A soil loss calculation method considering soil flux migration due to tillage

Abstract

The invention discloses a soil loss calculation method considering soil flux of tillage migration, comprising: measuring soil background magnetic intensity values ​​for sloping cultivated land with different slopes, adding magnetic tracers to the sloping cultivated land; carrying out conventional tillage and protective tillage measures on the sloping cultivated land with the same slope, recording the index affecting the displacement degree of cultivated soil in each tillage activity and collecting soil samples of conventional tillage and protective tillage measures, obtaining the corresponding soil magnetic susceptibility based on the magnetic tracer of the soil sample; obtaining a correction coefficient based on the soil background magnetic intensity value, the index affecting the displacement degree of cultivated soil and the soil magnetic susceptibility; correcting the universal soil loss equation based on the correction coefficient to obtain a corrected soil loss equation, and calculating the soil loss amount based on the corrected soil loss equation. The method takes into account the influence of tillage activities on soil erosion, improves the accuracy of calculating the soil loss amount by the RUSLE model, and at the same time, the experimental operation cycle is short and has strong operability.

Description

Technical Field

[0001] The invention belongs to the technical field of soil and water conservation, and in particular relates to a soil loss calculation method taking into account soil flux of tillage migration. Background Art

[0002] Soil erosion is one of the most serious environmental problems in the world. Severe soil erosion can cause soil degradation, reduced land productivity, mudslides and other mountain disasters. At present, an important and popular method for quantitatively predicting the degree of soil erosion is the universal soil road soil erosion model. Among them, the most widely used is the RUSLE soil erosion equation model. Based on this model, the factors that cause soil erosion are summarized as rainfall erosivity, topography (slope length, slope), soil erodibility and soil and water conservation measures. However, although the RUSLE model has a good performance in identifying erosion hotspots and studying erosion potential, there is great uncertainty in the study of soil erosion process and precise erosion amount. In addition, soil erosion is a complex multi-factor coupling process, so it is necessary to continuously optimize the RUSLE model and consider and quantify the influence of more factors on soil erosion.

[0003] Tillage is a key link in agricultural production. It can improve the quality of the soil plow layer, improve soil fertility, and effectively improve the structure of the soil, creating favorable external conditions for the growth of crops, and has a very important impact on the soil ecological environment. However, unreasonable tillage without any soil conservation measures often causes soil to move, accumulate, and redistribute to the downslope or upslope (depending on the direction of tillage) due to the action of agricultural tools and gravity, thus forming a slope erosion pattern of convex erosion and concave deposition. This type of erosion will change the physical properties of the soil surface, affect the migration of soil moisture and nutrients, thereby reducing the fertility and quality of the soil, and ultimately seriously affecting the development of agricultural production in the region. Although reasonable tillage measures can effectively control soil erosion. However, it does not completely eliminate soil erosion. The soil will still migrate with the direction of tillage tools and gravity, eventually causing the redistribution of sloping cultivated land soil in the landscape, causing soil erosion. At present, the main methods for obtaining soil loss under different farming measures include water conservancy survey results query, regional soil and water loss dynamic monitoring query, soil and water conservation farming measures assignment, land use type classification formula, runoff area formula and slope classification method. However, the above methods are mostly based on the collection of literature and monitoring data for summary statistics, which are cumbersome, long cycle, low data accuracy, and difficult to obtain data in most areas.

[0004] In summary, any farming activity will cause soil migration under the action of gravity and tools, and the impact on soil erosion will also be different. There is currently no efficient and reliable method to quickly quantify the impact of different farming measures on soil erosion. At the same time, when implementing conservation tillage, a reasonable angle between the tillage direction and the slope will slow down or offset the impact of the slope on soil migration, thereby reducing the degree of soil erosion and loss. In this case, the choice of angle can have a certain regulatory effect on the direction of soil migration. However, the factors considered in the universal soil loss equation RUSLE model have not yet taken into account the impact of the tillage method and the angle between the tillage direction and the slope on soil erosion. Therefore, this embodiment proposes a soil loss calculation method that takes into account the tillage migration soil flux. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a soil loss calculation method taking into account the soil flux of tillage migration to solve the problems existing in the above prior art.

[0006] To achieve the above object, the present invention provides a soil loss calculation method considering tillage migration soil flux, which establishes a calculation model formula of tillage and soil displacement by calculating the soil migration amount under different tillage measures and combining relevant indicators affecting tillage soil migration such as slope, tillage rate and soil bulk density, and obtains the correction coefficient under a certain tillage measure, and finally corrects the universal soil loss equation, including the following steps:

[0007] Determining soil background magnetic intensity values ​​of sloping cultivated land with different slopes, and adding magnetic tracers to the sloping cultivated land;

[0008] After conventional tillage and conservation tillage measures were carried out on sloping cultivated land of the same slope, the displacement index of cultivated soil in each tillage activity was recorded, soil samples of conventional tillage and conservation tillage measures were collected, and the soil magnetic susceptibility was obtained based on the magnetic tracer of the soil samples;

[0009] Obtaining a correction coefficient based on the soil background magnetic intensity value, an index affecting the displacement degree of cultivated soil, and the soil magnetic susceptibility;

[0010] The universal soil loss equation is corrected based on the correction coefficient to obtain a corrected soil loss equation, and the soil loss amount is calculated based on the corrected soil loss equation.

[0011] Optionally, the conservation tillage measures include: contour tillage, ridge tillage and pit field tillage.

[0012] Optionally, the indices affecting the displacement degree of cultivated soil include: tillage depth, tillage rate, tillage direction angle, soil bulk density and soil quality per unit area of ​​the cultivated layer.

[0013] Optionally, the process of obtaining the correction coefficient includes:

[0014] The migration soil flux under conventional tillage was obtained based on the soil background magnetic intensity value, soil magnetic susceptibility, soil bulk density and soil mass per unit area of ​​the tillage layer under conventional tillage.

[0015] Obtaining the soil displacement distance under the conservation tillage measure based on the migration soil flux under the conventional tillage and the tillage rate;

[0016] Obtaining a correction value under the conservation tillage measure based on the soil displacement distance under the conservation tillage measure;

[0017] A correction value under conventional tillage is obtained, and a correction coefficient is obtained based on the correction value under conventional tillage and the correction value under the protective tillage measure.

[0018] Optionally, the index affecting the migration soil flux also includes the angle between the soil migration direction under different conservation tillage measures and the conventional downslope tillage direction.

[0019] Alternatively, the soil flux under single tillage is calculated as:

[0020]

[0021] Where Q is the soil flux under single tillage, unit: kg / s; ρ is the soil bulk density, unit: kg / m 3 ; θ is the angle between the tillage direction and the downslope direction under single tillage, and its value range is [0°, 90°); D t is the tillage depth, unit: cm; C (x) is the magnetic susceptibility of soil after tillage; C0 is the magnetic susceptibility of soil in the marked area before tillage; M s is the soil mass per unit area of ​​the tillage layer, unit: kg / m 2 , l represents the maximum sampling distance, unit: m.

[0022] Optionally, the soil tillage displacement flux calculation formula is:

[0023]

[0024] Where, T n is the soil tillage displacement flux under conservation tillage measures; V is the tillage rate, unit: m / s; V ref is the reference tillage rate, unit: m / s; β is the regression coefficient.

[0025] Optionally, the calculation formula of the correction coefficient is:

[0026]

[0027] In the formula, α is the correction coefficient; α n is the correction coefficient of a certain farming measure; T n is the soil tillage displacement flux under conservation tillage measures; T c is the soil tillage displacement flux under conventional tillage; M n is the area of ​​a certain farming measure, in m 2 , M is the total cultivated land area in the experimental area, unit is m 2 .

[0028] Optionally, the modified soil loss equation is:

[0029] A=R·K·L·S·C·P·α

[0030] In the formula, A is the amount of soil loss, R represents the rainfall erosivity factor, K is the soil erodibility factor, L is the slope length factor, S is the slope factor, C is the vegetation coverage and management factor, P is the soil conservation measures factor, and α is the correction coefficient.

[0031] Compared with the prior art, the present invention has the following advantages and technical effects:

[0032] The soil background magnetic intensity value of sloping cultivated land with different slopes is measured, and a magnetic tracer is added to the sloping cultivated land; after conventional tillage and protective tillage measures are respectively carried out on the sloping cultivated land with the same slope, the displacement degree index affecting the cultivated soil in each tillage activity is recorded, and soil samples of conventional tillage and protective tillage measures are collected, and the corresponding soil magnetic susceptibility is obtained based on the magnetic tracer of the soil sample; the correction coefficient is obtained based on the soil background magnetic intensity value, the displacement degree index affecting the cultivated soil, and the soil magnetic susceptibility; the universal soil loss equation is corrected based on the correction coefficient to obtain a corrected soil loss equation, and the soil loss amount is calculated based on the corrected soil loss equation. Based on this, the present invention overcomes the limitation of the poor calculation accuracy of the current soil loss equation RUSLE model.

[0033] The present invention is based on the principles of soil and water conservation and soil erosion, combined with the empirical research of predecessors, takes into account the direction of soil migration under different tillage measures (i.e. tillage direction), uses the currently more mature magnetic tracer technology to quickly determine the soil migration distance under a certain tillage measure, and calculates the soil tillage migration flux through a formula. By comparing the soil tillage migration flux under different tillage measures with that under conventional tillage, the model correction coefficient under a certain tillage measure can be obtained, and finally the universal soil loss equation RUELS model is corrected. This method takes into account the impact of tillage activities on soil erosion, improves the accuracy of the RUSLE model in calculating soil loss, and at the same time, the experimental operation cycle is short and has strong operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0035] Figure 1 is a flow chart of an embodiment of the present invention;

[0036] Figure 2 This is an example diagram of the magnetic tracing technology according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0039] Embodiment 1

[0040] like Figure 1 As shown, in this embodiment, a soil loss calculation method considering the soil flux of tillage migration is provided, including: selecting sloping cultivated land with different slopes, measuring the soil background magnetic intensity value by using a magnetometer, adding and mixing a magnetic tracer; carrying out agricultural tillage activities under certain protective tillage measures and conventional tillage on the tracer plots of sloping cultivated land with the same slope; continuously sampling from the base of the marked plot to the farthest point of diffusion, and the sampling distance is until three similar magnetic intensity values ​​appear between the soil sample and the background; measuring the magnetic susceptibility of the soil sample by using a magnetic susceptibility meter; combining relevant indicators, and obtaining the ratio of certain protective tillage measures and conventional tillage in the regional cultivated land area as the model correction coefficient. Through case analysis, the revised RUSLE is closer to the actual soil loss amount, and the prediction accuracy is greatly improved. This method not only improves the accuracy of the universal soil loss equation USLE model, but also clarifies the impact of different tillage measures on soil erosion.

[0041] The soil background magnetic intensity values ​​of sloping farmland with different slopes were measured, and magnetic tracers were added to the sloping farmland. The specific implementation process includes:

[0042] Step 1: Establish a rectangular tracer area with a length of 100 cm, a width of 20 cm, and a height of 20 cm in sloping farmland of different slopes. Dig out the soil in each area and pile it on a plastic sheet. Use a magnetometer to measure the soil background magnetic intensity value. Then add and mix 1 kg of magnetic tracer (ilmenite powder rich in titanium dioxide and iron oxide made of metal), such as Figure 2 shown.

[0043] After conventional tillage and conservation tillage measures were carried out on sloping farmland with the same slope, the displacement index of cultivated soil in each tillage activity was recorded, and soil samples of conventional tillage and conservation tillage measures were collected. The soil magnetic susceptibility was obtained based on the magnetic tracer of the soil samples. The specific implementation process includes:

[0044] Step 2: Agricultural tillage activities under certain conservation tillage measures and conventional tillage were carried out in the tracer plots of sloping cultivated land with the same slope, covering the entire experimental area of ​​the magnetic tracer plot. The tillage rate and tillage depth were carried out according to the actual local operation methods.

[0045] Step 3: After tillage is completed, continuous sampling is performed from the base of the marked area to the farthest point of diffusion. A metal frame with a length, width, and height of 60, 20, and 30 cm, respectively, is vertically inserted into the tilled soil to the tillage depth, and soil samples are collected from the metal frame. The sampling depth is the actual tillage depth, the sampling width is 20 cm, the spacing is 10 cm, and the sampling distance is until three similar magnetic intensity values ​​appear between the tilled soil sample and the background.

[0046] Step 4: Use a magnetic susceptibility meter to measure the magnetic susceptibility of the soil sample. Measure 5 to 7 times and take the average value as the sample magnetic value. Use the formula to calculate the soil displacement distance under each tillage method.

[0047] The correction coefficient is obtained based on the soil background magnetic intensity value, the index affecting the displacement degree of cultivated soil and the soil magnetic susceptibility; the general soil loss equation is corrected based on the correction coefficient to obtain the corrected soil loss equation, and the soil loss amount is calculated based on the corrected soil loss equation. The specific implementation process includes:

[0048] Step 5: Consider the slope, tillage rate, tillage direction angle, soil bulk density and other indicators during the experiment, and use ArcGIS and other means to obtain the proportion of a certain conservation tillage measure and conventional tillage in the regional cultivated land area, use the weighted average method to calculate the correction value under a certain conservation tillage measure, and finally correct the universal soil loss equation RUSLE.

[0049] This example uses a relatively mature magnetic tracing technique to calculate the migration soil flux under conventional tillage and conservation tillage measures.

[0050] The experimental sloping farmland selected in this embodiment must be typical and uniform (the planting pattern, fertilization management and crop system must be the same).

[0051] The agricultural farming activities described in step 2 of this embodiment are carried out without rainfall during the farming period and the farming practices are based on actual farming activities of local farmers.

[0052] The calculation formula of the revised model is:

[0053] A=R·K·L·S·C·P·α

[0054] The calculation scheme for other factors in the model is:

[0055] (1) Rainfall erosivity factor (R)

[0056] The rainfall erosivity (R) is calculated based on the "Technical Guidelines for Dynamic Monitoring of Soil and Water Loss in 2021 of the Soil and Water Conservation Monitoring Center of the Ministry of Water Resources". The annual rainfall erosivity is estimated according to the formula based on the daily rainfall data of China Meteorological Data (about 10km away from the study area). The specific formula is as follows:

[0057]

[0058] In the formula: In the formula, is the average annual rainfall erosivity over many years, MJ·mm / hm 2 ·h -1 ·a -1 ; k—1, 2, ..., 24, which means that a year is divided into 24 half months; is the rainfall erosivity in the kth half month, MJ·mm / hm 2 ·h -1 ; i—1, 2, ..., N; N refers to the time series from 2000 to 2019, and will be updated in five-year series; j—0, 1, ..., m; m—the number of erosive rainfall days in the kth half month of the i-th year (erosive rainfall days refer to daily rainfall greater than or equal to 10 mm); P i,j,k is the jth erosive rainfall in the kth half month of the i-th year, mm; if there is no erosive rainfall in a half month of a certain year, that is, j = 0, then let P i,j,k =0; α is a parameter, α in the warm season (May-September) is 0.3937, and α in the cold season (October-December, January-April) is 0.3101; is the average rainfall erosivity in the kth half month Average annual rainfall erosivity proportion.

[0059] (2) Soil erodibility factor (K)

[0060] The soil erodibility factor is an important factor used to measure the sensitivity of soil erosion. The specific formula of the soil erodibility factor K value is as follows:

[0061]

[0062] D g =exp(0.01·∑f i ln(m i))

[0063] Where: OM is soil organic matter content (%), D g is the geometric mean diameter of soil particles GMD (mm), f i is the weight percentage (%) of silt, clay and sand, m i It is the arithmetic mean of silt, clay and sand particles (mm).

[0064] (3) Slope length factor (LS)

[0065] According to the currently recognized calculation formula, the slope and length factor value is obtained.

[0066]

[0067] Where λ is the horizontal projection of the slope length (m); m is the slope length index, which varies with the slope. The modified values ​​of m are: m = 0.2, θ ≤ 0.5°; m = 0.3, 0.5° < θ ≤ 1.5°; m = 0.4, 1.5° < θ ≤ 3°; m = 0.5, θ > 3°; S is the slope factor (dimensionless); θ is the slope (°).

[0068] (4) Vegetation coverage and management factors (C)

[0069]

[0070] Where c is the coverage of crops or plants in a certain growing season (%).

[0071] (5) The calculation formula of the correction coefficient in this embodiment is:

[0072]

[0073]

[0074] Among them, α is the correction coefficient; α n is the correction coefficient of a certain farming measure; T n is the soil tillage displacement flux under conservation tillage measures; T c is the soil tillage displacement flux under conventional tillage, and the calculation method of the soil tillage displacement flux under conventional tillage is the same as that under conservation tillage measures; M n is the area of ​​a certain farming measure, in m 2 , M is the total cultivated land area in the experimental area, unit is m 2 ; Q is the soil flux under single tillage (kg / s); V is the tillage rate under a certain tillage measure (m / s); V ref is the reference tillage rate, which is set at 1.4 m / s; β is the regression coefficient; ρ is the soil bulk density (kg / m3 );θ is the angle between the tillage direction and the conventional downslope direction, and its value range is [0°, 90°); D t is tillage depth (cm); C (x) is the soil magnetic susceptibility (SI) after tillage; C0 is the soil magnetic susceptibility (SI) of the marked area before tillage; M s is the soil mass per unit area of ​​the tillage layer (kg / m 2 ), l represents the maximum sampling distance, the unit is: m.

[0075] Embodiment 2

[0076] Below, a soil loss calculation method considering tillage migration soil flux of the present invention is described in detail with an implementation example:

[0077] The case selection was conducted in Xide County, Xichang (28°32′, 102°42′E).

[0078] First, a typical uniform sloping farmland in Xide County, Xichang was selected for the experiment. Two rectangular tracer plots with a length of 100 cm, a width of 20 cm, and a height of 20 cm were dug on the sloping farmland. The soil in each plot was dug out and piled on a plastic sheet. The soil background magnetic intensity value was measured using a magnetometer. Then 1 kg of magnetic tracer (ilmenite powder rich in titanium dioxide and iron oxide made of metal) was added and mixed.

[0079] Secondly, agricultural tillage activities were carried out under contour tillage and conventional downslope tillage (no rainfall during tillage) in the tracer plot of the sloping cultivated land, and the tillage range covered the entire experimental area of ​​the magnetic tracer plot. The tillage rate and tillage depth were carried out according to the actual local operation method, and the tillage angle was recorded. After tillage was completed, continuous sampling was taken from the base of the marked plot to the farthest point of diffusion. A metal frame with a length, width, and height of 60, 20, and 30 cm was vertically inserted into the tilled soil to the tillage depth, and soil samples were collected in the metal frame. The sampling depth was the actual tillage depth, the sampling width was 20 cm, the spacing was 10 cm, and the sampling distance was until three similar magnetic intensity values ​​appeared between the tilled soil sample and the background.

[0080] Then, the magnetic susceptibility of the soil sample was measured using a magnetic susceptibility meter. The measurement was performed 5 to 7 times, and the average value was taken as the magnetic value of the sample. The soil displacement distance under contour tillage and conventional downslope tillage was calculated using the formula. The formula is as follows:

[0081]

[0082] Among them, T n is the soil tillage displacement flux under the contour tillage measures; V is the tillage rate, unit: m / s; V refis the reference tillage rate, which is set at 1.4 m / s; β is the regression coefficient, which is taken as 0.5; Q is the migration soil flux under single tillage, unit: kg / s; ρ is the soil bulk density, unit: kg / m 3 ; θ is the angle between the contour tillage direction and the conventional downslope direction, and its value range is [0°, 90°); D t is the tillage depth, unit: cm; C (x) is the magnetic susceptibility of soil after tillage; C0 is the magnetic susceptibility of soil in the marked area before tillage; M s is the soil mass per unit area of ​​the tillage layer, unit: kg / m 2 , l represents the maximum sampling distance, unit: m.

[0083] Finally, ArcGIS and other means are used to obtain the proportion of contour farming and conventional downslope farming in the regional cultivated land area, and the weighted average method is used to calculate the correction values ​​under contour farming and conventional downslope farming. The two values ​​are compared to obtain the model correction coefficient under contour farming, and finally the model is corrected. The formula is as follows:

[0084]

[0085]

[0086] Among them, α is the correction coefficient; α n is the correction coefficient of a certain farming measure; T n is the soil tillage displacement flux under the contour tillage measures; T c is the soil tillage displacement flux under conventional tillage, and the calculation method of the soil tillage displacement flux under conventional tillage is the same as that under conservation tillage measures; M n is the area of ​​contour tillage measures, in m 2 , M is the total cultivated land area in the experimental area, unit is m 2 .

[0087] The final correction coefficient under contour tillage was calculated to be 0.611.

[0088] Other factors of the model, such as rainfall erosivity factor R and soil erodibility factor K, are obtained using commonly used calculation formulas. Finally:

[0089] R=1796.4MJ·mm / hm 2 ·h·a

[0090] K=0.0243

[0091] LS=2.698

[0092] C=1

[0093] Therefore, the calculation accuracy is:

[0094] A 未修正 =117.77t / (hm 2 a)

[0095] A 修正后 =71.96t / (hm 2 a)

[0096] Using the radioactive nuclide cesium-137 (137Cs), which is widely used to calculate soil erosion rate, as the true value of slope erosion rate, the calculation result is: A 真 =82.13t / (hm 2 a)

[0097] Therefore, the soil loss calculated by the revised model is closer to the actual soil loss and the accuracy is greatly improved, as shown in Table 1.

[0098] Table 1

[0099]

[0100]

[0101] The advantages of the present invention are:

[0102] 1. High precision and strong operability

[0103] At present, the methods for quantifying the amount of soil loss under different tillage measures include water conservancy survey results query, regional soil and water loss dynamic monitoring query, soil and water conservation tillage measure assignment, land use type classification formula, runoff plot formula and slope classification method. However, the above methods are mostly carried out by querying literature and materials, and the commonly used runoff plot formula method has the disadvantages of long cycle and low precision. The present invention combines field experiments and adopts the currently more mature magnetic tracing technology to calculate the amount of soil migration under different tillage measures. From this perspective, the model correction coefficient under a certain tillage measure is finally calculated by the ratio method. The use of the revised universal soil loss equation RUSLE model to calculate the amount of soil loss is more accurate. At the same time, the original RUSLE model does not consider the impact of tillage soil migration on soil erosion, so the accuracy of the model is also improved.

[0104] 2. Scientificity

[0105] The present invention is based on the principles of soil and water conservation and soil science, combined with previous empirical research, and uses the currently more mature magnetic tracer technology to quickly determine the soil migration distance under a certain tillage measure, and calculates the tillage migration soil flux through a formula, and takes into account the tillage direction angle. This method is currently widely used and relatively mature. Most scholars have used the above method to master the soil erosion laws under different tillage methods, providing some reference for regional soil and water loss dynamic monitoring and soil and water conservation related work.

[0106] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A soil loss calculation method considering tillage migration soil flux, characterized in that: The following steps are involved: Determining soil background magnetic intensity values ​​of sloping cultivated land with different slopes, and adding magnetic tracers to the sloping cultivated land; After conventional tillage and conservation tillage measures were carried out on sloping cultivated land of the same slope, the displacement index of cultivated soil in each tillage activity was recorded, soil samples of conventional tillage and conservation tillage measures were collected, and the soil magnetic susceptibility was obtained based on the magnetic tracer of the soil samples; Obtaining a correction coefficient based on the soil background magnetic intensity value, an index affecting the displacement degree of cultivated soil, and the soil magnetic susceptibility; The universal soil loss equation is corrected based on the correction coefficient to obtain a corrected soil loss equation, and the soil loss amount is calculated based on the corrected soil loss equation; The conservation tillage measures include: contour tillage, furrow ridge tillage and pit field tillage; The indices affecting the displacement degree of cultivated soil include: tillage depth, tillage rate, tillage direction angle, soil bulk density and soil quality per unit area of ​​the cultivated layer; The process of obtaining the correction coefficient includes: The migration soil flux under conventional tillage was obtained based on the soil background magnetic intensity value, soil magnetic susceptibility, soil bulk density and soil mass per unit area of ​​the tillage layer under conventional tillage. Obtaining the soil displacement distance under the conservation tillage measure based on the migration soil flux under the conventional tillage and the tillage rate; Obtaining a correction value under the conservation tillage measure based on the soil displacement distance under the conservation tillage measure; Obtaining a correction value under conventional tillage, and obtaining a correction coefficient based on the correction value under conventional tillage and the correction value under the conservation tillage measure; The indexes affecting the migration soil flux also include the angle between the soil migration direction under different conservation tillage measures and the conventional downslope tillage direction; The calculation formula of the migration soil flux under single tillage is: Where Q is the soil flux under single tillage, unit: kg / s; ρ is the soil bulk density, unit: kg / m 3 ; θ is the angle between the tillage direction and the downslope direction under single tillage, and its value range is [0°, 90°); D t is the tillage depth, unit: cm; C (x) is the magnetic susceptibility of soil after tillage; C0 is the magnetic susceptibility of soil in the marked area before tillage; M s is the soil mass per unit area of ​​the tillage layer, unit: kg / m 2 , l represents the maximum distance of sampling, the unit is: m; The calculation formula of soil tillage displacement flux is: Where, T n is the soil tillage displacement flux under conservation tillage measures; V is the tillage rate, unit: m / s; V ref is the reference tillage rate, unit: m / s; β is the regression coefficient; The calculation formula of the correction coefficient is: In the formula, α is the correction coefficient; α n is the correction coefficient of a certain farming measure; T n is the soil tillage displacement flux under conservation tillage measures; T c is the soil tillage displacement flux under conventional tillage; M n is the area of ​​a certain farming measure, in m 2 , M is the total cultivated land area in the experimental area, unit is m 2 .

2. The soil loss calculation method considering tillage migration soil flux according to claim 1 is characterized in that: The modified soil loss equation is: A=R·K·L·S·C·P·α In the formula, A is the amount of soil loss, R represents the rainfall erosivity factor, K is the soil erodibility factor, L is the slope length factor, S is the slope factor, C is the vegetation coverage and management factor, P is the soil conservation measures factor, and α is the correction factor.

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