Water and fertilizer integrated irrigation device and method

Abstract

The application discloses a water and fertilizer integrated device and method, and belongs to the technical field of agricultural automation. The device comprises a water and fertilizer mixing unit, an irrigation execution unit, a control unit and a mounting base. The irrigation method comprises the following steps: constructing a water and fertilizer integrated decision model, taking irrigation water quantity and nitrogen fertilizer application quantity within 7 days as decision variables, taking the minimum water stress index and the minimum nitrogen stress index as target functions, taking upper and lower limits of the irrigation water quantity and the nitrogen fertilizer application quantity, proportion constraints, water and fertilizer matching constraints, non-negative constraints of the water stress index and the nitrogen stress index as constraints, obtaining data required by the model, obtaining an optimal solution of the model by using an improved grey wolf algorithm, and outputting the irrigation water quantity and the nitrogen fertilizer application quantity. The control unit delivers the water and fertilizer mixing ratio to the water and fertilizer mixing unit for water and fertilizer mixing, and controls the irrigation execution unit to irrigate. The application considers precipitation conditions, solves the repeated irrigation phenomenon, avoids causing water resource waste and low rainwater utilization rate, and improves the intelligent degree of irrigation and fertilization.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural automation, in particular to a water and fertilizer integrated device and method. BACKGROUND

[0002] The farms and large-scale planters in each region have formed a certain basic scale, but the matching fertilization and irrigation facilities are still relatively backward. At present, most planting personnel still use traditional fertilization methods, such as broadcast or large water flushing fertilization, which has low fertilization efficiency. In terms of irrigation, traditional flooding irrigation is still used in many regions, which not only ignores the consideration of future precipitation, but also is prone to repeated irrigation, thereby causing waste of water resources and low rainwater utilization rate. In addition, most irrigation operations are completely completed by manual work, which is labor-intensive, and the irrigation cycle is completely determined by the subjective decision of the planters, which makes the matching degree of irrigation and the growth demand of crops low. Therefore, it is urgent to construct an intelligent water and fertilizer integrated device and a self-adaptive irrigation control method considering the precipitation condition, and to construct a database suitable therefor, while improving the intelligent degree of irrigation and fertilization decision. SUMMARY

[0003] To solve the problems in the prior art, a water and fertilizer integrated irrigation device and method are provided.

[0004] The present application is realized by the following technical solutions. In a first aspect, a water and fertilizer integrated irrigation device is provided, which comprises a water and fertilizer mixing unit, an irrigation execution unit, a control unit, and a mounting base. The water and fertilizer mixing unit is mounted on the mounting base, and the control unit is mounted on one side of the mounting base.

[0005] The water and fertilizer mixing unit comprises a water pump, a water and fertilizer mixing box, a water and fertilizer mixing box top cover, a liquid fertilizer suction pipe, a water and fertilizer mixer, a nitrogen fertilizer storage tank, a phosphorus fertilizer storage tank, a potassium fertilizer storage tank, a water pump water suction pipe, a water pump water outlet pipe, a fertilizer injection port, and a fertilizer outlet pump.

[0006] The top of the water and fertilizer mixing box is provided with a water and fertilizer mixing box top cover, and the bottom of the water and fertilizer mixing box is provided with a water and fertilizer mixer. The water and fertilizer mixer is provided with a paddle connected to the control unit, and the bottom of the water and fertilizer mixer is provided with an outlet connected to the irrigation execution unit. One side of the water pump is connected to irrigation water through a water pump water suction pipe, and the other side of the water pump is connected to the water and fertilizer mixing box through a water pump water outlet pipe. The top of each of the nitrogen fertilizer storage tank, the phosphorus fertilizer storage tank, and the potassium fertilizer storage tank is provided with a fertilizer outlet pump. The fertilizer outlet pump is provided with a fertilizer injection port. The fertilizer outlet pump is connected to the water and fertilizer mixing box top cover through a liquid fertilizer suction pipe. The water pump and the fertilizer outlet pump are connected to the control unit, and the control unit controls the irrigation water volume of the water pump and the fertilizer mixing ratio of the fertilizer outlet pump.

[0007] The irrigation execution unit comprises a water pipe belt, an irrigation frame and a sprinkler head; the water pipe is arranged at one end of the irrigation frame, the sprinkler head is arranged at the lower side of the cross beam of the irrigation frame, the sprinkler head is connected with the water pipe, and the water pipe is connected with the water and fertilizer mixing unit;

[0008] The control unit is provided with a full-automatic weather station, a soil moisture meter, a crop growth sensor and a control panel, and the control unit calculates irrigation water and nitrogen fertilizer application amount according to the obtained data.

[0009] Further, the first suction port of the water pump suction pipe is provided with a plurality of filter screens to filter the irrigation water entering the water and fertilizer mixer.

[0010] Further, the nitrogen fertilizer storage tank, the phosphorus fertilizer storage tank and the potassium fertilizer storage tank are all provided with liquid level detectors, and when the storage amount of the liquid fertilizer in the nitrogen fertilizer storage tank, the phosphorus fertilizer storage tank and the potassium fertilizer storage tank is less than 10% of the total amount, the liquid level detector sends a signal to the control panel in the control unit.

[0011] Further, one end of the irrigation execution unit is provided with a water pipe reel, one end of the water pipe is connected with the outlet of the water and fertilizer mixer of the water and fertilizer mixing unit, and the other end of the water pipe is wound on the water pipe reel.

[0012] Further, the bottom of the irrigation frame on both sides is respectively provided with a track, the upper side of the cross beam of the irrigation frame is provided with an irrigation execution controller, the irrigation execution controller is connected with the control unit, the irrigation execution controller is provided with a differential positioning chip, the irrigation execution unit can enhance the GPS signal according to the correction signal of the ground base station, and the track is driven to adjust the advancing direction and speed in real time.

[0013] In the second aspect, the application provides a water and fertilizer integrated irrigation method, which comprises the following steps:

[0014] S1, connecting the water pump suction pipe (1-9) with irrigation water; S2, constructing a water and fertilizer integrated decision-making model: taking the irrigation water W i , i=[1,7] and the nitrogen fertilizer application amount N i in 7 days as decision variables; taking the minimum water stress index FWS in 7 days and the minimum nitrogen stress index FNS in 7 days as objective functions; the constraint conditions are the upper and lower limit constraints of the irrigation water W i and the nitrogen fertilizer application amount N i , the proportional constraint of the irrigation water W i and the nitrogen fertilizer application amount N i , the non-negative constraint of the water stress index FWS in 7 days and the nitrogen stress index FNS in 7 days;

[0015] S3, data acquisition: real-time monitoring of environmental information in the irrigation area, obtaining meteorological data, soil data and crop data;

[0016] S4, solving the water and fertilizer integration decision model using the data obtained in step S3: using the improved grey wolf algorithm to solve the optimal solution set of the water and fertilizer integration decision model, then determining the optimal solution according to the maximum value of the vector angle formed by the adjacent solutions in the solution set, and outputting the optimal irrigation water quantity W every day within 7 days i and nitrogen fertilizer application amount N i ;

[0017] S5, irrigation execution: the control unit obtains the phosphorus fertilizer application amount and the potassium fertilizer application amount according to the nitrogen, phosphorus and potassium fertilizer application ratio and the nitrogen fertilizer application amount output by the water and fertilizer integration decision model, and sends the irrigation water quantity, the nitrogen fertilizer application amount, the phosphorus fertilizer application amount and the potassium fertilizer application amount to the fertilizer outlet pump of the water pump, the nitrogen fertilizer storage tank, the phosphorus fertilizer storage tank and the potassium fertilizer storage tank respectively, the fertilizer outlet pump delivers the fertilizer to the water and fertilizer mixing box through the liquid fertilizer suction pipe, the irrigation water is delivered to the water and fertilizer mixing box through the water pump outlet pipe by the water pump, the water and fertilizer are mixed in the water and fertilizer mixing box by the water and fertilizer mixer, and then delivered to the water hose pipe through the outlet at the bottom of the water and fertilizer mixer, and finally the crops are irrigated by the spray tank head.

[0018] Further, the water and fertilizer integration decision model constructed in step S2 is specifically:

[0019] Objective function 1: minimum water stress index FWS within 7 days:

[0020]

[0021]

[0022] W T =(θ max -θ min )·D R (3)

[0023] W A =(θ max -θ * )·D R (4)

[0024] W C,i+1 =W C,i -α·W P,i -W i -W CR +W ETC,i +W DP (5)

[0025]

[0026] In the formula, WSi is the water stress index on day i, WS i ≥ 1 means no water stress, 0 < WS i < 1 means water stress, WS i = 0 means full water stress; W T is the total available water of the soil; W A is the available water within the crop root zone; θ max is the maximum value of water that the soil can hold; θ min is the soil water content at which the crop can no longer extract water from the soil; θ * is the critical water content at which water stress occurs; D R is the effective depth of the crop root zone;

[0027] W C,i is the root zone water consumption at which water stress occurs on day i, where W C,i , i = 1 is the W C,i , i = 7, the first running period W C,i = 0, i = 1; W P，i is the rainfall within the irrigation zone on day i; W i is the irrigation water on day i; W ETC，i is the evaporation on day i; W CR is the daily groundwater recharge; W DP is the leakage; a is the rainfall infiltration coefficient;

[0028] k C is the crop correction factor; ET i is the reference evapotranspiration on day i; R i is the net radiation on day i; G i is the soil heat flow on day i, G i = 0.1 R i ; y is the air humidity constant; T i is the daily average air temperature on day i; u i is the wind speed at two meters on day i; e s,i - e a,i is the water vapor pressure difference on day i, i.e. the difference between the saturated water vapor pressure and the actual water vapor pressure; a is the slope of the saturated water vapor pressure curve;

[0029] Objective function 2: Minimize the nitrogen stress index FNSover 7 days:

[0030]

[0031]

[0032] N * = e 1.52-2·phen(t)(9)

[0033] N act,i+1 = N act,i + N Mine,i + N i - N Up,i - N DP,i (10)

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041] In the formula, NS i is the nitrogen stress index of the ith day, NS i ≥ 1 indicates no nitrogen stress, 0 < NS i < 1 indicates nitrogen stress, NS i = 0 indicates complete nitrogen stress; N min is the minimum amount of nitrogen element; N * is the critical amount of nitrogen element; phen(t) is a parameter of the growth stage of the crop, determined by the actual growth day of the crop, 0 ≤ phen(t) ≤ 1;

[0042] N act，i is the actual amount of soil nitrogen element on the ith day, wherein N act，i of each operation period, i = 1 is equal to N act，i of the last operation period, i = 7, in the first operation period, N act，i , i = 1 is obtained by pre-experiment on the soil; N Mine，i is the amount of mineralized nitrogen element on the ith day; N i is the amount of nitrogen fertilizer applied on the ith day; N Up，i is the amount of nitrogen element actually absorbed by the crop on the ith day; N DP，i is the amount of leached nitrogen element on the ith day; E SOM is the influence coefficient of soil organic matter on the supply of soil nitrogen element; q 10 is the soil mineralization temperature coefficient; T S,i is the soil temperature on the ith day; MR is the proportion of mineralized nitrogen in total nitrogen; SOM is the soil organic matter content;

[0043] N Spl，i is the amount of nitrogen that the soil can provide for the crop on the i-th day; N Rq，i is the amount of nitrogen required by the crop on the i-th day;

[0044] RLD i is the root length density on the i-th day; p S is the soil dry bulk density; ΔBio t is the potential biological increment of the crop on the t-th day; k is the crop growth coefficient; m is the correlation coefficient; Bio max is the maximum theoretical size of the organism; t0 is the initial crop age; t is the actual growth day of the crop, t≥t0>0; θ i is the average water content in the root zone on the i-th day;

[0045] Constraint 1: upper and lower limits of the irrigation water amount W i and the nitrogen fertilizer application amount N i :

[0046]

[0047] wherein, Q max is the maximum water supply amount of the water pump; N max is the maximum amount of nitrogen fertilizer of the nitrogen fertilizer storage tank; S is the irrigation area;

[0048] Constraint 2: proportion constraint of the irrigation water amount W i and the nitrogen fertilizer application amount N i :

[0049] β min ≤N i :W i ≤β max (19)

[0050] wherein, β max and β min are the maximum and minimum values of the volume ratio of the nitrogen fertilizer application amount and the irrigation water amount;

[0051] Constraint 3: water-fertilizer matching constraint:

[0052]

[0053] Constraint 4: non-negative constraint of the water stress index within 7 days and the nitrogen stress index within 7 days:

[0054]

[0055] Further, in the step S4, the improved grey wolf algorithm is solved specifically as follows:

[0056] S4-1 parameter initialization: initialize convergence coefficient A, swing coefficient C, upper limit of individuals in archive population AP max , maximum iteration number h max , randomly assign individuals in population, that is, randomly assign irrigation water amount W i and nitrogen fertilizer amount N i ; the randomly assigned values meet the constraint conditions described in step S2;

[0057] S4-2 calculate two objective functions of all individuals, if one solution does not exist any other solution simultaneously superior or equal to the solution in all objectives, the solution is non-dominated solution, store the solution into the archive population, and update parameters A and C:

[0058] A = 2a rand1-a (22)

[0059] C = 2 rand2 (23)

[0060] In the formula, a is a control parameter, and the value is 0-2; rand1 and rand2 are random numbers of 0-1;

[0061] S4-3 randomly select leader individuals according to probability: randomly select 3 leader individuals p in the archive population according to a certain probability, p∈α1, α2 and α3, the probability P j that each individual in the archive population is selected as a leader individual is calculated as:

[0062]

[0063] In the formula, c is a constant greater than 1; TNI j is the total number of individuals in the population where the individual j is located;

[0064] S4-4 update leader individuals p in the population:

[0065] D p = |C X tag (h)-X p (h) | (25)

[0066] X p (h+1) = X p (h)-A D p (26)

[0067] In the formula, D p is the distance vector between the leader individual p and the target; h is the iteration number; X tag (h) is the position vector of the target in the hth iteration; X p (h) and X p (h+1) are the position vectors of the leader individual p in the hth and h+1th iterations;

[0068] Update the position of other individuals ω in the population:

[0069] D ω = |C · X p (h)- X ω (h) | (p = a1, a2, a3) (27)

[0070]

[0071] In the formula, D ω is the distance vector of the ω individual and the leader individual p; X p (h) is the position vector of the leader individual in the hth iteration; X ω (h) and X ω (h+1) are the position vectors of the ω individual in the hth and h+1th iterations;

[0072] S4-5 compares the dominance relationship between the individual obtained in this iteration and the individual in the archive population, and deletes the individual in the archive population dominated by the new individual, if the number of individuals in the archive population is greater than AP max , then calculate the crowding distance of each individual in the archive population, and delete the individual with the largest crowding distance; the crowding distance of the jth individual in the archive population is:

[0073]

[0074] In the formula, f k,max and f k,min are the maximum value and the minimum value of the individual in the archive population on the kth objective; f k, (j+1) and f k, (j-1) are the kth objective values of the individual j+1 and the individual j-1 adjacent to the individual j; n is the number of objective functions, n = 2;

[0075] S4-6 repeats steps S4-2 to S4-4 until the iteration number h ≥ h max , and obtains the final solution set from the archive population, representing the optimal solution set of the water and fertilizer integration decision model;

[0076] S4-7 determines the optimal solution from the optimal solution set: calculates the angle η j between the vector M j-1 and the vector N j+1 formed by the adjacent points AP j and AP j of each point AP j in the optimal solution set of the water and fertilizer integration decision model, if η j > η j+1 , then η jThe corresponding point j is the optimal solution of the water and fertilizer integrated decision model:

[0077] M j = AP j - AP j-1 (30)

[0078] N j = AP j+1 - AP j (31)

[0079]

[0080] In the formula, eta j is the included angle of AP j and the vectors formed by adjacent points AP j-1 and AP j+1 ; M j，x , N j，x and M j，y , N j，y are the components of vectors M j and N j in the x and y directions.

[0081] Further, in the step S5, the nitrogen, phosphorus and potassium fertilization ratio is determined according to the crop type and the experienced fertilization volume ratio; if there is no experience value, the volume ratio of the applied nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer is 1.00:0.50:0.67.

[0082] The present application has the following beneficial effects: (1) the present application provides a water and fertilizer integrated device, which calculates the daily irrigation water volume and nitrogen fertilizer application amount within 7 days through the control unit according to the data, and then calculates the phosphorus fertilizer and potassium fertilizer application amount according to the nitrogen, phosphorus and potassium fertilizer ratio, and the control unit delivers the irrigation water volume and the nitrogen, potassium and phosphorus fertilizer application amount to the water pump and the fertilizer pump respectively, controls the water and fertilizer ratio according to the actual situation and mixes them, and then sprays the crops through the irrigation execution unit after mixing, solves the problem of ignoring future precipitation in the prior art, which is easy to cause repeated irrigation and causes water resource waste and low rainwater utilization rate; realizes self-adaptive irrigation.

[0083] (2) the device of the present application adopts advanced differential positioning technology, and combines the setting of the irrigation path, not only greatly saves the human resources and reduces the cost, but also effectively avoids the problem of repeated irrigation caused by improper manual operation, thereby improving the irrigation efficiency and the quality of crop growth.

[0084] (3) The water and fertilizer integrated irrigation decision-making model of the application, according to the intelligent water and fertilizer integrated demand, comprehensively considers future meteorological conditions and crop growth demand, takes the minimum water stress index (FWS) in 7 days and the minimum nitrogen stress index (FNS) in 7 days as the target, constructs an intelligent irrigation and fertilization decision-making method, and can output accurate irrigation and fertilization amount, and outputs the decision-making result to a water and fertilizer integrated device, thereby improving the intelligent degree of irrigation and fertilization decision-making. BRIEF DESCRIPTION OF DRAWINGS

[0085] Figure 1 is a water and fertilizer integrated device water and fertilizer mixing unit schematic diagram provided by the embodiment of the application;

[0086] Figure 2 is a water and fertilizer integrated device irrigation execution unit schematic diagram provided by the embodiment of the application;

[0087] Figure 3 is a water and fertilizer integrated device supplementary diagram provided by the embodiment of the application;

[0088] Figure 4 is a flowchart of the solution of the target function provided by the embodiment of the application.

[0089] In the figure, 1-1 is a water pump, 1-2 is a water and fertilizer mixing box, 1-3 is a water and fertilizer mixing box top cover, 1-4 is a liquid fertilizer suction pipe, 1-5 is a water and fertilizer mixer, 1-6 is a nitrogen fertilizer storage tank, 1-7 is a phosphorus fertilizer storage tank, 1-8 is a potassium fertilizer storage tank, 1-9 is a water pump water suction pipe, 1-10 is a water pump water outlet pipe, 1-11 is a fertilizer injection port, 1-12 is a fertilizer outlet pump, 2-1 is a water pipe belt, 2-2 is a water pipe reel, 2-3 is an irrigation execution controller, 2-4 is an irrigation frame, 2-5 is a sprinkler head, 2-6 is a track, 3 is a control unit, and 4 is a mounting base. DETAILED DESCRIPTION

[0090] The application will be further described below in combination with the drawings and the description of the drawings:

[0091] A water and fertilizer integrated device, the device comprising: a water and fertilizer mixing unit, an irrigation execution unit, a control unit 3, and a mounting base 4.

[0092] The water and fertilizer mixing unit comprises: a water pump 1-1, a water and fertilizer mixing box 1-2, a water and fertilizer mixing box top cover 1-3, a liquid fertilizer suction pipe 1-4, a water and fertilizer mixer 1-5, a nitrogen fertilizer storage tank 1-6, a phosphorus fertilizer storage tank 1-7, a potassium fertilizer storage tank 1-8, a water pump water suction pipe 1-9, a water pump water outlet pipe 1-10, a fertilizer injection port 1-11, and a fertilizer outlet pump 1-12.

[0093] The water and fertilizer mixing unit is installed on the installation base 4; the water and fertilizer mixing box 1-2 is installed in the center of the installation base 4, the top of the water and fertilizer mixing box 1-2 is provided with a water and fertilizer mixing box top cover 1-3, and the bottom is provided with a water and fertilizer mixer 1-5; a paddle is arranged in the water and fertilizer mixer 1-5 and connected with the control unit 3, the control unit 3 controls the paddle to fully mix the injected liquid fertilizer and irrigation water through mechanical stirring; the bottom of the water and fertilizer mixer 1-5 is provided with an outlet and connected to the irrigation execution unit; the left side of the water and fertilizer mixing box 1-2 is provided with a water pump 1-1, the water pump 1-1 is fixed on the installation base 4 through a water pump base; the water suction port of the water pump suction pipe 1-9 is provided with a plurality of filter screens to filter the irrigation water entering the water and fertilizer mixer 1-5; the water pump 1-1 is connected with the water and fertilizer mixing box 1-2 through a water pump outlet pipe 1-10; the front side of the water and fertilizer mixing box 1-2 is provided with a nitrogen fertilizer storage tank 1-6, a phosphorus fertilizer storage tank 1-7 and a potassium fertilizer storage tank 1-8, and is fixed on the installation base 4; the top of the nitrogen fertilizer storage tank 1-6, the phosphorus fertilizer storage tank 1-7 and the potassium fertilizer storage tank 1-8 is provided with a fertilizer outlet pump 1-12; the fertilizer outlet pump 1-12 is provided with a fertilizer injection port 1-11, liquid fertilizer can be supplemented into the storage tank through the fertilizer injection port 1-11; the nitrogen fertilizer storage tank 1-6, the phosphorus fertilizer storage tank 1-7 and the potassium fertilizer storage tank 1-8 are connected with the water and fertilizer mixing box top cover 1-3 through a liquid fertilizer suction pipe 1-4 and penetrate the water and fertilizer mixer 1-5, the liquid fertilizer stored in the tank is injected into the water and fertilizer mixing box 1-2 through the liquid fertilizer suction pipe 1-4; the nitrogen fertilizer storage tank 1-6, the phosphorus fertilizer storage tank 1-7 and the potassium fertilizer storage tank 1-8 are provided with a liquid level detector, when the storage amount of liquid fertilizer in the tank is less than 10% of the total amount, the liquid level detector sends a signal to the control panel in the control unit 3 and displays on the control panel, reminding the user; the water pump 1-1 and the fertilizer outlet pump 1-12 in the tank body are connected with the control unit 3, and the mixing ratio of irrigation water and liquid fertilizer in the water and fertilizer mixing box 1-2 can be accurately controlled.

[0094] The irrigation execution unit comprises a water pipe belt 2-1, a water pipe reel 2-2, an irrigation execution controller 2-3, an irrigation frame 2-4, a sprinkler head 2-5 and a track 2-6.

[0095] The water pipe belt 2-1 is connected with the outlet at the bottom of the water and fertilizer mixing device 1-5 and is wound on the water pipe reel 2-2; the water pipe belt 2-1 can be extended according to actual irrigation needs; the water pipe reel 2-2 is installed on the side longitudinal beam of the irrigation frame 2-4; the irrigation execution controller 2-3 and the sprinkler head 2-5 are installed on the upper side and the lower side of the middle cross beam of the irrigation frame 2-4; the sprinkler head 2-5 is connected with the water pipe belt 2-1; the irrigation frame 2-4 is provided with the caterpillar track 2-6 at the bottom of both sides; the irrigation execution controller 2-3 is connected with the control unit 3, the control unit 3 sends the preset irrigation path to the irrigation execution controller 2-3, the irrigation execution controller 2-3 is provided with a differential positioning chip, which can enhance the GPS signal according to the correction signal of the ground base station and drive the caterpillar track 2-6 to adjust the advancing direction and speed in real time, so as to ensure accurate movement according to the predetermined path.

[0096] The control unit 3 is fixed to the front side of the installation base 4; the control unit 3 is provided with a full-automatic weather station, a soil moisture meter, a crop growth sensor and a control panel, which realize comprehensive monitoring and control of the whole irrigation process; the full-automatic weather station is used to obtain the rainfall in the irrigation area in 7 days, the daily average temperature, the wind speed at 2m, the net radiation, the actual water vapor pressure; the soil moisture meter is used to obtain the real-time temperature of the soil in the irrigation area, the average water content in the root zone, the groundwater recharge, the leakage, the maximum value of the soil that can contain water, the soil water content when the crop cannot absorb water from the soil and the minimum amount of nitrogen element are obtained through soil pre-experiment and input into the control panel; the crop growth sensor is used to detect the effective depth of the crop root system; the control panel is used to input the preset irrigation path and the irrigation area, the influence coefficient of soil organic matter on soil nitrogen supply, the soil mineralization temperature coefficient, the proportion of mineralized nitrogen in total nitrogen, the soil organic matter content, the soil dry bulk density, the crop type and the actual generation days of the crop.

[0097] In operation, the control unit 3 calculates the amount of phosphorus fertilizer and potassium fertilizer according to the nitrogen-phosphorus-potassium fertilizer ratio and the nitrogen fertilizer application amount output by the water-fertilizer integration decision model, and sends the irrigation water amount, the nitrogen fertilizer application amount, the phosphorus fertilizer application amount, and the potassium fertilizer application amount output by the water-fertilizer integration decision model to the water pump 1-1 and the fertilizer outlet pump 1-12 at the top of the nitrogen fertilizer storage tank 1-6, the phosphorus fertilizer storage tank 1-7, and the potassium fertilizer storage tank 1-8. The fertilizer outlet pump 1-12 delivers the liquid fertilizer to the water-fertilizer mixing box 1-2 through the liquid fertilizer suction pipe 1-4. At the same time, the irrigation water is first pumped by the water pump 1-1 and delivered to the water-fertilizer mixing box 1-2 through the water pump water suction pipe 1-9 and the water pump water outlet pipe 1-10. In the water-fertilizer mixing box 1-2, the water-fertilizer mixer 1-5 fully mixes the irrigation water and the liquid fertilizer, and then delivers the mixed water and fertilizer to the water pipe belt 2-1 through the outlet at the bottom of the water-fertilizer mixer 1-5. Finally, the sprinkler head 2-5 completes the irrigation of the crops, realizing the integration of irrigation and fertilization. In addition, according to the instructions of the control unit 3, the irrigation execution controller 2-3 drives the crawler belt 2-6 installed at the bottom of the irrigation frame 2-4 to move along the predetermined path, and uniformly irrigates the entire irrigation area through the sprinkler head 2-5.

[0098] The water-fertilizer integrated irrigation method includes the following steps:

[0099] S1 connect the water pump water suction pipe 1-9 to the irrigation water, and connect the outlet at the bottom of the water-fertilizer mixer 1-5 to the water pipe belt 2-1;

[0100] S2 build a water-fertilizer integration decision model in the control unit 3: take the irrigation water amount W i (i = 1-7) and the nitrogen fertilizer application amount N i in 7 days as decision variables; take the minimum water stress index (FWS) in 7 days and the minimum nitrogen stress index (FNS) in 7 days as the objective functions, as shown in equations (33)-(49); and take the upper and lower limit constraints of the irrigation water amount W i and the nitrogen fertilizer application amount N i , the proportion constraints of the irrigation water amount W i and the nitrogen fertilizer application amount N i , the water-fertilizer matching constraints, and the non-negative constraints of the water stress index (FWS) in 7 days and the nitrogen stress index (FNS) in 7 days as constraint conditions, as shown in equations (50), (51), (52), and (53);

[0101] Objective function 1: minimum water stress index (FWS) in 7 days:

[0102]

[0103]

[0104] W T = (θ max - θmin )·D R (35)

[0105] W A =(θ max -θ * )·D R (36)

[0106] W C,i+1 =W C,i -α·W P,i -W i -W CR +W ETC,i +W DP (37)

[0107]

[0108] In the formula, WS i is the water stress index on the i (i = 1-7) day, WS i ≥ 1 indicates no water stress, 0 < WS i < 1 indicates water stress, WS i = 0 indicates complete water stress, W T , W A is the total available water of the soil, the available water in the crop root zone; W C,i+1 is the root zone water consumption when water stress occurs on the i+1 day; W C,i is the root zone water consumption when water stress occurs on the i day, wherein W C,i (i = 1) of each operation cycle is equal to W C,i (i = 7) of the last operation cycle, W C,i (i = 1) = 0 in the first operation cycle; W P，i , W i and W ETC , i (mm / d) is the rainfall, irrigation water and evaporation in the irrigation area on the i day; W CR and W DP (mm / d) indicate the daily groundwater recharge and leakage; θ max , θ min and θ * (m 3 / m 3 ) are the maximum value of the soil capable of containing water, the soil water content when the crop can no longer extract water from the soil and the critical water content when water stress occurs; D R is the effective depth of crop roots (cm); α is the rainfall infiltration coefficient, α = 0 when W P，i < 5 mm / d, and α = 0 when 5 ≤ W P，i<50 mm / d, a = 0.9, when W P，i ≥ 50 mm / d, a = 0.7; k C is the crop correction factor; R i (MJ / (m 2 ·d)) is the net radiation on the i-th day, G i (G i = 0.1 R i )(MJ / (m 2 ·d)) is the soil heat flow on the i-th day; T i (°C) is the daily average air temperature on the i-th day; γ (kPa / °C) is the air humidity constant, in the present example γ = 0.0673 kPa / °C; e s,i -e a,i (kPa) is the water vapor pressure difference (difference between the saturated water vapor pressure and the actual water vapor pressure) on the i-th day; u i (m / s) is the wind speed at two meters on the i-th day; Δ is the slope of the saturation water vapor pressure curve; ET i is the reference evapotranspiration on the i-th day.

[0109] Objective function 2: minimum nitrogen stress index (FNS) over 7 days:

[0110]

[0111]

[0112] N * = e 1.52-2·phen(t) (41)

[0113] N act,i+1 = N act,i +N Mine,i +N i -N Up,i -N DP,i (42)

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121] where NSi is the nitrogen stress index on the i-th day (i = 1-7), NS i ≥ 1 means no nitrogen stress, 0 < NS i < 1 means nitrogen stress, NS i = 0 means complete nitrogen stress; N min and N * (N-g / m 2 ) is the amount of minimum nitrogen element and the amount of critical nitrogen element; N act，i+1 is the amount of actual soil nitrogen element on the i+1-th day; N act，i is the amount of actual soil nitrogen element on the i-th day, where N act，i (i = 1) of the last running cycle equals N act，i (i = 7) of the first running cycle, N act，i (i = 1) of the initial value is obtained by pre-experiment on soil; N Mine，i , N i , N Up，i and N DP，i (N-g / m 2 ) is the amount of mineralized nitrogen element, nitrogen fertilizer amount, the amount of actual nitrogen element absorbed by crops and leached nitrogen element on the i-th day; N Spl，i and N Rq，i (N-g / m 2 ) is the amount of nitrogen that soil can provide for crops and the amount of nitrogen demand required by crops on the i-th day; phen(t) is the parameter of crop growth stage and is determined by the actual growth day of crops, 0 ≤ phen(t) ≤ 1; E SOM is the influence coefficient of soil organic matter on soil nitrogen element supply; q 10 is the soil mineralization temperature coefficient; T S,i (℃) is the soil temperature on the i-th day; MR is the proportion of mineralized nitrogen in total nitrogen; SOM (g / kg) is the soil organic matter content; RLD i (cm / cm 3 ) is the root length density on the i-th day, RLD i = D R * the distance between two crops; p S (g / cm 3 ) is the soil dry bulk density; t0(d) is the initial crop age, which is zero (usually a very small value or approximately zero); t(d) is the actual growth day of crops, t ≥ t0> 0; ΔBio t is the potential biological increment of crops on the t-th day; k is the crop growth coefficient; m is the correlation coefficient, which is determined by fitting according to crop types through pre-experiment on crops; Bio max (cm) is the maximum theoretical size of the organism; θ i (m 3 / m3 ) is the average water content of the root zone on day i.

[0122] Constraint 1: irrigation water amount W i (mm / d) and nitrogen fertilizer amount N i (N-g / m 2 ·d) are within the upper and lower limits:

[0123]

[0124] where Q max (m 3 / h) is the maximum water supply of the water pump in the device; N max (kg) is the maximum amount of nitrogen fertilizer stored in the device; S is the irrigation area (m 2 ) controlled by the device.

[0125] Constraint 2: the ratio constraint of irrigation water amount W i and nitrogen fertilizer amount N i :

[0126] β min ≤ N i : W i ≤ β max (51)

[0127] where β max and β min are the maximum and minimum values of the volume ratio of nitrogen fertilizer amount and irrigation water amount, β max = 4%, and β min = 1%.

[0128] Constraint 3: water-fertilizer matching constraint, for day i, if irrigation water amount W i is 0 mm / d, then the corresponding fertilizer amount N i must be 0 N-g / m 2 ·d; if irrigation water amount W i is greater than 0 mm / d, then the fertilizer amount is any non-negative value that satisfies the constraint:

[0129]

[0130] Constraint 4: non-negative constraint of water stress index within 7 days and nitrogen stress index within 7 days:

[0131]

[0132] (S2) Data acquisition: real-time monitoring of information in the irrigation area, the first type is meteorological data, including rainfall W P，i , daily average temperature T i , wind speed u i, net radiation R i , water vapor pressure difference e s,i -e a,i , obtained by the automatic weather station; the second type is soil data, including soil temperature T S,i , average water content of root zone θ i , obtained by soil moisture meter, groundwater recharge W CR , leakage W DP , the maximum value of water that soil can hold θ max , soil water content θ min when the plant can no longer extract water from the soil, and the minimum amount of nitrogen element N min , obtained by soil pre-experiment; the influence coefficient of soil organic matter on soil nitrogen supply E SOM , soil mineralization temperature coefficient q 10 , the proportion of mineralized nitrogen in total nitrogen MR, soil organic matter content SOM and soil dry bulk density ρ S , obtained by inputting the control panel; the third type is crop data, including crop type, actual growth days of crop t, critical amount of nitrogen element N * , critical water content θ * when water stress occurs, the crop type is obtained by inputting the control panel, and the effective depth of crop root system D R , obtained by crop growth sensor.

[0133] (S3) Solution of the above water and fertilizer integrated decision model: using the improved grey wolf algorithm, adding an adaptive local search mechanism, initializing a population, and iterating the solution by simulating the behavior of individuals in the population, evaluating the dominance relationship between these solutions, obtaining an optimal solution set, and determining the theoretically optimal solution according to the maximum value of the vector angle formed by adjacent solutions in the solution set, and finally outputting the irrigation amount W i (i=1-7) and nitrogen fertilizer application amount N i (i=1-7) in 7 days, the specific method is as follows:

[0134] S3-1 parameter initialization: initialize convergence coefficient A, swing coefficient C, and upper limit of number of individuals in archive population AP max , maximum iteration number h max , randomly assign values to individuals in the population, that is, randomly assign irrigation water amount W i and nitrogen fertilizer application amount N i , the random assignment satisfies the above constraint conditions.

[0135] S3-2 Calculate two objective functions of all individuals, if a solution does not exist any other solution simultaneously superior or equal to the solution in all objectives, the solution is a non-dominated solution, store the solution in the archive population, and update parameters A and C

[0136] A = 2a • randl - a (54)

[0137] C = 2 • rand2 (55)

[0138] In the formula, A is the convergence coefficient; C is the swing coefficient; a is the control parameter, which is 0-2; randl and rand2 are random numbers between 0 and 1.

[0139] S3-3 Randomly select leader individuals according to probability: randomly select three leader individuals p (p e a1, a2 and a3) in the archive population according to a certain probability based on the roulette method, and the probability P that each individual in the archive population is selected as a leader individual is j The calculation formula is:

[0140]

[0141] In the formula, c is a constant greater than 1; TNI j is the total number of individuals in the population where the individual j is located.

[0142] S3-4 Update the position update mode of the leader individual p (p e a1, a2 and a3) and other individuals ω in the population:

[0143] D p = | C • X tag (h) - X p (h) | (p e a1, a2, a3) (57)

[0144] X p (h+1) = X p (h) - A • D p (p e a1, a2, a3) (58)

[0145] In the formula, D p is the distance vector between the leader individual p and the target; h is the iteration number; X tag (h) is the position vector of the target in the hth iteration; X p (h) and X p (h+1) are the position vectors of the leader individual p (p e a1, a2 and a3) in the hth and (h+1)th iterations; A is the convergence coefficient; C is the swing coefficient.

[0146] The other individuals ω in the population search for the target under the leadership of the leader individual p, and the position update mode is:

[0147] D ω = | C • X p (h) - X ω (h) | (p = a1, a2, a3) (59)

[0148]

[0149] where D ω is the distance vector of ω individual and leader individual p (p e a1, a2 and a3); X p (h) is the position vector of leader individual in the hth iteration; X ω (h) and X ω (h+1) are the position vector of ω individual in the hth and (h+1)th iteration.

[0150] S3-5 Compare the dominance relation of the individual obtained in this iteration and the individual in the archive population, and delete the individual in the archive population dominated by the new individual, if the number of individual in the archive population is greater than AP max , then calculate the crowding distance of each individual in the archive population, and delete the individual with the largest crowding distance; the crowding distance of the jth individual in the archive population is:

[0151]

[0152] where f k,max and f k,min are the maximum and minimum values of the individual in the archive population on the kth objective; f k, (j+1) and f k, (j-1) are the kth objective values of the (j+1)th and (j-1)th individuals adjacent to the individual j; n is the number of objective functions, n = 2.

[0153] S3-6 Repeat steps S3-2 to S3-4 until the iteration number h ≥ h max , obtain the final solution set from the archive population, which represents the optimal solution set of the water and fertilizer integration decision model.

[0154] S3-7 Determine the optimal solution from the optimal solution set: calculate the angle η j between the vector M j-1 and the vector N j+1 formed by the adjacent points AP j and AP j of the point AP j in the optimal solution set of water and fertilizer management strategy, if η j > η j+1 , then η j corresponding to the point j is the optimal solution of the water and fertilizer integration decision model:

[0155] M j = AP j - AP j-1 (62)

[0156] N j= AP j+1 - AP j (63)

[0157]

[0158] wherein η j is the angle between the vectors formed by the adjacent points AP j and AP j-1 and AP j+1 ; M j，x , N j，x and M j , y , N j，y are the components of the vectors M j and N j in the x and y directions, respectively;

[0159] S4 irrigation execution: one irrigation is carried out immediately after planting, and the irrigation amount is determined to reach θ max , at which time the water and fertilizer integration decision model is the first running cycle, W C,i (i = 1) = 0, N act,i = 0 (i = 1) are obtained through soil pre-experiment; then, the running is repeated every 7 days, and the control unit 3 obtains the phosphorus fertilizer application amount and the potassium fertilizer application amount according to the nitrogen, phosphorus and potassium fertilizer application ratio and the nitrogen fertilizer application amount output by the water and fertilizer integration decision model, and the control unit sends the irrigation water amount, the nitrogen fertilizer application amount, the phosphorus fertilizer application amount and the potassium fertilizer application amount to the fertilizer outlet pump of the water pump, the nitrogen fertilizer storage tank, the phosphorus fertilizer storage tank and the potassium fertilizer storage tank, respectively, and the fertilizer outlet pump delivers the fertilizer to the water and fertilizer mixing box through the liquid fertilizer suction pipe, the irrigation water is delivered to the water and fertilizer mixing box through the water pump outlet pipe, the water and fertilizer are mixed in the water and fertilizer mixing box by the water and fertilizer mixer, and then delivered to the water hose pipe through the outlet at the bottom of the water and fertilizer mixer, and finally the crops are irrigated by the spray tank head. The application amounts of phosphorus fertilizer and potassium fertilizer are determined according to the crop type and the experienced fertilizer volume ratio; if there is no experience value, the volume ratio of applied nitrogen, phosphorus and potassium fertilizers is 1.00:0.50:0.67.

[0160] Table 1 Experience values of nitrogen, phosphorus and potassium fertilizer application ratio of part of crops

[0161]

[0162] The following will be specifically described with examples. Taking the period from March 21, 2023 to March 27, 2023 in Hongjin irrigation area of Huai'an, Jiangsu as an example, the planted crop is winter wheat, the maximum value of soil water content that can be contained by the soil θ max = 0.40 m 3 / m 3 , and the soil water content when the crop can no longer absorb water from the soil θ min = 0.10 m3 / m 3 , critical water content θ at the time of just occurring moisture stress * = 0.19 m 3 / m 3 , critical amount of nitrogen element N * = 18 N-g / m 2 , minimum amount of nitrogen element N min = 5 N-g / m 2 , leakage amount W DP = 7 mm / d, groundwater recharge amount W CR = 5 mm / d, soil dry bulk density ρ S = 1.325 g / cm 3 , soil organic matter content SOM = 33.5 (g / kg), soil mineralization temperature coefficient q 10 = 1.5, soil temperature T s，i = 10℃, ratio of mineralized nitrogen to total nitrogen MR = 15%, maximum theoretical size of organism Bio max = 80 cm, ratio of nitrogen, phosphorus, and potassium fertilizers = 1:0.44:0.93; in the improved grey wolf algorithm, population number = 100, maximum iteration number h max = 150, upper limit of individuals in the archive population AP max = 50.

[0163] Table 2: Parameters in the example

[0164] Number Date ET i ]] D R ]]> [WC A ]]> k C ]]> [WC P，i ]]> RLD i ]]> t

[0010] N act，i ]]> i ]]> ​ Unit mm / d m mm 1 mm cm / cm 3 ]]> d N-g / m 2 ]]> m 3 / m 3 ]]> 1 2023 / 3 / 21 3.8 0.21 26 1 10 1.8 165 25 0.21 2 2023 / 3 / 22 4.9 0.21 24 1 0 1.8 166 25 0.25 3 2023 / 3 / 23 3.9 0.21 25 1 12 1.8 167 24 0.28 4 2023 / 3 / 24 5.1 0.22 24 1 0 1.8 168 24 0.26 5 2023 / 3 / 25 5.0 0.22 25 1 0 1.8 169 23 0.23 6 2023 / 3 / 26 4.8 0.23 24 1 0 1.8 170 22 0.2 7 2023 / 3 / 27 5.8 0.23 23 1 0 1.8 171 26 0.26

[0165] Table 3: Calculated daily irrigation and fertilization amounts

[0166] Number i Date Irrigation water volume W i ]]> Nitrogen fertilization amount N i ]]> mm / d N-g / m 2 ·d]]> 1 2023 / 3 / 21 0 0 2 2023 / 3 / 22 0 0 3 2023 / 3 / 23 0 0 4 2023 / 3 / 24 0 0 5 2023 / 3 / 25 0 0 6 2023 / 3 / 26 10 6 7 2023 / 3 / 27 0 0

[0167] The basic principles, main features, and advantages of the present application are shown and described above. However, the above description is only a specific embodiment of the present application, and the technical features of the present application are not limited thereto. Any other embodiments obtained by those skilled in the art without departing from the technical solution of the present application should be covered in the patent scope of the present application.

Claims

1. A method of water and fertilizer integrated irrigation, characterized by, Comprise the following steps: S1, the water pump suction pipe (1-9) is connected with irrigation water; S2, constructing water and fertilizer integration decision model: taking irrigation water W i , i = [1, 7] and nitrogen fertilizer application amount N i in 7 days as decision variables; taking the minimum of water stress index FWS in 7 days and the minimum of nitrogen stress index FNS in 7 days as objective functions; the constraint conditions are the upper and lower limit constraints of irrigation water W i and nitrogen fertilizer application amount N i , the proportion constraints of irrigation water W i and nitrogen fertilizer application amount N i , water and fertilizer matching constraints, non-negative constraints of water stress index FWS in 7 days and nitrogen stress index FNS in 7 days; The water and fertilizer integrated decision model in the step S2 is specifically: Objective function 1: the water stress index FWS in 7 days is minimum: W T = (θ max - θ min ) · D R (3) W A = (θ max - θ * ) · D R (4) W C,i+1 = W C,i - a - W P,i - W i - W CR + W ETC,i + W DP (5) In the formula, WS i WS is the water stress index on day i. i ≥1 indicates no water stress, 0 <WS i <1 indicates water stress, WS i =0 indicates complete water stress; W T Total available water in the soil; W A It is the amount of available water in the crop root zone; θ max θ represents the maximum amount of water that the soil can hold; min θ represents the soil moisture content at which crops can no longer absorb water from the soil. * D is the critical water content at which water stress just begins; R It is the effective depth of the crop root system; W C,i This is the root zone water consumption on day i when water stress occurs, where W is the water consumption for each operating cycle. C,i i=1 equals W of the previous running cycle C,i i=7, first running cycle W C,i =0, i=1; W P，i W represents the rainfall in the irrigation area on day i. i W represents the irrigation water volume on day i. ETC，i W represents the evaporation on day i. CR W represents the daily groundwater recharge. DP α is the leakage rate; k is the rainfall infiltration coefficient; C It is the crop correction factor; ET i R is the reference evapotranspiration on day i; i It is the net air radiation on day i; G i It is the soil heat flow on day i, G i =0.1R i γ is the air humidity constant; T i It is the average daily temperature of day i; u i It is the wind speed at two meters on day i; e s,i -e a,i is the water vapor pressure difference on day i, that is, the difference between the saturated water vapor pressure and the actual water vapor pressure; Δ is the slope of the saturated water vapor pressure curve; Objective function 2: the nitrogen stress index FNS in 7 days is minimum: N * = e 1.52-2·phen(t) (9) N act,i+1 = N act,i + N Mine,i + N i - N Up,i - N DP,i (10) wherein NS i is the nitrogen stress index of the i-th day, NS i ≥ 1 means no nitrogen stress, 0 < NS i < 1 means nitrogen stress, NS i = 0 means complete nitrogen stress; N min is the minimum amount of nitrogen element; N * is the critical amount of nitrogen element; phen(t) is a parameter of the growth stage of the crop, determined by the actual growth days of the crop, 0 ≤ phen(t) ≤ 1; N act，i is the actual amount of nitrogen element in the soil of the i-th day, wherein N act，i of each operation cycle is the N act，i of the previous operation cycle, i = 1; N act，i of the first operation cycle, i = 7, N Mine，i is obtained by pre-experiment on the soil; N Mine，i is the amount of mineralized nitrogen element of the i-th day; N i is the amount of nitrogen fertilizer applied on the i-th day; N Up，i is the amount of nitrogen element actually absorbed by the crop on the i-th day; N DP，i is the amount of leached nitrogen element on the i-th day; E SOM is the influence coefficient of soil organic matter on the supply of soil nitrogen element; q 10 is the soil mineralization temperature coefficient; T S,i is the soil temperature of the i-th day; MR is the proportion of mineralized nitrogen in total nitrogen; SOM is the soil organic matter content; N Spl，i is the amount of nitrogen that the soil can provide for the crop on the i-th day; N Rq，i is the amount of nitrogen required by the crop on the i-th day; RLD i is the root length density of the i-th day; p S is the dry bulk density of the soil; ABio t is the potential biological increment of the crop on the t-th day; k is the growth coefficient of the crop; m is the correlation coefficient; Bio max is the maximum theoretical size of the organism; t0 is the initial crop age; t is the actual growth days of the crop, t ≥ t0 > 0; q i is the average water content in the root zone of the i-th day; Constraint 1: irrigation water amount W i and nitrogen fertilizer amount N i upper and lower limits: In the formula, Q max is the maximum water supply of the water pump; N max is the maximum amount of nitrogen fertilizer in the nitrogen fertilizer storage tank; S is the irrigation area; Constraint 2: irrigation water amount W i and nitrogen fertilizer amount N i ratio constraint: β min ≤N i :W i ≤β max (19) where β max and β min are the maximum and minimum values of the volume ratio of nitrogen fertilizer application and irrigation water quantity; Constraint condition 3: water and fertilizer matching constraint: Constraint condition 4: the water stress index in 7 days and the nitrogen stress index in 7 days are non-negative constraints: S3, data acquisition: real-time monitoring of environmental information in irrigation area, obtaining meteorological data, soil data and crop data; S4, using the data obtained in step S3 to solve the water and fertilizer integration decision model: using the improved grey wolf algorithm to solve the optimal solution set of the water and fertilizer integration decision model, then determining the optimal solution according to the maximum value of the vector angle formed by the adjacent solutions in the solution set, and outputting the optimal irrigation water amount W per day within 7 days i and nitrogen fertilizer application amount N i ; In the step S4, the improved grey wolf algorithm is solved as follows: S4-1 parameter initialization: initialize convergence coefficient A, swing coefficient C, upper limit AP of individuals in archive population max , maximum iteration number h max , randomly assign individuals in the population, that is, randomly assign irrigation water W i and nitrogen fertilizer N i ; the random assignment satisfies the constraint conditions described in step S2; S4-2, the two objective functions of all individuals are calculated, if a solution does not exist any other solution simultaneously superior or equal to the solution in all targets, the solution is a non-dominated solution, the solution is stored in the archive population, and the parameters A and C are updated: A=2a·rand1-a (22) C=2·rand2 (23) In the formula, a is a control parameter, and the value is 0-2;rand1 and rand2 are random numbers of 0-1; S4-3 Randomly selecting leader individuals according to probability: three leader individuals p, p e ai, a2 and a3, are randomly selected from the archive population according to a certain probability P j The calculation formula is: where c is a constant greater than 1; TNI j is the total number of individuals in the population in which the individual j is located; S4-4, the position of the leader individual p in the population is updated: D p = |C·X tag (h)-X p (h)| (25) X p (h+1) = X p (h) - A - D p (26) where D p is the distance vector between the leader p and the target; h is the iteration number; X tag (h) is the position vector of the target in the hth iteration; X p (h) and X p (h+1) is the position vector of the leader p in the hth and h+1th iteration. The position of other individuals ω in the population is updated: D ω = |C · X p (h)-X ω (h) | (p = a1, a2, a3) (27) where D ω is the distance vector of the ω individual from the leader individual p; X p (h) is the position vector of the leader individual in the hth iteration; X ω (h) and X ω (h+1) is the position vector of the ω individual in the hth and h+1th iteration; S4-5 compare the dominance relation between the individual obtained in this iteration and the individuals in the archive population, and delete the individuals in the archive population dominated by the new individual, if the number of individuals in the archive population is greater than AP max Then, calculate the crowding distance of each individual in the archive population, and delete the individual with the largest crowding distance; the crowding distance of the jth individual in the archive population is: where f k,max and f k,min are the maximum and minimum values of the individual in the archive on the kth objective; f k , (j + 1) and f k , (j - 1) are the kth objective values of the individual j + 1 and j - 1 individuals that are adjacent to the individual j; n is the number of objective functions, n = 2; S4-6 repeat steps S4-2 to S4-4 until the iteration number h≥h max The final solution set is obtained from the archive population, representing the optimal solution set of the water and fertilizer integration decision model. S4-7 determining the optimal solution from the optimal solution set: calculating each point AP on the optimal solution set of the water and fertilizer integration decision model j and its adjacent point AP j-1 and AP j+1 The angle η between the vector M j and the vector N j j If η j > η j+1 , then η j The corresponding point j is the optimal solution of the water and fertilizer integration decision model:​ M j = AP j - AP j-1 (30) N j = AP j+1 - AP j (31) wherein η j is the angle between the vectors formed by the adjacent points AP j and AP j-1 and AP j+1 ; M j，x , N j，x and M j， y, N j，y are the components of the vectors M j and N j in the x and y directions, respectively; S5, irrigation execution: according to the nitrogen, phosphorus and potassium fertilizer application ratio and the nitrogen fertilizer application amount output by the water and fertilizer integrated decision model, the phosphorus fertilizer application amount and the potassium fertilizer application amount are obtained, the irrigation water amount, the nitrogen fertilizer application amount, the phosphorus fertilizer application amount and the potassium fertilizer application amount are sent to the water pump (1-1), the nitrogen fertilizer storage tank (1-6), the phosphorus fertilizer storage tank (1-7) and the potassium fertilizer storage tank (1-8) respectively, the fertilizer pump (1-12) is used to deliver the fertilizer to the water and fertilizer mixing box (1-2) through the liquid fertilizer suction pipe (1-4), the irrigation water is pumped by the water pump (1-1) through the water pump outlet pipe (1-10) and delivered to the water and fertilizer mixing box (1-2), the water and fertilizer mixer (1-5) is used for water and fertilizer mixing in the water and fertilizer mixing box (1-2), and then delivered to the water pipe belt (2-1) through the outlet at the bottom of the water and fertilizer mixer (1-5), finally, the crops are irrigated by the sprinkler head (2-5).

2. The method of water and fertilizer integrated irrigation according to claim 1, characterized in that, In the step S5, the nitrogen, phosphorus and potassium fertilizer application ratio is determined according to the crop type and the experienced fertilizer volume ratio;If there is no experience value, the volume ratio of the applied nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer is 1.00:0.50:0.

67.

3. A water and fertilizer integrated irrigation device for implementing the water and fertilizer integrated irrigation method of claim 1, characterized in that, It comprises a water and fertilizer mixing unit, an irrigation execution unit, a control unit (3) and a mounting base (4), the water and fertilizer mixing unit is installed on the mounting base (4), and the control unit (3) is installed on one side of the mounting base (4). The water and fertilizer mixing unit comprises a water pump (1-1), a water and fertilizer mixing box (1-2), a water and fertilizer mixing box top cover (1-3), a liquid fertilizer suction pipe (1-4), a water and fertilizer mixer (1-5), a nitrogen fertilizer storage tank (1-6), a phosphorus fertilizer storage tank (1-7), a potassium fertilizer storage tank (1-8), a water pump water suction pipe (1-9), a water pump water outlet pipe (1-10), a fertilizer injection port (1-11), and a fertilizer outlet pump (1-12); the top of the water and fertilizer mixing box (1-2) is provided with the water and fertilizer mixing box top cover (1-3), and the bottom of the water and fertilizer mixing box (1-2) is provided with the water and fertilizer mixer (1-5); the water and fertilizer mixer (1-5) is provided with a paddle, the paddle is connected with a control unit (3), the bottom of the water and fertilizer mixer (1-5) is provided with an outlet, and the outlet is connected to an irrigation execution unit; one side of the water pump (1-1) is connected with irrigation water through the water pump water suction pipe (1-9), and the other side of the water pump (1-1) is connected with the water and fertilizer mixing box (1-2) through the water pump water outlet pipe (1-10); the top of each of the nitrogen fertilizer storage tank (1-6), the phosphorus fertilizer storage tank (1-7), and the potassium fertilizer storage tank (1-8) is provided with the fertilizer outlet pump (1-12); the fertilizer outlet pump (1-12) is provided with the fertilizer injection port (1-11); the fertilizer outlet pump (1-12) is connected with the water and fertilizer mixing box top cover (1-3) through the liquid fertilizer suction pipe (1-4); the water pump (1-1) and the fertilizer outlet pump (1-12) are connected with the control unit (3), and the control unit (3) controls irrigation water quantity of the water pump (1-1) and a fertilizer mixing ratio of the fertilizer outlet pump (1-12). The irrigation execution unit comprises a water pipe belt (2-1), an irrigation frame (2-4), and a sprinkler head (2-5); the water pipe belt (2-1) is arranged at one end of the irrigation frame (2-4), the sprinkler head (2-5) is arranged at the lower side of a cross beam of the irrigation frame (2-4), the sprinkler head (2-5) is connected with the water pipe belt (2-1), and the water pipe belt (2-1) is connected with the water and fertilizer mixing unit. The control unit (3) is provided with a full-automatic weather station, a soil moisture meter, a crop growth sensor, and a control panel, the control unit (3) calculates irrigation water quantity and nitrogen fertilizer application quantity according to obtained data. 4.The water and fertilizer integrated irrigation device according to claim 3, characterized in that, The water pump water suction pipe (1-9) is provided with multiple layers of filter screens. 5.The water and fertilizer integrated irrigation device according to claim 3, characterized in that, The nitrogen fertilizer storage tank (1-6), the phosphorus fertilizer storage tank (1-7), and the potassium fertilizer storage tank (1-8) are each provided with a liquid level detector, and when the storage quantity of the liquid fertilizer in the nitrogen fertilizer storage tank (1-6), the phosphorus fertilizer storage tank (1-7), or the potassium fertilizer storage tank (1-8) is less than 10% of the total quantity, the liquid level detector sends a signal to a control panel in the control unit (3). 6.The water and fertilizer integrated irrigation device according to claim 3, characterized in that, One end of the irrigation execution unit is provided with a water pipe reel (2-2), one end of the water pipe belt (2-1) is connected with the outlet of the water and fertilizer mixer (1-5) of the water and fertilizer mixing unit, and the other end of the water pipe belt (2-1) is wound on the water pipe reel (2-2). 7.The water and fertilizer integrated irrigation device according to claim 3, characterized in that, The irrigation frame (2-4) is provided with a track (2-6) on the bottom of each side, the upper side of the beam of the irrigation frame (2-4) is provided with an irrigation execution controller (2-3), the irrigation execution controller (2-3) is connected with a control unit (3), a differential positioning chip is arranged in the irrigation execution controller (2-3), so that the irrigation execution unit can enhance the GPS signal according to the correction signal of the ground base station, and drive the track (2-6) to adjust the traveling direction and speed in real time.

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