer outlet flow rate Q (L / h) in the supplementary fertilizer stage is obtained, and the calculation formula is as follows: Q=q 主 +q*3, where q 主 is the water inlet flow rate of the main pipeline (L / h), and the number of fertilization channels of the fertilizer spreader is 3; S26. According to the fertilization outlet flow Q 补 , the maximum volume V when the nutrient solution tank is full 补 , calculate the total fertilizer supplementation time T 补 (s), the calculation formula is as follows: T 补 =V 补 / 1000 / Q 补 *3600。 2. The water-fertilizer mixing system and mixing method based on fish farming tail water according to claim 1, characterized in that: The irrigation sequence is: irrigate with fish tail water and fertilizer at the same time - then irrigate with fish tail water - the liquid level reaches h max Stop irrigation and the last fertilization time is T>T1>T2.

3. The water-fertilizer mixing system and mixing method based on fish tail water according to claim 1, characterized in that: The flow rate of the fertilization channel can be manually adjusted by the linear valve on the fertilization channel according to the fertilization time. The fertilizer absorption amount of each channel must be the same, and the fertilizer absorption flow rate setting range is 60-160L / h.

4. The water-fertilizer mixing system and mixing method based on fish farming tail water according to claim 1, characterized in that: During the filling phase, the maximum liquid level h is reached. max The default nutrient solution conductivity is the standard conductivity of the standard nutrient solution formula.

5. The water-fertilizer mixing system and mixing method based on fish tail water according to claim 1, characterized in that: By fixing the flow rate of each fertilization channel and changing the fertilization time of the nitrogen fertilizer channel, the nitrogen in the fish tail water can be fully utilized. The time ratio of the nitrogen fertilizer fertilization channel A to the fertilization channels B and C of other fertilizers is (1-e):1:

1.

6. The water-fertilizer mixing system and mixing method based on fish tail water according to claim 5, characterized in that: The A channel, the B channel, and the C channel are opened at the same time, and the B channel and the C channel are closed at the same time.

7. The water-fertilizer mixing system and mixing method based on fish farming tail water according to claim 1, characterized in that: During the fertilizer supplementation stage, the conductivity value is quantified by the liquid level, and the maximum liquid level h max The conductivity at 100 °C is the conductivity of the standard nutrient solution formula. t It is the liquid level depth when the deviation rate is less than the conductivity target value EC.

8. The water-fertilizer mixing system and mixing method based on fish tail water according to claim 1, characterized in that: The A channel, the B channel, and the C channel realize the standard nutrient solution formula by controlling the time, and the D channel adopts the position PID algorithm to realize the pH adjustment of the standard nutrient solution. The standard nutrient solution obtained by fertilizer preparation is stored in the nutrient solution tank, and the nutrient solution tank is equipped with an EC sensor, a pH sensor, and a liquid level sensor.

9. The water-fertilizer mixing system and mixing method based on fish tail water according to claim 1, characterized in that: The executive equipment carrier of the fertilizer distribution system is a fertilizer spreader.

Images