A method for regulating water and fertilizer in sprinkler irrigation for water-saving and high-yield wheat

Abstract

The invention discloses a water-saving and high-yield sprinkler irrigation water and fertilizer control method for wheat, which comprises determining the application amount of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer of winter wheat in the whole growth period; after applying basic fertilizer, selecting drought-resistant wheat varieties for sowing; calculating the irrigation amount for wheat seedling emergence, and performing variable sprinkler irrigation; in the wheat overwintering period, calculating the irrigation amount according to soil moisture content and a second planned moist layer depth, and performing variable sprinkler irrigation; in the wheat greening to jointing period, determining the irrigation and fertilization period based on seedling conditions and soil moisture conditions, performing sprinkler irrigation, and performing variable nitrogen application according to a second preset proportion of the remaining nitrogen fertilizer application amount according to the nitrogen fertilizer deficiency spatial distribution; performing sprinkler irrigation from wheat heading to the early grain filling period, and performing variable nitrogen application according to the remaining nitrogen fertilizer application amount according to the nitrogen fertilizer deficiency spatial distribution; in the wheat filling period, dividing a research area into a plurality of management subareas according to the spatial distribution of normalized relative canopy temperature NRCT, determining the irrigation amount of each management subarea, and performing variable sprinkler irrigation.

Description

Technical Field

[0001] The invention relates to the technical field of crop irrigation and fertilization, and in particular to a water-saving and high-yield wheat sprinkler irrigation water and fertilizer regulation method. Background Art

[0002] Carrying out the action of increasing grain yield per unit area is an important measure to ensure national food security. As one of the key methods to increase grain yield per unit area, integrated water and fertilizer management is the key to further promoting the integration of good methods, good machines and good systems on the basis of good fields and good varieties. Constrained by labor costs, my country's farmland water and fertilizer management is gradually developing in the direction of simplification and intelligence. For example, the five irrigations of winter wheat in the North China Plain before sowing, wintering period, greening period, jointing period and flowering period are gradually being simplified to three irrigations before sowing, jointing period and flowering period. However, the simplified water management is difficult to match with different rainfall years, and there is a risk of frostbite of wheat in extremely cold years, or the risk of nutrient loss caused by excessive water volume during emergence. The goal of continuous water conservation and stable yield of wheat is difficult to achieve.

[0003] Compared with empirical irrigation, the irrigation system based on soil moisture conditions makes full use of natural rainfall by continuously monitoring the degree of soil moisture deficit. However, its shallow and frequent irrigation characteristics not only increase the number of irrigation times (7 to 10 times), but also its irrigation time does not match the farmers' conventional irrigation management time, which also limits the farmers' acceptance and use. In addition, water management based on soil moisture conditions can only achieve water-saving and stable yield effects because it ignores the seedling conditions, which is quite different from the expected water-saving and high-yield goals. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the water-saving and high-yield wheat sprinkler irrigation water and fertilizer regulation method provided by the present invention solves the problem that the prior art irrigation system based on soil moisture conditions has poor user acceptance and is difficult to achieve water-saving and high-yield.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] A method for regulating water and fertilizer in sprinkler irrigation for water-saving and high-yield wheat is provided, which comprises the following steps:

[0007] S1. Calculate the application amount of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer for winter wheat throughout the growth period based on the historical yield of the study area;

[0008] S2. According to the fertility level of the study area, all the phosphate fertilizers and potash fertilizers and the first preset ratio of nitrogen fertilizer are applied by broadcasting and mixed with the tillage layer soil;

[0009] S3, selecting a wheat variety with a water-saving coefficient greater than a preset value, and sowing at a preset density during the appropriate sowing period for wheat;

[0010] S4. Divide the study area into multiple management areas according to soil moisture content, calculate the irrigation amount for wheat emergence according to the average soil moisture content of the management area and the first planned wet layer depth, and carry out variable sprinkler irrigation;

[0011] S5. During the wintering period of wheat, the study area was divided into multiple management areas according to the soil moisture content. The irrigation amount was calculated according to the average soil moisture content of the management area and the second planned wet layer depth, and variable sprinkler irrigation was carried out;

[0012] S6. During the wheat greening to jointing period, determine the irrigation and fertilization period based on the seedling condition and soil moisture condition, perform sprinkler irrigation, and perform variable nitrogen application according to the second preset ratio of the remaining nitrogen fertilizer application amount based on the spatial distribution of nitrogen fertilizer deficiency;

[0013] S7. Sprinkler irrigation is carried out from the beginning of wheat heading to the early stage of grain filling, and the remaining nitrogen fertilizer application amount is variable nitrogen application according to the spatial distribution of nitrogen fertilizer deficiency;

[0014] S8. During the wheat filling period, the study area was divided into multiple management zones according to the spatial distribution of normalized relative canopy temperature (NRCT). The irrigation amount of each management zone was determined based on the center and filling watering amount of each management zone, and variable sprinkler irrigation was carried out.

[0015] Furthermore, the method for determining the irrigation and fertilization period in step S6 is:

[0016] When the seedlings are vigorous, if the soil moisture is severely water-deficient, the irrigation and fertilization period is the middle jointing stage; if the soil moisture is light to moderate water-deficient, the irrigation and fertilization period is the late jointing stage;

[0017] When the seedling condition is Class I, if the soil moisture condition is severe water shortage, the irrigation and fertilization period is the soil moisture collection period of the greening period; if the soil moisture condition is mild to moderate water shortage, the irrigation and fertilization period is the early to middle stage of jointing;

[0018] When the seedlings are of Class II, if the soil moisture is moderately water-deficient, the irrigation and fertilization period is the soil moisture collection period of the greening period; if the soil moisture is slightly water-deficient or not water-deficient, the irrigation and fertilization period is the late rising period;

[0019] When the seedling condition is Class III, if the soil moisture condition is slightly water-deficient, the period for irrigation and fertilization is the greening-rising stage; if the soil moisture condition is not water-deficient, the period for irrigation and fertilization is the rising stage.

[0020] Furthermore, the method of performing variable nitrogen application according to the spatial distribution of nitrogen fertilizer deficiency in step S6 and step S7 includes:

[0021] During the period from 11:00 to 14:00, a multispectral UAV imaging system was used to collect multispectral data of the study area, and after mosaicking, the spatial distribution map of the red-edge soil-adjusted vegetation index of the entire farmland was obtained;

[0022] According to the water distribution characteristics of the sprinkler, the study area was divided into several grid cells, and the average value of the red edge soil conditioned vegetation index of each grid cell was calculated;

[0023] According to the average value of grid cells, the K-means clustering method was used to divide the study area into three management sub-areas;

[0024] The nitrogen application amount in each management sub-area was calculated based on the variable nitrogen application model. The variable nitrogen application model is:

[0025]

[0026] RESAVI=1.5×(NIR-RE) / (NIR+RE+0.5)

[0027] Where k is a variable with values ​​of 1 and 2. When k=1, N max1 is the planned fertilizer amount for wheat during the period from greening to jointing. When k=2, N max2 RESAVI is the planned fertilizer application amount for wheat from heading to the initial grain filling period; RESAVI is the red edge soil regulated vegetation index; max is the maximum RESAVI average value in all grid cells; RESAVI i is the average value of RESAVI in the ith management sub-area; RESAVI min is the minimum RESAVI average value in all grid cells; NIR is the reflectivity of the near-infrared band, and RE is the reflectivity of the red-edge band;

[0028] Planned fertilizer application amount during wheat greening to jointing period N max1 The planned fertilizer application amount N from wheat heading to early grain filling period max2 The expressions are:

[0029] N max1 =b*(1-a)N fert , N max2 =(1-a)(1-b)N fert

[0030] Wherein, b is the second preset ratio; a is the first preset ratio; N fert The amount of nitrogen fertilizer applied.

[0031] Furthermore, in step S1, the expression of the application amount of nitrogen fertilizer is:

[0032]

[0033] Among them, N fert is the amount of nitrogen fertilizer applied; is the average value of historical production over many consecutive years; N 100is the nitrogen requirement per 100 kg of wheat grain; c is the increasing rate;

[0034] When the fertility level is medium fertility or above, the application amount of phosphorus fertilizer P and potassium fertilizer K is based on the application amount of nitrogen fertilizer N. fert OK: N fert : P:K = 1: 0.3~0.5: 0.3~0.5; when the fertility level is below medium fertility, the application amount of phosphorus fertilizer and potassium fertilizer is equal to 1.0~1.5 times the phosphorus and potassium requirements of the crop.

[0035] Furthermore, both step S4 and step S5 adopt the grid sampling method to take soil to measure the surface soil moisture content, and the K-means clustering method is used to divide the study area into three management areas;

[0036] The expressions for the irrigation amount during wheat emergence and the irrigation amount during the wintering period are:

[0037] I 1 =(90%θ f -β 1j )×f 1 , I 2 =(θ f -β 2j )×f 2

[0038] Among them, I 1 I is the amount of irrigation for wheat seedling emergence; 2 is the irrigation amount of wheat during the wintering period; θ f is the field water holding capacity; β 1j and β 2j are the average soil moisture content of the jth management area corresponding to the wheat seedling period and wintering period; f 1 and f 2 They are the first planned wet layer depth and the second planned wet layer depth respectively.

[0039] Furthermore, in both step S6 and step S7, a plurality of soil moisture sensors are used to measure the soil moisture content to obtain an average soil moisture content;

[0040] According to the average soil moisture content during the wheat greening-jointing period and the wheat heading-early filling period, the irrigation amount during the wheat greening-jointing period and the wheat heading-early filling period is calculated respectively:

[0041] I 3 =(95%θ f -β 3 )×f 3 , I 4 =(85%θ f -β 4 )×f 4

[0042] Among them, I 3 and I 4 The irrigation amount during the wheat greening to jointing period and the wheat heading to the early grain filling period; θ f is the field water capacity; f 3 and f 4 They are the third-plan moist layer depth and the fourth-plan moist layer depth corresponding to the wheat greening to jointing period and the wheat heading to early filling period, respectively.

[0043] Furthermore, the expression for calculating the irrigation amount of each management zone in step S8 is:

[0044] I max =(80%θ f -70% θ f )×f 5 , I i =I max ×k i

[0045] Among them, I max is the grouting water volume; θ f I is field water holding capacity; i and k i are the center and irrigation amount of the ith management zone respectively; f 5 The depth of the wet layer for the fifth plan.

[0046] Furthermore, the preset value is 0.8; the nitrogen fertilizer is organic fertilizer or decomposed farmyard manure; when the nitrogen fertilizer is organic fertilizer, the dosage per mu is 100-200 kg; when the nitrogen fertilizer is decomposed farmyard manure, the dosage per mu is 2.5 m 3 ~4.0m 3 .

[0047] The beneficial effects of the present invention are as follows: this scheme not only optimizes the number of irrigation times to match it with the farmers' regular management time, but also fully considers the seedling conditions and meteorological conditions, and realizes the timely and accurate distribution and management of water and fertilizer, thereby ensuring the abundance of ears per mu, the uniformity of ear layers, the uniformity of ears and the fullness of grains, achieving the goal of high wheat yield while saving water and fertilizer.

[0048] According to statistics, after applying the sprinkler irrigation and fertilizer control method of this scheme, compared with the irrigation system based on soil moisture, winter wheat can save more than 25% of water, save more than 18% of fertilizer, increase production by more than 15%, and improve water use efficiency by more than 20%, which provides important scientific and technological support for the improvement of national grain production capacity and the management of groundwater over-exploitation areas in North China. In addition, after developing the irrigation method of this scheme into a decision support system, the automatic analysis, processing and decision-making control functions of the collected data can be realized, which will effectively promote the intelligent development of variable fertilization (variable nitrogen fertilizer application) irrigation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The present invention is a flow chart of a method for regulating water and fertilizer in sprinkler irrigation for water-saving and high-yield wheat. DETAILED DESCRIPTION

[0050] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0051] refer to Figure 1 , Figure 1 A flow chart of a method for controlling water and fertilizer in sprinkler irrigation for water-saving and high-yield wheat is shown; Figure 1 As shown, the method S includes steps S1 to S8.

[0052] In step S1, the application amount of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer of winter wheat in the whole growth period is calculated according to the historical yield of the study area; wherein the expression of nitrogen fertilizer application amount is:

[0053]

[0054] Among them, N fert is the amount of nitrogen fertilizer applied; The average value of historical production over many consecutive years, preferably the average value of historical production over the previous three years; N 100 is the nitrogen requirement per 100 kg of wheat grain; c is the increasing rate; the preferred increasing rate is 5%.

[0055] When the fertility level is medium fertility or above, the application amount of phosphorus fertilizer P and potassium fertilizer K is based on the application amount of nitrogen fertilizer N. fert OK: N fert : P:K = 1:0.3~0.5:0.3~0.5; when the fertility level is below medium fertility, the application amount of phosphorus fertilizer and potassium fertilizer is equal to 1.0~1.5 times the phosphorus and potassium requirements of the crop.

[0056] The evaluation criteria for the fertility level of this plan can refer to the soil nutrient classification indicators of the second national soil survey.

[0057] In step S2, according to the fertility level of the study area, all phosphate fertilizers and potash fertilizers and a first preset ratio of nitrogen fertilizer are applied by broadcasting, and then the land is plowed to mix the inorganic fertilizer with the topsoil; the preferred first preset ratio of this solution is 40%.

[0058] The nitrogen fertilizer in this scheme can be organic fertilizer or decomposed farmyard manure; when organic fertilizer is used as nitrogen fertilizer, the dosage per mu is 100-200 kg; when decomposed farmyard manure is used as nitrogen fertilizer, the dosage per mu is 2.5 m 3 ~4.0m 3 .

[0059] In step S3, wheat varieties with water-saving coefficients greater than a preset value are selected. Specifically, wheat varieties with strong water-saving properties (water-saving coefficients above 1.200), relatively strong (water-saving coefficients 1.000-1.199) and medium (0.800-0.9999) are preferably selected, that is, the preset value is 0.8. The preset density is sown during the suitable sowing period for wheat (for example, October 8-20 in the North China Plain), and the preset density needs to ensure that the basic seedlings are between 200,000 and 250,000.

[0060] In step S4, the study area is divided into a plurality of management areas according to the soil moisture content, and the irrigation amount for wheat seedling emergence is calculated according to the average soil moisture content of the management area and the first planned wet layer depth, and variable sprinkler irrigation is performed;

[0061] In step S5, during the wintering period of wheat, the study area is divided into multiple management areas according to the soil moisture content, the irrigation amount is calculated according to the average soil moisture content of the management area and the second planned wet layer depth, and variable sprinkler irrigation is performed;

[0062] In both step S4 and step S5, the grid sampling method was used to take soil to measure the surface soil moisture content, and the K-means clustering method was used to divide the study area into three management areas;

[0063] The expressions for the irrigation amount during wheat emergence and the irrigation amount during the wintering period are:

[0064] I 1 =(90%θ f -β 1j )×f 1 , I 2 =(θ f -β 2j )×f 2

[0065] Among them, I 1 I is the amount of irrigation for wheat seedling emergence; 2 is the irrigation amount of wheat during the wintering period; θ f is the field water holding capacity; β 1j and β 2j are the average soil moisture content of the jth management area corresponding to the wheat seedling period and wintering period; f 1 and f 2 They are the first planned wet layer depth and the second planned wet layer depth respectively.

[0066] The present scheme preferably measures the soil moisture content of the surface layer 0-20 cm by the grid sampling method after sowing, and measures the soil moisture content of the frozen soil layer 0-40 cm by the grid sampling method during the wintering period (e.g., mid-to-late November in the North China Plain).

[0067] The first planned wetting layer depth and the second planned wetting layer depth are 200 mm and 400 mm, respectively.

[0068] In step S6, during the wheat greening to jointing period, the irrigation and fertilization period is determined based on the seedling condition and soil moisture conditions, and sprinkler irrigation is performed and variable nitrogen application is performed according to the second preset proportion of the remaining nitrogen fertilizer application amount according to the spatial distribution of nitrogen fertilizer deficiency.

[0069] During the greening to jointing period, soil moisture sensors are randomly placed in the farmland to collect soil moisture conditions, and irrigation and fertilization management is carried out after comprehensive consideration of the seedling conditions and soil moisture conditions. In order to rationally utilize the second tillering of wheat seedlings and ensure normal growth after greening, and avoid conflicts when variable sprinkler irrigation and variable fertilization are applied at the same time, uniform irrigation and variable fertilization are adopted in the entire farmland.

[0070] During implementation, the method for determining the optimal irrigation and fertilization period of this scheme is:

[0071] When the seedlings are vigorous, if the soil moisture is severely water-deficient, the irrigation and fertilization period is the middle jointing stage; if the soil moisture is light to moderate water-deficient, the irrigation and fertilization period is the late jointing stage;

[0072] When the seedling condition is Class I, if the soil moisture condition is severe water shortage, the irrigation and fertilization period is the soil moisture collection period of the greening period; if the soil moisture condition is mild to moderate water shortage, the irrigation and fertilization period is the early to middle stage of jointing;

[0073] When the seedlings are of Class II, if the soil moisture is moderately water-deficient, the irrigation and fertilization period is the soil moisture collection period of the greening period; if the soil moisture is slightly water-deficient or not water-deficient, the irrigation and fertilization period is the late rising period;

[0074] When the seedling condition is Class III, if the soil moisture condition is slightly water-deficient, the period for irrigation and fertilization is the greening-rising stage; if the soil moisture condition is not water-deficient, the period for irrigation and fertilization is the rising stage.

[0075] Among them, the indicators of light, medium and severe water shortage are implemented in accordance with DB 13 / T 2364-2016 "Technical Regulations for Soil Moisture Measurement and Irrigation of Winter Wheat". The classification of seedling conditions is implemented in accordance with DB13T2061-2014 Technical Specifications for Monitoring Winter Wheat Seedling Condition.

[0076] In step S7, sprinkler irrigation is performed during the wheat heading to early grain filling period, and the remaining nitrogen fertilizer application amount (i.e., N calculated below) is max2 ) Variable nitrogen application according to the spatial distribution of nitrogen fertilizer deficit;

[0077] The method of performing variable nitrogen application according to the spatial distribution of nitrogen fertilizer deficiency in step S6 and step S7 includes:

[0078] During the period from 11:00 to 14:00, a multispectral UAV imaging system was used to collect multispectral data of the study area, and after mosaicking, the spatial distribution map of the red-edge soil-adjusted vegetation index of the entire farmland was obtained;

[0079] According to the water distribution characteristics of the sprinkler, the study area was divided into several grid cells, and the average value of the red edge soil conditioned vegetation index of each grid cell was calculated;

[0080] According to the average value of grid cells, the K-means clustering method was used to divide the study area into three management sub-areas;

[0081] The nitrogen application amount in each management sub-area was calculated based on the variable nitrogen application model. The variable nitrogen application model is:

[0082]

[0083] RESAVI=1.5×(NIR-RE) / (NIR+RE+0.5)

[0084] Where k is a variable with values ​​of 1 and 2. When k=1, N max1 is the planned fertilizer amount for wheat during the greening to jointing period. When k=2, N max2 RESAVI is the planned fertilizer application amount for wheat from heading to the initial grain filling period; RESAVI is the red edge soil regulated vegetation index; max is the maximum RESAVI average value in all grid cells; RESAVI i is the average value of RESAVI in the ith management sub-area; RESAVI min is the minimum RESAVI average value in all grid cells; NIR is the reflectivity of the near-infrared band, and RE is the reflectivity of the red-edge band;

[0085] Planned fertilizer application amount during wheat greening to jointing period N max1 The planned fertilizer application amount N from wheat heading to early grain filling period max2 The expressions are:

[0086] N matx1 =b*(1-a)N fert , N max2 =(1-a)(1-b)N fert

[0087] Wherein, b is the second preset ratio; a is the first preset ratio; N fert The amount of nitrogen fertilizer applied.

[0088] In both step S6 and step S7, a plurality of soil moisture sensors are used to measure the soil moisture content to obtain the average soil moisture content;

[0089] According to the average soil moisture content during the wheat greening-jointing period and the wheat heading-early filling period, the irrigation amount during the wheat greening-jointing period and the wheat heading-early filling period is calculated respectively:

[0090] I 3 =(95%θ f -β 3 )×f 3 , I 4 =(85%θ f -β 4 )×f 4

[0091] Among them, I 3 and I 4 The irrigation amount during the wheat greening to jointing period and the wheat heading to the early grain filling period; θ f is the field water capacity; f 3 and f 4 They are the third-plan moist layer depth and the fourth-plan moist layer depth corresponding to the wheat greening to jointing period and the wheat heading to early filling period, respectively.

[0092] In step S8, during the wheat filling period, the study area is divided into multiple management zones according to the spatial distribution of the normalized relative canopy temperature NRCT, and the irrigation amount of each management zone is determined according to the center and filling irrigation amount of each management zone, and variable sprinkler irrigation is carried out.

[0093] The expression for calculating the irrigation amount of each management zone in step S8 is:

[0094] I max =(80%θ f -70% θ f )×f 5 , I i =I max ×k i

[0095] Among them, I max is the grouting water volume; θ f I is field water holding capacity; i and k i are the center and irrigation amount of the ith management zone respectively; f 5 The depth of the wet layer for the fifth plan.

[0096] During implementation, this scheme preferably sets the third planned wetting layer depth, the fourth planned wetting layer depth and the fifth planned wetting layer depth to 600 mm, 600 mm and 60 cm respectively.

[0097] In this scheme, when variable fertilization (variable nitrogen fertilizer application), a constant fertilizer concentration is maintained, and the amount of fertilizer applied to each management area is adjusted by adjusting the solenoid valve duty cycle CT i The travel speed of the sprinkler is adjusted according to the maximum amount of fertilizer injected. After variable fertilization, variable sprinkler irrigation is carried out. By setting the duty cycle of the solenoid valve in each management area to 1-CT i To achieve uniform irrigation management.

[0098] The variable sprinkler irrigation mentioned in this plan is based on the irrigation volume in each management area, by adjusting the travel speed of the sprinkler and the pulse duty cycle of the solenoid valve installed above the sprinkler head to achieve uniform irrigation management.

[0099] To sum up, this plan takes into account the seedling conditions and meteorological conditions, realizes the timely and precise distribution and management of water and fertilizer, ensures the abundance of ears per mu, the uniformity of ear layers, the uniformity of ears and the fullness of grains; by optimizing the number and time of irrigation, it ensures water saving, and also matches the farmers' regular management time, thereby improving the farmers' acceptance and utilization.

Claims

1. A method for regulating water and fertilizer in sprinkler irrigation for water-saving and high-yield wheat, characterized in that: Includes steps: S1. Calculate the application amount of nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer for winter wheat throughout the growth period based on the historical yield of the study area; S2. According to the fertility level of the study area, all the phosphate fertilizers and potash fertilizers and the first preset ratio of nitrogen fertilizer are applied by broadcasting and mixed with the tillage layer soil; S3, selecting a wheat variety with a water-saving coefficient greater than a preset value, and sowing at a preset density during the appropriate sowing period for wheat; S4. Divide the study area into multiple management areas according to soil moisture content, calculate the irrigation amount for wheat emergence according to the average soil moisture content of the management area and the first planned wet layer depth, and carry out variable sprinkler irrigation; S5. During the wintering period of wheat, the study area was divided into multiple management areas according to the soil moisture content. The irrigation amount was calculated according to the average soil moisture content of the management area and the second planned wet layer depth, and variable sprinkler irrigation was carried out; S6. During the wheat greening to jointing period, determine the irrigation and fertilization period based on the seedling condition and soil moisture condition, perform sprinkler irrigation, and perform variable nitrogen application according to the second preset ratio of the remaining nitrogen fertilizer application amount based on the spatial distribution of nitrogen fertilizer deficiency; S7. Sprinkler irrigation is carried out from the early stage of wheat heading to grain filling, and the remaining nitrogen fertilizer application amount is variable nitrogen application according to the spatial distribution of nitrogen fertilizer deficiency; S8. During the wheat filling period, the study area was divided into multiple management zones according to the spatial distribution of normalized relative canopy temperature (NRCT). The irrigation amount of each management zone was determined according to the center and filling irrigation amount of each management zone, and variable sprinkler irrigation was carried out. The method of performing variable nitrogen application according to the spatial distribution of nitrogen fertilizer deficiency in step S6 and step S7 includes: During the period from 11:00 to 14:00, a multispectral UAV imaging system was used to collect multispectral data of the study area, and after mosaicking, the spatial distribution map of the red-edge soil-adjusted vegetation index of the entire farmland was obtained; According to the water distribution characteristics of the sprinkler, the study area was divided into several grid cells, and the average value of the red edge soil conditioned vegetation index of each grid cell was calculated; According to the average value of grid cells, the K-means clustering method was used to divide the study area into three management sub-areas; The nitrogen application amount in each management sub-area was calculated based on the variable nitrogen application model. The variable nitrogen application model is: Among them, k is a variable with values ​​of 1 and 2. When k=1, N max1 is the planned fertilizer amount for wheat during the greening to jointing period. When k=2, N max2 The planned fertilizer amount for wheat during the early stages of heading and grain filling; RESAVI Adjusting vegetation index for red-edge soils; RESAVI max is the maximum value among all grid cells. RESAVI average value; RESAVI i For the i within the management sub-area RESAVI average value; RESAVI min is the minimum value among all grid cells. RESAVI average value; NIR is the reflectivity in the near-infrared band, RE is the reflectivity of the red edge band; Planned fertilizer application amount during wheat greening to jointing period N max1 Planned fertilizer application amount during the early stage of wheat heading and grain filling N max2 The expressions are: ， in, b is a second preset ratio; a is a first preset ratio; The amount of nitrogen fertilizer applied.

2. The sprinkler irrigation water and fertilizer control method according to claim 1, characterized in that: The method for determining the irrigation and fertilization period in step S6 is: When the seedlings are vigorous, if the soil moisture is severely water-deficient, the irrigation and fertilization period is the middle jointing stage; if the soil moisture is light to moderate water-deficient, the irrigation and fertilization period is the late jointing stage; When the seedling condition is Class I, if the soil moisture condition is severe water shortage, the irrigation and fertilization period is the soil moisture collection period of the greening period; if the soil moisture condition is mild to moderate water shortage, the irrigation and fertilization period is the early to middle stage of jointing; When the seedlings are of Class II, if the soil moisture is moderately water-deficient, the irrigation and fertilization period is the soil moisture collection period of the greening period; if the soil moisture is slightly water-deficient or not water-deficient, the irrigation and fertilization period is the late rising period; When the seedling condition is Class III, if the soil moisture condition is slightly water-deficient, the period for irrigation and fertilization is the greening-rising stage; if the soil moisture condition is not water-deficient, the period for irrigation and fertilization is the rising stage.

3. The sprinkler irrigation water and fertilizer control method according to claim 1, characterized in that: The expression of the application amount of nitrogen fertilizer in step S1 is: in, is the amount of nitrogen fertilizer applied; It is the average value of historical production over many consecutive years; The nitrogen requirement of 100 kg wheat grain; c is the increasing rate; When the fertility level is medium fertility or above, the amount of phosphorus fertilizer applied P and potassium fertilizer application K According to nitrogen fertilizer application Sure: : P : K =1:0.3~0.5:0.3~0.5; when the fertility level is below medium fertility, the application amount of phosphorus fertilizer and potassium fertilizer is equal to 1.0~1.5 times the phosphorus and potassium requirements of the crop.

4. The sprinkler irrigation water and fertilizer control method according to claim 1, characterized in that: In both step S4 and step S5, the grid sampling method was used to take soil samples to measure the surface soil moisture content, and the K-means clustering method was used to divide the study area into three management areas; The expressions for the irrigation amount during wheat emergence and the irrigation amount during the wintering period are: ， in, The amount of irrigation for wheat emergence; The amount of irrigation for wheat during the wintering period; is the field water capacity; and The first j Average soil moisture content in each management area; and They are the first planned wet layer depth and the second planned wet layer depth respectively.

5. The sprinkler irrigation water and fertilizer control method according to claim 1, characterized in that: In both step S6 and step S7, a plurality of soil moisture sensors are used to measure the soil moisture content to obtain the average soil moisture content; According to the average soil moisture content during the wheat greening-jointing period and the wheat heading-early filling period, the irrigation amount during the wheat greening-jointing period and the wheat heading-early filling period is calculated respectively: ， in, and They are the irrigation amounts during the wheat greening to jointing stage and the wheat heading to the early grain filling stage; is the field water capacity; and They are the third-plan moist layer depth and the fourth-plan moist layer depth corresponding to the wheat greening to jointing period and the wheat heading to early grain filling period, respectively.

6. The sprinkler irrigation water and fertilizer control method according to claim 1, characterized in that: The expression for calculating the irrigation amount of each management zone in step S8 is: ， in, Amount of water for grouting; is the field water capacity; and Respectively i The center and irrigation amount of each management zone; The depth of the wet layer for the fifth plan.

7. The sprinkler irrigation water and fertilizer control method according to any one of claims 1 to 6, characterized in that: The preset value is 0.8; The nitrogen fertilizer is organic fertilizer or decomposed farmyard manure; when organic fertilizer is selected as nitrogen fertilizer, the amount per mu is 100-200 kg; when decomposed farmyard manure is selected as nitrogen fertilizer, the amount per mu is 2.5 m 3 ~4.0 m 3 .

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