Method for making soil attribute graph

Abstract

The invention relates to a method for making a soil attribute map, which comprises the following steps of: dividing a plurality of sampling units by combining a GIS (Geographic Information System) according to terrain and landform characteristics of a target area, determining a sampling point coordinate, a sampling depth and a sampling quantity of each sampling unit, and generating a sampling route planning map; a soil sampling and detecting all-in-one machine is adopted, accurate collection of soil samples is completed according to the planned sampling route and parameters, and spatial position information, sampling depth information and detection data of sampling points are synchronously recorded; screening and correcting the collected detection data, position data and depth data, removing abnormal data, and generating a standardized soil attribute data set; a spatial interpolation algorithm is adopted to obtain soil attribute estimated values of all positions in the target area, and a soil attribute spatial distribution matrix is formed; and combining a GIS geographic information system, superposing a basic geographic map layer of the target area, and drawing an initial soil attribute map. According to the method, multiple attributes of soil can be integrated, and a more accurate and comprehensive attribute graph can be obtained.

Description

Technical Field

[0001] This invention relates to the field of soil property map production technology, and more specifically to a method for producing soil property maps. Background Technology

[0002] Soil property maps are essential basic data for agricultural production, land planning, and ecological protection. Their core is to accurately obtain the physical and chemical properties of the soil (such as water content, organic matter content, pH value, nitrogen, phosphorus and potassium content, etc.) and combine them with spatial location information to draw a property distribution map with spatial distribution characteristics. Currently, the main methods for creating soil property maps are divided into traditional sampling methods and semi-automatic sampling methods. Traditional sampling methods rely on manual collection of soil samples using tools such as shovels and soil drills, which are then sent to the laboratory for property parameter testing. The data is then manually entered and the map is drawn using GPS positioning information. This method is extremely inefficient, involves a large amount of sampling work, and the inconsistent depth and force of manual sampling can easily lead to sample distortion, affecting the accuracy of the property map. At the same time, manual sampling cannot achieve large-area, high-density continuous sampling, making it difficult to reflect the spatial continuous distribution characteristics of soil properties. While existing semi-automatic sampling methods introduce simple sampling devices, these devices are rudimentary in structure, mostly consisting of a single drill rod design. They lack precise depth positioning and sampling volume control structures, and problems such as drill rod deviation and soil sample mixing (mixing of samples from different depths) are prone to occur during the sampling process. Furthermore, the sampling device is disconnected from the detection and positioning modules, making it impossible to achieve integrated sampling, detection, and positioning operations. Manual sample transfer and data entry are still required, resulting in cumbersome processes, error accumulation, and low efficiency.

[0003] In addition, existing methods have low matching accuracy between soil property detection data and spatial location information, lack an effective data calibration mechanism, and the soil property maps drawn are mostly static maps that cannot be updated in real time according to the dynamic changes in soil properties, resulting in poor applicability. In view of the shortcomings of the existing technologies, there is an urgent need for a method that can achieve accurate and efficient sampling, precise data matching, and high-precision soil property maps. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for creating soil property maps, so as to solve the problem that existing technologies cannot accurately match data and draw high-precision soil property maps.

[0005] This invention is achieved through the following technical solution: A method for creating a soil property map includes the following steps: I. Sampling Area Planning: Based on the topography and geomorphological features of the target area, and in conjunction with the GIS geographic information system, divide the area into several sampling units, determine the coordinates of the sampling points, sampling depth, and sampling quantity for each sampling unit, and generate a sampling route planning map; 2. Using a soil sampling and testing integrated machine, the machine moves to each sampling point according to the sampling route and parameters planned in step S1 to complete the accurate collection of soil samples. At the same time, the detection module on the integrated machine is used to detect the physical and chemical properties of the soil samples in real time, and the spatial location information, sampling depth information and detection data of the sampling point are recorded simultaneously. 3. The detection data, location data and depth data collected in step S2 are screened and corrected, abnormal data are removed, missing data are interpolated and supplemented, and the corrected data are associated according to the sampling point coordinates to generate a standardized soil property dataset. Fourth, a spatial interpolation algorithm is used to interpolate the standardized soil attribute dataset obtained in step S3 to obtain the estimated soil attribute values ​​for all locations within the target area, forming a spatial distribution matrix of soil attributes. 5. Combine the spatial distribution matrix of soil attributes obtained in step S4 with the GIS geographic information system, overlay the basic geographic layer (topography, roads, water system, etc.) of the target area, and draw the initial soil attribute map; verify and optimize the accuracy of the initial soil attribute map, remove areas with errors exceeding the threshold, and recalculate the interpolation to obtain the final soil attribute map. 6. Output the final soil property map obtained in step S5 according to the preset format (vector map, raster map), and at the same time establish a soil property database. Repeat steps S1-S5 periodically to update the soil property map in real time. Furthermore, the dedicated soil sampling and testing integrated machine described in step S2 includes a sampling mechanism, a positioning component, a lifting and adjusting mechanism, and a machine body support. The specific structure of each mechanism is as follows: It is made of high-strength aluminum alloy and has a frame structure. The bottom is equipped with brakeable casters. A crossbeam is located on the top of the support for mounting the lifting and adjusting mechanism and the testing module mounting plate. A control panel and data storage module are located on the side of the support to enable / disable the corresponding actuators, adjust parameters, and temporarily store data. The machine body support is fixedly mounted on the crossbeam and includes a lifting motor, a ball screw, a guide rail, and a lifting platform. The lifting motor is connected to the ball screw via a transmission. The ball screw is vertically positioned, and the guide rail is arranged parallel to the ball screw. The lifting platform is fitted onto the ball screw and the guide rail. The lifting motor drives the ball screw to rotate, causing the lifting platform to move up and down along the guide rail.

[0006] Specifically, it also includes an upper mounting plate and a lower mounting plate fixed on the machine body bracket. The two mounting plates are fixed together by a pair of parallel guide rails. A ball screw is provided parallel between the two guide rails. The two ends of the ball screw are rotatably installed in the two mounting plates, and one end is fixed to the main shaft of the lifting motor. The lifting platform has a U-shaped groove structure, and its two side plates are slidably sleeved on the guide rails. The ball screw is threaded through a sliding block fixed at the bottom of the lifting platform groove.

[0007] Furthermore, the sampling drill rod has threads on its outer side and a strip groove on its surface, which is parallel to the axial direction. A threaded sleeve and a bottom sleeve are fixed to the side of the lifting platform near the sampling drill rod, respectively. A worm gear, coaxial with the two sleeves, is rotatably mounted between them. A worm wheel is fixed to the output shaft of the transmission gear set, meshing with the worm gear. A limit block is fixed to the bore wall of the worm gear, slidingly installed within the strip groove to guide the sampling drill rod vertically. The threaded sleeve allows the sampling drill rod to pass through threadedly, while the bottom sleeve allows the sampling rotating rod to pass freely without contact, so that the sampling drill rod is fed axially when the transmission gear assembly is activated.

[0008] Furthermore, in this invention, it is preferable to fix a pair of vertically downward-facing hydraulic columns on the lower mounting plate. When the lifting motor adjusts the sampling mechanism to the corresponding height, the hydraulic columns extend to press against the ground or the machine body support to transfer the load on the lifting platform. Furthermore, it also includes a sampling motor, a transmission gear set, a sampling drill rod, and a sampling sleeve. The sampling motor is connected to the sampling drill rod via the transmission gear set. The sampling drill rod is set vertically downwards. The sampling sleeve is fitted onto the lower end of the sampling drill rod. The side wall of the sampling sleeve is provided with several ventilation holes, and the bottom is provided with a serrated sampling cutting edge. The sampling drill rod has a hollow channel inside, and the inner wall of the channel is provided with spiral conveying blades. The sampling motor drives the sampling drill rod to rotate, the serrated cutting edge of the sampling sleeve cuts into the soil, and the spiral conveying blades transport the soil sample along the hollow channel to the sample testing box above the lifting platform. The invention also includes a GPS positioning module and an inclination sensor. The GPS positioning module is fixedly installed on the top of the machine body support to obtain the latitude and longitude coordinates of the sampling point. The inclination sensor is fixedly installed on the sampling drill rod to detect the inclination angle of the sampling drill rod. The detection module is fixedly installed on one side of the sample detection box of the lifting platform and includes a soil moisture sensor, a pH sensor and an organic matter sensor. The detection probes of the sensors extend into the sample detection box. When the soil sample is transported to the sample detection box, the detection probes are in full contact with the sample to detect the soil moisture content, pH value and organic matter content in real time. The detection data is transmitted to the display screen of the control panel and the data storage module through a data cable to realize the real-time display and storage of the detection data. Furthermore, in step S2, the specific process of sampling and detection is as follows: (1) Move the dedicated soil sampling and testing integrated machine to the first sampling point planned in step S1 and position it; (2) Set the sampling depth and sampling quantity through the control panel, start the lifting motor, and let the bottom of the sampling sleeve contact the ground; (3) Start the sampling motor, the serrated edge of the sampling sleeve cuts into the soil, and the spiral conveying blades transport the soil sample upward along the hollow channel of the sampling drill rod to the designated area. (4) The detection probes of the moisture content sensor, pH sensor and organic matter sensor are in full contact with the soil sample in the sample detection box to detect soil property parameters in real time and synchronously associate the latitude and longitude coordinates and sampling depth information of the sampling point. Further, in step S3, the specific process of data preprocessing is as follows: the 3σ principle is used to screen the detection data and remove abnormal data that exceed the standard deviation of the mean set range; the real-time detection data is corrected according to the standard sample data calibrated by the laboratory; the missing detection data is supplemented by interpolation using the Kriging interpolation method; the corrected detection data, sampling point coordinate data and sampling depth data are organized in a unified format to generate a standardized soil attribute dataset, each data entry containing information such as the latitude and longitude of the sampling point, sampling depth, water content, pH value, and organic matter content; in step (4), the spatial interpolation algorithm adopts the improved Kriging interpolation method.

[0009] The beneficial effects of this invention are as follows: This method for creating soil property maps produces highly accurate maps, establishes a comprehensive soil property database, and enables systematic management of soil property data and maps. Furthermore, it allows for regular, real-time updates without requiring rework across the entire area; updates are only needed for specific areas of change, reducing operational costs and improving the applicability and timeliness of the soil property maps. This method can be widely applied in various fields such as agricultural production, land planning, and ecological protection.

[0010] This invention accurately reflects the distribution characteristics of various properties of farmland soil, providing precise basic data for agricultural production. In particular, it integrates a sampling mechanism, a lifting and adjusting mechanism, a positioning component, and a detection module, achieving integrated sampling, detection, and positioning operations. This completely solves the problems of low efficiency and sample distortion associated with traditional manual sampling methods. The lifting and adjusting mechanism allows for precise adjustment of sampling depth, while the spiral conveying blades and serrated sampling edge of the sampling mechanism ensure rapid and pure sample collection. The positioning component prevents sampling deviation, significantly improving the accuracy and efficiency of sampling and detection. Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the external structure of one type of integrated soil sampling and testing machine used in this method; Figure 2 This is a partial cross-sectional view of one of the integrated soil sampling and testing machines used in this method; Figure 3 This is a side view of the lifting platform; Figure 4 A schematic diagram showing the lifting platform as an enclosed structure; Figure 5 This is a schematic diagram of the drive structure of the sampling drill rod; Figure 6 This is a schematic diagram showing the connection between the sampling sleeve and the sampling drill rod.

[0012] In the diagram: 1. Sampling drill rod; 101. Strip groove; 2. Threaded sleeve; 3. Worm gear; 4. Limiting block; 5. Bottom sleeve; 6. Helical blade; 7. Sampling sleeve; 701. Vent hole; 702. Sampling cutting edge; 8. Upper mounting plate; 9. Lower mounting plate; 10. Lifting motor; 11. Transmission gear set; 12. Machine body support; 13. Worktable; 14. Lifting platform; 14. Side plate; 1401. Sliding block; 1402. Guide rail; 15. Ball screw; 16. Sample detection box; 17. Worm gear; 18. Bearing hydraulic column; 19. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0014] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0015] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0016] This invention provides a technical solution: a method for creating a soil property map, comprising the following steps: S1. Sampling Area Planning: Select a farmland area as the target area. Use a GIS geographic information system to obtain topographic, geomorphological, and land use data of the area. Divide the target area into several sampling units. Set 3 sampling points in each sampling unit. Determine the latitude and longitude coordinates, sampling depth, and sampling quantity of each sampling point. For example, collect 100g of soil sample at each sampling point. Generate a sampling route planning map to ensure that the sampling points are evenly distributed and cover the entire target area. S2. Sampling and Testing: A dedicated integrated soil sampling and testing machine is used, the structure of which is as follows: Figures 1-2 As shown, it includes a body support 12, a lifting and adjusting mechanism, a sampling mechanism, and a positioning component, with the specific structure as follows: (1) Body support 12: Made of high-strength aluminum alloy, with a frame structure. The top of the support is equipped with a worktable 13, and the side of the support can be adapted to be equipped with a control panel and a data storage module. (2) Lifting and adjusting mechanism: It is fixedly installed on the worktable 13 and includes a lifting motor 10, a ball screw 16, a guide rail 15 and a lifting platform 14. The lifting motor 10 is connected to the ball screw 16 for transmission. The ball screw 16 is set vertically. The guide rail 15 is arranged parallel to the ball screw 16. The lifting platform 14 is sleeved on the ball screw 16 and the guide rail 15 to stably realize the position lifting and adjusting. (3) Sampling mechanism: It is mainly fixedly installed on the lifting platform 14, such as Figures 1-2 As shown, the device includes a sampling motor, a transmission gear set 11, a sampling drill rod 1, and a sampling sleeve 7. The sampling drill rod 1 is connected to the sampling drill rod 1 via the transmission gear set 11. The sampling drill rod 1 has a hollow channel inside, and a spiral blade 6 is provided on the inner wall of the channel. The spiral blade 6 can be coaxially fixed inside the channel, or it can be driven to rotate actively by existing drive components to improve conveying efficiency. During manufacturing, the sampling sleeve 7 is coaxially and integrally fitted onto the lower end of the sampling drill rod 1, as shown below. Figure 6The sampling sleeve 7 has eight vent holes 701 with a diameter of 0.5 cm on its side wall and a serrated sampling blade 702 at the bottom. When drilling to the corresponding depth, the sampling drill rod 1 is taken out and the soil in the sampling sleeve 7 is taken out to achieve accurate sampling and detection of the soil at the corresponding depth. If macroscopic analysis is to be performed on the soil within a certain depth range on the ground, the soil continuously output from the top of the sampling drill rod 1 can be intermittently detected directly. This is the main detection method for soil property image production. It can achieve the effect of automatically and continuously obtaining soil property detection data in the depth direction without the need for manual marking of the order to represent the depth hierarchy of the soil sample. (4) Positioning components: including a GPS positioning module and an inclination sensor. The GPS positioning module is fixed on the top of the workbench 13 or other fixed components, and the inclination sensor is fixed in the middle of the sampling drill rod 1. Specifically, it can be fixed on one side of the middle section of the rod and set parallel to the axis.

[0017] More specifically, as one of the specific implementation structures, such as Figure 2 as well as Figure 3 This embodiment also includes an upper mounting plate 8 and a lower mounting plate 9 fixed on the machine body bracket 12, forming a U-shaped mounting structure with the base plate. The two mounting plates are fixed together by a pair of parallel guide rails 15. The guide rails 15 are rectangular tracks, and a ball screw 16 is provided parallel between the two guide rails 15. The two ends of the ball screw 16 are rotatably mounted in the two mounting plates, and one end is fixed to the main shaft of the lifting motor 10. Since the lifting platform 14 has a U-shaped groove structure, its two side plates 1401 can be vertically slidably sleeved on the guide rails 15, while the ball screw 16 is threaded through the sliding block 1402 fixed at the bottom of the groove of the lifting platform 14 to achieve threaded feed. In addition, as Figure 5 In this embodiment, the sampling drill rod 1 has threads on its outer side and a strip groove 101 on its surface. The strip groove 101 is parallel to the axial direction. The two side plates 1401 of the lifting platform 14, near the sampling drill rod 1, are respectively fixed to the ground via flange plates with threaded sleeves 2 and bottom sleeves 5, to achieve coaxial fixed installation of the threaded sleeves 2 and bottom sleeves 5. The distance between them must be such that a worm gear 3, coaxial with the two sleeves, is rotatably installed between them, that is, both ends of the worm gear 3 are rotatably sleeved within the opposite end faces of the threaded sleeve 2 and the bottom sleeve 5. Figure 2A worm gear 18 is fixed on the output shaft of the transmission gear set 11. The worm gear 18 meshes with the worm 3. A limit block 4 is fixed on the bore wall of the worm 3. The limit block 4 can be a rectangular block, and the strip groove 101 is also a rectangular groove. The limit block 4 is slidably installed in the strip groove 101, with its end fitting against the bottom of the groove 101. While transmitting torque, it guides the direction of movement, thereby guiding the sampling drill rod 1 to drill vertically. As for the driving mechanism, the threaded sleeve 2 allows the sampling drill rod 1 to pass through threadedly to apply driving force, and the bottom sleeve 5 allows the sampling rotating rod to pass through freely without contact, so that when the transmission gear set 11 is started, i.e., when the motor is started, the sampling drill rod 1 feeds axially for sampling. In the above design, in order to protect the lifting motor 10 and its transmission gear set 11 and other components, the lifting platform 14 can be made as follows: Figure 4 The enclosed housing structure shown allows one side of the worm gear 18 to be exposed for engagement with the worm 3.

[0018] In this embodiment, the sampling sleeve 7 is changed to different lengths according to the sampling depth requirements, with a recommended length range of 20cm-100cm. To comprehensively consider economy and practicality, the adjustment accuracy of the lifting mechanism is set to ±0.5cm. To avoid excessive load on the screw drive structure, in this embodiment, as... Figure 1 A pair of vertically downward-facing hydraulic columns 19 are fixed on the lower mounting plate 9. When the lifting motor 10 adjusts the sampling mechanism to the corresponding height, the hydraulic columns 19 extend to press against the ground or the machine support 12. This can transfer the load on the lifting platform 14, avoid excessive vibration during sampling or affect the service life of the lead screw. Only the lead screw feed is used for initial position adjustment or fine adjustment of the drilling depth. Once the adjustment is in place, the lead screw no longer mainly supports the lifting platform 14, but relies on the hydraulic columns 19 for support.

[0019] In this embodiment, all auxiliary structures such as the detection module can be fixed inside the sample detection box 17 of the lifting platform 14 (when the sample detection box 17 is used to directly hold samples or to house sample containers), such as soil moisture sensor, pH sensor and organic matter sensor. In this embodiment, the specific process of sampling and detection is as follows: Move the all-in-one machine to the first sampling point, activate the positioning component, and the GPS positioning module obtains the latitude and longitude coordinates of the sampling point. The tilt sensor detects the tilt angle of the sampling drill rod 1, with a detection value of 1.2° (assuming a reasonable range of less than ±3°), so no adjustment of the machine position is required. Then, set the sampling depth to 50cm and the sampling quantity to 100g via the control panel, and start the lifting motor 10 to drive the ball screw 16 to rotate, causing the lifting platform 14 and the sampling mechanism to move downwards until the bottom of the sampling sleeve 7 contacts the ground. When the depth of the ground depression to be sampled is not large, it is advisable to directly use the lifting motor 10 to achieve the contact between the bottom of the sampling sleeve 7 and the ground. During sampling, start the sampling motor to drive the sampling drill rod 1 to rotate at a speed of 300r / min. The serrated sampling blade 702 cuts into the soil, and the spiral conveying blades transport the soil sample along the hollow channel to the sample conveying pipe at the top (not shown in the figure), and then through the sample conveying pipe to the sample detection box 17 or the internal designated sample container. When the sample weight reaches the sampling quantity, the sampling motor automatically stops. Subsequently, the aforementioned detection module automatically starts, and the corresponding detection probe comes into contact with the soil sample to detect the moisture content (e.g., 22.5%), pH value (e.g., 6.8), and organic matter content (e.g., 3.2%) in real time. The detection data is transmitted to the control panel display and data storage module, synchronously linking the sampling point coordinates and sampling depth information. After sampling and testing are completed, the lifting motor 10 rotates in the reverse direction, driving the sampling mechanism to reset. If necessary, the sample detection box 17 is cleaned, and the integrated machine is moved to the next sampling point. The aforementioned steps are repeated until the sampling and testing work for multiple sampling points is completed. In this embodiment, the data preprocessing for the detection involves: outlier removal, which can be performed using the 3σ principle to screen all groups of detection data and remove one group of outliers in organic matter content caused by sampling contamination (e.g., 10.5%, exceeding the mean range of 3.2% ± 3 × 0.8%). Then, data correction is performed: using laboratory-calibrated standard soil samples (20% moisture content, 6.5 pH, 3.0% organic matter), all detection data are corrected. For example, the moisture content detection value of a certain sampling point (22.7%) is corrected to 22.5%. Missing data supplementation: if one sampling point fails to detect, Kriging interpolation can be used to supplement the moisture content (22.3%), pH (6.7), and organic matter (3.1%) of that sampling point based on the detection data of surrounding sampling points. Finally, all data is processed to generate a standardized dataset containing the latitude and longitude of the sampling point, sampling depth, moisture content, pH value, and organic matter content. In this embodiment, a soil property spatial interpolation method can also be used, specifically an improved Kriging interpolation method. The specific process is as follows: Trend analysis was performed on the standardized dataset to remove the macro-trend component of soil moisture content (the gradient change in moisture content caused by topographic differences), retaining the random component. The variogram of the random component was calculated, and a spherical model was selected as the theoretical model. The model was optimized using cross-validation to obtain a sill value of 0.8, a range of 50m, and a nugget value of 0.1. Based on the optimized parameters, the soil property values ​​of unsampled points in the target area were interpolated to obtain the estimated values ​​of moisture content, pH value, and organic matter content for each unsampled point. The actual values ​​of the sampled points and the estimated values ​​of the unsampled points were arranged according to spatial coordinates to form a spatial distribution matrix of soil properties. After performing the above series of operations, in order to optimize the soil attribute map drawing, the soil attribute spatial distribution matrix can be combined with a GIS geographic information system, and basic geographic layers such as topography, roads, and water systems of the target area can be overlaid to draw an initial soil attribute map. For example, 8 verification points (13.3% of the total number of sampling points) can be randomly selected in the target area, resampled and tested, and the root mean square error (RMSE) is calculated to be 3.2% (≤5%), which meets the accuracy requirements, to obtain the final soil attribute map. The final soil attribute map is output as a vector map for use in farmland fertilization planning. A soil attribute database is established to store all sampling data and map data, and the update cycle is set to six months. During the next update, only areas with significant changes in irrigation conditions at the edge of farmland (e.g., about 5 acres) are resampled and tested to complete the map update.

[0020] In the above description of the present invention, it should be noted that the terms "one side," "the other side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is conventionally placed during use. These terms are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0021] Furthermore, terms such as "identical" do not imply that components must be absolutely identical; minor differences are permissible. The term "perpendicular" simply means that the positional relationship between components is more perpendicular than "parallel," not that the structure must be perfectly perpendicular; a slight tilt is acceptable.

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for creating a soil property map, characterized in that, Includes the following steps: S1. Sampling Area Planning: Based on the topography and geomorphological features of the target area, and in conjunction with the GIS geographic information system, divide the area into several sampling units, determine the coordinates of the sampling points, sampling depth, and sampling quantity of each sampling unit, and generate a sampling route planning map. S2. Sampling and Testing: Using an integrated soil sampling and testing machine, the machine moves to each sampling point according to the sampling route and parameters planned in step S1. The sampling mechanism completes the accurate collection of soil samples, and the detection module on the integrated machine performs real-time detection of the physicochemical properties of the soil samples, and records the spatial location information, sampling depth information and detection data of the sampling points simultaneously. S3. Data preprocessing: The detection data, location data and depth data collected in step S2 are screened and corrected, abnormal data are removed, missing data are interpolated and supplemented, and the corrected data are correlated according to the sampling point coordinates to generate a standardized soil property dataset. S4. Spatial interpolation of soil properties: Using a spatial interpolation algorithm, the standardized soil property dataset obtained in step S3 is interpolated to obtain the estimated values ​​of soil properties at all locations within the target area, forming a spatial distribution matrix of soil properties. S5. Soil Attribute Mapping and Optimization: Combine the spatial distribution matrix of soil attributes obtained in step S4 with a GIS geographic information system, overlay the basic geographic layer of the target area, and draw an initial soil attribute map; verify and optimize the accuracy of the initial soil attribute map to obtain the final soil attribute map. S6. Map Output and Update: Output the final soil property map obtained in step S5 according to the preset format, and establish a soil property database. Repeat steps S1-S5 periodically to update the soil property map in real time.

2. The method for creating a soil property map according to claim 1, characterized in that, The integrated soil sampling and testing machine in step S2 includes a body support (12), a lifting and adjusting mechanism, a sampling mechanism and a positioning component. The lifting and adjusting mechanism is fixedly installed on the top of the body support (12), the sampling mechanism is fixedly installed on the lifting and adjusting mechanism, and the positioning component is fixedly installed on the body support (12) and the sampling mechanism. The sampling mechanism includes a sampling motor, a transmission gear set (11), a sampling drill rod (1), and a sampling sleeve (7). The sampling motor is connected to the sampling drill rod (1) through the transmission gear set (11). The sampling drill rod (1) is set vertically downward. The sampling sleeve (7) is fitted on the lower end of the sampling drill rod (1). The side wall of the sampling sleeve (7) is provided with several ventilation holes (701), and the bottom is provided with a serrated sampling cutting edge (702). The sampling drill rod (1) is provided with a hollow channel inside, and the inner wall of the channel is provided with spiral conveying blades. The lifting adjustment mechanism includes a lifting motor (10), a ball screw (16), a guide rail (15), and a lifting platform (14). The lifting motor (10) is connected to the ball screw (16) for transmission. The ball screw (16) is set vertically. The guide rail (15) is arranged parallel to the ball screw (16). The lifting platform (14) is sleeved on the ball screw (16) and the guide rail (15). The lifting motor (10) drives the ball screw (16) to rotate, which drives the lifting platform (14) to move up and down along the guide rail (15) to achieve precise adjustment of the sampling depth.

3. The method for creating a soil property map according to claim 2, characterized in that, The machine body support (12) is a frame structure in the shape of a frustum cone. The top of the machine body support (12) is provided with a workbench (13) for installing a lifting and adjusting mechanism. The machine body support (12) is also provided with a control panel and a data storage module to realize the start and stop of sampling, parameter adjustment and data temporary storage.

4. The method for creating a soil property map according to claim 2, characterized in that, It also includes an upper mounting plate (8) and a lower mounting plate (9) fixed on the body bracket (12). The two mounting plates are fixed together by a pair of parallel guide rails (15). The ball screw (16) is arranged parallel between the two guide rails (15). The two ends of the ball screw (16) are rotatably installed in the two mounting plates, and one end is fixed to the main shaft of the lifting motor (10). The lifting platform (14) is a U-shaped groove structure. Its two side plates (1401) are slidably sleeved on the guide rails (15). The ball screw (16) is threaded through the sliding block (1402) fixed at the bottom of the groove of the lifting platform (14).

5. The method for creating a soil property map according to claim 4, characterized in that, The sampling drill rod (1) has threads on its outer side and a strip groove (101) on its surface, which is parallel to the axial direction. The two side plates (1401) of the lifting platform (14) are respectively fixed with threaded sleeves (2) and bottom sleeves (5) on the side of the sampling drill rod (1). A worm gear (3) is rotatably installed between the two sleeves and is coaxial with them. A worm wheel (18) is fixed on the output shaft of the transmission gear set (11). The worm wheel (18) meshes with the worm gear (3). A limit block (4) is fixed on the hole wall of the worm gear (3). The limit block (4) is slidably installed in the strip groove (101) to guide the sampling drill rod (1) to drill vertically. The threaded sleeve (2) is for the sampling drill rod (1) to pass through threadedly, and the bottom sleeve (5) is for the sampling rotating rod to pass through freely without contact, so that when the transmission gear set (11) is started, the sampling drill rod (1) is fed axially.

6. The method for creating a soil property map according to claim 4, characterized in that, The sampling sleeve (7) can be changed to different lengths according to the sampling depth requirements, with a length range of 20cm-100cm; a pair of vertically downward-facing bearing hydraulic columns (19) are fixed on the lower mounting plate (9). When the lifting motor (10) adjusts the sampling mechanism to the corresponding height, the bearing hydraulic columns (19) extend to press against the ground or the machine body support (12) to transmit the load on the lifting platform (14).

7. The method for creating a soil property map according to claim 2, characterized in that, The sampling drill rod (1) is also provided with a spiral blade (6) so that when the soil passing through the sampling sleeve (7) enters the sampling drill rod (1), it is transported upward along the spiral blade (6); The positioning components include a GPS positioning module and an inclination sensor. The GPS positioning module is fixedly installed on the top of the body support (12) to obtain the latitude and longitude coordinates of the sampling point. The inclination sensor is fixedly installed on the sampling drill rod (1) to detect the tilt angle of the sampling drill rod (1). When the tilt angle exceeds the set value, an alarm signal is sent to the control panel.

8. The method for creating a soil property map according to claim 2, characterized in that, The specific process of sampling and detection in step S2 is as follows: S21. Move the soil sampling and testing integrated machine to the sampling point, start the positioning component, obtain the coordinates of the sampling point and detect the tilt angle of the sampling drill rod (1), and adjust the position of the machine body to ensure that the sampling drill rod (1) is perpendicular to the ground. S22. Set the sampling depth and sampling quantity, start the lifting motor (10) or the lifting motor (10) to drive the sampling mechanism to move downward until the sampling sleeve (7) contacts the ground; S23. Start the sampling motor to drive the sampling drill rod (1) to rotate and cut into the soil through the serrated sampling blade (702). The spiral conveying blade transports the soil sample to the sample detection box (17) on one side. Sampling stops after the preset sampling quantity is reached. S24. Start the detection module, the detection probe contacts the soil sample, detects the soil physicochemical properties in real time, and transmits the detection data to the control panel and data storage module, synchronously linking the sampling point coordinates and sampling depth information. S25. After sampling and testing are completed, the lifting mechanism drives the sampling mechanism to reset, cleans up residual samples, and moves the integrated machine to the next sampling point to repeat the operation.

9. The method for creating a soil property map according to claim 1, characterized in that, The specific process of data preprocessing in step S3 is as follows: outlier data is removed using the 3σ principle, test data is corrected based on standard sample data calibrated by the laboratory, missing data is supplemented using Kriging interpolation, and all data are organized into a standardized soil property dataset. The spatial interpolation algorithm described in step S4 uses an improved Kriging interpolation method. First, the macro-trend component in the soil attribute data is removed, then the variogram of the random component is calculated and the parameters are optimized. Finally, the soil attribute values ​​of unsampled points are interpolated to form a spatial distribution matrix of soil attributes.

10. The method for creating a soil property map according to claim 1, characterized in that, The accuracy verification method in step S5 is as follows: randomly select 10%-15% of the total number of sampling points as verification points, resample and test, compare with the interpolated estimated value, calculate the root mean square error, if the root mean square error is ≤5%, the accuracy meets the requirements; otherwise, re-optimize the interpolation parameters and draw the soil property map. The soil property database mentioned in step S6 includes sampling point information, soil property detection data, soil property map data, and update records. It supports data query, modification, and export. The regular update cycle is quarterly, semi-annually, or annually. During the update, only areas with significant changes are resampled, detected, and interpolated.

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