A method for detecting and analyzing agricultural soil

Abstract

The present invention relates to the field of detection, and in particular to an agricultural soil detection and analysis method. The method can realize a comprehensive analysis of the detection results of various detection points in a region, and then determine the flow of the detected pollutant elements in the soil of the region, so as to determine the area suitable for planting crops in the region, that is, it can give constructive suggestions on the planting location of crops to ensure that the crops are affected by the pollutants as little as possible.

Description

Technical Field

[0001] The present invention relates to the field of detection, and in particular to an agricultural soil detection and analysis method. Background Art

[0002] With the development of economy, rural economy has also grown significantly, and more and more industrial enterprises have appeared in rural areas, which will also cause industrial pollution of industrial enterprises to pollute agricultural soil;

[0003] In order to determine the impact of industrial pollution on agricultural soil, it is necessary to detect the polluting elements in agricultural soil to determine the degree of contamination of agricultural soil; the test data obtained from soil testing needs to be analyzed and processed by computer, but the existing soil test data processing method often only analyzes the test results of samples at a single test point for each test, and it is difficult to conduct a comprehensive analysis of the test data of a large area of ​​soil, and thus it is difficult to obtain constructive analysis results. Summary of the invention

[0004] Based on this, it is necessary to provide an agricultural soil detection and analysis method to address the above-mentioned problems.

[0005] The embodiment of the present invention is implemented as follows: an agricultural soil detection and analysis method, the method comprising:

[0006] S1: Determine the detection points pre-arranged in the set area, and take samples at each detection point according to the set time interval;

[0007] S2: pre-treat the collected samples, and detect the pollutant elements of the pre-treated samples by mass spectrometry to obtain the content of various pollutant elements at each detection point at different time points;

[0008] S3: Determine the upper limit of crop tolerance for each pollutant element based on historical information;

[0009] S4: Generate a map of the set area and mark each detection point on the map;

[0010] S5: for each pollutant element, a plurality of isoquant lines of the pollutant element are generated on the map according to the content of the pollutant element at each detection point;

[0011] S6: determining the changing trend of each isoline over time, and determining the impact area of ​​the pollutant on the crops in the set area according to the determined changing trend and the upper limit of the tolerance of the crops to the pollutant;

[0012] S7: Determine a recommended planting area for crops in the set area according to the impact area of ​​various pollution elements on crops in the set area, and output the recommended planting area.

[0013] Preferably, pre-processing the collected samples comprises:

[0014] Weigh the sample to obtain the initial mass of the sample;

[0015] The samples are dried in the sun to obtain the dry matter mass of the samples, and then the dry matter content of the samples is calculated;

[0016] Grind the sample, pack the ground sample into sample containers, and fill in sample labels on the sample containers;

[0017] Weigh 0.25 g of soil sample sieved through a 100-mesh sieve into a microwave digestion tube, add 9 mL of nitric acid and 3 mL of hydrochloric acid and mix well. After the reaction is stable, tighten the tube cap to perform microwave digestion on the sample.

[0018] After microwave digestion is completed, move the sample to a crucible, add 2 mL of hydrofluoric acid to the crucible, place the crucible on a hot plate, and heat at 120-140 degrees until the sample is in a non-flowing viscous state;

[0019] Remove the crucible, cool it to room temperature, add 1 mL of perchloric acid, and then place the crucible on a hot plate and continue heating at 160-180 degrees until the white smoke disappears and the sample becomes solid;

[0020] Remove the crucible, add a small amount of 1% nitric acid to rinse the inner wall of the crucible, heat to dissolve the sample, cool to room temperature, transfer the sample to a 50mL volumetric flask, rinse the inner wall of the crucible repeatedly with 1% nitric acid, transfer the rinse liquid to the volumetric flask, and dilute to the scale line with 1% nitric acid to obtain the sample solution.

[0021] Preferably, detecting contaminant elements on the pre-treated sample by mass spectrometry comprises:

[0022] Taking a set amount of sample solution into the automatic sampler of the mass spectrometer, so that the automatic sampler automatically injects the sample solution;

[0023] While the sample is being automatically injected, a pre-prepared internal standard solution is added to the mass spectrometer via a peristaltic pump;

[0024] The mass spectrometer performs the measurement and outputs the mass concentration of each pollutant element in the sample test solution to the computer device;

[0025] Adding a pre-prepared blank test solution to the mass spectrometer for measurement, so that the mass spectrometer outputs the mass concentration of each contaminant element in the blank test solution to the computer device;

[0026] For each contaminant element, the computer device calculates the content of the contaminant element in the sample using the following formula:

[0027]

[0028] in, is the content of the contaminant element in the sample, is the mass concentration of the pollutant element in the sample solution, f is the dilution multiple of the sample solution, is the mass concentration of the contaminating element in the blank test solution, is the constant volume of the sample solution, m is the initial mass of the sample, is the dry matter content of the sample.

[0029] Preferably, steps S3 to S7 are applied to a computer device; for each pollutant element, generating a plurality of isolines of the pollutant element on a map according to the content of the pollutant element at each detection point includes:

[0030] Obtain the content of the pollutant element corresponding to each detection point at the first sampling time node;

[0031] Mark the corresponding content at each test point on the map;

[0032] Connect the detection points with the same content into lines to obtain several isoquant lines of the pollutant element.

[0033] Preferably, determining the changing trend of each isoline over time, and determining the impact area of ​​the pollutant on the crops in the set area according to the determined changing trend and the upper limit of the tolerance of the crops to the pollutant includes:

[0034] S51: determining the distribution of each isoquant line at each time node after the first time node;

[0035] S52: Determine the emission point and emission period of the pollutant element;

[0036] S53: For each emission period, the moving area of ​​the pollutant emitted in the emission period is determined according to the change of the distribution of each isoquant line with the backward shift of the time node and the upper limit of the tolerance of crops to the pollutant;

[0037] S54: Determine the impact area of ​​the pollutant element on crops in the set area according to the moving area corresponding to each emission period.

[0038] Preferably, determining the emission point and emission period of the pollutant element includes:

[0039] Locate each pollution source on a map;

[0040] For each pollution source location, determine whether the content corresponding to the isoline closest to the location has a sudden increase. If so, the location is the emission point of the pollutant element. Otherwise, the location is not the emission point of the pollutant element. The content corresponding to the isoline closest to the location has a sudden increase, that is, the content of the isoline closest to the location at a time node exceeds the set value of the content of the isoline closest to the location at the previous time node.

[0041] The time point at which the content of the isoquant line closest to the emission point suddenly increases is determined as the emission time point;

[0042] The time interval between every two adjacent emission time points is determined as an emission cycle.

[0043] Preferably, the moving area of ​​the pollutant element emitted in the emission period is determined according to the change of the distribution of each isoquant line with the backward shift of the time node and the upper limit of the tolerance of crops to the pollutant element, including:

[0044] S531: taking the first time node of the emission cycle as the target time node;

[0045] S532: Displaying each isoquant line at the target time node on the map;

[0046] S533: Determine, from the displayed isoquants, a target isoquant whose corresponding content is greater than the upper tolerance limit of the crop for the pollutant element;

[0047] S534: The area between every two target isoquant lines is taken as a target sub-area, and the area formed by the target sub-areas is the target area of ​​the pollutant element corresponding to the target time node;

[0048] S535: Take the next time node of the emission cycle as the target time node, and execute steps S532 to S535 until the target area of ​​the pollutant element corresponding to each time node of the emission cycle is obtained, and the area composed of the target areas is used as the moving area of ​​the pollutant element emitted in the emission cycle.

[0049] Preferably, determining the impact area of ​​the pollutant element on crops in a set area according to the moving area corresponding to each emission period includes:

[0050] The movement areas corresponding to each emission period are simultaneously displayed on the map;

[0051] Determine a boundary line that just surrounds all moving areas, and determine the overlapping ratio of the moving areas of each position point within the boundary line;

[0052] An area consisting of position points whose overlapping ratio of the impact areas exceeds a preset ratio is determined as the impact area of ​​the pollutant element on crops in the set area.

[0053] Preferably, the moving area overlap ratio of each position point within the boundary line is calculated by the following formula:

[0054]

[0055] in, is the overlap ratio of the moving area of ​​the position point, is the total number of mobile areas, is the number of moving areas overlapping the position point.

[0056] Preferably, determining the recommended planting area of ​​crops in the set area according to the impact area of ​​various pollution elements on crops in the set area includes:

[0057] Identify planting areas on the map for growing crops;

[0058] Display all impact areas of crops on a map;

[0059] Determine whether beneficial reactions can occur between various polluting elements, and if so, determine the reaction elements that can cause beneficial reactions, wherein a beneficial reaction is a reaction whose product is a non-polluting substance;

[0060] Determine on the map whether the influence area corresponding to the reaction element has a common area, and if so, determine the common area;

[0061] The planting areas not covered by the impacted areas and the identified common areas are identified as recommended planting areas for crops.

[0062] The present invention provides an agricultural soil detection and analysis method, comprising: determining detection points pre-arranged in a set area, and sampling at each detection point at a set time interval; pre-processing the collected samples, and detecting the pollutant elements of the pre-processed samples by mass spectrometry to obtain the content of various pollutant elements at each detection point at different time points; determining the upper limit of tolerance of crops to each pollutant element according to historical information; generating a map of the set area, and marking each detection point on the map; for each pollutant element, generating a plurality of isoquant lines of the pollutant element on the map according to the content of the pollutant element at each detection point; determining the change trend of each isoquant line over time, The influence area of ​​the pollutant on the crops in the set area is determined based on the determined change trend and the upper limit of the tolerance of the crops to the pollutant; the recommended planting area of ​​the crops is determined in the set area based on the influence area of ​​various pollutants on the crops in the set area, and the recommended planting area is output; in the present application, a comprehensive analysis of the detection results of each detection point in an area can be achieved, and then the flow of the detected pollutant in the soil in the area can be determined, so that the area suitable for planting crops in the area can be determined, that is, constructive suggestions can be given for the planting location of the crops to ensure that the crops are affected as little as possible by the pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 A flow chart of an agricultural soil detection and analysis method provided by an embodiment of the present invention;

[0064] Figure 2 A schematic diagram of a computer device execution environment for the agricultural soil detection and analysis method provided by an embodiment of the present invention;

[0065] Figure 3 A schematic diagram of isometric lines of the agricultural soil detection and analysis method provided by an embodiment of the present invention;

[0066] Figure 4 A schematic diagram of the impact area of ​​the agricultural soil detection and analysis method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0068] It is understood that the terms "first", "second", etc. used in the present invention may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first xx script may be referred to as a second xx script, and similarly, a second xx script may be referred to as a first xx script without departing from the scope of the present invention.

[0069] like Figure 1 As shown, in one embodiment, a method for agricultural soil detection and analysis is proposed, the method comprising:

[0070] S1: Determine the detection points pre-arranged in the set area, and take samples at each detection point according to the set time interval;

[0071] S2: pre-treat the collected samples, and detect the pollutant elements of the pre-treated samples by mass spectrometry to obtain the content of various pollutant elements at each detection point at different time points;

[0072] S3: Determine the upper limit of crop tolerance for each pollutant element based on historical information;

[0073] S4: Generate a map of the set area and mark each detection point on the map;

[0074] S5: for each pollutant element, a plurality of isoquant lines of the pollutant element are generated on the map according to the content of the pollutant element at each detection point;

[0075] S6: determining the changing trend of each isoline over time, and determining the impact area of ​​the pollutant on the crops in the set area according to the determined changing trend and the upper limit of the tolerance of the crops to the pollutant;

[0076] S7: Determine a recommended planting area for crops in the set area according to the impact area of ​​various pollution elements on crops in the set area, and output the recommended planting area.

[0077] In this embodiment, a mass spectrometer is used to detect the contamination elements of the sample, such as an inductively coupled plasma mass spectrometer (the mass range that can be scanned is 5amu to 250amu, and the resolution is that the peak width at the peak height of 10% is between 0.6amu and 0.8amu); Steps S3-S7 are performed in a computer device, and the computer device can be an independent physical server or terminal, or a server cluster composed of multiple physical servers, and can be a cloud server that provides basic cloud computing services such as cloud servers, cloud databases, cloud storage and CDN, such as Figure 2 As shown, the computer device is connected to the mass spectrometer, so that the computer device can perform data analysis on the detection results of the mass spectrometer.

[0078] In this embodiment, steps S1 to S2 are performed by the detection personnel, and the set area is the area pre-demarcated by the detection personnel including farmland and pollution sources (such as township-run enterprises); in this embodiment, the detection personnel can use the radial distribution method, the strip distribution method and the uniform distribution method to arrange the detection points according to the distribution and type of the pollution sources, the distribution of the farmland and the accuracy requirements for the detection. For example, the surface solid waste pile can be distributed by the radial distribution method and the point distribution method in combination with the surface runoff and the local perennial dominant wind direction; on both sides of the pollution irrigation water, the strip distribution method is adopted according to the direction of water flow, and the distribution density gradually increases from the pollution inlet of the irrigation water body, and each irrigation section is relatively uniform; in the zoning units at all levels (such as sewage tank areas, areas around industrial and mining enterprises, large and medium-sized The uniform point distribution method can be adopted for monitoring areas (urban suburbs, general agricultural areas, etc.); the specific layout method is selected by the detection personnel according to the specific conditions of the area, which is not limited here; in this embodiment, the number of points can be determined according to the specific conditions of farmland soil background value investigation, agricultural product production area pollution census, agricultural product production area safety and quality division, and pollution accident investigation and monitoring. If the situation is complicated and the monitoring accuracy needs to be improved, the number of points can be appropriately increased. For example, for monitoring agricultural product production areas around industrial enterprises, 5 to 12 points can be used in each area; for monitoring agricultural product production areas in sewage irrigation areas, 10 to 12 points can be used in each area; for agricultural product production areas in suburban areas of large and medium-sized cities, 10 to 15 points can be used in each area, and for important agricultural product production areas, 5 to 15 points can be used in each area.

[0079] In this embodiment, sampling is performed on each detection point at each set time node (in order to provide detection personnel with sufficient time for sampling, the time node set in this embodiment represents a time zone, such as a whole day), and the time difference between every two time nodes is the preset time interval (for example, if the two time nodes are September 1 and September 6, the time interval is 5 days); different sampling methods can be used for different types of soil plots. For example, for farmland soil irrigated with sewage, the diagonal method can be used; for plots with a small area, flat terrain, and uneven soil, the plum blossom method can be used; for plots with a large area, uneven soil, and uneven terrain, the snake method can be used for sampling.

[0080] In this embodiment, historical experimental information is pre-stored in the computer device. The experimental information is data obtained from experiments conducted by inspectors on the effects of various polluting elements on each crop in the past, including the upper tolerance limit of each crop for each polluting element (that is, when the content of the polluting element in the soil does not exceed the upper tolerance limit, the crop can grow normally, and when the content exceeds the upper tolerance limit, the crop will be affected and unable to grow normally); the crop described in this embodiment is one of the crops grown locally, and this method can be executed for each crop to determine the recommended planting area for the crop.

[0081] In the present application, a comprehensive analysis of the detection results of various detection points in an area can be achieved, and then the flow of the detected pollutant elements in the soil of the area can be determined, so as to determine the areas in the area suitable for growing crops, that is, constructive suggestions can be given for the planting locations of crops to ensure that the crops are affected as little as possible by the pollutants.

[0082] As a preferred embodiment, preprocessing the collected samples includes:

[0083] Weigh the sample to obtain the initial mass of the sample;

[0084] The samples are dried in the sun to obtain the dry matter mass of the samples, and then the dry matter content of the samples is calculated;

[0085] Grind the sample, pack the ground sample into sample containers, and fill in sample labels on the sample containers;

[0086] Weigh 0.25 g of soil sample sieved through a 100-mesh sieve into a microwave digestion tube, add 9 mL of nitric acid and 3 mL of hydrochloric acid and mix well. After the reaction is stable, tighten the tube cap to perform microwave digestion on the sample.

[0087] After microwave digestion is completed, move the sample to a crucible, add 2 mL of hydrofluoric acid to the crucible, place the crucible on a hot plate, and heat at 120-140 degrees until the sample is in a non-flowing viscous state;

[0088] Remove the crucible, cool it to room temperature, add 1 mL of perchloric acid, and then place the crucible on a hot plate and continue heating at 160-180 degrees until the white smoke disappears and the sample becomes solid;

[0089] Remove the crucible, add a small amount of 1% nitric acid to rinse the inner wall of the crucible, heat to dissolve the sample, cool to room temperature, transfer the sample to a 50mL volumetric flask, rinse the inner wall of the crucible repeatedly with 1% nitric acid, transfer the rinse liquid to the volumetric flask, and dilute to the scale line with 1% nitric acid to obtain the sample solution.

[0090] In this embodiment, the sample is air-dried, that is, the wet sample is placed on a sample drying tray in a drying room, spread into a thin layer of 2 cm thick, and cut into short pieces, crushed, stirred, and impurities such as gravel or plant residues are picked out; the sample is ground, including coarse grinding and fine grinding; coarse grinding of the sample: pour the air-dried sample on a plexiglass plate in the sample grinding room, crush it again with a hammer, roller, and rod, pick out impurities, and use quartering to divide the crushed sample, all of which are passed through a 20-mesh nylon sieve, and all the sieved samples are placed on a colorless polyethylene film, fully mixed until uniform, and the coarsely ground sample is divided into two by quartering One portion is delivered to the sample warehouse for storage, and the other portion is used for fine grinding of samples. The coarsely ground sample can be directly used for soil pH, soil cation exchange capacity and other content analysis; sample fine grinding: the sample used for fine grinding is divided into two portions for the second time by the quartering method, one portion is reserved, and the other portion is ground until all of it passes through a 60-mesh or 100-mesh nylon sieve. Soil samples that pass through a 60-mesh (pore size 0.25mm) sieve are used for analysis of pesticides or soil organic matter, and soil samples that pass through a 100-mesh sieve (0.149mm) sieve are used for full analysis of soil elements; microwave digestion is carried out using a microwave digestion instrument with a power of 400 W to 1600 W, a temperature control accuracy of ±2.5℃, a programmed power setting function, and a microwave digestion tank made of polytetrafluoroethylene or other high temperature, high pressure and corrosion-resistant materials; the digestion process is carried out according to the procedures shown in the table below:

[0091] Table 1 Reference heating program for microwave digestion

[0092]

[0093] After digestion, cool to room temperature, take out the digestion tube from the microwave digestion instrument, slowly release the pressure and air in the fume hood, open the digestion tube, transfer all the contents in the tube to a polytetrafluoroethylene crucible, wash the tube and lid with a little experimental water, and transfer them to the crucible together.

[0094] As a preferred embodiment, detecting contamination elements on the pretreated sample by mass spectrometry includes:

[0095] Taking a set amount of sample solution into the automatic sampler of the mass spectrometer, so that the automatic sampler automatically injects the sample solution;

[0096] While the sample is being automatically injected, a pre-prepared internal standard solution is added to the mass spectrometer via a peristaltic pump;

[0097] The mass spectrometer performs the measurement and outputs the mass concentration of each pollutant element in the sample test solution to the computer device;

[0098] Adding a pre-prepared blank test solution to the mass spectrometer for measurement, so that the mass spectrometer outputs the mass concentration of each contaminant element in the blank test solution to the computer device;

[0099] For each contaminant element, the computer device calculates the content of the contaminant element in the sample using the following formula:

[0100]

[0101] in, is the content of the contaminant element in the sample, is the mass concentration of the pollutant element in the sample solution, f is the dilution multiple of the sample solution, is the mass concentration of the contaminating element in the blank test solution, is the constant volume of the sample solution, m is the initial mass of the sample, is the dry matter content of the sample.

[0102] In this embodiment, the reference condition of the mass spectrometer is a power of 1200W, the material of the sampling cone and the intercepting cone is nickel, the carrier gas speed is 0.7L / min, and the detection mode is peak jump detection (automatic detection 3 times); before the sample is measured, the system is first flushed with nitric acid, and the internal standard solution is added online while testing the sample, and the test is performed according to the same instrument analysis conditions and operating steps as the standard solution. If the result exceeds the concentration of the standard curve, it should be appropriately diluted (by multiple dilution for ease of calculation) and then re-measured; during the detection process, the mass spectrometer uses the mass concentration of the target element as the horizontal coordinate and the corresponding element signal response value after internal standard correction as the vertical coordinate to establish a linear regression equation; thereby, the mass concentration of the target element (i.e., the contamination element to be detected, including lead, chromium, chromium, cadmium, copper, nickel, zinc, mercury, arsenic and other elements) obtained can be transmitted to the meter computer equipment; the components of the internal standard solution include: one or more internal standard substances (compounds with similar analytical responses to the substances to be tested but which will not interfere with the samples are selected. The specific substances selected are determined by the test personnel based on the contaminant elements to be tested and are not limited here), and solvents for dissolving the internal standard substances. The internal standard solution can be used to correct errors caused by sample processing, instrument response, etc. during the analysis process, thereby improving the accuracy of the analysis results; in mass spectrometry detection, the blank test solution refers to a sample solution that does not contain any substances to be tested, usually composed of pure solvents or solvents. The blank test solution plays a vital role in mass spectrometry detection. It helps ensure that the background signal of the detection instrument is clear, verifies the purity of reagents and equipment, eliminates potential sources of contamination, sets reasonable detection limits, and effectively reduces background interference to ensure the accuracy and reliability of the analysis results.

[0103] As a preferred embodiment, steps S3 to S7 are applied to a computer device; for each pollutant element, generating a plurality of isolines of the pollutant element on a map according to the content of the pollutant element at each detection point includes:

[0104] Obtain the content of the pollutant element corresponding to each detection point at the first sampling time node;

[0105] Mark the corresponding content at each test point on the map;

[0106] Connect the detection points with the same content into lines to obtain several isoquant lines of the pollutant element.

[0107] Determine the changing trend of each isoline over time, and determine the impact area of ​​the pollutant on the crops in the set area based on the determined changing trend and the upper limit of the crops' tolerance to the pollutant, including:

[0108] S51: determining the distribution of each isoquant line at each time node after the first time node;

[0109] S52: Determine the emission point and emission period of the pollutant element;

[0110] S53: For each emission period, the moving area of ​​the pollutant emitted in the emission period is determined according to the change of the distribution of each isoquant line with the backward shift of the time node and the upper limit of the tolerance of crops to the pollutant;

[0111] S54: Determine the impact area of ​​the pollutant element on crops in the set area according to the moving area corresponding to each emission period.

[0112] In this embodiment, if Figure 3 As shown, the isoline is a line connecting detection points with equal element content. The distribution of the isoline can characterize the content distribution of the pollutant element in the set area. By determining the distribution change of the isoline in the set area with time nodes, the position change of the pollutant element in the set area can be determined (the moving area is the sum of the positions of the area with higher content of the pollutant element at each time node). The position with a higher content of the pollutant element will have an impact on the crops. Therefore, the impact area of ​​the pollutant element on the crops can be determined accordingly, so as to determine the recommended planting area of ​​the crops based on the impact area in the later stage; in addition, after determining the impact area of ​​a pollutant element, the impact area is stored, and then the map is restored to determine the impact area of ​​the next pollutant element.

[0113] As a preferred embodiment, determining the emission point and emission period of the pollutant element includes:

[0114] Locate each pollution source on a map;

[0115] For each pollution source location, determine whether the content corresponding to the isoline closest to the location has a sudden increase. If so, the location is the emission point of the pollutant element. Otherwise, the location is not the emission point of the pollutant element. The content corresponding to the isoline closest to the location has a sudden increase, that is, the content of the isoline closest to the location at a time node exceeds the set value of the content of the isoline closest to the location at the previous time node.

[0116] The time point at which the content of the isoquant line closest to the emission point suddenly increases is determined as the emission time point;

[0117] The time interval between every two adjacent emission time points is determined as an emission cycle.

[0118] According to the change of the distribution of each isoline with the time node and the upper limit of the tolerance of crops to this pollutant, the moving area of ​​the pollutant emitted in this emission period is determined to include:

[0119] S531: taking the first time node of the emission cycle as the target time node;

[0120] S532: Displaying each isoquant line at the target time node on the map;

[0121] S533: Determine, from the displayed isoquants, a target isoquant whose corresponding content is greater than the upper tolerance limit of the crop for the pollutant element;

[0122] S534: The area between every two target isoquant lines is taken as a target sub-area, and the area formed by the target sub-areas is the target area of ​​the pollutant element corresponding to the target time node;

[0123] S535: Take the next time node of the emission cycle as the target time node, and execute steps S532 to S535 until the target area of ​​the pollutant element corresponding to each time node of the emission cycle is obtained, and the area composed of the target areas is used as the moving area of ​​the pollutant element emitted in the emission cycle.

[0124] The impact areas of this pollutant on crops in the set area are determined based on the moving areas corresponding to each emission period, including:

[0125] The movement areas corresponding to each emission period are simultaneously displayed on the map;

[0126] Determine a boundary line that just surrounds all moving areas, and determine the overlapping ratio of the moving areas of each position point within the boundary line;

[0127] An area consisting of position points whose overlapping ratio of the impact areas exceeds a preset ratio is determined as the impact area of ​​the pollutant element on crops in the set area.

[0128] The overlap ratio of the moving area for each location point within the boundary line is calculated using the following formula:

[0129]

[0130] in, is the overlap ratio of the moving area of ​​the position point, is the total number of mobile areas, is the number of moving areas overlapping the position point.

[0131] In this embodiment, the location of the pollution source is the location where the polluting elements are generated, such as various factories, garbage disposal sites, etc. These locations are fixed locations and can be directly marked on the map; different polluting elements often come from different emission sources, so for each polluting element, it is necessary to first determine which emission sources it is discharged from, that is, determine the emission point (there are one or more); the pollution discharge at the emission point is often periodic, that is, it is discharged once every period of time, and the content of the polluting element around the emission point will increase suddenly during the discharge (for example, the content increases by more than 30%). After the discharge, due to the diffusion of the polluting elements, the element content around the emission point will gradually decrease to a lower level, while the content on the moving path of the polluting element will increase successively, and this cycle will be repeated;

[0132] In this embodiment, the contents corresponding to any two target isoquant lines are higher than the corresponding upper tolerance limit, and the contents corresponding to the area between the two target isoquant lines (theoretically, there are also isoquant lines distributed in this area, but it is not measured because the detection points are not divided) are higher than the corresponding upper tolerance limit, that is, the contents of the entire target sub-area are higher than the upper tolerance limit; therefore, the moving area determined in this embodiment is the sum of all areas that will exceed the upper tolerance limit in one emission cycle (due to the diffusion of elements, these areas are often not generated at the same time node);

[0133] In this embodiment, ideally, the moving area of ​​each emission cycle is the same area, but there are often deviations in the actual diffusion process, that is, most of the moving areas are consistent, and a small number of areas do not completely overlap. These incompletely overlapping areas (especially areas with a low overlap ratio) are affected by pollutants accidentally, that is, the probability and degree of being affected by pollutants are relatively small. Therefore, they can also be used as crop planting areas, and then only areas with a high overlap ratio (such as 50%) need to be determined as affected areas.

[0134] As a preferred embodiment, Figure 4 As shown, the recommended planting areas for crops in the set area are determined based on the impact of various pollution elements on crops in the set area, including:

[0135] Identify planting areas on the map for growing crops;

[0136] Display all impact areas of crops on a map;

[0137] Determine whether beneficial reactions can occur between various polluting elements, and if so, determine the reaction elements that can cause beneficial reactions, wherein a beneficial reaction is a reaction whose product is a non-polluting substance;

[0138] Determine on the map whether the influence area corresponding to the reaction element has a common area, and if so, determine the common area;

[0139] The planting areas not covered by the impacted areas and the identified common areas are identified as recommended planting areas for crops.

[0140] In this embodiment, different polluting elements may send out reactions, and the substances produced after the reaction may not be polluting. This reaction is a beneficial reaction. Therefore, the area where the reaction elements of the beneficial reaction are mixed, that is, the common area, can also be used to grow crops. Therefore, it is also included in the recommended planting area, so as to ensure the full utilization of the land.

[0141] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0142] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for detecting and analyzing agricultural soil, characterized in that: The method comprises: S1: Determine the detection points pre-arranged in the set area, and take samples at each detection point according to the set time interval; S2: pre-treat the collected samples, and detect the pollutant elements of the pre-treated samples by mass spectrometry to obtain the content of various pollutant elements at each detection point at different time points; S3: Determine the upper limit of crop tolerance for each pollutant element based on historical information; S4: Generate a map of the set area and mark each detection point on the map; S5: for each pollutant element, a plurality of isoquant lines of the pollutant element are generated on the map according to the content of the pollutant element at each detection point; S6: determining the changing trend of each isoline over time, and determining the impact area of ​​the pollutant on the crops in the set area according to the determined changing trend and the upper limit of the tolerance of the crops to the pollutant; S7: determining a recommended planting area for crops in the set area according to the impact area of ​​various pollution elements on crops in the set area, and outputting the recommended planting area; Determine the changing trend of each isoline over time, and determine the impact area of ​​the pollutant on the crops in the set area based on the determined changing trend and the upper limit of the crops' tolerance to the pollutant, including: S51: Determine the distribution of each isoquant line at each time node after the first time node; S52: Determine the emission point and emission period of the pollutant element; S53: For each emission period, the moving area of ​​the pollutant emitted in the emission period is determined according to the change of the distribution of each isoquant line with the backward shift of the time node and the upper limit of the tolerance of crops to the pollutant; S54: determining the impact area of ​​the pollutant element on crops in the set area according to the moving area corresponding to each emission period; According to the change of the distribution of each isoline with the time node and the upper limit of the tolerance of crops to this pollutant, the moving area of ​​the pollutant emitted in this emission period is determined to include: S531: taking the first time node of the emission cycle as the target time node; S532: Displaying each isoquant line at the target time node on the map; S533: Determine, from the displayed isoquants, a target isoquant whose corresponding content is greater than the upper tolerance limit of the crop for the pollutant element; S534: The area between every two target isoquant lines is taken as a target sub-area, and the area formed by the target sub-areas is the target area of ​​the pollutant element corresponding to the target time node; S535: taking the next time node of the emission cycle as the target time node, executing steps S532 to S535 until the target area of ​​the pollutant element corresponding to each time node of the emission cycle is obtained, and taking the area composed of the target areas as the moving area of ​​the pollutant element emitted in the emission cycle; The impact areas of this pollutant on crops in the set area are determined based on the moving areas corresponding to each emission period, including: The movement areas corresponding to each emission period are simultaneously displayed on the map; Determine a boundary line that just surrounds all moving areas, and determine the overlapping ratio of the moving areas of each position point within the boundary line; An area consisting of position points whose overlapping ratio of the impact areas exceeds a preset ratio is determined as the impact area of ​​the pollutant element on crops in the set area.

2. The method according to claim 1, characterized in that Pre-processing of collected samples includes: Weigh the sample to obtain the initial mass of the sample; The samples are dried in the sun to obtain the dry matter mass of the samples, and then the dry matter content of the samples is calculated; Grind the sample, pack the ground sample into sample containers, and fill in sample labels on the sample containers; Weigh 0.25 g of soil sample sieved through a 100-mesh sieve into a microwave digestion tube, add 9 mL of nitric acid and 3 mL of hydrochloric acid and mix well. After the reaction is stable, tighten the tube cap to perform microwave digestion on the sample. After microwave digestion is completed, move the sample to a crucible, add 2 mL of hydrofluoric acid to the crucible, place the crucible on a hot plate, and heat at 120-140 degrees until the sample is in a non-flowing viscous state; Remove the crucible, cool it to room temperature, add 1 mL of perchloric acid, and then place the crucible on a hot plate and continue heating at 160-180 degrees until the white smoke disappears and the sample becomes solid; Remove the crucible, add a small amount of 1% nitric acid to rinse the inner wall of the crucible, heat to dissolve the sample, cool to room temperature, transfer the sample to a 50mL volumetric flask, rinse the inner wall of the crucible repeatedly with 1% nitric acid, transfer the rinse liquid to the volumetric flask, and dilute to the scale line with 1% nitric acid to obtain the sample solution.

3. The method according to claim 2, characterized in that Detection of contaminants in pre-treated samples by mass spectrometry includes: Taking a set amount of sample solution into the automatic sampler of the mass spectrometer, so that the automatic sampler automatically injects the sample solution; While the sample is being automatically injected, a pre-prepared internal standard solution is added to the mass spectrometer via a peristaltic pump; The mass spectrometer performs the measurement and outputs the mass concentration of each pollutant element in the sample test solution to the computer device; Adding a pre-prepared blank test solution to the mass spectrometer for measurement, so that the mass spectrometer outputs the mass concentration of each contaminant element in the blank test solution to the computer device; For each contaminant element, the computer device calculates the content of the contaminant element in the sample using the following formula: in, is the content of the contaminant element in the sample, is the mass concentration of the pollutant element in the sample solution, f is the dilution multiple of the sample solution, is the mass concentration of the contaminating element in the blank test solution, is the constant volume of the sample solution, m is the initial mass of the sample, is the dry matter content of the sample.

4. The method according to claim 3, characterized in that Steps S3 to S7 are applied to a computer device; for each pollutant element, a plurality of isolines of the pollutant element are generated on a map according to the content of the pollutant element at each detection point, including: Obtain the content of the pollutant element corresponding to each detection point at the first sampling time node; Mark the corresponding content at each test point on the map; Connect the detection points with the same content into lines to obtain several isoquant lines of the pollutant element.

5. The method according to claim 1, characterized in that Determine the emission point and emission period of the pollutant element including: Locate each pollution source on a map; For each pollution source location, determine whether the content corresponding to the isoline closest to the location has a sudden increase. If so, the location is the emission point of the pollutant element. Otherwise, the location is not the emission point of the pollutant element. The content corresponding to the isoline closest to the location has a sudden increase, that is, the content of the isoline closest to the location at a time node exceeds the set value of the content of the isoline closest to the location at the previous time node. The time point at which the content of the isoquant line closest to the emission point suddenly increases is determined as the emission time point; The time interval between every two adjacent emission time points is determined as an emission cycle.

6. The method according to claim 5, characterized in that The overlap ratio of the moving area for each location point within the boundary line is calculated using the following formula: in, is the overlap ratio of the moving area of ​​the position point, is the total number of mobile areas, is the number of moving areas overlapping the position point.

7. The method according to claim 6, characterized in that Based on the impact of various pollution elements on crops in the set area, the recommended planting areas for crops in the set area include: Identify planting areas on the map for growing crops; Display all impact areas of crops on a map; Determine whether beneficial reactions can occur between various polluting elements, and if so, determine the reaction elements that can cause beneficial reactions, wherein a beneficial reaction is a reaction whose product is a non-polluting substance; Determine on the map whether the influence area corresponding to the reaction element has a common area, and if so, determine the common area; The planting areas not covered by the impacted areas and the identified common areas are identified as recommended planting areas for crops.

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