A method for evaluating crop land productivity and yield capacity in coordination based on mechanical compaction effect

Abstract

The present application relates to the field of agricultural data processing, and more particularly to a crop land productivity synergistic evaluation method based on mechanical compaction effect, which comprises: acquiring and processing the multi-depth layer soil physical index and chemical nutrient index of the target farmland to obtain the land productivity synergistic evaluation basic data; performing vertical space mutation gradient and local extreme amplification analysis on the soil bulk density sequence to obtain the profile compaction mutation barrier factor; combining the chemical land basic score and cumulative compaction resistance of each depth layer to obtain the deep layer land effectiveness reduction factor; then correcting the total score of the full profile chemical land base to obtain the crop comprehensive land productivity index, and outputting the crop productivity evaluation result and farmland improvement strategy, so as to avoid the overestimation of the land productivity evaluation result caused by the unidentified mechanical compaction barrier layer, and improve the accuracy of evaluation and improvement decision.

Description

Technical Field

[0001] This invention relates to the field of agricultural data processing technology, and in particular to a method for synergistic evaluation of crop soil fertility and productivity based on the mechanical compaction effect. Background Technology

[0002] In agricultural production management and soil fertility evaluation, crop productivity assessment typically requires comprehensive consideration of soil physical structure and chemical nutrient status. Existing assessment methods often involve collecting soil bulk density, organic matter, total nitrogen, available phosphorus, and available potassium from different depths of the target farmland, averaging the soil physical indicators across the entire profile, and normalizing, weighting, or summing the chemical nutrient indicators at different depths to obtain a comprehensive assessment result that characterizes the basic soil fertility level and crop productivity potential of the farmland.

[0003] However, agricultural machinery, during long-term field operations, easily causes uneven compaction of the soil, forming locally dense soil layers with high bulk density and low porosity at specific depths below the surface. Existing methods compress the bulk density of soil layers at multiple depths into a single average bulk density across the entire profile. This can easily lead to the neutralization of locally high bulk density data by the lower bulk density data of adjacent loose soil layers, making it difficult to effectively reflect the location and intensity of abrupt changes in soil bulk density along the vertical profile. Consequently, it is impossible to accurately identify the mechanically compacted barrier layers that hinder crop root penetration.

[0004] In cases where the mechanically compacted barrier layer cannot be identified, existing methods typically still include chemical nutrients at all depths below the barrier layer in the overall soil fertility score as if they were fully available. This fails to adequately consider the impact of restricted root penetration on the accessibility and actual utilization efficiency of deep nutrients, easily leading to inflated soil fertility productivity assessments and reducing the accuracy of subsequent farmland improvement and mechanized operation decisions. Therefore, how to accurately assess the effectiveness of deep chemical soil fertility under mechanical compaction barriers by combining the vertical spatial abrupt changes in soil bulk density has become an urgent problem to be solved in the field of collaborative assessment of crop soil fertility productivity. Summary of the Invention

[0005] In view of this, the present invention aims to propose a method for synergistic evaluation of crop soil fertility productivity based on the mechanical compaction effect, so as to solve the problem that the existing methods cannot identify the mechanical compaction barrier layer, resulting in inflated soil fertility productivity evaluation results.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] A method for synergistic assessment of crop soil fertility productivity based on mechanical compaction effect, the method comprising:

[0008] Step S1: Collect and process physical and chemical nutrient indicators of soil at multiple depths in the target farmland to obtain basic data for the synergistic assessment of soil fertility and productivity;

[0009] Step S2: Obtain the profile compaction mutation barrier factor by performing vertical spatial abrupt change gradient and local extreme value amplification analysis on the soil bulk density sequence;

[0010] Step S3: Obtain the deep soil fertility effectiveness reduction factor by performing negative exponential reduction on the chemical soil fertility basic score and cumulative compaction resistance of each depth layer;

[0011] Step S4: Obtain the comprehensive crop soil fertility productivity index by multiplying and correcting the total score of the full profile chemical soil fertility basis with the deep soil fertility effectiveness reduction factor;

[0012] Step S5: By jointly analyzing the comprehensive soil fertility productivity index of crops and the mechanical compaction characteristics of soil profiles, crop productivity assessment results and farmland improvement strategies are obtained.

[0013] Furthermore, the process involves collecting and processing physical and chemical nutrient indicators from multiple soil layers at various depths in the target farmland to obtain basic data for the synergistic assessment of soil fertility and productivity, including:

[0014] Soil profile sampling points were set up in the target farmland. The soil profile of the target farmland was continuously divided into a predetermined number of soil depth layers of equal thickness from the surface downwards, and the center depth coordinates of each soil depth layer were obtained. Soil samples were collected from each soil depth layer using a stratified soil sampling device, and the soil bulk density corresponding to each soil depth layer was obtained by measuring the soil bulk density. The soil bulk densities corresponding to all soil depth layers were arranged in ascending order of center depth coordinates to obtain a soil bulk density sequence.

[0015] Soil samples collected from each soil depth layer were subjected to physicochemical tests to obtain the soil organic matter content, total nitrogen content, available phosphorus content, and available potassium content corresponding to each soil depth layer. The maximum values ​​of soil organic matter content, total nitrogen content, available phosphorus content, and available potassium content for all soil depth layers were statistically analyzed to obtain the maximum values ​​of organic matter content, total nitrogen content, available phosphorus content, and available potassium content for the entire soil profile.

[0016] For any target soil depth layer, the soil organic matter content of the target soil depth layer is used as the numerator, the maximum organic matter content of the entire profile is used as the denominator, and the corresponding fraction is used as the normalized organic matter assessment; the total nitrogen content of the target soil depth layer is used as the numerator, the maximum total nitrogen content of the entire profile is used as the denominator, and the corresponding fraction is used as the normalized total nitrogen assessment; the available phosphorus content of the target soil depth layer is used as the numerator, the maximum available phosphorus content of the entire profile is used as the denominator, and the corresponding fraction is used as the normalized available phosphorus assessment; the available potassium content of the target soil depth layer is used as the numerator, the maximum available potassium content of the entire profile is used as the denominator, and the corresponding fraction is used as the normalized available potassium assessment; the sum of the normalized organic matter assessment, normalized total nitrogen assessment, normalized available phosphorus assessment, and normalized available potassium assessment is used as the chemical fertility basis score of the target soil depth layer.

[0017] The sum of the chemical fertility baseline scores of all soil depth layers is used as the total chemical fertility baseline score of the entire profile. The total number of soil depth layers, the center depth coordinates of each soil depth layer, the soil bulk density sequence, the soil organic matter content, total nitrogen content, available phosphorus content and available potassium content of each soil depth layer, the chemical fertility baseline score of each soil depth layer and the total chemical fertility baseline score of the entire profile are used as the basic data for the collaborative assessment of soil fertility productivity.

[0018] Furthermore, the step of obtaining the profile compaction mutation barrier factor by performing vertical spatial abrupt change gradient and local extremum amplification analysis on the soil bulk density sequence includes:

[0019] By performing differential analysis of adjacent depth layers and positive gradient screening on the soil bulk density sequence in the basic data of the synergistic assessment of soil fertility productivity, the vertical spatial abrupt gradient data of soil bulk density were obtained.

[0020] By performing local extremum amplification and nonlinear aggregation processing on the deviation relationship between the vertical spatial abrupt change gradient data of soil bulk density and the local bulk density of each depth layer relative to the average bulk density of the whole profile, the profile compaction abrupt change barrier factor is obtained.

[0021] Furthermore, the step of obtaining vertical spatial abrupt gradient data of soil bulk density by performing adjacent depth layer difference analysis and positive gradient screening on the soil bulk density sequence in the basic data of soil fertility productivity collaborative assessment includes:

[0022] Extract the total number of soil depth layers, the center depth coordinates of each soil depth layer, and the soil bulk density sequence from the basic data of the soil fertility productivity assessment. Then, according to the order of the center depth coordinates of each soil depth layer from small to large, combine any soil depth layer with the next adjacent soil depth layer to form a target adjacent depth layer combination.

[0023] For any combination of adjacent depth layers, the difference between the soil bulk density of the next soil depth layer and the soil bulk density of the previous soil depth layer in the combination of adjacent depth layers is used as the bulk density difference assessment between adjacent layers, and the difference between the center depth coordinates of the next soil depth layer and the center depth coordinates of the previous soil depth layer is used as the depth interval between adjacent layers.

[0024] The difference in bulk density between adjacent layers is used as the numerator, the depth interval between adjacent layers is used as the denominator, and the resulting fraction is used as the initial vertical spatial gradient of bulk density of the target adjacent depth layer combination.

[0025] When the initial vertical spatial variation gradient of bulk density is greater than a constant 0, the initial vertical spatial variation gradient of bulk density is taken as the positive vertical spatial abrupt change gradient of bulk density of the target adjacent depth layer combination; when the initial vertical spatial variation gradient of bulk density is less than or equal to a constant 0, the positive vertical spatial abrupt change gradient of bulk density of the target adjacent depth layer combination is set to a constant 0.

[0026] The vertical spatial gradient of soil bulk density corresponding to all adjacent depth layers of the target is arranged in ascending order according to the corresponding center depth coordinates to obtain the vertical spatial gradient data of soil bulk density.

[0027] Furthermore, the method involves performing local extremum amplification and nonlinear aggregation processing on the deviation relationship between the vertical spatial abrupt change gradient data of soil bulk density and the local bulk density of each depth layer relative to the average bulk density of the entire profile, to obtain the profile compaction abrupt change barrier factor, including:

[0028] The total number of soil depth layers and soil bulk density sequence are extracted from the basic data of soil fertility productivity assessment. The total bulk density of the whole profile is calculated by adding the soil bulk densities corresponding to all soil depth layers in the soil bulk density sequence. The total bulk density of the whole profile is used as the numerator, the total number of soil depth layers is used as the denominator, and the corresponding fraction is used as the average bulk density of the whole profile.

[0029] For any target adjacent depth layer combination, extract the positive bulk density vertical spatial abrupt gradient corresponding to the target adjacent depth layer combination from the soil bulk density vertical spatial abrupt gradient data, and extract the soil bulk density of the next soil depth layer in the target adjacent depth layer combination from the soil bulk density sequence.

[0030] The soil bulk density of the next soil depth layer in the target adjacent depth layer combination is used as the numerator, the average bulk density of the whole profile is used as the denominator, and the corresponding fraction is used as the local bulk density extreme value amplification weight of the target adjacent depth layer combination.

[0031] The result of multiplying the positive bulk vertical spatial abrupt change gradient corresponding to the target adjacent depth layer combination with the local bulk extreme value amplification weight is used as the local compaction amplification evaluation of the target adjacent depth layer combination, and the square of the local compaction amplification evaluation is used as the local compaction intensity evaluation of the target adjacent depth layer combination.

[0032] The calculation result of summing the local compact mutation intensity assessments corresponding to all adjacent depth layer combinations of the target is used as the full profile compact mutation aggregation assessment. The calculation result of summing the full profile compact mutation aggregation assessment with constant 1 is mapped by the natural logarithm, and the corresponding mapping result is used as the profile compact mutation blocking factor.

[0033] Furthermore, the method of obtaining a deep soil fertility effectiveness reduction factor by negatively reducing the basic chemical fertility score and cumulative compaction resistance of each depth layer includes:

[0034] By positively screening and layer-by-layer accumulation of the deviation relationship between the soil bulk density of each depth layer and the average bulk density of the whole profile, the cumulative compaction resistance corresponding to each depth layer is obtained.

[0035] By performing negative exponential decay mapping on the basic chemical geotechnical scores of each depth layer, the cumulative compaction resistance of each depth layer and the profile compaction abrupt barrier factor, the effective chemical geotechnical scores of each depth layer are obtained.

[0036] By normalizing the ratio between the effective chemical fertility score and the basic chemical fertility score of each depth layer, the deep fertility effectiveness reduction factor is obtained.

[0037] Furthermore, the method of obtaining the cumulative compaction resistance corresponding to each depth layer by positively screening and layer-by-layer accumulation of the deviation relationship between the soil bulk density at each depth layer and the average bulk density of the entire profile includes:

[0038] The total number of soil depth layers, the center depth coordinates of each soil depth layer, and the soil bulk density sequence are extracted from the basic data of the soil fertility productivity assessment. The total bulk density of the whole profile is calculated by adding up the soil bulk density corresponding to all soil depth layers in the soil bulk density sequence. The total bulk density of the whole profile is used as the numerator, the total number of soil depth layers is used as the denominator, and the corresponding fraction is used as the average bulk density of the whole profile.

[0039] For any target soil depth layer, determine the target cumulative depth layer set from the first soil depth layer on the surface to the target soil depth layer in ascending order of the center depth coordinates corresponding to each soil depth layer.

[0040] For any target cumulative soil depth layer in the target cumulative depth layer set, the difference between the soil bulk density of the target cumulative soil depth layer and the average bulk density of the entire profile is used as the initial bulk density deviation assessment; when the initial bulk density deviation assessment is greater than a constant 0, the initial bulk density deviation assessment is used as the positive bulk density excess assessment of the target cumulative soil depth layer; when the initial bulk density deviation assessment is less than or equal to a constant 0, the positive bulk density excess assessment of the target cumulative soil depth layer is set to a constant 0.

[0041] The calculation result of summing the positive bulk density excess assessments corresponding to all target cumulative soil depth layers in the target cumulative depth layer set is used as the cumulative compaction resistance corresponding to the target soil depth layer. Then, the cumulative compaction resistance corresponding to each depth layer is obtained by performing layer-by-layer accumulation processing on all soil depth layers.

[0042] Furthermore, the effective chemical chemistry score for each depth layer is obtained by performing negative exponential decay mapping on the basic chemical chemistry score of each depth layer, the cumulative compaction resistance corresponding to each depth layer, and the profile compaction abrupt change barrier factor, including:

[0043] The total number of soil depth layers, soil bulk density sequence, and basic chemical fertility score of each depth layer are extracted from the basic data of the soil fertility productivity collaborative assessment. The total bulk density of the whole profile is calculated by adding up the soil bulk density corresponding to all soil depth layers in the soil bulk density sequence. The total bulk density of the whole profile is used as the numerator, the total number of soil depth layers is used as the denominator, and the corresponding fraction is used as the average bulk density of the whole profile.

[0044] For any target soil depth layer, obtain the cumulative compaction resistance, chemical geotechnical base score, and profile compaction abrupt change barrier factor corresponding to the target soil depth layer; use the cumulative compaction resistance corresponding to the target soil depth layer as the numerator, the average bulk density of the whole profile as the denominator, and the corresponding fraction as the normalized cumulative compaction resistance corresponding to the target soil depth layer.

[0045] The result of multiplying the normalized cumulative compaction resistance corresponding to the target soil depth layer with the profile compaction abrupt change barrier factor is used as the soil fertility attenuation intensity assessment corresponding to the target soil depth layer. The negative number of the soil fertility attenuation intensity assessment is subjected to exponential mapping with the natural constant as the base, and the corresponding mapping result is used as the soil fertility effectiveness attenuation weight corresponding to the target soil depth layer.

[0046] The effective chemical fertility score corresponding to the target soil depth layer is calculated by multiplying the soil fertility effectiveness attenuation weight corresponding to the basic chemical fertility score. Negative exponential attenuation mapping is then applied to all soil depth layers to obtain the effective chemical fertility score for each depth layer.

[0047] Furthermore, the process of obtaining the deep soil fertility effectiveness reduction factor by normalizing the ratio of the effective chemical fertility score to the basic chemical fertility score of each depth layer includes:

[0048] The effective chemical chemistry score corresponding to each depth layer is obtained, and the sum of the effective chemical chemistry scores corresponding to all soil depth layers is used as the total effective chemical chemistry score of the entire profile.

[0049] The chemical geofertility baseline score for each depth layer is extracted from the basic data of the soil fertility productivity synergistic assessment, and the sum of the chemical geofertility baseline scores corresponding to all soil depth layers is used as the total chemical geofertility baseline score for the entire profile.

[0050] The total effective chemical geofertility score of the entire profile is used as the numerator, the basic total score of chemical geofertility of the entire profile is used as the denominator, and the corresponding fraction is used as the reduction factor for the effectiveness of deep geofertility.

[0051] Furthermore, the process of obtaining the comprehensive crop soil fertility productivity index by multiplying the total score of the full profile chemical soil fertility baseline with the deep soil fertility effectiveness reduction factor includes:

[0052] Extract the total score of the full profile chemical geofertility from the basic data of the geofertility productivity synergistic assessment, and obtain the deep geofertility effectiveness reduction factor;

[0053] The result of multiplying the total score of the full profile chemical soil fertility foundation by the deep soil fertility effectiveness reduction factor is used as the comprehensive crop soil fertility productivity index of the target farmland.

[0054] Compared with the prior art, the present invention has the following advantages:

[0055] This invention presents a method for synergistic assessment of crop soil fertility and productivity based on mechanical compaction effects. By extracting the positive abrupt gradient of soil bulk density along a vertical profile and nonlinearly amplifying the deviation of locally high bulk density from the overall profile average, it effectively identifies highly dense barrier layers formed at specific depths by long-term mechanical compaction, avoiding the smoothing and masking of local compaction characteristics by traditional average bulk density processing. In actual farmland scenarios, it can accurately distinguish between two soil structure states: uniform compaction across the entire profile and localized plow pan barrier layers, improving the targeting and reliability of mechanical compaction feature identification. Furthermore, this invention differentiates the chemical fertility baseline score for each depth layer based on the cumulative compaction resistance that crop roots need to overcome to reach different depths, transforming the overall profile chemical nutrient reserves into effective productivity that conforms to the current soil physical structure conditions. This can reduce the overestimation caused by indiscriminately accumulating deep nutrients below the barrier layer that are difficult for roots to utilize, and form a more targeted basis for deep tillage improvement based on the location of the barrier layer and the degree of yield reduction, thereby improving the accuracy of farmland fertility evaluation, crop yield analysis and agricultural machinery operation decisions. Attached Figure Description

[0056] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0057] Figure 1 This is a flowchart of a method for synergistic evaluation of crop soil fertility and productivity based on mechanical compaction effect, as described in an embodiment of the present invention. Detailed Implementation

[0058] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0059] See Figure 1 This is a flowchart of a method for synergistic evaluation of crop soil fertility and productivity based on mechanical compaction effect, provided in Embodiment 1 of the present invention. Figure 1 As shown, a method for synergistic assessment of crop soil fertility productivity based on mechanical compaction effects may include:

[0060] Step S1 involves collecting and processing physical and chemical nutrient indicators from multiple soil layers at the target farmland to obtain basic data for the collaborative assessment of soil fertility and productivity.

[0061] First, soil profile sampling points are set up in the target farmland. The soil profile of the target farmland is continuously divided into a predetermined number of soil depth layers of equal thickness from the surface downwards, and the center depth coordinates of each soil depth layer are obtained. In this embodiment of the invention, the number of soil depth layers is set to 6, and the thickness of each soil layer is 10 cm, that is, soil bulk density data within the depth range of 0 to 60 cm are obtained. The compaction depth of conventional agricultural machinery is usually concentrated in the range of 15 to 30 cm. The sampling range of 0 to 60 cm can completely cover the compaction area and the subsoil transition area below, thereby ensuring the integrity of feature extraction. Soil samples are collected from each soil depth layer using a stratified soil sampling device, and the soil bulk density corresponding to each soil depth layer is obtained by soil bulk density measurement. The soil bulk density corresponding to all soil depth layers is arranged in ascending order of center depth coordinates to obtain a soil bulk density sequence. Soil physicochemical tests are performed on the soil samples collected from each soil depth layer to obtain the soil organic matter content, total nitrogen content, available phosphorus content, and available potassium content corresponding to each soil depth layer. Maximum values ​​of soil organic matter content, total nitrogen content, available phosphorus content, and available potassium content were statistically analyzed for all soil depth layers to obtain the maximum values ​​of organic matter content, total nitrogen content, available phosphorus content, and available potassium content for the entire soil profile.

[0062] For any target soil depth layer, the soil organic matter content of the target soil depth layer is used as the numerator, and the maximum organic matter content of the entire profile is used as the denominator. The resulting formula is used as the normalized assessment of organic matter. Similarly, the total nitrogen content of the target soil depth layer is used as the numerator, and the maximum total nitrogen content of the entire profile is used as the denominator. The resulting formula is used as the normalized assessment of total nitrogen. The available phosphorus content of the target soil depth layer is used as the numerator, and the maximum available phosphorus content of the entire profile is used as the denominator. The resulting formula is used as the normalized assessment of available phosphorus. Finally, the sum of the normalized assessments of organic matter, total nitrogen, available phosphorus, and available potassium is used as the chemical fertility baseline score for the target soil depth layer.

[0063] The sum of the chemical fertility baseline scores of all soil depth layers is used as the total chemical fertility baseline score of the entire profile. The total number of soil depth layers, the center depth coordinates of each soil depth layer, the soil bulk density sequence, the soil organic matter content, total nitrogen content, available phosphorus content and available potassium content of each soil depth layer, the chemical fertility baseline score of each soil depth layer and the total chemical fertility baseline score of the entire profile are used as the basic data for the collaborative assessment of soil fertility productivity.

[0064] Thus, the basic data for the synergistic assessment of soil fertility and productivity has been obtained by collecting and processing physical and chemical nutrient indicators from multiple soil layers at the target farmland.

[0065] Step S2: By performing vertical spatial abrupt change gradient and local extreme value amplification analysis on the soil bulk density sequence, the profile compaction abrupt change barrier factor is obtained.

[0066] The compaction of agricultural machinery does not uniformly alter the physical structure of the soil from the topsoil to the subsoil. Instead, mechanical compaction typically creates a locally denser layer at a specific depth below the surface, known as the plow pan. When crop roots grow downwards, their extension into this denser layer is hindered. Existing soil productivity assessment algorithms extract soil characteristics by calculating the arithmetic mean bulk density across the entire soil profile. When such a locally denser layer exists in the soil profile, its higher bulk density value cancels out the lower bulk density values ​​of the loose topsoil above and the normal subsoil below in the arithmetic mean calculation. This approach smooths out the spatial abrupt changes in soil bulk density at the data level, making it impossible for the algorithm to distinguish between uniformly compacted farmland and locally obstructed compacted farmland. To address the problem of existing algorithms masking locally obstructed layers due to their reliance on average calculations, this step constructs an analytical mechanism to extract the vertical spatial variation gradient of soil bulk density by obtaining the soil bulk density sequence of multiple consecutive depths below the soil profile. By calculating the difference in soil bulk density between adjacent depth layers and focusing on identifying the spatial range where bulk density increases abruptly with depth, and amplifying the extreme values ​​of the abrupt increase by combining the average bulk density of the entire profile, the local high-density barrier characteristics caused by mechanical compaction are identified, providing data basis for subsequent correction of the effectiveness of deep soil fertility.

[0067] In summary, this invention first analyzes the differences between adjacent depth layers and performs positive gradient screening on the soil bulk density sequence in the basic data of geofertility productivity collaborative assessment to obtain the vertical spatial abrupt change gradient data of soil bulk density. Specifically, it extracts the total number of soil depth layers, the center depth coordinates of each soil depth layer, and the soil bulk density sequence from the basic data of geofertility productivity collaborative assessment. Then, according to the order of the center depth coordinates of each soil depth layer from smallest to largest, any soil depth layer is combined with its next adjacent soil depth layer to form a target adjacent depth layer combination. For any target adjacent depth layer combination, the difference between the soil bulk density of the next soil depth layer and the soil bulk density of the previous soil depth layer in the target adjacent depth layer combination is used as the adjacent layer bulk density difference assessment, and the difference between the center depth coordinates of the next soil depth layer and the center depth coordinates of the previous soil depth layer is used as the adjacent layer depth interval. Using the adjacent layer bulk density difference assessment as the numerator and the adjacent layer depth interval as the denominator, the resulting fraction is used as the initial vertical spatial change gradient of bulk density for the target adjacent depth layer combination. When the initial vertical spatial variation gradient of bulk density is greater than a constant 0, it is used as the positive vertical spatial abrupt change gradient of bulk density for the target adjacent depth layer combination; when the initial vertical spatial variation gradient of bulk density is less than or equal to a constant 0, the positive vertical spatial abrupt change gradient of bulk density for the target adjacent depth layer combination is set to a constant 0. The positive vertical spatial abrupt change gradients of bulk density corresponding to all target adjacent depth layer combinations are arranged in ascending order of their corresponding center depth coordinates to obtain soil bulk density vertical spatial abrupt change gradient data.

[0068] After obtaining the vertical spatial abrupt change gradient data of soil bulk density, the deviation relationship between the vertical spatial abrupt change gradient data of soil bulk density and the local bulk density of each depth layer relative to the average bulk density of the entire profile is further processed by local extremum amplification and nonlinear aggregation to obtain the profile compaction abrupt change barrier factor. Specifically, the total number of soil depth layers and the soil bulk density sequence are extracted from the basic data of soil fertility productivity collaborative assessment. The sum of the soil bulk densities corresponding to all soil depth layers in the soil bulk density sequence is used as the total bulk density of the entire profile. The total bulk density of the entire profile is used as the numerator, the total number of soil depth layers is used as the denominator, and the corresponding fraction is used as the average bulk density of the entire profile. For any target adjacent depth layer combination, the positive vertical spatial abrupt change gradient of bulk density corresponding to the target adjacent depth layer combination is extracted from the vertical spatial abrupt change gradient data of soil bulk density, and the soil bulk density of the next soil depth layer in the target adjacent depth layer combination is extracted from the soil bulk density sequence. The soil bulk density of the next soil depth layer in the target adjacent depth layer combination is used as the numerator, the average bulk density of the entire profile is used as the denominator, and the corresponding fraction is used as the local bulk density extremum amplification weight of the target adjacent depth layer combination. The calculation result of multiplying the positive bulk vertical spatial abrupt change gradient corresponding to the target adjacent depth layer combination with the local bulk extremum amplification weight is used as the local compaction amplification evaluation of the target adjacent depth layer combination, and the square of the local compaction amplification evaluation is used as the local compaction intensity evaluation of the target adjacent depth layer combination. The calculation result of summing the local compaction intensity evaluations corresponding to all target adjacent depth layer combinations is used as the full-profile compaction aggregation evaluation. The calculation result of adding the full-profile compaction aggregation evaluation to the constant 1 is mapped using the natural logarithm, and the corresponding mapping result is used as the profile compaction blocking factor.

[0069] In one embodiment, it is assumed that the total number of soil depth layers is ;No. The soil bulk density of each soil depth layer is ;No. The soil bulk density of each soil depth layer is ;No. The center depth of each soil layer is ;No. The center depth of each soil layer is The average bulk density of the entire profile across all soil depth layers is: The formula for calculating the profile compaction mutation barrier factor of the target farmland is:

[0070]

[0071] in, Indicates the profile compaction mutation barrier factor of the target farmland; This represents the logarithmic function with the natural constant e as the base. Indicates the total number of soil depth layers; Represents the maximum value function; Indicates the first Soil bulk density at each soil depth layer; Indicates the first Soil bulk density at each soil depth layer; Indicates the first The center depth of each soil depth layer; Indicates the first The center depth of each soil depth layer; It represents the average bulk density of the entire profile across all soil depth layers.

[0072] It should be noted that the profile compaction abrupt change barrier factor formula constructed in this step aims to accurately quantify the characteristics of locally highly dense soil layers produced by mechanical compaction. In actual farmland environments, the degree to which dense soil layers hinder root growth depends not only on their absolute hardness but also on the severity of the abrupt change in hardness with depth. To extract this abrupt change characteristic in the calculation, the formula first calculates the difference in unit weight between the adjacent lower and upper soil layers divided by the corresponding depth difference, i.e. The calculation results in this section characterize the first-order spatial gradient of soil bulk density in the vertical direction. Subsequently, the formula uses a maximum value function to perform unidirectional numerical filtering on this vertical gradient. When soil bulk density increases significantly with depth, the vertical gradient is positive, and the maximum value function retains it accurately; when the soil becomes looser from top to bottom, the gradient is negative, and the maximum value function forces it to zero. This design strictly eliminates the interference of the non-densification transition layer on feature extraction, enabling the algorithm to accurately pinpoint the spatial range where roots encounter a sudden increase in resistance as they grow downwards. Based on the extraction of the positive abrupt change in bulk density gradient, the formula introduces local extremum amplification weights. This weight term represents the ratio of the absolute unit weight of the soil layer below the abrupt change to the average unit weight of the entire profile. The logic behind multiplying it by the abrupt change gradient is that for a soil layer to constitute a substantial barrier, its unit weight must not only increase significantly relative to the soil layers above it, but its absolute unit weight must also be significantly higher than the average profile level. By introducing this weight, the formula effectively amplifies the barrier characteristics of the actual plow pan. Finally, the formula squares the product to further suppress background noise caused by minor measurement fluctuations in a non-linear manner and amplify the signal value of extremely dense layers. After summing the calculation results for all depth intervals, the result is then processed using the natural logarithm function. Data smoothing and compression are performed to prevent output values ​​from overflowing. The resulting profile compaction abrupt change barrier factor has the ability to independently identify the local mechanical compaction intensity of farmland, effectively overcoming the technical defect of existing algorithms that rely on a single average bulk density, which leads to the masking of local barrier features.

[0073] Thus, the analysis of vertical spatial abrupt change gradient and local extreme value amplification of soil bulk density sequence was completed to obtain the profile compaction abrupt change barrier factor.

[0074] Step S3: Obtain the deep soil fertility effectiveness reduction factor by performing negative exponential reduction on the chemical soil fertility base score and cumulative compaction resistance of each depth layer.

[0075] After determining the existence and strength of the mechanically compacted barrier layer in the soil profile through the profile compaction mutation barrier factor in step S2, it is necessary to further evaluate the actual impact of this barrier layer on the comprehensive chemical fertility of farmland. In real agricultural production, the fertility productivity of farmland depends not only on the total chemical nutrient reserves of the entire profile, but also on the spatial accessibility of these nutrients to crop roots. Existing algorithms statically sum the chemical nutrient indices of each depth layer when calculating the comprehensive fertility index, without establishing a correlation mechanism between the soil barrier layer and the availability of chemical nutrients. When there is a locally high-density soil layer formed by mechanical compaction in the soil profile, the deep nutrient resources located below this soil layer are difficult for crops to fully absorb and utilize due to the limited root penetration. If the algorithm continues to blindly accumulate nutrients across the entire profile, it will overestimate the actual productivity of farmland affected by compaction. In order to accurately assess the fertility productivity under complex environments, this step, based on the basic chemical fertility scores of each depth layer, combines the excess soil bulk density value accumulated above the layer to construct a deep fertility availability reduction factor. By quantifying the cumulative resistance that crop roots need to overcome to reach a specific depth, the score of deep chemical fertility that is blocked is reduced to correct the calculation bias in the existing algorithm during the chemical fertility weighting process.

[0076] In summary, this invention first obtains the cumulative compaction resistance corresponding to each depth layer by positively screening and layer-by-layer accumulation of the deviation relationship between the soil bulk density of each depth layer and the average bulk density of the entire profile. Specifically, it extracts the total number of soil depth layers, the center depth coordinates of each soil depth layer, and the soil bulk density sequence from the basic data of the soil fertility productivity collaborative assessment. The calculation result of adding up the soil bulk densities corresponding to all soil depth layers in the soil bulk density sequence is taken as the total bulk density of the entire profile. The total bulk density of the entire profile is taken as the numerator, the total number of soil depth layers is taken as the denominator, and the corresponding fraction is taken as the average bulk density of the entire profile. For any target soil depth layer, the target cumulative depth layer set from the first soil depth layer on the surface to the target soil depth layer is determined according to the order of the center depth coordinates of each soil depth layer from small to large. For any target cumulative soil depth layer in the target cumulative depth layer set, the difference between the soil bulk density of the target cumulative soil depth layer and the average bulk density of the entire profile is used as the initial bulk density deviation assessment. When the initial bulk density deviation assessment is greater than a constant 0, it is used as the positive bulk density excess assessment of the target cumulative soil depth layer. When the initial bulk density deviation assessment is less than or equal to a constant 0, the positive bulk density excess assessment of the target cumulative soil depth layer is set to a constant 0. The sum of the positive bulk density excess assessments corresponding to all target cumulative soil depth layers in the target cumulative depth layer set is used as the cumulative compaction resistance corresponding to the target soil depth layer. Layer-by-layer accumulation processing is then performed on all soil depth layers to obtain the cumulative compaction resistance corresponding to each depth layer.

[0077] After obtaining the cumulative compaction resistance corresponding to each depth layer, the effective chemical fertility score for each depth layer is obtained by performing negative exponential decay mapping on the chemical fertility baseline score, the cumulative compaction resistance corresponding to each depth layer, and the profile compaction abrupt change barrier factor. Specifically, the total number of soil depth layers, soil bulk density sequence, and chemical fertility baseline score for each depth layer are extracted from the soil fertility productivity collaborative assessment baseline data. The calculated result of adding up the soil bulk density corresponding to all soil depth layers in the soil bulk density sequence is taken as the total bulk density of the entire profile. The total bulk density of the entire profile is taken as the numerator, the total number of soil depth layers is taken as the denominator, and the corresponding fraction is taken as the average bulk density of the entire profile. For any target soil depth layer, the cumulative compaction resistance, chemical fertility baseline score, and profile compaction abrupt change barrier factor corresponding to the target soil depth layer are obtained. The cumulative compaction resistance corresponding to the target soil depth layer is taken as the numerator, the average bulk density of the entire profile is taken as the denominator, and the corresponding fraction is taken as the normalized cumulative compaction resistance corresponding to the target soil depth layer. The result of multiplying the normalized cumulative compaction resistance corresponding to the target soil depth layer by the profile compaction abrupt change barrier factor is used as the soil fertility attenuation intensity assessment for the target soil depth layer. The negative of the soil fertility attenuation intensity assessment is then subjected to an exponential mapping with the natural constant as the base, and the resulting mapping is used as the soil fertility effectiveness attenuation weight for the target soil depth layer. The result of multiplying the soil fertility effectiveness attenuation weight for the target soil depth layer by the chemical fertility baseline score is used as the effective chemical fertility score for the target soil depth layer. Negative exponential attenuation mapping is then applied to all soil depth layers to obtain the effective chemical fertility score for each depth layer.

[0078] After obtaining the effective chemical fertility scores for each depth layer, the effective chemical fertility scores for each depth layer are normalized to their corresponding basic chemical fertility scores to obtain the deep fertility effectiveness reduction factor. Specifically, the effective chemical fertility scores for each depth layer are obtained, and the sum of these scores for all soil depth layers is used as the total effective chemical fertility score for the entire profile. The basic chemical fertility scores for each depth layer are extracted from the soil fertility productivity collaborative assessment data, and the sum of these scores for all soil depth layers is used as the total basic chemical fertility score for the entire profile. The total effective chemical fertility score for the entire profile is used as the numerator, and the total basic chemical fertility score for the entire profile is used as the denominator. The resulting fraction is used as the deep fertility effectiveness reduction factor.

[0079] In one implementation, assume the first The chemical and geological foundation score for each depth layer is: The formula for calculating the deep soil fertility effectiveness reduction factor of the target farmland is:

[0080]

[0081] in, This represents the reduction factor for the deep soil fertility effectiveness of the target farmland. Indicates the first Chemical and geochemical basis score of each depth layer; Indicates the total number of soil depth layers; Indicates the first Soil bulk density at each soil depth layer; This represents the average bulk density of the entire profile across all soil depths. Represents an exponential function with the natural constant as the base; This indicates the profile compaction mutation barrier factor of the target farmland.

[0082] It should be noted that the deep soil fertility effectiveness reduction factor formula constructed in this step aims to establish a numerical correction for the effect of soil compaction on the chemical fertility effectiveness of vertical profiles. In reality, whether nutrients in a certain soil layer can be utilized depends on the magnitude of the cumulative resistance exerted on crop roots by all the soil layers above it. To quantify this cumulative resistance in the calculation, the formula introduces an integral term. This calculation measures the distance from the Earth's surface to the [missing information]. Before a certain depth layer, the unit weight of all soil layers above it exceeds the average unit weight. The cumulative excess value. Using a maximum value function, the formula only accumulates the portion of the soil layer above the average unit weight that exceeds the standard, eliminating the interference of loose topsoil in the calculation. This accumulated value represents the extent to which the crop roots extend. The cumulative compaction resistance that needs to be overcome during layering. After obtaining the cumulative compaction resistance, the formula divides it by the average unit weight. Normalization is performed, and then multiplied by the profile compaction mutation blocking factor extracted in step S2 to form the decay coefficient of the negative exponential function, which is then applied to the current... Chemical and geotechnical basis score of the layer If the first If a layer lies beneath a highly dense barrier layer (such as a hard plow pan), and a high excess bulk density has accumulated above it, and the barrier layer has a large abrupt barrier factor due to its compact profile, then the attenuation coefficient corresponding to the negative exponential term approaches 0, resulting in a lower soil fertility score for that layer. The significant reduction in the total reflects the ineffectiveness of deep nutrients due to their unavailability; if the bulk density of the entire farmland profile is uniform, no excess bulk density accumulation occurs, and the profile compaction abrupt change barrier factor value approaches 0, then the exponential decay term approaches 1, and the soil fertility score of this layer... The complete results are preserved. Finally, the formula sums up the soil force scores of each layer after reduction and divides them by the total unreduced base score. Normalization is performed. The resulting deep soil fertility effectiveness reduction factor is a correction coefficient ranging from 0 to 1, quantifying the proportion of deep soil fertility resources rendered ineffective by mechanically compacted barrier layers.

[0083] Thus, the deep soil fertility effectiveness reduction factor was obtained by applying a negative exponential reduction to the chemical soil fertility base score and cumulative compaction resistance of each depth layer.

[0084] Step S4: The comprehensive soil fertility productivity index of crops is obtained by multiplying and correcting the total score of the full profile chemical soil fertility basis with the deep soil fertility effectiveness reduction factor.

[0085] In existing crop fertility assessment systems, the basic comprehensive fertility index is typically calculated by summing the basic chemical fertility scores of each depth layer, or by assigning fixed depth weights and then summing them. This static calculation method presupposes an ideal premise: that the entire crop profile is uniform and unobstructed, allowing crop roots to extend downwards without hindrance and utilize nutrients at all depths. This step applies the deep fertility effectiveness reduction factor constructed above to the basic full-profile chemical fertility score obtained by the existing algorithm. Through dynamic correction, the algorithm transforms the original chemical nutrient reserves into an effective nutrient accessibility quantity that synergizes with penetration resistance. When the target farmland experiences significant obstruction due to mechanical compaction, this correction method can directly deduct the deep ineffective nutrients that cannot be utilized due to root obstruction at the total score level, thereby accurately correcting the overestimation bias of the existing algorithm in complex farmland environments and providing numerical support that conforms to objective reality for the final productivity potential classification.

[0086] Specifically, the total score of the full-profile chemical soil fertility baseline is extracted from the basic data of the soil fertility productivity collaborative assessment, and the deep soil fertility effectiveness reduction factor is obtained. The result of multiplying the total score of the full-profile chemical soil fertility baseline by the deep soil fertility effectiveness reduction factor is used as the comprehensive crop soil fertility productivity index of the target farmland.

[0087] It should be noted that the calculation in this step integrates the soil spatial physical structure characteristic optimization factor with the existing conventional chemical fertility assessment algorithm. In the formula, the total score of the full profile chemical fertility provides the original baseline of the basic chemical nutrient volume of the entire farmland profile, ensuring the assessment model's ability to distinguish between infertile and fertile land. The deep fertility effectiveness reduction factor, as a correction multiplier, is directly affected by the presence of a barrier layer with localized abrupt changes in bulk density in the soil profile and the cumulative isolation effect of this barrier layer on the deeper soil. When the target farmland is well-managed and the bulk density of the entire profile is uniform without abrupt changes, the value of the deep fertility effectiveness reduction factor approaches 1, and the calculated comprehensive crop fertility productivity index is almost equivalent to the theoretical baseline score, indicating that the farmland's fertility resources have been fully and effectively utilized. However, when the target farmland has formed a compacted barrier layer with a sudden increase in bulk density under the topsoil due to long-term mechanical compaction, the value of the deep fertility effectiveness reduction factor will be significantly less than 1. Through multiplication, the formula forcibly deducts the basic soil fertility score of the farmland proportionally. This correction mechanism completely eliminates the data processing defects of the original evaluation model, which blindly accumulates nutrients across the entire profile without considering root accessibility, from the underlying algorithm. This ensures that the final output crop comprehensive soil fertility productivity index can truly reflect the actual productivity potential that crops can convert and utilize under the current physical compaction conditions.

[0088] Thus, the comprehensive crop soil productivity index was obtained by multiplying and correcting the total score of the full profile chemical soil fertility basis with the deep soil fertility effectiveness reduction factor.

[0089] Step S5 involves jointly analyzing the comprehensive soil fertility productivity index of crops and the mechanical compaction characteristics of soil profiles to obtain crop productivity assessment results and farmland improvement strategies.

[0090] The comprehensive soil fertility productivity index of the target farmland is obtained, and the positive vertical spatial gradient of bulk density and its corresponding center depth coordinates are extracted from the vertical spatial gradient of soil bulk density. The target adjacent depth layer combination with the largest positive vertical spatial gradient of bulk density is determined as the target barrier layer combination, and the center depth coordinates of the next soil depth layer in the target barrier layer combination are used as the mechanical compaction barrier layer depth, thereby forming the mechanical compaction characteristics of the soil profile.

[0091] The comprehensive soil fertility productivity index of crops is graded according to preset productivity level classification rules. When the comprehensive soil fertility productivity index of crops reaches the preset excellent productivity range and the profile compaction mutation barrier factor is lower than the preset barrier judgment threshold, the productivity assessment result of crops with excellent productivity conversion is obtained, and a farmland improvement strategy of maintaining the current tillage method and reducing repeated heavy machinery compaction is generated. When the comprehensive soil fertility productivity index of crops is lower than the preset limited productivity threshold and the profile compaction mutation barrier factor reaches the preset barrier judgment threshold, the productivity assessment result of crops with limited productivity due to mechanical compaction barrier is obtained, and a farmland improvement strategy of implementing deep tillage operation for the mechanical compaction barrier layer is generated, wherein the depth of deep tillage operation is greater than the depth of the mechanical compaction barrier layer.

[0092] Thus, the combined analysis of the comprehensive soil fertility productivity index and the mechanical compaction characteristics of soil profiles has been completed, yielding crop productivity assessment results and farmland improvement strategies.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect, characterized in that, The method includes: Step S1: Collect and process physical and chemical nutrient indicators of soil at multiple depths in the target farmland to obtain basic data for the synergistic assessment of soil fertility and productivity; Step S2: Obtain the profile compaction mutation barrier factor by performing vertical spatial abrupt change gradient and local extreme value amplification analysis on the soil bulk density sequence; Step S3: Obtain the deep soil fertility effectiveness reduction factor by performing negative exponential reduction on the chemical soil fertility basic score and cumulative compaction resistance of each depth layer; Step S4: Obtain the comprehensive crop soil fertility productivity index by multiplying and correcting the total score of the full profile chemical soil fertility basis with the deep soil fertility effectiveness reduction factor; Step S5: By jointly analyzing the comprehensive soil fertility productivity index of crops and the mechanical compaction characteristics of soil profiles, crop productivity assessment results and farmland improvement strategies are obtained.

2. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 1, characterized in that, The process involves collecting and processing physical and chemical nutrient indicators from multiple soil layers at various depths in the target farmland to obtain basic data for the synergistic assessment of soil fertility and productivity, including: Soil profile sampling points were set up in the target farmland. The soil profile of the target farmland was continuously divided into a predetermined number of soil depth layers of equal thickness from the surface downwards, and the center depth coordinates of each soil depth layer were obtained. Soil samples were collected from each soil depth layer using a stratified soil sampling device, and the soil bulk density corresponding to each soil depth layer was obtained by measuring the soil bulk density. The soil bulk densities corresponding to all soil depth layers were arranged in ascending order of center depth coordinates to obtain a soil bulk density sequence. Soil samples collected from each soil depth layer were subjected to physicochemical tests to obtain the soil organic matter content, total nitrogen content, available phosphorus content, and available potassium content corresponding to each soil depth layer. The maximum values ​​of soil organic matter content, total nitrogen content, available phosphorus content, and available potassium content for all soil depth layers were statistically analyzed to obtain the maximum values ​​of organic matter content, total nitrogen content, available phosphorus content, and available potassium content for the entire soil profile. For any target soil depth layer, the soil organic matter content of the target soil depth layer is used as the numerator, the maximum organic matter content of the entire profile is used as the denominator, and the corresponding fraction is used as the normalized organic matter assessment; the total nitrogen content of the target soil depth layer is used as the numerator, the maximum total nitrogen content of the entire profile is used as the denominator, and the corresponding fraction is used as the normalized total nitrogen assessment; the available phosphorus content of the target soil depth layer is used as the numerator, the maximum available phosphorus content of the entire profile is used as the denominator, and the corresponding fraction is used as the normalized available phosphorus assessment; the available potassium content of the target soil depth layer is used as the numerator, the maximum available potassium content of the entire profile is used as the denominator, and the corresponding fraction is used as the normalized available potassium assessment; the sum of the normalized organic matter assessment, normalized total nitrogen assessment, normalized available phosphorus assessment, and normalized available potassium assessment is used as the chemical fertility basis score of the target soil depth layer. The sum of the chemical fertility baseline scores of all soil depth layers is used as the total chemical fertility baseline score of the entire profile. The total number of soil depth layers, the center depth coordinates of each soil depth layer, the soil bulk density sequence, the soil organic matter content, total nitrogen content, available phosphorus content and available potassium content of each soil depth layer, the chemical fertility baseline score of each soil depth layer and the total chemical fertility baseline score of the entire profile are used as the basic data for the collaborative assessment of soil fertility productivity.

3. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 1, characterized in that, The method involves performing vertical spatial abrupt change gradient and local extremum amplification analysis on the soil bulk density sequence to obtain the profile compaction abrupt change barrier factor, including: By performing differential analysis of adjacent depth layers and positive gradient screening on the soil bulk density sequence in the basic data of the synergistic assessment of soil fertility productivity, the vertical spatial abrupt gradient data of soil bulk density were obtained. By performing local extremum amplification and nonlinear aggregation processing on the deviation relationship between the vertical spatial abrupt change gradient data of soil bulk density and the local bulk density of each depth layer relative to the average bulk density of the whole profile, the profile compaction abrupt change barrier factor is obtained.

4. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 3, characterized in that, The process involves analyzing the differences between adjacent depth layers and performing positive gradient screening on the soil bulk density sequence in the basic data for the collaborative assessment of soil fertility productivity to obtain vertical spatial abrupt gradient data of soil bulk density, including: Extract the total number of soil depth layers, the center depth coordinates of each soil depth layer, and the soil bulk density sequence from the basic data of the soil fertility productivity assessment. Then, according to the order of the center depth coordinates of each soil depth layer from small to large, combine any soil depth layer with the next adjacent soil depth layer to form a target adjacent depth layer combination. For any combination of adjacent depth layers, the difference between the soil bulk density of the next soil depth layer and the soil bulk density of the previous soil depth layer in the combination of adjacent depth layers is used as the bulk density difference assessment between adjacent layers, and the difference between the center depth coordinates of the next soil depth layer and the center depth coordinates of the previous soil depth layer is used as the depth interval between adjacent layers. The difference in bulk density between adjacent layers is used as the numerator, the depth interval between adjacent layers is used as the denominator, and the resulting fraction is used as the initial vertical spatial gradient of bulk density of the target adjacent depth layer combination. When the initial vertical spatial variation gradient of bulk density is greater than a constant 0, the initial vertical spatial variation gradient of bulk density is taken as the positive vertical spatial abrupt change gradient of bulk density of the target adjacent depth layer combination; when the initial vertical spatial variation gradient of bulk density is less than or equal to a constant 0, the positive vertical spatial abrupt change gradient of bulk density of the target adjacent depth layer combination is set to a constant 0. The vertical spatial gradient of soil bulk density corresponding to all adjacent depth layers of the target is arranged in ascending order according to the corresponding center depth coordinates to obtain the vertical spatial gradient data of soil bulk density.

5. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 3, characterized in that, The process involves local extremum amplification and nonlinear aggregation of the vertical spatial abrupt change gradient data of soil bulk density and the deviation relationship between the local bulk density of each depth layer and the average bulk density of the entire profile, to obtain the profile compaction abrupt change barrier factor, including: The total number of soil depth layers and soil bulk density sequence are extracted from the basic data of soil fertility productivity assessment. The total bulk density of the whole profile is calculated by adding the soil bulk densities corresponding to all soil depth layers in the soil bulk density sequence. The total bulk density of the whole profile is used as the numerator, the total number of soil depth layers is used as the denominator, and the corresponding fraction is used as the average bulk density of the whole profile. For any target adjacent depth layer combination, extract the positive bulk density vertical spatial abrupt gradient corresponding to the target adjacent depth layer combination from the soil bulk density vertical spatial abrupt gradient data, and extract the soil bulk density of the next soil depth layer in the target adjacent depth layer combination from the soil bulk density sequence. The soil bulk density of the next soil depth layer in the target adjacent depth layer combination is used as the numerator, the average bulk density of the whole profile is used as the denominator, and the corresponding fraction is used as the local bulk density extreme value amplification weight of the target adjacent depth layer combination. The result of multiplying the positive bulk vertical spatial abrupt change gradient corresponding to the target adjacent depth layer combination with the local bulk extreme value amplification weight is used as the local compaction amplification evaluation of the target adjacent depth layer combination, and the square of the local compaction amplification evaluation is used as the local compaction intensity evaluation of the target adjacent depth layer combination. The calculation result of summing the local compact mutation intensity assessments corresponding to all adjacent depth layer combinations of the target is used as the full profile compact mutation aggregation assessment. The calculation result of summing the full profile compact mutation aggregation assessment with constant 1 is mapped by the natural logarithm, and the corresponding mapping result is used as the profile compact mutation blocking factor.

6. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 1, characterized in that, The method involves applying a negative exponential reduction to the chemical fertility baseline score and cumulative compaction resistance of each depth layer to obtain a deep fertility effectiveness reduction factor, including: By positively screening and layer-by-layer accumulation of the deviation relationship between the soil bulk density of each depth layer and the average bulk density of the whole profile, the cumulative compaction resistance corresponding to each depth layer is obtained. By performing negative exponential decay mapping on the basic chemical geotechnical scores of each depth layer, the cumulative compaction resistance of each depth layer and the profile compaction abrupt barrier factor, the effective chemical geotechnical scores of each depth layer are obtained. By normalizing the ratio between the effective chemical fertility score and the basic chemical fertility score of each depth layer, the deep fertility effectiveness reduction factor is obtained.

7. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 6, characterized in that, The method involves positively screening and layer-by-layer accumulation of the deviation relationship between the soil bulk density at each depth layer and the average bulk density of the entire profile to obtain the cumulative compaction resistance corresponding to each depth layer, including: The total number of soil depth layers, the center depth coordinates of each soil depth layer, and the soil bulk density sequence are extracted from the basic data of the soil fertility productivity assessment. The total bulk density of the whole profile is calculated by adding up the soil bulk density corresponding to all soil depth layers in the soil bulk density sequence. The total bulk density of the whole profile is used as the numerator, the total number of soil depth layers is used as the denominator, and the corresponding fraction is used as the average bulk density of the whole profile. For any target soil depth layer, determine the target cumulative depth layer set from the first soil depth layer on the surface to the target soil depth layer in ascending order of the center depth coordinates corresponding to each soil depth layer. For any target cumulative soil depth layer in the target cumulative depth layer set, the difference between the soil bulk density of the target cumulative soil depth layer and the average bulk density of the entire profile is used as the initial bulk density deviation assessment; when the initial bulk density deviation assessment is greater than a constant 0, the initial bulk density deviation assessment is used as the positive bulk density excess assessment of the target cumulative soil depth layer; when the initial bulk density deviation assessment is less than or equal to a constant 0, the positive bulk density excess assessment of the target cumulative soil depth layer is set to a constant 0. The calculation result of summing the positive bulk density excess assessments corresponding to all target cumulative soil depth layers in the target cumulative depth layer set is used as the cumulative compaction resistance corresponding to the target soil depth layer. Then, the cumulative compaction resistance corresponding to each depth layer is obtained by performing layer-by-layer accumulation processing on all soil depth layers.

8. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 6, characterized in that, The effective chemical fertility score for each depth layer is obtained by performing negative exponential decay mapping on the basic chemical fertility score of each depth layer, the cumulative compaction resistance corresponding to each depth layer, and the profile compaction abrupt change barrier factor, including: The total number of soil depth layers, soil bulk density sequence, and basic chemical fertility score of each depth layer are extracted from the basic data of the soil fertility productivity collaborative assessment. The total bulk density of the whole profile is calculated by adding up the soil bulk density corresponding to all soil depth layers in the soil bulk density sequence. The total bulk density of the whole profile is used as the numerator, the total number of soil depth layers is used as the denominator, and the corresponding fraction is used as the average bulk density of the whole profile. For any target soil depth layer, obtain the cumulative compaction resistance, chemical geotechnical base score, and profile compaction abrupt change barrier factor corresponding to the target soil depth layer; use the cumulative compaction resistance corresponding to the target soil depth layer as the numerator, the average bulk density of the whole profile as the denominator, and the corresponding fraction as the normalized cumulative compaction resistance corresponding to the target soil depth layer. The result of multiplying the normalized cumulative compaction resistance corresponding to the target soil depth layer with the profile compaction abrupt change barrier factor is used as the soil fertility attenuation intensity assessment corresponding to the target soil depth layer. The negative number of the soil fertility attenuation intensity assessment is subjected to exponential mapping with the natural constant as the base, and the corresponding mapping result is used as the soil fertility effectiveness attenuation weight corresponding to the target soil depth layer. The effective chemical fertility score corresponding to the target soil depth layer is calculated by multiplying the soil fertility effectiveness attenuation weight corresponding to the basic chemical fertility score. Negative exponential attenuation mapping is then applied to all soil depth layers to obtain the effective chemical fertility score for each depth layer.

9. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 6, characterized in that, The process involves normalizing the ratio of the effective chemical fertility score to the basic chemical fertility score for each depth layer to obtain the deep fertility effectiveness reduction factor, including: The effective chemical chemistry score corresponding to each depth layer is obtained, and the sum of the effective chemical chemistry scores corresponding to all soil depth layers is used as the total effective chemical chemistry score of the entire profile. The chemical geofertility baseline score for each depth layer is extracted from the basic data of the soil fertility productivity synergistic assessment, and the sum of the chemical geofertility baseline scores corresponding to all soil depth layers is used as the total chemical geofertility baseline score for the entire profile. The total effective chemical geofertility score of the entire profile is used as the numerator, the basic total score of chemical geofertility of the entire profile is used as the denominator, and the corresponding fraction is used as the reduction factor for the effectiveness of deep geofertility.

10. The method for synergistic evaluation of crop soil fertility productivity based on mechanical compaction effect according to claim 1, characterized in that, The process involves multiplying and correcting the total score of the full-profile chemical soil fertility baseline with the deep soil fertility effectiveness reduction factor to obtain the comprehensive crop soil fertility productivity index, including: Extract the total score of the full profile chemical geofertility from the basic data of the geofertility productivity synergistic assessment, and obtain the deep geofertility effectiveness reduction factor; The result of multiplying the total score of the full profile chemical soil fertility foundation by the deep soil fertility effectiveness reduction factor is used as the comprehensive crop soil fertility productivity index of the target farmland.

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