A high-standard farmland soil moisture monitoring method and system

Abstract

The present invention relates to the technical field of soil moisture monitoring, and in particular to a method and system for monitoring soil moisture in high-standard farmland. The method analyzes the distribution of soil moisture by analyzing the overall distribution relationship between soil layers at different depths and volumetric water content, and identifies salt anomalies in combination with EC value fluctuations in a time series; analyzes the water migration phenomenon in the soil by matrix potential deviation, and screens monitoring points with upward water migration from monitoring points based on the acquired water migration index; analyzes the degree of interference of salt on the volumetric water content data of different monitoring points by combining the water migration and salt anomaly of the water upward migration monitoring points, obtains the depth interference coefficient, and corrects the volumetric water content to obtain soil moisture. The present invention analyzes the dynamic changes in the overall soil moisture, corrects soil moisture data by the influence of water migration and salt in vertical depth, improves the accuracy and reliability of monitoring, and provides reliable data support for the subsequent scientific management of high-standard farmland.

Description

Technical Field

[0001] The present invention relates to the technical field of soil moisture monitoring, and in particular to a method and system for monitoring soil moisture in high-standard farmland. Background Art

[0002] High-standard farmland aims to ensure stable and high yields regardless of drought or flood. Soil moisture, as a direct indicator of crop water supply, directly determines irrigation efficiency and yield stability. Soil moisture specifically refers to the moisture status of the topsoil. Quantitative indicators include absolute moisture content (such as the percentage of water weight to oven-dry soil weight) and relative moisture content (such as field capacity or saturated water content). This influences soil microbial activity, nutrient migration, and carbon cycling, and is a crucial parameter for ecosystem health.

[0003] In existing soil moisture monitoring technologies, it is difficult to capture dynamic migration processes such as water evaporation and infiltration in the soil. Water migration will cause the soil moisture data obtained at the monitoring points to be interfered with by soil salt, resulting in falsely high readings. Salt affects electrical conductivity and thus changes the dielectric constant, distorting the measurement results of the physical presence of water. In addition, the osmotic pressure generated by salt will hinder root water absorption and change the water migration path, making it impossible for the water status monitoring results to accurately reflect the true soil moisture conditions. Summary of the Invention

[0004] In order to solve the technical problem in the prior art that water migration causes the soil moisture data obtained at the monitoring point to be interfered with by soil salinity, resulting in falsely high readings, and salt affects the electrical conductivity and thus changes the dielectric constant, thus distorting the measurement results of the physical presence of water, the purpose of the present invention is to provide a high-standard farmland soil moisture monitoring method and system. The technical solutions adopted are as follows:

[0005] The present invention provides a method for monitoring soil moisture conditions in high-standard farmland, the method comprising:

[0006] At monitoring points in different depth layers of high-standard farmland soil, the volumetric water content, matrix potential, and EC value at each sampling moment were obtained;

[0007] The current moisture index is obtained based on the volumetric moisture content deviation between adjacent monitoring points at the current moment, as well as the relationship between volumetric moisture content and soil depth. The current salt anomaly index of each monitoring point is determined based on the EC value fluctuation distribution of each monitoring point before the current moment and the moisture index.

[0008] Based on the matrix potential deviation between each monitoring point and adjacent shallow monitoring points, combined with the salinity anomaly index, the water migration index of each monitoring point was determined. Based on the water migration index, the water migration monitoring points were selected. The local water migration index distribution of each water migration monitoring point was analyzed, and the depth interference coefficient of the water migration monitoring point was obtained in combination with the current salinity anomaly index.

[0009] The volumetric water content is corrected according to the depth interference coefficient of the water upward movement monitoring point to obtain the corrected volumetric water content; the soil moisture condition is obtained based on the corrected volumetric water content at the current moment.

[0010] Furthermore, the method for obtaining the moisture index includes:

[0011] At the current moment, after calculating the difference between each two adjacent depth layer self-test monitoring points, the mean of all differences is used as the inter-adjacent deviation degree at the current moment;

[0012] Establish a two-dimensional spatial coordinate system, with the depth of the depth layer corresponding to the monitoring point as the horizontal axis and the volumetric water content as the vertical axis. Map the volumetric water content of all monitoring points at the current moment to the two-dimensional spatial coordinate system to obtain data points; obtain the slope of all data points after fitting a straight line, and use the value of the slope mapped by negative exponential power as the distribution trend at the current moment;

[0013] The moisture index at the current moment is obtained by combining the inter-neighbor deviation and distribution trend at the current moment.

[0014] Furthermore, the method for obtaining the salt abnormality index includes:

[0015] For any monitoring point, the EC value size and fluctuation of all sampling times within the preset range before the current moment of the monitoring point are used to obtain the abnormal salt fluctuation degree of the monitoring point;

[0016] The product of the abnormal salt fluctuation degree of the monitoring point and the moisture index at the current moment is used as the current abnormal salt index of the monitoring point.

[0017] Furthermore, the method for obtaining abnormal salinity fluctuation includes:

[0018] The mean of the EC values ​​of all sampling times within a preset range before the current moment of the monitoring point is used as the significance of the salt distribution of the monitoring point; the standard deviation of the EC values ​​of all sampling times within a preset range before the current moment of the monitoring point is used as the significance of the salt change of the monitoring point;

[0019] The abnormal fluctuation degree of salt content at the monitoring point is obtained by combining the salt distribution significance and salt change significance of the monitoring point.

[0020] Furthermore, the method for obtaining the water migration index includes:

[0021] For any monitoring point with an upper depth layer, the monitoring point in the adjacent upper depth layer is regarded as the adjacent shallow monitoring point;

[0022] Calculate the difference in matric potential between the monitoring point and the adjacent shallow monitoring point as the water potential gradient value of the monitoring point; calculate the depth difference between the monitoring point and the adjacent shallow monitoring point as the depth difference; calculate the ratio of the water potential gradient value to the depth difference of the monitoring point as the migration significance of the monitoring point;

[0023] The average value of the salt anomaly index between the monitoring point and the adjacent shallow monitoring points is taken as the local difference of the monitoring point;

[0024] The water migration index of the monitoring point is obtained by combining the migration significance and local difference of the monitoring point.

[0025] Furthermore, the method for obtaining the moisture upward movement monitoring point includes:

[0026] When the moisture migration index of a monitoring point is negative, the corresponding monitoring point will be used as a moisture upward migration monitoring point.

[0027] Furthermore, the method for obtaining the depth interference coefficient includes:

[0028] For any water upward migration monitoring point, the absolute value of the water migration index of the monitoring point at the adjacent upper depth layer of the water upward migration monitoring point and the absolute value of the water migration index of the water upward migration monitoring point are averaged to obtain the migration degree of the water upward migration monitoring point;

[0029] The ratio between the migration degree of the water upward migration monitoring point and the sum of the absolute values ​​of the water migration indices of all monitoring points is used as the relative migration index of the water upward migration monitoring point;

[0030] The product of the relative migration index of the water upward movement monitoring point and the current salt anomaly index is used as the depth interference coefficient of the water upward movement monitoring point.

[0031] Furthermore, the method for obtaining the corrected volumetric water content includes:

[0032] For any of the water upward movement monitoring points, a negative correlation mapping is performed on the ratio between the depth interference coefficient of the water upward movement monitoring point and the depth of the corresponding depth layer, which is used as the correction coefficient of the water upward movement monitoring point;

[0033] The product of the volumetric water content of the moisture upward monitoring point and the correction coefficient is used as the corrected volumetric water content of the moisture upward monitoring point.

[0034] Furthermore, the preset range before the current moment is a time range within 10 minutes before the current moment.

[0035] The present invention also provides a high-standard farmland soil moisture monitoring system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the above methods when executing the computer program.

[0036] The present invention has the following beneficial effects:

[0037] The present invention analyzes the moisture conditions at different depths of high-standard farmland soil, combines the overall distribution relationship between depth and volumetric water content, and more comprehensively characterizes the soil moisture conditions at the moment, and then combines the EC value fluctuations in the time series to more accurately identify salt anomalies. The water migration phenomenon existing in the soil is analyzed. Since the stronger the water evaporation at the current position, the more significant the salt interference caused by the corresponding water migration and salt separation on the moisture conditions is. Therefore, based on the obtained water migration index, the monitoring points with upward water migration are screened from the monitoring points for correction. Combined with the water migration and salt anomalies of the water upward migration monitoring points, the degree of interference of salt on the volumetric water content data of different monitoring points is analyzed, the depth interference coefficient is obtained, and the volumetric water content is corrected accordingly to obtain more accurate soil moisture data. The present invention analyzes the dynamic changes of the overall soil moisture, corrects the soil moisture data through the influence of water migration and salt in vertical depth, improves the accuracy and reliability of monitoring, and provides reliable data support for the subsequent scientific management of high-standard farmland. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 A flow chart of a method for monitoring soil moisture in high-standard farmland provided by one embodiment of the present invention;

[0040] Figure 2 A schematic diagram of a two-dimensional space coordinate system provided by one embodiment of the present invention;

[0041] Figure 3 A schematic diagram of the distribution of a water migration indicator at different depth layers provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail a high-standard farmland soil moisture monitoring method and system proposed by the present invention, including its specific implementation, structure, features, and effects. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable form.

[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0044] The following describes in detail a method and system for monitoring soil moisture in high-standard farmland provided by the present invention with reference to the accompanying drawings.

[0045] See also Figure 1 , which shows a flow chart of a method for monitoring soil moisture in high-standard farmland provided by one embodiment of the present invention, the method comprising the following steps:

[0046] S1: At monitoring points in different depth layers of high-standard farmland soil, obtain the volumetric water content, matrix potential and EC value at each sampling moment.

[0047] For the high-standard farmland to be monitored, different depth layers are selected for monitoring in combination with the crops, crop growth period and root depth in the actual high-standard farmland. In an embodiment of the present invention, at the monitoring point of each depth layer, a dielectric principle fixed tubular sensor, such as TDR / FDR, is preferably used. The sensor accuracy must reach ±3%, and the protection level must be IP67 or above to obtain the volumetric water content. The volumetric water content reflects the basic indicator of soil water storage capacity, but the effectiveness must be judged in combination with salt. Therefore, a four-pin EC sensor is buried in the root layer, and an AC electric field is applied to measure the electrical conductivity, which is also the EC value. The soil EC value is a key indicator for measuring the soluble salt content in the soil, which directly affects crop growth and soil health. Then, the soil matrix potential is directly measured based on the negative pressure gauge. The matrix potential is an energy indicator that characterizes the ability of the soil matrix to absorb water, and reflects the difficulty of crops to absorb water.

[0048] In a specific embodiment of the present invention, real-time data collection is performed at intervals of 1 minute to ensure that the collected data is accurate and complete. The collected data is preprocessed, including data cleaning to remove abnormally large or abnormally small data caused by sensor failure or signal interference. For missing data, linear interpolation or spline interpolation and other methods are used to supplement to ensure the continuity of the data. Each type of data is normalized to remove the dimensional influence between the data. It should be noted that data collection and preprocessing are technical means well known to those skilled in the art. Implementers can adjust and control them according to the specific implementation scenario. The choice of normalization can be linear normalization or standard normalization, etc., which is not limited or elaborated here.

[0049] S2: Based on the volumetric water content deviation between adjacent monitoring points at the current moment and the relationship between volumetric water content and soil depth, the current moisture index is obtained; based on the EC value fluctuation distribution of each monitoring point before the current moment, combined with the moisture index, the current salt anomaly index of each monitoring point is determined.

[0050] When volumetric water content at monitoring points at different soil depths shows a higher volumetric water content at shallower depths, this is evidence of the dynamics of water-salt co-migration in salinized farmland. The physical mechanism of salt accumulation can lead to falsely high volumetric water content readings, which requires correction to ensure accurate soil moisture measurements.

[0051] First, the overall change trend of the volumetric water content from top to bottom of all monitoring points in the high-standard farmland is identified to more fully characterize the soil moisture situation at the current moment. Preferably, in an embodiment of the present invention, the method for obtaining the moisture index includes:

[0052] At the current moment, the difference between self-checked monitoring points in each adjacent depth layer is calculated, and the mean of all these differences is used as the inter-neighborhood deviation. By testing the difference in volumetric water content data between all adjacent monitoring points in the farmland with high standards, the distribution of water in adjacent depth layers is reflected. The more obvious the layer-by-layer difference in volumetric water content between different soil layers, the greater the inter-neighborhood deviation, indicating a more uneven distribution of water in the current soil, and a greater likelihood of salt accumulation or water leaching.

[0053] Further establish a two-dimensional spatial coordinate system, with the depth of the monitoring point corresponding to the depth layer as the horizontal axis and the volumetric water content as the vertical axis, and map the volumetric water content of all monitoring points at the current moment to the two-dimensional spatial coordinate system to obtain data points. Please refer to Figure 2 , which shows a schematic diagram of a two-dimensional space coordinate system provided by an embodiment of the present invention.

[0054] Obtain the slope after all data points are fitted to a straight line, and the value of the slope mapped by the negative exponential power is used as the distribution trend degree at the current moment. As the depth increases, the volumetric water content may increase or decrease, that is, the slope may be a positive or negative value. When the slope is negative and the absolute value of the numerical value is larger, the moisture anomaly is more significant, that is to say, the volumetric water content of the monitoring point gradually decreases as the depth increases, and the possibility of the coordinated migration of water and salt in farmland is higher. Therefore, in an embodiment of the present invention, the negative exponential power of the slope with a natural constant as the base is used as the distribution trend degree, and the larger the distribution trend degree is, the more significant the anomaly is. It should be noted that the negative exponential power calculation is a known technical means well known to those skilled in the art, and will not be elaborated and limited herein.

[0055] Finally, the moisture index at the current moment is obtained by combining the inter-neighbor deviation and distribution trend at the current moment. In an embodiment of the present invention, the product of the inter-neighbor deviation and distribution trend at the current moment is used as the moisture index at the current moment. When the value is larger, it is considered that there is a deviation in the acquisition of volumetric moisture content data in the current high-standard farmland, and its validity needs to be judged in combination with salt and corresponding corrections need to be made.

[0056] Soil salinization is typically caused by excessive salt accumulation in the soil, which impacts plant growth. The EC value directly reflects the electrical conductivity of the soil solution. High conductivity indicates high salinity and is used to estimate soil salinity. Therefore, the higher the EC value, the more severe the salinization of the farmland tested. Based on the temporal data of the soil EC values ​​at the monitoring site, a high long-term trend in the data indicates salt accumulation, while short-term fluctuations may be related to irrigation.

[0057] Therefore, the salt abnormality can be analyzed based on the EC value of the monitoring point within the time range before the current moment and the EC value fluctuation over time. In an embodiment of the present invention, the method for obtaining the salt abnormality indicator includes:

[0058] For any monitoring point, the EC value and fluctuation at all sampling times within a preset range before the current moment are used to determine the abnormal salt fluctuation at that monitoring point. The larger the EC value and the more significant the fluctuation within the current time range, the higher the degree of salt abnormality. In this embodiment of the present invention, the preset range before the current moment is the time range within 10 minutes before the current moment, and the implementation of the preset time range can adjust it at will.

[0059] In one embodiment of the present invention, the mean EC value for all sampling times within a preset range before the current time at a monitoring point is used as the salt distribution significance at that monitoring point, and the standard deviation of the EC value for all sampling times within a preset range before the current time at that monitoring point is used as the salt change significance at that monitoring point. A higher mean EC value indicates a higher likelihood of salt accumulation anomaly, while a larger standard deviation indicates a more significant data change and a higher degree of soil salt anomaly.

[0060] Therefore, the abnormal salt fluctuation of the monitoring point is obtained by combining the salt distribution significance and the salt change significance of the monitoring point. In an embodiment of the present invention, the product of the salt distribution significance and the salt change significance of the monitoring point is used to obtain the abnormal salt fluctuation of the monitoring point. The higher the abnormal salt fluctuation, the more significant the abnormality analyzed from the salt situation.

[0061] Combined with the distribution of water, the product of the abnormal salt fluctuation of the monitoring point and the moisture index at the current moment is used as the current abnormal salt index of the monitoring point. The larger the abnormal salt index, the greater the degree of abnormal salt interference at the current monitoring point.

[0062] Combined with the more accurate analysis of the EC value, the presence of abnormal conditions in reflecting farmland moisture when the volumetric moisture content data is measured by the dielectric method can further determine the impact of water-salt coupling in high-standard farmland at this time, and then remove the salt interference in the volumetric moisture content data, and correct it to moisture data that more accurately reflects the actual soil moisture conditions.

[0063] S3: Determine the water migration index of each monitoring point based on the matrix potential deviation between each monitoring point and the adjacent shallow monitoring point, combined with the salinity anomaly index; select the water upward migration monitoring points based on the water migration index; analyze the local water migration index distribution of each water upward migration monitoring point, and obtain the depth interference coefficient of the water upward migration monitoring point in combination with the current salinity anomaly index.

[0064] When monitoring moisture conditions and abnormal salt levels in high-standard farmland as reflected in EC data, the high salt content in the volumetric water content data directly measured by the dielectric method will trigger the ion relaxation effect of salt. That is, when electromagnetic waves propagate in the soil, the polarity of water molecules makes their contribution to the dielectric constant the largest (about 80), while the soil solids only contribute 4-9.

[0065] However, salt ions interfere with measurements through two mechanisms: ionic conductivity loss increases the imaginary part of the dielectric constant, while ionic polarization relaxation raises the real part in specific frequency bands. This can be understood as the presence of more conductive substances in pure water, causing the sensor to detect more water-like substances, resulting in artificially high readings.

[0066] Considering the differences in water potential direction in real-world scenarios, upward water migration indicates that evaporation is the dominant factor in the soil's moisture content. This leads to the most severe surface salt accumulation, resulting in significantly higher readings at shallow monitoring points. However, downward water migration indicates leaching, which dilutes the salt content and reduces interference with volumetric water content readings. Therefore, the need for volumetric water content data correction is low.

[0067] Therefore, the water potential migration situation is reflected by the matrix potential deviation between vertical layers of different depths, and the water migration index characterizing the interference effect is obtained by comprehensively considering the salt acceleration of water potential migration caused by salt anomalies. Preferably, in an embodiment of the present invention, the method for obtaining the water migration index includes:

[0068] For any monitoring point with an upper depth layer, the monitoring point in the adjacent upper depth layer is used as the adjacent shallow monitoring point. The difference between the deep and shallow layers reflects the water migration in the soil. The difference in matric potential between this monitoring point and the adjacent shallow monitoring point is calculated as the water potential gradient value for that monitoring point. When the water potential gradient value is less than zero, it reflects upward water migration. When the water potential gradient value is greater than zero, it reflects downward water leaching. Otherwise, it indicates no water migration.

[0069] The depth difference between the monitoring point and the adjacent shallow monitoring point is taken as the depth difference, and the ratio of the water potential gradient value of the monitoring point to the depth difference is taken as the migration significance of the monitoring point. The ratio of the water potential gradient change between two adjacent deep soil layers to their distance reflects the water potential difference per unit distance and the intensity of the water gradient. When the migration significance is negative and the absolute value is larger, the stronger the hydraulic gradient is, and the salt accelerates surface accumulation.

[0070] The average value of the salt anomaly index between the monitoring point and the adjacent shallow monitoring point is further used as the local difference of the monitoring point. Combined with the monitoring salt anomaly degree of the two monitoring points in the adjacent soil layers, its water migration degree is supplemented.

[0071] Finally, the migration significance and local difference of the monitoring point are combined to obtain the water migration index of the monitoring point. In the embodiment of the present invention, the product of the migration significance and local difference of the monitoring point is used as the water migration index of the monitoring point. The positive and negative signs and the magnitude of the water migration index can reflect the dominant situation of the migration direction and the degree of interference. Figure 3 , which shows a schematic diagram of the distribution of a moisture migration index at different depth layers provided by an embodiment of the present invention.

[0072] Moisture upward migration monitoring points are screened based on the moisture migration index. In an embodiment of the present invention, when the moisture migration index of a monitoring point is negative, it reflects that the salt abnormality between the two adjacent depth layers in the farmland is high and the evaporation of moisture upward migration is dominant. The corresponding monitoring point is used as a moisture upward migration monitoring point.

[0073] A larger water migration index indicates that as water migrates upward, salt interference at the surface monitoring points becomes more severe, leading to greater errors in the volumetric water content readings. Therefore, for all water migration monitoring points experiencing upward water migration, the intensity of water migration at the corresponding locations is analyzed. The larger the absolute value of the local water migration index distribution, the more intense the water evaporation at the current location, and the more significant the salt interference caused by salt ions driven by the corresponding water migration on the water content. This allows the depth interference coefficient to be determined for each water migration monitoring point.

[0074] Preferably, in an embodiment of the present invention, the method for obtaining the depth interference coefficient includes:

[0075] For any moisture upward migration monitoring point, the absolute value of the moisture migration index of the monitoring point in the adjacent upper depth layer of the moisture upward migration monitoring point and the absolute value of the moisture migration index of the moisture upward migration monitoring point are averaged to obtain the migration degree of the moisture upward migration monitoring point. The intensity of local moisture upward migration at the moisture upward migration monitoring point is characterized according to the size of the moisture migration index of the moisture upward migration monitoring point and the monitoring point adjacent to it.

[0076] Then, the ratio of the migration degree of the water upward migration monitoring point to the sum of the absolute values ​​of the water migration indicators of all monitoring points is used as the relative migration index of the water upward migration monitoring point, reflecting the relative migration degree of the water upward migration monitoring point in the overall trend of farmland water migration. The larger the relative migration index, the stronger the water migration trend, and the greater the interference to the water content data at that location.

[0077] As an example, the expression for the relative migration index is: Where, Expressed as The relative migration index of each water upward monitoring point, Expressed as The moisture migration index of each moisture upward monitoring point, Expressed as The water migration index of the monitoring point is The water migration index of each water upward monitoring point in the adjacent upper depth layer is: It is expressed as the sum of the absolute values ​​of the water migration index of all monitoring points. Expressed as The migration degree of each moisture upward monitoring point.

[0078] The greater the degree of salt anomaly at a water migration monitoring point, the greater the interference at that location. Therefore, the product of the relative migration index and the current salt anomaly index for that water migration monitoring point is used as the depth interference coefficient for that water migration monitoring point. The greater the water migration, the greater the salt interference, the greater the probability of salt surface accumulation, and the greater the need for correction and adjustment.

[0079] S4: Correct the volumetric water content according to the depth interference coefficient of the water upward movement monitoring point to obtain the corrected volumetric water content; obtain the soil moisture condition based on the corrected volumetric water content at the current moment.

[0080] In the vertical profile, the salt interference intensity varies linearly with depth among all monitoring points where water upward movement occurs. The shallower the monitoring point, the more serious the false increase in dielectric constant due to the salt surface aggregation effect, and the more significant the correction should be. Therefore, the volumetric water content correction is performed based on the depth interference coefficient and the depth.

[0081] In an embodiment of the present invention, for any one of the moisture upward movement monitoring points, a negative correlation mapping is performed on the ratio between the depth interference coefficient of the moisture upward movement monitoring point and the depth of the corresponding depth layer, which is used as the correction coefficient of the moisture upward movement monitoring point. The smaller the depth layer, the shallower the depth and the more serious the salt surface accumulation phenomenon. Therefore, the larger the correction amount should be. The larger the depth interference coefficient, the stronger the salt interference and the larger the correction amount should be.

[0082] When the ratio is larger, the correction amount required is greater and the volumetric water content should be smaller, so the correction coefficient is obtained through negative correlation mapping. It should be noted that negative correlation mapping is a technical means well known to those skilled in the art, such as using negative exponential power or inverse proportional form, etc., which will not be limited or elaborated here.

[0083] The product of the volumetric water content at the water-upward monitoring point and the correction coefficient is ultimately used as the corrected volumetric water content at that water-upward monitoring point. The smaller the correction coefficient, the smaller the volumetric water content after the product correction, and the higher the degree of correction, resulting in varying degrees of restoration of the official water content data at different water-upward monitoring points.

[0084] At this point, the volumetric moisture content data of different depth layers in the soil have been corrected to avoid the inflated moisture content readings of traditional FDR in heavily saline soils. For example, when the soil is already dry, the system still shows sufficient moisture, eliminating the inflated moisture readings caused by salt.

[0085] Furthermore, in an embodiment of the present invention, salt osmotic stress is dynamically coupled with the migration of corrected volumetric water content in the soil, and the physical water content is converted into actual water available for crops, thereby determining the vertical variation pattern of soil moisture. Soil moisture data from monitoring points in each soil layer is imported into a GIS platform, and a spatial interpolation algorithm (such as Kriging interpolation) is used to generate a high-standard heat map of the spatial distribution of soil moisture in farmland. By combining factors such as topography and soil texture, differences in soil moisture in different regions can be identified, providing a visual basis for decision-making on differentiated irrigation, accurately marking true drought and salinized areas, and improving the accuracy and practicality of soil moisture monitoring results.

[0086] In summary, the present invention analyzes the moisture conditions at different depths of high-standard farmland soil, combines the overall distribution relationship between depth and volumetric water content, and more comprehensively characterizes the soil moisture conditions at the moment, and then combines the EC value fluctuations in the time series to more accurately identify salt anomalies. The water migration phenomenon existing in the soil is analyzed. Since the stronger the water evaporation at the current position, the more significant the salt interference caused by the corresponding water migration and salt separation on the moisture conditions will be. Therefore, based on the obtained water migration index, the monitoring points with upward water migration are screened from the monitoring points for correction. Combined with the water migration and salt anomalies of the water upward monitoring points, the degree of interference of salt on the volumetric water content data of different monitoring points is analyzed, the depth interference coefficient is obtained, and the volumetric water content is corrected accordingly to obtain more accurate soil moisture data. The present invention analyzes the dynamic changes of the overall soil moisture, corrects the soil moisture data through the influence of water migration and salt in vertical depth, improves the accuracy and reliability of monitoring, and provides reliable data support for the subsequent scientific management of high-standard farmland.

[0087] The present invention also provides a high-standard farmland soil moisture monitoring system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the above methods when executing the computer program.

[0088] It should be noted that the order in which the embodiments of the present invention are described above is for illustrative purposes only and does not necessarily represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0089] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

Claims

1. A method for monitoring soil moisture in high-standard farmland, characterized in that: The method comprises: At monitoring points in different depth layers of high-standard farmland soil, the volumetric water content, matrix potential, and EC value at each sampling moment were obtained; The current moisture index is obtained based on the volumetric moisture content deviation between adjacent monitoring points at the current moment, as well as the relationship between volumetric moisture content and soil depth. The current salt anomaly index of each monitoring point is determined based on the EC value fluctuation distribution of each monitoring point before the current moment and the moisture index. Based on the matrix potential deviation between each monitoring point and adjacent shallow monitoring points, combined with the salinity anomaly index, the water migration index of each monitoring point was determined. Based on the water migration index, the water migration monitoring points were selected. The local water migration index distribution of each water migration monitoring point was analyzed, and the depth interference coefficient of the water migration monitoring point was obtained in combination with the current salinity anomaly index. The volumetric water content is corrected according to the depth interference coefficient of the water upward monitoring point to obtain the corrected volumetric water content; the soil moisture condition is obtained based on the corrected volumetric water content at the current moment; The method for obtaining the moisture index includes: at the current moment, calculating the difference between each two adjacent depth layer self-inspection monitoring points, and using the mean of all differences as the inter-adjacent deviation at the current moment; establishing a two-dimensional spatial coordinate system, with the depth of the depth layer corresponding to the monitoring point as the horizontal axis and the volumetric water content as the vertical axis, mapping the volumetric water content of all monitoring points at the current moment to the two-dimensional spatial coordinate system to obtain data points; obtaining the slope of all data points after fitting a straight line, and using the value of the slope mapped by a negative exponential power as the distribution trend at the current moment; combining the inter-adjacent deviation and the distribution trend at the current moment to obtain the moisture index at the current moment; The method for obtaining the salt abnormality index includes: for any monitoring point, calculating the EC value and fluctuation at all sampling times within a preset range before the current time of the monitoring point to obtain the salt abnormality fluctuation degree of the monitoring point; multiplying the salt abnormality fluctuation degree of the monitoring point by the moisture index at the current time as the current salt abnormality index of the monitoring point; The method for obtaining abnormal salt fluctuation includes: taking the mean EC value of all sampling moments within a preset range before the current moment of the monitoring point as the salt distribution significance of the monitoring point; taking the standard deviation of the EC value of all sampling moments within the preset range before the current moment of the monitoring point as the salt change significance of the monitoring point; and combining the salt distribution significance and the salt change significance of the monitoring point to obtain the abnormal salt fluctuation of the monitoring point; The method for obtaining the water migration index includes: for any monitoring point with an upper depth layer, taking the monitoring point of the monitoring point in the adjacent upper depth layer as the adjacent shallow monitoring point; calculating the difference in matric potential between the monitoring point and the adjacent shallow monitoring point as the water potential gradient value of the monitoring point; taking the depth difference between the monitoring point and the adjacent shallow monitoring point as the depth difference; taking the ratio of the water potential gradient value of the monitoring point to the depth difference as the migration significance of the monitoring point; taking the average value of the salt anomaly index between the monitoring point and the adjacent shallow monitoring point as the local difference of the monitoring point; and combining the migration significance and the local difference of the monitoring point to obtain the water migration index of the monitoring point; The method for obtaining the water upward migration monitoring point includes: when the water migration index of the monitoring point is negative, using the corresponding monitoring point as the water upward migration monitoring point; The method for obtaining the depth interference coefficient includes: for any water upward migration monitoring point, averaging the absolute value of the water migration index of the monitoring point at the adjacent upper depth layer of the water upward migration monitoring point and the absolute value of the water migration index of the water upward migration monitoring point to obtain the migration degree of the water upward migration monitoring point; using the ratio of the migration degree of the water upward migration monitoring point to the sum of the absolute values ​​of the water migration indexes of all monitoring points as the relative migration index of the water upward migration monitoring point; and multiplying the relative migration index of the water upward migration monitoring point and the current salinity anomaly index as the depth interference coefficient of the water upward migration monitoring point; The method for obtaining the corrected volumetric moisture content includes: for any one of the moisture upward movement monitoring points, performing negative correlation mapping on the ratio between the depth interference coefficient of the moisture upward movement monitoring point and the depth of the corresponding depth layer, as the correction coefficient of the moisture upward movement monitoring point; and multiplying the volumetric moisture content of the moisture upward movement monitoring point by the correction coefficient as the corrected volumetric moisture content of the moisture upward movement monitoring point.

2. The method for monitoring soil moisture in high-standard farmland according to claim 1, wherein: The preset range before the current moment is a time range within 10 minutes before the current moment.

3. A high-standard farmland soil moisture monitoring system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of a high-standard farmland soil moisture monitoring method as described in any one of claims 1 to 2 are implemented.

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