Agricultural ecological soil quality category delimiting method based on machine learning

Abstract

The invention relates to the field of soil science, in particular to an agricultural ecological soil quality category designation method based on machine learning, and the method comprises the steps: obtaining a soil physicochemical property evaluation coefficient of each land sub-region through 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, so that the soil quality evaluation index of each land sub-region is obtained through analysis, and the environmental influence evaluation coefficient of soil is obtained through analysis by obtaining local environmental parameters. According to the soil quality evaluation index of each land sub-region and the environmental influence evaluation coefficient of the soil, the comprehensive evaluation index of the soil of each land sub-region is obtained through analysis, and the land sub-regions are graded, 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. Specifically, it is a method for delimiting agricultural ecological soil quality categories based on machine learning. Background Art

[0002] With the growth of the population and the continuous increase in the demand for agricultural products, traditional agriculture has relied too much on chemical inputs such as chemical fertilizers and pesticides. Although this has increased yields in the short term, it has posed a serious threat to soil quality in the long term. In many areas, soil fertility has declined, soil structure has been damaged, pollution has intensified, the soil microbial community has been affected, the balance of the agricultural ecosystem has been broken, the quality and safety of agricultural products are at risk, and the sustainable development of agriculture has been restricted.

[0003] In this context, studying the quality of agricultural ecological soil is of great significance. Accurately evaluating the soil quality status and exploring scientific and reasonable soil improvement and management strategies can help restore the ecological functions of the soil. This can not only ensure the yield and quality of agricultural products, but also promote the virtuous cycle of the agricultural ecosystem and drive the transformation and development of agriculture towards the green and sustainable direction.

[0004] For example, the Chinese patent with the publication number CN213302207U discloses a soil quality evaluation system. This solution evaluates soil quality by obtaining the geographical location information of the location to be evaluated and the soil data (including soil acidity, various nutrient contents, heavy metal contents, etc.) in the storage server. It can obtain results based on one or more soil data respectively and obtain regional results by synthesizing the results of multiple locations, and can accurately grasp the soil quality status of the region.

[0005] However, the following problems exist in the above patent: When evaluating soil quality, this solution only considers the internal data of the soil (soil acidity, nutrients, heavy metals), and does not fully consider the impact of external factors on the soil quality results. For example, precipitation, temperature, sunlight, etc. will make the evaluation results one-sided, and the obtained soil quality results may not conform to the actual situation. Summary of the Invention

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

[0007] The object of the present invention can be achieved by the following technical solutions: A method for delimiting agricultural ecological soil quality categories based on machine learning, the method comprising the following steps: S1. Soil sample collection: Divide the land in the research area into each land sub-region, obtain a set amount of soil from each soil sampling point in each land sub-region at each set soil depth, and mix them to obtain the soil sample of each land sub-region.

[0008] S2. Soil physical and chemical property analysis: Detect the soil physical and chemical property parameters of each land sub-region, and analyze to obtain the soil physical and chemical property evaluation coefficients of each land sub-region. The soil physical and chemical property parameters include the pH value, conductivity, and organic matter content of the soil samples.

[0009] S3. Soil pollution analysis: Detect the soil pollution indicators of each land sub-region, and analyze to obtain the soil pollution indicator evaluation coefficients of each land sub-region. The soil pollution indicators include the heavy metal content and pesticide residue of the soil samples.

[0010] S4. Soil quality evaluation: Analyze to obtain the soil quality evaluation index of each land sub-region based on the soil physical and chemical property evaluation coefficients and soil pollution indicator evaluation coefficients of each land sub-region.

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

[0012] S6. Soil quality category demarcation: According to the soil quality evaluation index of each land sub-region and the environmental impact evaluation coefficient ω of the soil, analyze to obtain the comprehensive evaluation index l of the soil for each land sub-region i , and conduct grade division for each land sub-region. i represents the number of the i-th land sub-region, and i = 1, 2,..., n.

[0013] Preferably, the specific operation method for collecting the soil samples is as follows: Divide the land within the research area into several equal-area sub-regions according to the set area, denoted as each land sub-region, number each land sub-region in sequence as 1, 2,..., i,..., n, select several soil sampling points at a fixed interval within each land sub-region, obtain a set amount of soil from each soil sampling point in each land sub-region according to the set soil depths, and mix them to obtain the soil samples for each land sub-region.

[0014] Preferably, the specific detection method for the soil physical and chemical property parameters of each land sub-region is as follows: First step, read the soil samples of each land sub-region, weigh a set amount from them, air-dry it and put it into a container, and obtain a soil suspension by adding a quantitative potassium chloride solution, denoted as the soil suspension of each land sub-region soil sample. Insert the electrode into the soil suspension of each land sub-region soil sample, and read the value after the pH meter stabilizes to obtain the pH value of the soil sample of each land sub-region.

[0015] Second step, weigh a set amount from the soil samples of each land sub-region, air-dry it and put it into a container, and obtain a prepared soil suspension by adding a quantitative amount of ionic water, which is denoted as the ionic suspension of the soil samples of each land sub-region. Insert the electrode of the conductivity meter into the ionic suspension of the soil samples of each land sub-region, and read the conductivity value displayed by the conductivity meter, which is denoted as the conductivity of the soil samples of each land sub-region.

[0016] Third step, weigh a set amount from the soil samples of each land sub-region, air-dry it, sieve it, and dry it in a dryer until it reaches a constant weight to obtain the air-dried soil samples of each land sub-region. Weigh it and then place it in a high-temperature furnace for combustion, uniformly pass oxygen, heat it to a predetermined temperature at a set heating rate and maintain it for a certain period of time. Prepare a quantitative sodium hydroxide solution to absorb the carbon dioxide generated by combustion. Finally, weigh the air-dried soil samples of each land sub-region again to calculate the organic matter content of the soil samples in each sub-region.

[0017] Preferably, the specific analysis method for the soil physical and chemical property evaluation coefficients of each land sub-region is as follows: Read the pH value, conductivity, and organic matter content of the soil samples of each land sub-region respectively, and denote them as pH i , α i , β i . Substitute them into the formula to obtain the soil physical and chemical property evaluation coefficient γ i of each land sub-region, where φ 1 , φ 2 , φ 3 represent the weight factors of the pH value, conductivity, and organic matter content of the soil samples respectively.

[0018] Preferably, the specific detection method for the soil pollution indicators of each land sub-region is as follows: First step, weigh a set amount from the soil samples of each land sub-region, air-dry it and sieve it to prepare the 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 setting, 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, and 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 samples of each land sub-region, which is denoted as ε i .

[0019] Step 2: Weigh a set amount from the soil samples of each land sub-region. After air-drying and sieving them, place them in a conical flask, add an appropriate amount of organic solvent and anhydrous sodium sulfate, oscillate for a set time on an oscillator, and then obtain the extract of the soil samples of each land sub-region through filtration. Transfer the extract of the soil samples of each land sub-region to a separatory funnel, add a quantitative sodium chloride solution, oscillate to separate the layers, discard the lower aqueous phase, transfer the upper organic phase to a concentration flask, concentrate it to near dryness on a rotary evaporator, and make up the volume to a set volume with a mixed solvent of n-hexane and acetone to obtain the concentrated solution of the soil samples of each land sub-region. By injecting the concentrated solution of the soil samples of each land sub-region into a gas chromatograph, measure the pesticide residue amount in the soil samples of each land sub-region, denoted as δ i 。

[0020] Preferably, the specific analysis method for the soil pollution index evaluation coefficient of each land sub-region is: read the heavy metal content ε of the soil samples of each land sub-region i ,and substitute it into the formula to obtain the soil pollution index evaluation coefficient ρ of each land sub-region i ,where ε 0 represents the preset reference value of heavy metal content, δ 0 represents the preset reference value of pesticide residue amount, represents the weight factor of the heavy metal content and pesticide residue amount of the soil sample

[0021] Preferably, the specific analysis method for the soil quality evaluation index of each land sub-region is: respectively read the soil physical and chemical property evaluation coefficient γi and the soil pollution index evaluation coefficient ρ of each land sub-region i ,and substitute them into the formula to obtain the soil quality evaluation index of each land sub-region where η 1 、η 2 respectively represent the set weight factors of the soil physical and chemical property evaluation coefficient and the soil pollution index evaluation coefficient

[0022] Preferably, the specific method for obtaining the environmental parameters is: Step 1, connect to the local meteorological station, respectively obtain the daily average temperature and daily precipitation of the previous historical year, obtain the annual average temperature by averaging the daily average temperature of the previous historical year, and obtain the annual precipitation by accumulating the daily precipitation of the previous historical year, respectively denoted as σ。

[0023] Second step, sampling points are respectively selected in each land sub-region, denoted as each sunshine sampling point. A time period of several days is selected, and several time points at equal time intervals are selected in each day. The sunshine intensity of each sunshine sampling point at each time point within the time period is detected by a sunshine recorder, and it is compared with a preset sunshine intensity threshold in sequence according to the order of the time points. The time point when the 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 sunshine intensity of each sunshine sampling point is less than or equal to the sunshine intensity threshold on each day is recorded as the sunshine end time point of each day. By taking the difference between the sunshine start time point and the sunshine end time point of each day of each sunshine sampling point, the sunshine duration of each day of each sunshine sampling point within the time period is obtained, and the average sunshine duration T of the soil is obtained through mean calculation 日照 。

[0024] Preferably, the specific analysis method for the environmental impact assessment coefficient of the soil is: read the annual average temperature annual precipitation σ, and the average sunshine duration T of the soil 日照 , and substitute them into the formula to obtain the environmental impact assessment coefficient ω of the soil, where w 1 , w 2 , w 3 respectively represent the weight factors of the preset annual average temperature, annual precipitation, and average sunshine duration, σ 0 , respectively represent the reference values of the preset annual average temperature, annual precipitation, and average sunshine duration

[0025] Preferably, the specific analysis method for the delineation of the soil quality category is: First step, respectively read the soil quality evaluation index the environmental impact assessment coefficient ω of the soil, and substitute them into the formula to obtain the comprehensive evaluation index l of the soil in each land sub-region i , where a 1 , a 2 respectively represent the weight factors of the preset soil quality evaluation index and the environmental impact assessment coefficient of the soil

[0026] In the second step, read the comprehensive evaluation indexes of the soils in each land sub-region, and compare them with the preset excellent threshold of the comprehensive evaluation index of the soil and the medium threshold of the comprehensive evaluation index of the soil respectively. If the comprehensive evaluation index of the soil in a certain land sub-region is greater than or equal to the preset excellent threshold of the comprehensive evaluation index of the soil, it means that the soil in this land sub-region is excellent soil. If the comprehensive evaluation index of the soil in a certain land sub-region is less than the preset excellent threshold of the comprehensive evaluation index of the soil and greater than or equal to the preset medium threshold of the comprehensive evaluation index of the soil, it means that the soil in this land sub-region is medium soil. If the comprehensive evaluation index of the soil in a certain land sub-region is less than the preset medium threshold of the comprehensive evaluation index of the soil, it means that the soil in this land sub-region is poor soil.

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

[0028] Second, the present invention obtains the local environmental parameters and analyzes to obtain the environmental impact evaluation coefficient of the soil, which can more comprehensively evaluate the performance of the soil under specific environments and provide support for local soil management.

[0029] Third, the present invention analyzes the comprehensive evaluation indexes of the soils in each land sub-region according to the soil quality evaluation indexes and the environmental impact evaluation coefficients of the soils in each land sub-region, and classifies each land sub-region, which can simply and clearly classify the soils of different land sub-regions and is convenient for management and decision-making. Description of the Drawings

[0030] The present invention is further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation to the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the following drawings without creative efforts.

[0031] Figure 1 It is a schematic flowchart of the method of the present invention.

[0032] Figure 2 is Figure 1 a schematic flowchart of the soil physical and chemical property parameters of each land sub-region in step S2 in

[0033] Figure 3 is Figure 1 a flowchart judgment block diagram of step S6 in Detailed Embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] Please refer to Figure 1 As shown in the figure, the present invention provides a method for delimiting agricultural ecological soil quality categories based on machine learning. The method includes the following steps: S1. Soil sample collection: Divide the land in the research area into each land sub-region, obtain a set amount of soil from each soil sampling point in each land sub-region according to the set soil depths, and mix them to obtain the soil samples of each land sub-region.

[0036] The specific operation method of the soil sample collection is as follows: Divide the land in the research area into several equal-area sub-regions according to the set area, denoted as each land sub-region, number each land sub-region in sequence as 1, 2,..., i,..., n, select several soil sampling points at a fixed interval in each land sub-region, obtain a set amount of soil from each soil sampling point in each land sub-region according to the set soil depths, and mix them to obtain the soil samples of each land sub-region.

[0037] S2. Soil physical and chemical property analysis: Detect the soil physical and chemical property parameters of each land sub-region, and analyze to obtain the soil physical and chemical property evaluation coefficients of each land sub-region. The soil physical and chemical property parameters include the pH value, conductivity, and organic matter content of the soil sample.

[0038] Please refer to Figure 2 As shown in the figure, the specific detection method of the soil physical and chemical property parameters of each land sub-region is as follows: First step, read the soil samples of each land sub-region, weigh a set amount from them, air-dry them and put them into a container, and obtain a soil suspension by adding a fixed amount of potassium chloride solution, denoted as the soil suspension of each land sub-region soil sample. Insert the electrode into the soil suspension of each land sub-region soil sample, and read the value after the pH meter stabilizes to 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 some heavy metals (such as cadmium, lead, etc.) in acidic soil may be higher, and it is easier to be absorbed by plants or migrate with water, thus posing a potential threat to the ecological environment and human health. By measuring the pH value, the soil environmental risk can be evaluated and corresponding prevention and control measures can be taken.

[0039] Second step: Weigh a set amount from the soil samples of each land sub-region, air-dry it and put it into a container, and obtain a prepared soil suspension by adding a fixed amount of ionic water, which is denoted as the ionic suspension of the soil samples in each land sub-region. Insert the electrode of the conductivity meter into the ionic suspension of the soil samples in each land sub-region, and read the conductivity value displayed by the conductivity meter, which is denoted as the conductivity of the soil samples in each land sub-region. By long-term monitoring of the change in conductivity, it is possible to preliminarily judge whether the soil is polluted and the approximate degree of pollution. At the same time, the salinization degree of the soil can be evaluated, and then improvement measures such as salt washing, soil replacement, or planting salt-tolerant plants can be taken.

[0040] Third step: Weigh a set amount from the soil samples of each land sub-region, air-dry it, sieve it, and place it in a dryer until it reaches a constant weight to obtain the air-dried soil samples of each land sub-region. Weigh it and then put it into a high-temperature furnace for combustion, evenly pass oxygen, heat it to a predetermined temperature at a set heating rate and maintain it for a certain period of time, prepare a fixed amount of sodium hydroxide solution, let the carbon dioxide generated by combustion be absorbed by the sodium hydroxide solution, and finally weigh the air-dried soil samples of each land sub-region again to calculate the organic matter content of the soil samples in each sub-region; Soil organic matter provides energy and nutrients for soil microorganisms, affects the types and quantities of microorganisms, and under different levels of soil organic matter content, the soil microbial community structure and function will vary greatly, thus affecting the ecological service functions of the soil, such as decomposing organic matter and fixing nitrogen.

[0041] It should be noted that the specific analysis method for the organic matter content of the soil samples in each sub-region is as follows: By weighing the air-dried soil samples of each land sub-region, the weight of the air-dried soil samples of each land sub-region is obtained. Put the air-dried soil samples of each land sub-region into a combustion tube and then into a high-temperature furnace, connect the oxygen supply device, adjust it according to the set oxygen flow rate to make it evenly pass through the air-dried soil samples of each land sub-region, heat the high-temperature furnace to the predetermined temperature at the set heating rate, and maintain it at this temperature for the set period of time. Prepare a set amount of sodium hydroxide solution, introduce the carbon dioxide generated by combustion into the absorption device containing sodium hydroxide solution through a conduit. After the absorption of carbon dioxide is completed, weigh the air-dried soil samples of each land sub-region again to obtain the weight of the air-dried soil samples of each land sub-region after absorption, and calculate the organic matter content of the soil samples in each land sub-region.

[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: Read the weight of the air-dried soil samples of each land sub-region, the set amount of sodium hydroxide solution, and the weight of the air-dried soil samples of each land sub-region after absorption respectively, and denote them as M i 、M 0 、 Substitute them into the formula to obtain the organic matter content β of the soil samples in each land 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 degree of 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: read the pH value, 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 , substituting it into the formula The soil physical and chemical property evaluation coefficient γ of each land sub-region is obtained i , where φ 1 ,φ 2 ,φ 3 They represent the weighting factors of the pH value, electrical conductivity, and organic matter content of the soil samples respectively; they help to scientifically and quantitatively evaluate the physical and chemical properties of the soil in each sub-region, thereby providing an accurate basis for land use planning, soil improvement, and agricultural planting suitability analysis, and also facilitate comparison of soil conditions in different sub-regions and formulation of reasonable soil management strategies in a targeted manner.

[0044] It should be noted that, in a specific embodiment, φ 1 Can be set to 0.3, φ 2 Can be set to 0.2, φ 3 It can be set to 0.5. The pH value affects the effectiveness 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. The electrical conductivity mainly reflects the degree of soil salinization. Although salinization will affect plant growth, not all areas have serious salinization problems, and the impact of other soil properties on the overall evaluation is more critical in more cases. Organic matter is an important indicator of soil fertility, affecting many key soil characteristics such as soil structure, water and fertilizer retention capacity, and microbial activity. It 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: The soil pollution indicators of each land sub-area are tested and analyzed to obtain the soil pollution index evaluation coefficient of each land sub-area. The soil pollution indicators include the heavy metal content and pesticide residues in the soil samples.

[0046] The specific detection method for the soil pollution index of each land sub-region is as follows: First step, weigh a set amount from the soil samples of each land sub-region, air-dry it and then sieve it to prepare the 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 setting, 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 samples of each land sub-region, denoted as ε i Heavy metal pollution can damage the structure and function of soil microbial communities and affect the ecological service functions of the soil. Accurately detecting the heavy metal content helps to take timely protective measures and maintain the balance of the soil ecosystem.

[0047] It should be noted that the specific analysis method for the soil metal solution of each land sub-region is as follows: Place it in a polytetrafluoroethylene digestion tank, add an appropriate amount of mixed acid, seal the digestion tank and put it into a microwave digestion instrument, and carry out digestion according to the set digestion temperature and duration. After digestion is completed, cool the digestion tank in a fume hood, then transfer it to a polytetrafluoroethylene crucible, heat it on a hot plate to drive off the acid until nearly dry, dissolve the residue with a small amount of dilute nitric acid, and make up the volume to a certain volume to obtain the soil metal solution of each land sub-region.

[0048] Second step, weigh a set amount from the soil samples of each land sub-region, air-dry and sieve it, then place it in a triangular flask, add an appropriate amount of organic solvent and anhydrous sodium sulfate, oscillate for a set duration on an oscillator, and obtain the extract of the soil samples of each land sub-region by filtration. Transfer the extract of the soil samples of each land sub-region to a separating funnel, add a quantitative sodium chloride solution, oscillate and layer, discard the lower aqueous phase, transfer the upper organic phase to a concentration bottle, concentrate it to nearly dry on a rotary evaporator, and make up the volume to a set volume with a n-hexane-acetone mixed solvent to obtain the concentrated solution of the soil samples of each land sub-region. By injecting the concentrated solution of the soil samples of each land sub-region into a gas chromatograph, the pesticide residue amount of the soil samples of each land sub-region is measured, denoted as δ i Understanding the pesticide residue situation in the soil can adjust the types, dosages and application frequencies of pesticides according to the carrying capacity of the soil, improve the use efficiency of pesticides, and at the same time reduce the pollution of pesticides to the soil environment.

[0049] The specific analysis method for the soil pollution index evaluation coefficient of each land sub-region is as follows: Read the heavy metal content ε of the soil samples of each land sub-region i , and substitute it into the formula to obtain the soil pollution index evaluation coefficient ρ of each land sub-region i , where ε0 represents the preset reference value of heavy metal content, δ 0 represents the preset reference value of pesticide residue, represents the weight factors of the preset heavy metal content and pesticide residue in soil samples; based on a unified evaluation coefficient, it can intuitively distinguish which sub-regions of the land have serious soil pollution and which are relatively less polluted, thus providing a basis for arranging the priority of soil pollution control.

[0050] It should be noted that in a specific embodiment, 0.7 can be set, 0.3 can be set. Heavy metals are difficult to degrade in soil, will exist for a long time and may accumulate through the food chain, causing serious and lasting harm to the ecosystem and human health. They are important and key considerations in soil pollution. Although pesticide residues will affect soil ecology and the safety of agricultural products, 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. Therefore, the corresponding weight of heavy metal content is higher.

[0051] S4. Soil quality evaluation: Analyze the soil quality evaluation index of each land sub-region 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: Read the soil physical and chemical property evaluation coefficient γi and soil pollution index evaluation coefficient ρ of each land sub-region respectively i , and substitute them into the formula to obtain the soil quality evaluation index of each land sub-region where η 1 , η 2 respectively represent the weight factors of the preset soil physical and chemical property evaluation coefficient and soil pollution index evaluation coefficient; by analyzing the contributions of the soil physical and chemical property evaluation coefficient and soil pollution index evaluation coefficient, it can be determined 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, η 1 0.5 can be set, η 2It can be set to 0.5. The physical and chemical properties of the soil are the basic attributes of soil quality. These properties directly affect the soil fertility status, microbial activity, and the growth environment of plants. Good physical and chemical properties of the soil can provide a stable foundation for the soil ecosystem. Even if the soil is contaminated to a certain extent, if its physical and chemical properties are good, the soil still has a certain self-repair ability and the ability to carry ecological functions. The soil pollution situation is directly related to the safety and applicability of the soil. If the soil is severely polluted, especially 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 the local environmental parameters, and analyze to obtain the environmental impact evaluation coefficient of the soil. The environmental parameters include the annual average temperature, annual precipitation, and average sunshine duration.

[0055] The specific method for obtaining the above-mentioned environmental parameters is as follows: In the first step, connect to the local meteorological station to obtain the daily average temperature and daily precipitation of the previous historical year respectively. Calculate the annual average temperature by taking the average value of the daily average temperature of the previous historical year, and calculate the annual precipitation by accumulating the daily precipitation of the previous historical year, which are respectively recorded as σ; According to the annual precipitation and its contribution to the soil environmental impact evaluation coefficient, it can be judged whether supplementary irrigation or strengthening of drainage facilities construction is needed to maintain the appropriate soil humidity and meet the growth requirements of crops.

[0056] In the second step, select sampling points in each land sub-region, denoted as each sunshine sampling point. Select a time period of several days, and select several time points at equal time intervals in each day. Detect the sunshine intensity of each sunshine sampling point at each time point within the time period through a sunshine recorder, and compare it with the preset sunshine intensity threshold in sequence according to the order of the time points. Record the time point when the sunshine intensity of each sunshine sampling point is greater than the sunshine intensity threshold on each day as the sunshine start time point of each day, and record the time point when the sunshine intensity of each sunshine sampling point is less than or equal to the sunshine intensity threshold on each day as the sunshine end time point of each day. Calculate the sunshine duration of each sunshine sampling point on each day within the time period by taking the difference between the sunshine start time point and the sunshine end time point of each day of each sunshine sampling point, and calculate the average sunshine duration T of the soil through mean calculation 日照 ; Understanding the sunshine duration helps to determine the planting time, growth cycle, and harvest time of crops, etc.

[0057] The specific analysis method for the environmental impact evaluation coefficient of the soil is as follows: Read the annual average temperature the annual precipitation σ, and the average sunshine duration T of the soil 日照 , and substitute them into the formula Obtain the environmental impact assessment coefficient ω of the soil, where w 1 , w 2 , w 3 respectively represent the weight factors of the preset annual average temperature, annual precipitation, and average sunshine duration, σ 0 , 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 environmental impact assessment coefficient of the soil, the comprehensive impact of the meteorological conditions of a specific land on the soil environment can be understood, and then the crop variety most suitable for the land's meteorological environment can be selected to improve the yield and quality of the crops.

[0058] It should be noted that in a specific embodiment, w 1 can be set to 0.3, w 2 can be set to 0.5, w 3 can be set to 0.2. Temperature affects the activity of microorganisms in the soil. Microorganisms have higher activity at suitable temperatures and can accelerate the decomposition of organic matter and nutrient transformation in the soil. At the same time, temperature also affects the evaporation and condensation of water in the soil, indirectly affecting the soil humidity and structure. Annual precipitation is an important source of soil moisture. Sufficient precipitation can replenish soil moisture, affect the soil humidity condition, and further affect the physical properties such as soil aeration and water permeability. The average sunshine duration mainly indirectly affects the soil environment by affecting soil temperature and plant growth. A long sunshine duration will increase the soil temperature and affect the microorganisms and biochemical processes in the soil, but this effect partially overlaps with the effect of the annual average temperature. Therefore, the corresponding weight of annual precipitation is higher.

[0059] S6. Soil quality category delineation: According to the soil quality evaluation index of each land sub-region and the environmental impact assessment coefficient ω of the soil, analyze to obtain the comprehensive evaluation index l of the soil in each land sub-region i , and conduct grade division for each land sub-region, where i represents the number of the i-th land sub-region, i = 1, 2,..., n.

[0060] Please refer to Figure 3 as shown. The specific analysis method for the soil quality category delineation is as follows: First step, respectively read the soil quality evaluation index and the environmental impact assessment coefficient ω of the soil, and substitute them into the formula to obtain the comprehensive evaluation index l of the soil in each land sub-region i , where a 1 , a 2respectively represent the preset soil quality evaluation index and the weight factor of the environmental impact evaluation coefficient of the soil; by analyzing each evaluation coefficient that makes up the index, it is possible to clarify whether there are problems in terms of 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, a 2 can be set to 0.6, a 3 can be set to 0.4. The soil quality evaluation index is an index that comprehensively reflects various properties of the soil. It comprehensively considers many 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 soil condition. The environmental impact evaluation coefficient of the soil mainly focuses on the situation of the soil being 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, such as soil physical and chemical properties, it is a manifestation after external factors act on the soil. Moreover, when constructing the soil comprehensive evaluation index, the basic characteristics and comprehensive quality status of the soil itself are more core considerations. The environmental impact evaluation coefficient more reflects the soil condition from the side. Therefore, the weight corresponding to the soil quality evaluation index is higher.

[0062] Second step, read the comprehensive evaluation index of the soil in each land sub-region, and compare it with the preset excellent threshold of the comprehensive evaluation index of the soil and the medium threshold of the comprehensive evaluation index of the soil respectively. If the comprehensive evaluation index of the soil in a certain land sub-region is greater than or equal to the preset excellent threshold of the comprehensive evaluation index of the soil, it means that the land sub-region is excellent soil. If the comprehensive evaluation index of the soil in a certain land sub-region is less than the preset excellent threshold of the comprehensive evaluation index of the soil and greater than or equal to the preset medium threshold of the comprehensive evaluation index of the soil, it means that the land sub-region is medium soil. If the comprehensive evaluation index of the soil in a certain land sub-region is less than the preset medium threshold of the comprehensive evaluation index of the soil, it means that the land sub-region is poor soil; classifying the comprehensive evaluation index of the soil according to the preset threshold can classify soils of different qualities, making the evaluation results of the soil condition more intuitive, easier to understand and compare, and clarifying the relative quality of the soil in different land sub-regions.

[0063] The present invention obtains the soil physical and chemical property evaluation coefficients of each land sub-region through the soil physical and chemical property parameter of each land sub-region, obtains the soil pollution index evaluation coefficients of each land sub-region through the soil pollution indexes of each land sub-region, thereby analyzes and obtains the soil quality evaluation indexes of each land sub-region, analyzes and obtains the environmental impact evaluation coefficients of the soil by obtaining the local environmental parameters, analyzes and obtains the comprehensive evaluation indexes of the soil of each land sub-region according to the soil quality evaluation indexes of each land sub-region and the environmental impact evaluation coefficients of the soil, and conducts grade division on each land sub-region, which can provide accurate soil quality information for agricultural production, thereby improving the efficiency and sustainability of agricultural production.

[0064] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention, and still be covered by the protection scope of the present invention.

Claims

1. A method for classifying agricultural ecological soil quality based on machine learning, characterized in that: The steps include: S1. Soil sample collection: Divide the land in the study area into various land sub-areas, 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 of each land sub-area by mixing; S2. Analysis of soil physical and chemical properties: The soil physical and chemical property parameters of each land sub-area are tested and analyzed to obtain the soil physical and chemical property evaluation coefficient of each land sub-area. The soil physical and chemical property parameters include soil sample pH value, electrical conductivity, and organic matter content; S3. Soil pollution analysis: soil pollution indicators of each land sub-region are tested and analyzed to obtain soil pollution index evaluation coefficients of each land sub-region. Soil pollution indicators include heavy metal content and pesticide residues in soil samples; 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; S5. Environmental impact analysis: Obtain local environmental parameters and analyze the environmental impact assessment coefficient of the soil. 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 The soil environmental impact assessment coefficient ω is analyzed to obtain the comprehensive assessment 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.

2. The method for classifying agricultural ecological soil quality based on machine learning according to claim 1, characterized in that: The specific operation method of soil sample collection is as follows: According to the set area, the land in the study area is divided into several sub-areas of equal area, recorded as land sub-areas, and each land sub-area is numbered 1, 2, ..., i, ..., n in sequence. In each land sub-area, several soil sampling points are selected at fixed intervals, 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.

3. The method for agricultural ecological soil quality classification based on machine learning according to claim 2 is characterized in that: The specific detection method of soil physical and chemical property parameters of each land sub-region is: The first step is to read the soil samples of each land sub-area, weigh a set amount, 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-area, insert the electrode into the soil sample suspension of each land sub-area, read the value of the pH meter after stabilization, and obtain the pH value of the soil sample of each land sub-area; The second step is to weigh a set amount of soil samples from each land sub-region, air-dry them and put them into a container, and add a certain amount of ionized water to obtain a soil suspension, which is recorded as the ion suspension of soil samples in each land sub-region. The electrodes of the conductivity meter are inserted into the ion suspension of soil samples in each land sub-region, 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-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 dryer 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 passed evenly 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 from each sub-area.

4. The method for classifying agricultural ecological soil quality based on machine learning according to claim 3 is characterized in that: 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, conductivity, and organic matter content of soil samples in each sub-area of ​​the land, recorded as pH i , α i , β i , substituting it into the formula The soil physical and chemical property evaluation coefficient γ of each land sub-region is obtained i , where φ1, φ2, and φ3 represent the weight factors of soil sample pH value, electrical conductivity, and organic matter content, respectively.

5. The method for classifying agricultural ecological soil quality based on machine learning according to claim 4 is characterized in that: The specific detection method of soil pollution indicators in each land sub-area is: The first step is to weigh a set amount of soil samples from each land sub-region, air-dry and sieve it to prepare a soil metal solution in each land sub-region, select a 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 in each land sub-region into the atomic absorption spectrometer, and obtain the absorbance of the soil metal solution in 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 in each land sub-region into the absorbance-heavy metal content standard curve, and obtain the heavy metal content of the soil sample in each land sub-region, which is recorded as ε i ; In the second step, a set amount of soil samples 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 extracts of each land sub-region are obtained by filtering. The soil sample extracts of each land sub-region are transferred to a separatory funnel, and a quantitative sodium chloride solution is added. The layers are oscillated 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 mixed solvent of n-hexane-acetone to obtain a concentrated solution of soil samples of each land sub-region. The concentrated solution of soil samples of each land sub-region is injected into a gas chromatograph to measure the pesticide residue in the soil samples of each land sub-region, which is recorded as δ i .

6. The method for classifying agricultural ecological soil quality based on machine learning according to claim 5, 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 ε i , substituting 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 the preset heavy metal content and pesticide residue in soil samples.

7. The method for classifying agricultural ecological soil quality based on machine learning according to claim 6 is 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 coefficient γi and soil pollution index evaluation coefficient ρ of each land sub-region respectively i , substituting 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.

8. The method for classifying agricultural ecological soil quality based on machine learning according to claim 1, characterized in that: The specific method for obtaining the environmental parameters is: The first step is to connect to the local meteorological 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 σ; 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 time points are 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 of 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 day at 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 average calculation. 日照 .

9. The method for classifying agricultural ecological soil quality based on machine learning according to claim 8, characterized in that: The specific analysis method of the soil environmental impact assessment coefficient is: Read the average annual temperature Annual precipitation σ, average sunshine duration T 日照 , substituting 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.

10. 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 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-area i , where a1 and a2 represent the weight factors of the preset soil quality evaluation index and soil environmental impact assessment coefficient respectively; 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.

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