Machine learning based method for delineating agricultural eco-soil quality classes

Abstract

The present application relates to the field of soil science, in particular to an agricultural ecological soil quality classification method based on machine learning, wherein the soil physicochemical property evaluation coefficient of each land sub-region is obtained through the soil physicochemical property parameters of each land sub-region, the soil pollution index evaluation coefficient of each land sub-region is obtained through the soil pollution index of each land sub-region, and the soil quality evaluation index of each land sub-region is analyzed and obtained, the environmental impact evaluation coefficient of the soil is analyzed by obtaining the local environmental parameters, the comprehensive evaluation index of the soil of each land sub-region is analyzed according to the soil quality evaluation index and the environmental impact evaluation coefficient of the soil, and the grade of each land sub-region is divided, so that accurate soil quality information can be provided for agricultural production, and the agricultural production efficiency and sustainability are improved.

Description

Technical Field

[0001] The present invention relates to the field of soil science, and in particular to a method for classifying agricultural ecological soil quality based on machine learning. Background Art

[0002] With the population growth and the increasing demand for agricultural products, traditional agriculture has become overly dependent on chemical inputs such as fertilizers and pesticides. Although this has increased production in the short term, it has posed a serious threat to soil quality in the long term. In many areas, soil fertility has declined, structure has been damaged, and pollution has increased, affecting the soil microbial community. The balance of the agricultural ecosystem has been disrupted, and the quality and safety of agricultural products are at risk, which has restricted the sustainable development of agriculture.

[0003] In this context, it is of great significance to study the quality of agricultural ecological soil. Accurately assessing the soil quality status and exploring scientific and reasonable soil improvement and management strategies will help restore the ecological functions of the soil. This will not only ensure the output and quality of agricultural products, but also promote the virtuous cycle of the agricultural ecosystem and promote the transformation and development of agriculture towards a green and sustainable direction.

[0004] For example, the existing Chinese patent with publication number CN213302207U discloses a soil quality assessment system. This solution evaluates soil quality by obtaining the geographic location information of the location to be assessed and storing soil data (including pH, multiple nutrients and heavy metal content, etc.) in the server. It can derive results based on one or more types of soil data separately, and obtain regional results by integrating results from multiple locations, so as to accurately grasp the regional soil quality status.

[0005] However, the aforementioned patent has the following problem: when assessing soil quality, the solution only considers internal soil data (pH, nutrients, and heavy metals), without fully considering the impact of external factors on soil quality, such as precipitation, temperature, and sunshine. This can lead to a one-sided assessment result, and the resulting soil quality results may not match the actual situation. Summary of the Invention

[0006] In order to overcome the shortcomings of the background technology, the embodiments of the present invention provide a method for delineating agricultural ecological soil quality categories based on machine learning, which can effectively solve the problems involved in the above-mentioned background technology.

[0007] The purpose of the present invention can be achieved through the following technical solutions: a method for delineating agricultural ecological soil quality categories based on machine learning, the method comprising the following steps: S1. Soil sample collection: the land in the study area is divided into land sub-areas, and a set amount of soil is obtained from each soil sampling point in each land sub-area according to the set soil depth, and soil samples of each land sub-area are obtained by mixing.

[0008] S2. Analysis of soil physical and chemical properties: The soil physical and chemical property parameters of each land sub-region are tested and analyzed to obtain the soil physical and chemical property evaluation coefficient of each land sub-region. The soil physical and chemical property parameters include the pH value, electrical conductivity, and organic matter content of the soil sample.

[0009] S3. Soil pollution analysis: Soil pollution indicators in each land sub-region are tested and analyzed to obtain soil pollution index evaluation coefficients for each land sub-region. Soil pollution indicators include heavy metal content and pesticide residues in soil samples.

[0010] S4. Soil quality evaluation: The soil quality evaluation index of each land sub-region is obtained based on the soil physical and chemical property evaluation coefficient and soil pollution index evaluation coefficient of each land sub-region.

[0011] S5. Environmental impact analysis: Obtain local environmental parameters and analyze them to obtain the environmental impact assessment coefficient of the soil. Environmental parameters include annual average temperature, annual precipitation, and average sunshine duration.

[0012] S6. Soil quality classification: Based on the soil quality evaluation index of each land sub-region The soil environmental impact assessment coefficient ω is analyzed to obtain the comprehensive evaluation index l of the soil in each land sub-region i , and each land sub-region is divided into levels, i represents the number of the i-th land sub-region, i = 1, 2, ..., n.

[0013] Preferably, the specific operation method for collecting soil samples is: dividing the land in the study area into several sub-areas of equal area according to the set area, recorded as land sub-areas, numbering each land sub-area in sequence as 1, 2, ..., i, ..., n, and selecting several soil sampling points at fixed intervals in each land sub-area, obtaining a set amount of soil from each soil sampling point in each land sub-area according to the set soil depth, and obtaining soil samples of each land sub-area by mixing.

[0014] Preferably, the specific detection method of the soil physical and chemical property parameters of each land sub-region is as follows: the first step is to read the soil sample of each land sub-region, weigh a set amount therefrom, air-dry it and place it in a container, and add a certain amount of potassium chloride solution to obtain a soil suspension, which is recorded as the soil sample suspension of each land sub-region, insert an electrode into the soil sample suspension of each land sub-region, read the value of the pH meter after stabilization, and obtain the pH value of the soil sample of each land sub-region.

[0015] In the second step, a set amount of soil samples from each land sub-area is weighed, air-dried, and placed in a container. A certain amount of ionized water is added to obtain a prepared soil suspension, which is recorded as the ion suspension of soil samples in each land sub-area. The electrodes of the conductivity meter are inserted into the ion suspension of soil samples in each land sub-area, and the conductivity value displayed by the conductivity meter is read, which is recorded as the conductivity of the soil samples in each land sub-area.

[0016] The third step is to weigh a set amount of soil samples from each land sub-area, air-dry them, sieve them, and place them in a desiccator to dry to constant weight to obtain air-dried soil samples from each land sub-area. After weighing them, they are placed in a high-temperature furnace for combustion, and oxygen is evenly passed through them. They are heated to a predetermined temperature at a set heating rate and maintained for a certain period of time to prepare a quantitative sodium hydroxide solution. The carbon dioxide produced by the combustion is absorbed by the sodium hydroxide solution. Finally, the air-dried soil samples from each land sub-area are weighed again to calculate the organic matter content of the soil samples in each sub-area.

[0017] Preferably, the specific analysis method of the soil physical and chemical property evaluation coefficient of each land sub-region is: read the pH value, electrical conductivity, and organic matter content of the soil samples of each land sub-region respectively, and record it as pH i , α i , β i , substitute it into the formula Get the soil physical and chemical property evaluation coefficient γ of each land sub-region i , where φ1, φ2, and φ3 represent the weighting factors of soil sample pH value, electrical conductivity, and organic matter content, respectively.

[0018] Preferably, the specific detection method of the soil pollution indicators of each land sub-region is as follows: the first step is to weigh a set amount from the soil sample of each land sub-region, air-dry it and then sieve it to prepare a soil metal solution of each land sub-region, select the corresponding hollow cathode lamp according to the heavy metal elements to be detected, adjust the working parameters of the instrument according to the settings, inject the soil metal solution of each land sub-region into the atomic absorption spectrometer to obtain the absorbance of the soil metal solution of each land sub-region, read the preset absorbance-heavy metal content standard curve from the management database, substitute the absorbance of the soil metal solution of each land sub-region into the absorbance-heavy metal content standard curve to obtain the heavy metal content of the soil sample of each land sub-region, recorded as ε i .

[0019] Secondly, a certain amount of soil sample from each sub-area of land is weighed, dried, sieved, and then placed in a triangular flask, and then a certain amount of organic solvent and anhydrous sodium sulfate is added, and then the mixture is shaken in a shaker for a certain period of time, and then the extraction liquid of the soil sample from each sub-area of land is obtained by filtration, and then the extraction liquid of the soil sample from each sub-area of land is transferred to a separatory funnel, and then a certain amount of sodium chloride solution is added, and then the mixture is shaken and layered, and then the lower aqueous phase is discarded, and then the upper organic phase is transferred to a concentration bottle, and then the mixture is concentrated on a rotary evaporator until it is almost dry, and then the mixture is diluted to a certain volume with a mixture of n-hexane and acetone to obtain the concentrated liquid of the soil sample from each sub-area of land, and then the pesticide residue of the soil sample from each sub-area of land is measured by injecting the concentrated liquid of the soil sample from each sub-area of land into a gas chromatograph, and then the pesticide residue of the soil sample from each sub-area of land is recorded as δ i .

[0020] Preferably, the specific analysis method of the soil pollution index evaluation coefficient of each sub-area of land is as follows: the heavy metal content ε i of the soil sample from each sub-area of land is read, and then the heavy metal content ε i is substituted into the formula to obtain the soil pollution index evaluation coefficient ρ i of each sub-area of land, wherein ε0 represents a preset reference value of heavy metal content, δ0 represents a preset reference value of pesticide residue, and the preset weight factor of the heavy metal content and the pesticide residue of the soil sample is represented by η0.

[0021] Preferably, the specific analysis method of the soil quality evaluation index of each sub-area of land is as follows: the soil physicochemical property evaluation coefficient γi and the soil pollution index evaluation coefficient ρ i of each sub-area of land are read respectively, and then the soil physicochemical property evaluation coefficient γi and the soil pollution index evaluation coefficient ρ i are substituted into the formula to obtain the soil quality evaluation index of each sub-area of land, wherein η1 and η2 represent the preset weight factors of the soil physicochemical property evaluation coefficient and the soil pollution index evaluation coefficient, respectively.

[0022] Preferably, the specific acquisition method of the environmental parameters is as follows: first, the local weather station is networked, and the daily average temperature and the daily precipitation of the previous historical year are obtained respectively, and then the annual average temperature is obtained by averaging the daily average temperature of the previous historical year, and the annual precipitation is obtained by accumulating the daily precipitation of the previous historical year, and then the annual average temperature and the annual precipitation are recorded as σ.

[0023] In the second step, sampling points are selected in each land sub-area, recorded as each sunshine sampling point, a time period of several days is selected, and several time points with equal time intervals are selected in each day. The sunshine intensity of each sunshine sampling point at each time point in the time period is detected by a sunshine meter, and the sunshine intensity is compared with the preset sunshine intensity threshold in the order of the time points. The time point at which the first sunshine intensity of each sunshine sampling point is greater than the sunshine intensity threshold on each day is recorded as the sunshine start time point of each day, and the time point at which the first sunshine intensity of each day is less than or equal to the sunshine intensity threshold on each day is recorded as the sunshine end time point of each day. The sunshine duration of each sunshine sampling point in the time period is obtained by subtracting the sunshine start time point and the sunshine end time point of each day. The average sunshine duration T of the soil is obtained by calculating the average value. 日照 .

[0024] Preferably, the specific analysis method of the soil environmental impact assessment coefficient is: reading the annual average temperature Annual precipitation σ, average sunshine duration T 日照 , substitute it into the formula The soil environmental impact assessment coefficient ω is obtained, where w1, w2, and w3 represent the weight factors of the preset annual average temperature, annual precipitation, and average sunshine duration, respectively. σ0, They respectively represent the preset reference values ​​of annual average temperature, annual precipitation, and average sunshine duration.

[0025] Preferably, the specific analysis method for the soil quality classification is as follows: the first step is to read the soil quality evaluation index respectively The soil environmental impact assessment coefficient ω is substituted into the formula Get the comprehensive evaluation index l of the soil in each land sub-region i , where a1 and a2 represent the weight factors of the preset soil quality evaluation index and soil environmental impact assessment coefficient, respectively.

[0026] The second step is to read the comprehensive evaluation index of the soil of each land sub-area and compare it with the preset excellent threshold value of the comprehensive evaluation index of the soil and the medium threshold value of the comprehensive evaluation index of the soil. If the comprehensive evaluation index of the soil of a certain land sub-area is greater than or equal to the preset excellent threshold value of the comprehensive evaluation index of the soil, it means that the soil of the land sub-area is excellent. If the comprehensive evaluation index of the soil of a certain land sub-area is less than the preset excellent threshold value of the comprehensive evaluation index of the soil and greater than or equal to the preset medium threshold value of the comprehensive evaluation index of the soil, it means that the soil of the land sub-area is medium. If the comprehensive evaluation index of the soil of a certain land sub-area is less than the preset medium threshold value of the comprehensive evaluation index of the soil, it means that the soil of the land sub-area is poor.

[0027] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects: First, the present invention obtains the soil physical and chemical property evaluation coefficient of each land sub-region through the soil physical and chemical property parameters of each land sub-region, and obtains the soil pollution index evaluation coefficient of each land sub-region through the soil pollution index of each land sub-region, which can intuitively show the differences in soil in each region and help to discover potential problems in the soil.

[0028] Second, the present invention obtains local environmental parameters and analyzes the environmental impact assessment coefficient of the soil, which can more completely evaluate the performance of the soil in a specific environment and provide support for soil management tailored to local conditions.

[0029] 3. The present invention obtains a comprehensive evaluation index of the soil in each land sub-region based on the soil quality evaluation index and the soil environmental impact evaluation coefficient of each land sub-region, and divides each land sub-region into grades, which can simply and clearly classify the soil in different land sub-regions, facilitating management and decision-making. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention is further described with reference to the accompanying drawings. However, the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative effort.

[0031] Figure 1 Schematic diagram of the method of the present invention.

[0032] Figure 2 for Figure 1 Schematic diagram of the flow chart of soil physical and chemical property parameters of each land sub-region in step S2.

[0033] Figure 3 for Figure 1 Flow judgment block diagram of step S6. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] See also Figure 1As shown, the present invention provides an agricultural ecological soil quality classification method based on machine learning, which includes the following steps: S1. Soil sample collection: the land in the study area is divided into land sub-areas, and a set amount of soil is obtained from each soil sampling point in each land sub-area according to the set soil depth, and soil samples of each land sub-area are obtained by mixing.

[0036] The specific operation method of soil sample collection is as follows: the land in the study area is divided into several sub-areas of equal area according to the set area, recorded as each land sub-area, and each land sub-area is numbered 1, 2, ..., i, ..., n in sequence, and several soil sampling points are selected at fixed intervals in each land sub-area, and a set amount of soil is obtained from each soil sampling point in each land sub-area according to the set soil depth, and soil samples of each land sub-area are obtained by mixing.

[0037] S2. Analysis of soil physical and chemical properties: The soil physical and chemical property parameters of each land sub-region are tested and analyzed to obtain the soil physical and chemical property evaluation coefficient of each land sub-region. The soil physical and chemical property parameters include the pH value, electrical conductivity, and organic matter content of the soil sample.

[0038] See also Figure 2 As shown, the specific detection method of the soil physical and chemical property parameters of each land sub-region is as follows: the first step is to read the soil sample of each land sub-region, weigh a set amount therefrom, air-dry it and put it into a container, and add a certain amount of potassium chloride solution to obtain a soil suspension, which is recorded as the soil sample suspension of each land sub-region, insert an electrode into the soil sample suspension of each land sub-region, read the value of the pH meter after stabilization, and obtain the pH value of the soil sample of each land sub-region; the soil pH value affects the activity and mobility of heavy metals in the soil. The activity of certain heavy metals (such as cadmium, lead, etc.) in acidic soil may be higher, and they are more easily absorbed by plants or migrate with water, thereby posing a potential threat to the ecological environment and human health. By measuring the pH value, the soil environmental risk can be assessed and corresponding prevention and control measures can be taken.

[0039] In the second step, a set amount of soil samples from each land sub-area is weighed, air-dried, and placed in a container. A certain amount of ionized water is added to obtain a prepared soil suspension, which is recorded as the ion suspension of soil samples in each land sub-area. The electrodes of the conductivity meter are inserted into the ion suspension of soil samples in each land sub-area, and the conductivity value displayed by the conductivity meter is read, which is recorded as the conductivity of soil samples in each land sub-area. By long-term monitoring of changes in conductivity, it is possible to preliminarily determine whether the soil is contaminated and the approximate extent of contamination. At the same time, the degree of soil salinization can be assessed, and improvement measures such as washing salt, replacing soil, or planting salt-tolerant plants can be taken.

[0040] The third step is to weigh a set amount of soil samples from each land sub-area, air-dry them, sieve them, and place them in a desiccator to dry to constant weight to obtain air-dried soil samples from each land sub-area. After weighing, they are placed in a high-temperature furnace for combustion, and oxygen is evenly passed through them. They are heated to a predetermined temperature at a set heating rate and maintained for a certain period of time to prepare a quantitative sodium hydroxide solution, and the carbon dioxide produced by the combustion is absorbed by the sodium hydroxide solution. Finally, the air-dried soil samples from each land sub-area are weighed again to calculate the organic matter content of the soil samples in each sub-area. Soil organic matter provides energy and nutrients for soil microorganisms, affecting the types and number of microorganisms. Under different soil organic matter content levels, the structure and function of soil microbial communities will vary greatly, which in turn affects the ecological service functions of the soil, such as decomposition of organic matter and fixation of nitrogen.

[0041] It should be noted that the specific analysis method for the organic matter content of the soil samples in each sub-area is as follows: the air-dried soil samples in each land sub-area are weighed to obtain the weight of the air-dried soil samples in each land sub-area, the air-dried soil samples in each land sub-area are placed in a combustion tube and then placed in a high-temperature furnace, an oxygen supply device is connected, and the oxygen flow rate is adjusted according to the set oxygen flow rate so that it passes evenly through the air-dried soil samples in each land sub-area, the high-temperature furnace is heated to a predetermined temperature according to a set heating rate, and maintained at the temperature for a set time, a set amount of sodium hydroxide solution is prepared, and the carbon dioxide generated by the combustion is introduced into an absorption device containing sodium hydroxide solution through a conduit. After the absorption of carbon dioxide is completed, the weight of the air-dried soil samples in each land sub-area is weighed again to obtain the weight of the air-dried soil samples in each land sub-area after absorption, and the organic matter content of the soil samples in each land sub-area is calculated.

[0042] It should be noted that the specific analysis method for the organic matter content of the soil samples in each land sub-region is as follows: the weight of the air-dried soil sample in each land sub-region and the set amount of sodium hydroxide solution are read respectively, and the weight of the air-dried soil sample in each land sub-region after absorption is recorded as M i 、M0、 Substitute it into the formula Get the organic matter content β of soil samples in each sub-region i , where 12 is the molar mass of carbon and 44 is the molar mass of carbon dioxide; it can be used to determine whether the improvement measures are effective and the specific extent of their contribution to improving soil fertility.

[0043] The specific analysis method of the soil physical and chemical property evaluation coefficient of each land sub-region is as follows: read the pH value, electrical conductivity, and organic matter content of the soil samples of each land sub-region respectively, and record them as pH i , α i , β i , substitute it into the formula Get the soil physical and chemical property evaluation coefficient γ of each land sub-region i, where φ1, φ2, and φ3 represent the weighting factors of soil sample pH, electrical conductivity, and organic matter content, respectively. This helps to scientifically and quantitatively evaluate the physical and chemical properties of soil in each sub-region, thereby providing an accurate basis for land use planning, soil improvement, and agricultural suitability analysis. It also facilitates the comparison of soil conditions in different sub-regions and the formulation of targeted and reasonable soil management strategies.

[0044] It should be noted that in a specific embodiment, φ1 can be set to 0.3, φ2 can be set to 0.2, and φ3 can be set to 0.5. The pH value affects the availability of nutrients and microbial activity in the soil, but in comparison, it is not the only factor that determines soil fertility and health. Many crops can tolerate changes within a certain pH range. Electrical conductivity mainly reflects the degree of soil salinization. Although salinization can affect plant growth, not all areas have serious salinization problems, and other soil properties are more critical to the overall evaluation in most cases. Organic matter is an important indicator of soil fertility, affecting many key soil properties such as soil structure, water and fertilizer retention capacity, and microbial activity, and has a broad and important impact on the overall health and productivity of the soil. Therefore, the weight corresponding to the organic matter content is the largest, and the weight corresponding to the pH value is second.

[0045] S3. Soil pollution analysis: Soil pollution indicators in each land sub-region are tested and analyzed to obtain soil pollution index evaluation coefficients for each land sub-region. Soil pollution indicators include heavy metal content and pesticide residues in soil samples.

[0046] The specific detection method of soil pollution indicators in each land sub-region is as follows: the first step is to weigh a set amount of soil samples from each land sub-region, air-dry and sieve the soil samples to prepare soil metal solutions in each land sub-region, select corresponding hollow cathode lamps according to the heavy metal elements to be detected, adjust the working parameters of the instrument according to the settings, inject the soil metal solutions in each land sub-region into an atomic absorption spectrometer to obtain the absorbance of the soil metal solutions in each land sub-region, read a preset absorbance-heavy metal content standard curve from a management database, substitute the absorbance of the soil metal solutions in each land sub-region into the absorbance-heavy metal content standard curve to obtain the heavy metal content of the soil samples in each land sub-region, which is recorded as ε i Heavy metal pollution can disrupt the structure and function of soil microbial communities, affecting the soil's ecological services. Accurately measuring heavy metal levels can help timely implement protective measures and maintain the balance of soil ecosystems.

[0047] It should be noted that the specific analysis method of the soil metal solution in each land sub-area is as follows: place it in a polytetrafluoroethylene digestion tank, add an appropriate amount of mixed acid, seal the digestion tank and place it in a microwave digester, digest according to the set digestion temperature and time, and after the digestion is completed, cool the digestion tank in a fume hood, and then transfer it to a polytetrafluoroethylene crucible, heat it on a hot plate to drive out the acid until it is almost dry, dissolve the residue with a small amount of dilute nitric acid, and adjust the volume to a certain volume to obtain the soil metal solution in each land sub-area.

[0048] In the second step, a set amount of soil sample was weighed from each land sub-region, air-dried, sieved, and placed in a conical flask. An appropriate amount of organic solvent and anhydrous sodium sulfate were added. After oscillating on an oscillator for a set time, the soil sample extract of each land sub-region was obtained by filtration. The soil sample extract of each land sub-region was transferred to a separatory funnel, and a quantitative sodium chloride solution was added. The layers were oscillated and the lower aqueous phase was discarded. The upper organic phase was transferred to a concentration bottle and concentrated on a rotary evaporator to near dryness. The volume was fixed to a set volume with a mixed solvent of n-hexane-acetone to obtain a concentrated solution of soil sample of each land sub-region. The concentrated solution of soil sample of each land sub-region was injected into a gas chromatograph to measure the pesticide residue in the soil sample of each land sub-region, which was recorded as δ i ; Understanding the pesticide residues in the soil can adjust the type, dosage and frequency of pesticide use according to the soil's carrying capacity, improve the efficiency of pesticide use, and reduce pesticide pollution to the soil environment.

[0049] The specific analysis method of the soil pollution index evaluation coefficient of each land sub-region is as follows: reading the heavy metal content ε of the soil sample of each land sub-region i , substitute it into the formula Get the soil pollution index evaluation coefficient ρ of each land sub-region i , where ε0 represents the preset reference value of heavy metal content, δ0 represents the preset reference value of pesticide residue, Represents the weighting factors of preset heavy metal content and pesticide residue in soil samples; using a unified evaluation coefficient as the standard, it can intuitively distinguish which land sub-regions have serious soil pollution and which are relatively light, thus providing a basis for the priority arrangement of soil pollution control.

[0050] It should be noted that, in a specific embodiment, You can set it to 0.7. It can be set to 0.3. Heavy metals are difficult to degrade in the soil, will exist for a long time and may be enriched through the food chain, causing serious and lasting harm to the ecosystem and human health. They are an important and key consideration for soil pollution. Although pesticide residues will affect soil ecology and agricultural product safety, some pesticides can be naturally degraded within a certain period of time, and the use of pesticides can be regulated through management measures. Compared with heavy metals, the long-term and severity of their harm are slightly lower in some cases, so the weight corresponding to heavy metal content is higher.

[0051] S4. Soil quality evaluation: The soil quality evaluation index of each land sub-region is obtained based on the soil physical and chemical property evaluation coefficient and soil pollution index evaluation coefficient of each land sub-region.

[0052] The specific analysis method of the soil quality evaluation index of each land sub-region is as follows: respectively reading the soil physical and chemical property evaluation coefficient γi and the soil pollution index evaluation coefficient ρ of each land sub-region. i , substitute it into the formula Get the soil quality evaluation index of each land sub-region Among them, η1 and η2 represent the weight factors of the set soil physical and chemical property evaluation coefficient and soil pollution index evaluation coefficient, respectively. By analyzing the contribution of the soil physical and chemical property evaluation coefficient and the soil pollution index evaluation coefficient, it can be clear whether it is necessary to improve the physical and chemical properties such as soil fertility and structure, or to focus on pollution control to improve soil quality.

[0053] It should be noted that, in a specific embodiment, η1 can be set to 0.5, and η2 can be set to 0.5. The physical and chemical properties of soil are the fundamental attributes of soil quality. These properties directly affect soil fertility, microbial activity, and the growth environment of plants. Good soil physical and chemical properties can provide a stable foundation for the soil ecosystem. Even if the soil is somewhat polluted, if its physical and chemical properties are good, the soil still has a certain degree of self-repair ability and the ability to carry ecological functions. Soil pollution is directly related to the safety and applicability of the soil. If the soil is seriously polluted, especially if it is polluted by heavy metals and persistent organic pollutants, it will pose a great threat to the soil ecosystem, crop safety, and groundwater quality. Therefore, the weights corresponding to the soil physical and chemical property evaluation coefficient and the soil pollution index evaluation coefficient are equal.

[0054] S5. Environmental impact analysis: Obtain local environmental parameters and analyze them to obtain the environmental impact assessment coefficient of the soil. Environmental parameters include annual average temperature, annual precipitation, and average sunshine duration.

[0055] The specific method for obtaining the environmental parameters is as follows: the first step is to connect to the local weather station to obtain the daily average temperature and daily precipitation of the previous historical year, and to obtain the annual average temperature by averaging the daily average temperature of the previous historical year, and to obtain the annual precipitation by accumulating the daily precipitation of the previous historical year, which are recorded as σ; Based on the annual precipitation and its contribution to the soil environmental impact assessment coefficient, it can be determined whether additional irrigation or strengthened drainage facilities are needed to maintain appropriate soil moisture to meet the growth needs of crops.

[0056] In the second step, sampling points are selected in each land sub-area, recorded as each sunshine sampling point, a time period of several days is selected, and several time points with equal time intervals are selected in each day. The sunshine intensity of each sunshine sampling point at each time point in the time period is detected by a sunshine meter, and the sunshine intensity is compared with the preset sunshine intensity threshold in the order of the time points. The time point at which the first sunshine intensity of each sunshine sampling point is greater than the sunshine intensity threshold on each day is recorded as the sunshine start time point of each day, and the time point at which the first sunshine intensity of each day is less than or equal to the sunshine intensity threshold on each day is recorded as the sunshine end time point of each day. The sunshine duration of each sunshine sampling point in the time period is obtained by subtracting the sunshine start time point and the sunshine end time point of each day. The average sunshine duration T of the soil is obtained by calculating the average value. 日照 ; Understanding the duration of sunshine helps determine the planting time, growth cycle, and harvest time of crops.

[0057] The specific analysis method of the soil environmental impact assessment coefficient is: reading the annual average temperature Annual precipitation σ, average sunshine duration T 日照 , substitute it into the formula The soil environmental impact assessment coefficient ω is obtained, where w1, w2, and w3 represent the weight factors of the preset annual average temperature, annual precipitation, and average sunshine duration, respectively. σ0, They respectively represent the reference values ​​of the preset annual average temperature, annual precipitation, and average sunshine duration; different crops have different requirements for temperature, precipitation, and sunshine. Through the soil environmental impact assessment coefficient, we can understand the comprehensive impact of the meteorological conditions of a specific land on the soil environment, and then select the crop varieties that are most suitable for the meteorological environment of the land to improve the yield and quality of crops.

[0058] It should be noted that, in a specific embodiment, w1 can be set to 0.3, w2 can be set to 0.5, and w3 can be set to 0.2. Temperature affects the activity of microorganisms in the soil. Microorganisms are more active at suitable temperatures and can accelerate the decomposition of organic matter and nutrient conversion in the soil. At the same time, temperature will also affect the evaporation and condensation of water in the soil, indirectly affecting the moisture and structure of the soil. Annual precipitation is an important source of soil moisture. Adequate precipitation can replenish soil moisture, affect the moisture conditions of the soil, and further affect the physical properties of the soil such as air permeability and water permeability. The average sunshine duration mainly indirectly affects the soil environment by affecting soil temperature and plant growth. Long sunshine duration will increase the soil temperature and affect the microorganisms and biochemical processes in the soil, but this influence partially overlaps with the influence of the annual average temperature. Therefore, the weight corresponding to annual precipitation is higher.

[0059] S6. Soil quality classification: Based on the soil quality evaluation index of each land sub-region The soil environmental impact assessment coefficient ω is analyzed to obtain the comprehensive evaluation index l of the soil in each land sub-region i , and each land sub-region is divided into levels, i represents the number of the i-th land sub-region, i = 1, 2, ..., n.

[0060] See also Figure 3 As shown, the specific analysis method for the soil quality classification is as follows: the first step is to read the soil quality evaluation index respectively The soil environmental impact assessment coefficient ω is substituted into the formula Get the comprehensive evaluation index l of the soil in each land sub-region i , where a1 and a2 represent the weight factors of the preset soil quality evaluation index and soil environmental impact evaluation coefficient respectively; by analyzing the various evaluation coefficients that make up the index, it can be determined whether the problem lies in the soil physical and chemical properties, soil quality or soil environmental impact, so as to formulate targeted soil improvement measures.

[0061] It should be noted that, in a specific embodiment, a2 can be set to 0.6, and a3 can be set to 0.4. The soil quality evaluation index is an indicator that comprehensively reflects the various properties of soil. It comprehensively considers multiple factors such as the physical, chemical and biological properties of the soil. In the comprehensive evaluation index, the soil quality evaluation index covers a lot of information and is a comprehensive measure of the overall condition of the soil. The environmental impact assessment coefficient of the soil mainly focuses on the situation in which the soil is affected by external environmental factors. Although the environmental impact of the soil is a very important aspect, compared with the basic properties of the soil itself, the physical and chemical properties of the soil, it is a manifestation of the effect of external factors on the soil. Moreover, when constructing the comprehensive soil evaluation index, the basic characteristics and comprehensive quality status of the soil itself are more core considerations. The environmental impact assessment coefficient reflects the condition of the soil more from the side, so the soil quality evaluation index has a higher weight.

[0062] The second step is to read the comprehensive evaluation index of the soil of each land sub-area and compare it with the preset excellent threshold value of the comprehensive evaluation index of the soil and the medium threshold value of the comprehensive evaluation index of the soil. If the comprehensive evaluation index of the soil of a certain land sub-area is greater than or equal to the preset excellent threshold value of the comprehensive evaluation index of the soil, it means that the land sub-area has excellent soil. If the comprehensive evaluation index of the soil of a certain land sub-area is less than the preset excellent threshold value of the comprehensive evaluation index of the soil and greater than or equal to the preset medium threshold value of the comprehensive evaluation index of the soil, it means that the land sub-area has medium soil. If the comprehensive evaluation index of the soil of a certain land sub-area is less than the preset medium threshold value of the comprehensive evaluation index of the soil, it means that the land sub-area has poor soil. The comprehensive evaluation index of the soil is graded according to the preset threshold value, which can classify soils of different qualities, make the evaluation results of the soil condition more intuitive, easy to understand and compare, and clarify the relative quality of the soil in different land sub-areas.

[0063] The present invention obtains the soil physical and chemical property evaluation coefficient of each land sub-region through the soil physical and chemical property parameters of each land sub-region, obtains the soil pollution index evaluation coefficient of each land sub-region through the soil pollution index of each land sub-region, thereby analyzing and obtaining the soil quality evaluation index of each land sub-region, and obtaining the environmental impact evaluation coefficient of the soil by acquiring local environmental parameters. The comprehensive evaluation index of the soil of each land sub-region is obtained according to the soil quality evaluation index and the environmental impact evaluation coefficient of the soil, and the land sub-region is graded. Accurate soil quality information can be provided for agricultural production, thereby improving agricultural production efficiency and sustainability.

[0064] Although the embodiments of the present application have been shown and described above, it is to be understood that the above-described embodiments are merely exemplary, and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made thereto without departing from the scope of the present application.

Claims

1. A method for classifying agricultural ecological soil quality based on machine learning, characterized by: The steps include: S1. Soil Sample Collection: Divide the land within the study area into sub-regions. Collect a set amount of soil from each soil sampling point in each sub-region at a set soil depth, and mix the soil samples from each sub-region. S2. Soil physical and chemical property analysis: Soil physical and chemical property parameters for each sub-region are tested and analyzed to obtain soil physical and chemical property evaluation coefficients for each sub-region. Soil physical and chemical property parameters include soil sample pH, electrical conductivity, and organic matter content. S3. Soil pollution analysis: Detect soil pollution indicators in each sub-region and analyze them to obtain soil pollution index evaluation coefficients for each sub-region. Soil pollution indicators include heavy metal content and pesticide residues in soil samples. S4. Soil quality evaluation: Calculate the soil quality evaluation index for each sub-region based on the soil physical and chemical property evaluation coefficient and soil pollution index evaluation coefficient of each sub-region; S5. Environmental Impact Analysis: Obtain local environmental parameters and analyze them to determine the soil's environmental impact assessment coefficient. Environmental parameters include annual average temperature, annual precipitation, and average sunshine duration. S6. Soil quality classification: Based on the soil quality evaluation index of each land sub-region , soil environmental impact assessment coefficient Analyze and obtain the comprehensive evaluation index of soil in each land sub-region , and classify each land sub-region into different levels, Indicates the The number of the land sub-area, ; The specific analysis method of the soil physical and chemical property evaluation coefficient of each land sub-region is as follows: Read the pH value, electrical conductivity, and organic matter content of soil samples in each sub-region of the land respectively and record them as , substitute it into the formula Get the soil physical and chemical property evaluation coefficient of each land sub-region ,in represent the weighting factors of soil sample pH value, electrical conductivity, and organic matter content respectively; The specific method for obtaining the environmental parameters is: The first step is to obtain the annual average temperature and annual precipitation based on the daily average temperature and daily precipitation of the previous historical year, which are recorded as ; The second step is to use a sunshine meter to detect the sunshine intensity at each sunshine sampling point at each time point during the time period and calculate the average sunshine duration of the soil. ; The specific analysis method of the soil environmental impact assessment coefficient is: Read the average annual temperature , annual precipitation , average sunshine duration of soil , substitute it into the formula Get the soil environmental impact assessment coefficient ,in Respectively represent the weight factors of the preset annual average temperature, annual precipitation, and average sunshine duration, They respectively represent the preset reference values ​​of annual average temperature, annual precipitation, and average sunshine duration.

2. The method for agricultural ecological soil quality classification based on machine learning according to claim 1 is characterized by: The specific operation method of collecting soil samples is as follows: According to the set area, the land in the study area is divided into several sub-areas of equal area, which are recorded as land sub-areas. Each land sub-area is numbered in sequence as , and select several soil sampling points at fixed intervals in each land sub-area, obtain a set amount of soil from each soil sampling point in each land sub-area according to the set soil depth, and obtain soil samples in each land sub-area by mixing.

3. The method for agricultural ecological soil quality classification based on machine learning according to claim 2 is characterized by: The specific detection method of the soil physical and chemical property parameters of each land sub-region is: The first step is to read the soil sample of each sub-region, weigh a set amount from it, air-dry it, and place it in a container. A certain amount of potassium chloride solution is added to obtain a soil suspension, which is recorded as the soil sample suspension of each sub-region. An electrode is inserted into the soil sample suspension of each sub-region, and the pH meter is read after it stabilizes to obtain the pH value of the soil sample of each sub-region. In the second step, a predetermined amount of soil sample is weighed from each soil sub-region, air-dried, and placed in a container. A predetermined amount of ionized water is added to prepare a soil suspension, which is recorded as the ion suspension of the soil sample of each soil sub-region. The electrodes of a conductivity meter are inserted into the ion suspension of the soil sample of each soil sub-region, and the conductivity value displayed by the conductivity meter is read, which is recorded as the conductivity of the soil sample of each soil sub-region. The third step is to weigh a set amount of soil samples from each land sub-area, air-dry them, sieve them, and place them in a desiccator to dry to constant weight to obtain air-dried soil samples from each land sub-area. After weighing them, they are placed in a high-temperature furnace for combustion, and oxygen is evenly passed through them. They are heated to a predetermined temperature at a set heating rate and maintained for a certain period of time to prepare a quantitative sodium hydroxide solution. The carbon dioxide produced by the combustion is absorbed by the sodium hydroxide solution. Finally, the air-dried soil samples from each land sub-area are weighed again to calculate the organic matter content of the soil samples in each sub-area.

4. The method for agricultural ecological soil quality classification based on machine learning according to claim 1 is characterized in that: The specific detection method of soil pollution indicators in each land sub-region is: In the first step, a set amount of soil sample from each land sub-region is weighed, air-dried and sieved to prepare a soil metal solution of each land sub-region, a corresponding hollow cathode lamp is selected according to the heavy metal elements to be detected, the working parameters of the instrument are adjusted according to the settings, the soil metal solution of each land sub-region is injected into the atomic absorption spectrometer to obtain the absorbance of the soil metal solution of each land sub-region, the preset absorbance-heavy metal content standard curve is read from the management database, the absorbance of the soil metal solution of each land sub-region is substituted into the absorbance-heavy metal content standard curve to obtain the heavy metal content of the soil sample of each land sub-region, which is recorded as ; In the second step, a set amount of soil sample from each land sub-region is weighed, air-dried, sieved, and placed in a conical flask, and an appropriate amount of organic solvent and anhydrous sodium sulfate are added. After oscillating on an oscillator for a set time, the soil sample extract of each land sub-region is obtained by filtration. The soil sample extract of each land sub-region is transferred to a separatory funnel, and a quantitative sodium chloride solution is added. The layers are shaken and separated, and the lower aqueous phase is discarded. The upper organic phase is transferred to a concentration bottle, concentrated on a rotary evaporator to near dryness, and fixed to a set volume with a n-hexane-acetone mixed solvent to obtain a soil sample concentrate of each land sub-region. The soil sample concentrate of each land sub-region is injected into a gas chromatograph to measure the pesticide residue in the soil sample of each land sub-region, which is recorded as .

5. The method for agricultural ecological soil quality classification based on machine learning according to claim 4 is characterized in that: The specific analysis method of the soil pollution index evaluation coefficient of each land sub-region is as follows: Read the heavy metal content of soil samples in each land sub-area , substitute it into the formula Get the soil pollution index evaluation coefficient of each land sub-region ,in Indicates the preset reference value of heavy metal content. Indicates the preset reference value of pesticide residues. Represents the weighting factors of the preset heavy metal content and pesticide residue in soil samples.

6. The method for agricultural ecological soil quality classification based on machine learning according to claim 5, characterized in that: The specific analysis method of the soil quality evaluation index of each land sub-region is as follows: Read the soil physical and chemical property evaluation coefficients of each land sub-area separately , soil pollution index evaluation coefficient , substitute it into the formula Get the soil quality evaluation index of each land sub-region ,in They respectively represent the weight factors of the set soil physical and chemical property evaluation coefficient and soil pollution index evaluation coefficient.

7. The method for agricultural ecological soil quality classification based on machine learning according to claim 1 is characterized in that: The specific method for obtaining the environmental parameters also includes: The first step is to connect with the local weather station to obtain the daily average temperature and daily precipitation of the previous historical year. The annual average temperature is obtained by averaging the daily average temperature of the previous historical year, and the annual precipitation is obtained by accumulating the daily precipitation of the previous historical year, which are recorded as ; In the second step, sampling points are selected in each land sub-area, recorded as each sunshine sampling point, a time period of several days is selected, and several time points with equal time intervals are selected in each day. The sunshine intensity of each sunshine sampling point at each time point in the time period is detected by a sunshine meter, and the sunshine intensity is compared with the preset sunshine intensity threshold in the order of time points. The time point when the first sunshine intensity of each sunshine sampling point is greater than the sunshine intensity threshold on each day is recorded as the sunshine start time point of each day, and the time point when the first sunshine intensity of each day is less than or equal to the sunshine intensity threshold is recorded as the sunshine end time point of each day. The sunshine duration of each sunshine sampling point in the time period is obtained by subtracting the sunshine start time point and the sunshine end time point of each day. The average sunshine duration of the soil is obtained by calculating the average value. .

8. The method for agricultural ecological soil quality classification based on machine learning according to claim 1 is characterized in that: The specific analysis method for determining the soil quality category is as follows: The first step is to read the soil quality evaluation index separately , soil environmental impact assessment coefficient , substitute it into the formula Get the comprehensive evaluation index of the soil in each land sub-region ,in Respectively represent the weighting factors of the preset soil quality evaluation index and soil environmental impact evaluation coefficient; The second step is to read the comprehensive evaluation index of the soil of each land sub-area and compare it with the preset excellent threshold value of the comprehensive evaluation index of the soil and the medium threshold value of the comprehensive evaluation index of the soil. If the comprehensive evaluation index of the soil of a certain land sub-area is greater than or equal to the preset excellent threshold value of the comprehensive evaluation index of the soil, it means that the soil of the land sub-area is excellent. If the comprehensive evaluation index of the soil of a certain land sub-area is less than the preset excellent threshold value of the comprehensive evaluation index of the soil and greater than or equal to the preset medium threshold value of the comprehensive evaluation index of the soil, it means that the soil of the land sub-area is medium. If the comprehensive evaluation index of the soil of a certain land sub-area is less than the preset medium threshold value of the comprehensive evaluation index of the soil, it means that the soil of the land sub-area is poor.

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