Crop variable rate fertilization method and equipment based on vegetation index spatial distribution

Abstract

The invention discloses a crop variable rate fertilization method and device based on vegetation index spatial distribution, and the method comprises the steps: carrying out the superposition average processing of vegetation index spatial distribution diagrams in different growth periods, and drawing a unit average vegetation index spatial distribution diagram of a research region, the average value of the first vegetation index average values of all the units is calculated; calculating standardized vegetation indexes of different units in the unit average vegetation index spatial distribution map by using the second vegetation index mean value, and drawing a standardized vegetation index distribution map; calculating a variable fertilization prescription of each unit based on the standardized vegetation index distribution map, a preset fertilization proportion and the historical nitrogen fertilizer delivery amount of the research area, and drawing a variable fertilization prescription distribution map, so as to carry out variable fertilization on target crops in the research area. According to the method, variable fertilization prescriptions are generated for different field parcels by utilizing vegetation index spatial distribution, so that accurate variable fertilization is realized, the cost of soil fertility detection is reduced, and the fertilization efficiency is improved.

Description

Technical Field

[0001] This application relates to the technical field of precise agricultural fertilization, and particularly to a variable fertilization method and device for crops based on the spatial distribution of vegetation indices. Background Art

[0002] With the rapid development of modern agriculture, precision agriculture technology has gradually become an important means to improve agricultural production efficiency and resource utilization rate. Among them, variable fertilization technology can significantly improve fertilizer utilization rate and reduce environmental pollution by implementing differential fertilization according to the growth demand distribution of farmland crops.

[0003] However, in some cases, variable fertilization technology mostly forms variable fertilization prescriptions based on grid soil sample collection. However, the methods for soil sample detection have disadvantages such as high test costs, large consumption of labor costs, and complex processes, which reduce the actual fertilization efficiency. Summary of the Invention

[0004] The purpose of this application is to provide a variable fertilization method and device for crops based on the spatial distribution of vegetation indices.

[0005] To achieve the above purpose, this application provides the following solutions:

[0006] In the first aspect, this application provides a variable fertilization method for crops based on the spatial distribution of vegetation indices, which is characterized in that the variable fertilization method for crops based on the spatial distribution of vegetation indices includes: obtaining a vector map of the target crop in the research area; the vector map of the target crop is a remote sensing image of the target crop drawn in the research area with plots as units; based on the spatial range of the vector map of the target crop, respectively obtain the spatial distribution maps of the vegetation indices of the target crop in different growth stages in the research area; perform superposition and averaging processing on the spatial distribution maps of the vegetation indices in different growth stages to obtain the first vegetation index mean value of each unit, and draw the spatial distribution map of the unit average vegetation index in the research area; calculate the average value of the first vegetation index mean values of all units in the spatial distribution map of the unit average vegetation index in the research area to obtain the second vegetation index mean value; use the second vegetation index mean value to calculate the standardized vegetation indices of different units in the spatial distribution map of the unit average vegetation index, and draw the standardized vegetation index distribution map in the research area; based on the standardized vegetation index distribution map, the preset fertilization ratio, and the historical nitrogen fertilizer application amount in the research area, calculate the variable fertilization prescription for each unit, and draw the variable fertilization prescription distribution map in the research area; the preset fertilization ratio at least includes: nitrogen fertilizer application ratio, phosphate fertilizer application ratio, and potassium fertilizer application ratio; use the variable fertilization prescription distribution map to perform variable fertilization on the target crops in the research area.

[0007] In a second aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor executes the computer program to implement the method for variable fertilization of crops based on the spatial distribution of vegetation indices described in any one of the above.

[0008] According to the specific embodiments provided by the present application, the following technical effects are disclosed:

[0009] By using the spatial distribution of vegetation indices to generate variable fertilization prescriptions for different fields, the present application realizes precise variable fertilization, reduces the cost of soil fertility detection, improves the fertilization efficiency, and reduces the soil pollution problem caused by excessive application of chemical fertilizers. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0011] Figure 1 It is a schematic flowchart of a method for variable fertilization of crops based on the spatial distribution of vegetation indices provided by an embodiment of the present application.

[0012] Figure 2 It is a vector map of the target crops in the research area provided by an embodiment of the present application.

[0013] Figure 3 It is a spatial distribution map of the vegetation index at the rosette stage in the research area provided by an embodiment of the present application.

[0014] Figure 4 It is a spatial distribution map of the vegetation index at the vigorous growth stage in the research area provided by an embodiment of the present application.

[0015] Figure 5 It is a spatial distribution map of the vegetation index at the topping stage in the research area provided by an embodiment of the present application.

[0016] Figure 6 It is a spatial distribution map of the average vegetation index of pixels in the research area provided by an embodiment of the present application.

[0017] Figure 7 It is a spatial distribution map of the average vegetation index of units in the research area provided by an embodiment of the present application.

[0018] Figure 8 It is a standardized vegetation index distribution map of the research area provided by an embodiment of the present application.

[0019] Figure 9 It is the nitrogen fertilizer variable distribution map of the research area provided by the embodiment of the present application.

[0020] Figure 10 It is the variable fertilization prescription distribution map of the research area provided by the embodiment of the present application.

[0021] Figure 11 It is the structural schematic diagram of a computer device provided by the embodiment of the present application. Specific implementation manners

[0022] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0023] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0024] Embodiment 1, as Figure 1 shown, this embodiment provides a variable fertilization method for crops based on the spatial distribution of vegetation indices. The method includes:

[0025] S1. Obtain the vector map of the target crops in the research area; the vector map of the target crops is the remote sensing image of the target crops drawn in the research area with the field block as the unit.

[0026] Further, step S1 specifically includes:

[0027] S11. Obtain the remote sensing image of the research area.

[0028] Use a multispectral drone to conduct remote sensing monitoring on the research area to obtain a remote sensing image.

[0029] S12. Divide the remote sensing image into grids with the field block as the unit to obtain the vector map of the research area.

[0030] S13. Screen out the units planting the target crops in the vector map of the research area and draw the vector map of the target crops in the research area.

[0031] In the actual application process, first select the research area (the area with relatively consistent fertilization amount), draw the vector map of the research area with the field block as the unit, and remove the areas of non-selected crops (non-target crops) to obtain the vector map of the research area.

[0032] S2. Based on the spatial range of the vector map of the target crop, obtain the spatial distribution maps of the vegetation indices of the target crop in different growth stages (key biological stages) in the study area; the growth stages are: the rosette stage or the vigorous growth stage or the topping stage.

[0033] Optionally, the vegetation index is the NDVI (Normalized Difference Vegetation Index) or the EVI (Enhanced Vegetation Index).

[0034] S3. Perform superposition averaging on the spatial distribution maps of the vegetation indices in different growth stages to obtain the first vegetation index mean value of each unit, and draw the spatial distribution map of the unit average vegetation index in the study area.

[0035] Further, step S3 specifically includes:

[0036] S31. Superimpose the spatial distribution maps of the vegetation indices in different growth stages to obtain the average value of the vegetation indices of each pixel, and draw the spatial distribution map of the pixel average vegetation index in the study area;

[0037] S32. Calculate the average value of the vegetation indices of the corresponding units in the spatial distribution map of the pixel average vegetation index to obtain the first vegetation index mean value of the corresponding units;

[0038] S33. Based on the first vegetation index mean values of all units, draw the spatial distribution map of the unit average vegetation index in the study area.

[0039] Further, use the Arcgis software to perform superposition averaging on the spatial distribution maps of the vegetation indices in different growth stages.

[0040] In the actual application process, use the Arcgis software to perform superposition averaging on the vegetation index data in the growth stages (key biological stages) to generate the spatial distribution map of the vegetation index averaged three times. The magnitude of the vegetation index is used to characterize the growth status of the crop and the soil fertility. In the high vegetation index area (where the crop growth is good), appropriately reduce the fertilization amount; in the low vegetation index area (where the crop growth is poor), appropriately increase the fertilization amount, so as to achieve the precise allocation of fertilization resources.

[0041] S4. Calculate the average value of the first vegetation index mean values of all units in the spatial distribution map of the unit average vegetation index in the study area to obtain the second vegetation index mean value.

[0042] In the actual application process, use the Arcgis software to calculate the second vegetation index mean value of the spatial distribution map of the unit average vegetation index.

[0043] S5. Calculate the standardized vegetation index of different units in the spatial distribution map of the average vegetation index using the second vegetation index mean value, and draw the standardized vegetation index distribution map of the study area.

[0044] Further, S5 specifically includes:

[0045] S51. For each unit in the spatial distribution map of the average vegetation index of the study area, calculate the ratio of the vegetation index difference to the second vegetation index as the standardized vegetation index; the vegetation index difference is the difference between the first vegetation index mean value and the second vegetation index mean value.

[0046] S52. Draw the standardized vegetation index distribution map (relative spatial difference map) of the study area based on the standardized vegetation indices of all units.

[0047] Optionally, the standardized vegetation index distribution map is used to characterize the level of soil fertility.

[0048] Optionally, the calculation formula of the standardized vegetation index is as follows:

[0049]

[0050] In the formula, E i is the standardized vegetation index of unit i; W i is the first vegetation index mean value of unit i; is the second vegetation index mean value.

[0051] S6. Based on the standardized vegetation index distribution map, the preset fertilization ratio, and the historical nitrogen fertilizer application amount in the study area, calculate the variable fertilization prescription for each unit, and draw the variable fertilization prescription distribution map of the study area; the preset fertilization ratio at least includes: nitrogen fertilizer application ratio, phosphorus fertilizer application ratio, and potassium fertilizer application ratio.

[0052] Further, the preset fertilization ratio is as follows:

[0053]

[0054] In the formula, V N is the preset nitrogen fertilizer application ratio in the target area; V P is the preset phosphorus fertilizer application ratio in the target area; V K is the preset potassium fertilizer application ratio in the target area.

[0055] Optionally, step S6 is implemented by ArcGIS software.

[0056] S7. Perform variable fertilization on the target crops in the study area using the variable fertilization prescription distribution map.

[0057] Further, the calculation formula for the variable fertilization prescription of each unit is as follows:

[0058] ΔQ Ni = Q N (1 - E i ).

[0059] ΔQ Pi = V P × ΔQ Ni .

[0060] ΔQ Ki = V K × ΔQ Ni .

[0061] In the formula, ΔQ Ni is the variable nitrogen fertilizer application rate for unit i; ΔQ Pi is the variable phosphate fertilizer application rate for unit i; ΔQ Ki is the variable potassium fertilizer application rate for unit i; Q N is the historical nitrogen fertilizer application amount in the study area; E i is the normalized difference vegetation index of unit i; V P is the preset phosphate fertilizer application ratio in the target area; V K is the preset potassium fertilizer application ratio in the target area.

[0062] The following takes a tobacco planting area as the study area to illustrate the specific process of the variable fertilization method for crops based on the spatial distribution of vegetation index in this application:

[0063] 1) Select the study area, draw a vector map, and remove non - tobacco areas.

[0064] As Figure 2 shown, a tobacco planting area is used as the study area, with a planting area of 500 mu and the target crop being tobacco.

[0065] 2) As Figures 3 - 5 shown, in different growth stages of tobacco (the rosette stage, the vigorous growth stage, and the topping stage), use a multispectral drone to obtain the spatial distribution map of NDVI (Normalized Difference Vegetation Index).

[0066] 3) Calculate the average vegetation index value of the study area.

[0067] As Figure 6 shown, use Arcgis software to perform superposition averaging on the vegetation indices of tobacco in the rosette stage, the vigorous growth stage, and the topping stage to generate a pixel - average vegetation index spatial distribution map.

[0068] 4) Calculate the second vegetation index mean.

[0069] As Figure 7As shown in the figure, the mean value of the second vegetation index was calculated using Arcgis to obtain the spatial distribution map of the unit average vegetation index.

[0070] 5) Standardization of the vegetation index.

[0071] As Figure 8 shown in the figure, the vegetation index of each unit was standardized using the standardization formula to obtain the standardized vegetation index distribution map.

[0072] 6) Generation of nitrogen fertilizer application rate prescriptions at the field scale.

[0073] The standardized vegetation index of each field and the conventional nitrogen application rate in the study area are as Figure 9 shown in the figure (the study area is 90 kg / hm 2 , local recommended application rate), and the variable fertilization prescription distribution map was generated using Arcgis, as Figure 10 shown in the figure.

[0074] The application rates of phosphorus and potassium fertilizers were determined according to the nitrogen fertilizer application rate; the recommended ratio of nitrogen, phosphorus pentoxide, and potassium oxide is N:P2O5:K2O = 1:1:2.5.

[0075] 7) Fertilization using the variable fertilization prescription distribution map.

[0076] The variable fertilization prescription distribution map was directly applied to variable fertilization machinery or equipment for precise fertilization.

[0077] The technical effects of this application are as follows:

[0078] First, there is no need to collect grid soil samples, saving soil testing costs.

[0079] Second, by using multispectral drones and historical data (historical nitrogen fertilizer application amounts), precise variable fertilization prescriptions are generated, improving fertilization efficiency.

[0080] Third, the data processing process is simplified, the method is efficient, and it is highly operable.

[0081] Fourth, the fertilizer utilization rate is significantly increased, reducing agricultural production costs.

[0082] Fifth, environmental pollution caused by excessive fertilization is reduced, with good ecological benefits.

[0083] Example 2, this application also provides a computer device, which can be a server or a terminal, and its internal structure diagram can be as Figure 11As shown in the figure. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store processed data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a method for variable fertilization of crops based on the spatial distribution of vegetation indices.

[0084] Those skilled in the art can understand that Figure 11 the structure shown in the figure is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0085] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tapes, floppy disks, flash memories, optical memories, high-density embedded non-volatile memories, resistive random access memories (ReRAM), magnetoresistive random access memories (MRAM), ferroelectric random access memories (FRAM), phase change memories (PCM), graphene memories, etc. Volatile memories can include random access memory (RAM) or external cache memories, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0086] All actions of obtaining signals, information, or data in this application are carried out on the premise of complying with the corresponding data protection regulations and policies of the country where it is located and with the authorization given by the owner of the corresponding device.

[0087] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0088] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A method for variable fertilization of crops based on the spatial distribution of vegetation indices, characterized in that The variable fertilization method for crops based on the spatial distribution of vegetation indices includes: Obtaining a vector map of the target crops in the study area; the vector map of the target crops is a remote sensing image of the target crops drawn in the study area with plots as units; Based on the spatial range of the vector map of the target crops, respectively obtaining the spatial distribution maps of the vegetation indices of the target crops in different growth stages in the study area; Performing superposition averaging on the spatial distribution maps of the vegetation indices in different growth stages to obtain the first vegetation index mean value of each unit, and drawing the spatial distribution map of the unit average vegetation index in the study area; Calculating the average value of the first vegetation index mean values of all units in the spatial distribution map of the unit average vegetation index in the study area to obtain the second vegetation index mean value; Calculating the standardized vegetation indices of different units in the spatial distribution map of the unit average vegetation index by using the second vegetation index mean value, and drawing the standardized vegetation index distribution map of the study area; Based on the standardized vegetation index distribution map, the preset fertilization ratio, and the historical nitrogen fertilizer application amount in the study area, calculating the variable fertilization prescription for each unit, and drawing the variable fertilization prescription distribution map of the study area; the preset fertilization ratio at least includes: nitrogen fertilizer application ratio, phosphate fertilizer application ratio, and potassium fertilizer application ratio; Performing variable fertilization on the target crops in the study area by using the variable fertilization prescription distribution map.

2. The method for variable fertilization of crops based on the spatial distribution of vegetation indices according to claim 1, characterized in that Obtaining the vector map of the target crops in the study area specifically includes: Obtaining the remote sensing image of the study area; Dividing the remote sensing image into grids with plots as units to obtain the vector map of the study area; Selecting the units planting the target crops in the vector map of the study area, and drawing the vector map of the target crops in the study area.

3. The crop variable fertilization method based on the spatial distribution of vegetation indices according to claim 2, wherein Obtaining the remote sensing image of the study area specifically includes: Performing remote sensing monitoring on the study area by using a multispectral drone to obtain the remote sensing image.

4. The crop variable fertilization method based on the spatial distribution of vegetation indices according to claim 1, characterized in that Performing superposition averaging on the spatial distribution maps of the vegetation indices in different growth stages to obtain the first vegetation index mean value of each unit, and drawing the spatial distribution map of the unit average vegetation index in the study area specifically includes: Superposing the spatial distribution maps of the vegetation indices in different growth stages to obtain the average value of the vegetation indices of each pixel, and drawing the spatial distribution map of the pixel average vegetation index in the study area; Calculating the average value of the vegetation indices of the corresponding units in the spatial distribution map of the pixel average vegetation index to obtain the first vegetation index mean value of the corresponding units; Based on the first vegetation index mean values of all units, drawing the spatial distribution map of the unit average vegetation index in the study area.

5. The variable fertilization method for crops based on the spatial distribution of vegetation indices according to claim 1, characterized in that Calculating the standardized vegetation indices of different units in the spatial distribution map of the unit average vegetation index by using the second vegetation index mean value, and drawing the standardized vegetation index distribution map of the study area specifically includes: For each unit in the spatial distribution map of the unit average vegetation index in the study area, calculating the ratio of the vegetation index difference to the second vegetation index as the standardized vegetation index; the vegetation index difference is the difference between the first vegetation index mean value and the second vegetation index mean value; Drawing the standardized vegetation index distribution map of the study area according to the standardized vegetation indices of all units.

6. The method for variable fertilization of crops based on the spatial distribution of vegetation indices according to claim 1, characterized in that, The preset fertilization ratio is as follows: where, V N is the preset nitrogen fertilizer application ratio in the target area; V P is the preset phosphorus fertilizer application ratio in the target area; V K is the preset potassium fertilizer application ratio in the target area.

7. The method for variable fertilization of crops based on the spatial distribution of vegetation indices according to claim 1, characterized in that The calculation formula for the variable fertilization prescription of each unit is as follows: ΔQ Ni = Q N (1 - E i ); ΔQ Pi = V P × ΔQ Ni ; ΔQ Ki = V K × ΔQ Ni ; where, ΔQ Ni is the variable nitrogen fertilizer application rate of unit i; ΔQ Pi is the variable phosphate fertilizer application rate of unit i; ΔQ Ki is the variable potassium fertilizer application rate of unit i; Q N is the historical nitrogen fertilizer application amount of the research area; E i is the normalized difference vegetation index of unit i; V P is the preset phosphate fertilizer application ratio of the target area; V K is the preset potassium fertilizer application ratio of the target area.

8. The method for variable rate fertilization of crops based on the spatial distribution of vegetation indices according to claim 1, wherein The growth period is: the rosette stage or the vigorous growth stage or the topping stage.

9. The method for variable fertilization of crops based on the spatial distribution of vegetation indices according to claim 1, characterized in that Use the Arcgis software to perform superposition averaging on the spatial distribution maps of vegetation indices at different growth stages.

10. A computer device, comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to implement the crop variable fertilization method based on the spatial distribution of vegetation indices according to any one of claims 1-9.

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