Method for measuring and calculating nitrogen and phosphorus emissions of rice farming terraced field

Abstract

The invention relates to the technical field of agriculture, in particular to a method for measuring and calculating nitrogen and phosphorus emissions of a rice farming terraced field. In order to solve the problem that the nitrogen and phosphorus emissions of the rice farming terraced field cannot be estimated and predicted, a ridge overflow device is designed to monitor ridge overflow and displacement, and the nitrogen and phosphorus emissions of the terraced field piece scale are estimated in combination with the nitrogen and phosphorus concentrations of drainage. According to the ridge overflow amount, a ridge overflow coefficient is constructed, parameters are provided for ridge overflow amount prediction, then the ridge height is regulated and controlled, and support is provided for effective farmland fertilization and agricultural non-point source pollution prevention and control. The invention aims to solve the problem of how to measure and calculate the nitrogen and phosphorus emission in the rice terraced field.

Description

Technical Field

[0001] The present application relates to the technical field of agriculture, and particularly relates to a method for measuring the nitrogen and phosphorus emissions of paddy terraced fields. Background Art

[0002] Terraced fields are mountain agricultural production systems dug by humans according to the mountain terrain and local conditions. Among them, paddy terraced fields are an extremely representative and important type. Paddy terraced fields maintain surface water for a long time, and the ridge becomes the most important factor for retaining water, fertilizer, and soil, maintaining the production function and landscape stability of the terraced fields. During the growth period of rice, the rainfall is usually relatively abundant. When the rainfall is large, the surface water overflows the ridge and flows out of the field block, resulting in nutrient loss, affecting crop yields, aggravating the risk of non-point source pollution in farmland, and possibly damaging the ridge.

[0003] At present, the monitoring of non-point source pollution runoff loss in paddy fields is mainly the runoff pond (box, barrel) method. This method has high input and large floor area, and is not suitable for paddy terraced fields. Paddy terraced fields are in a state of long-term flooding and less drainage. The drainage efficiency of temporarily digging drainage outlets on the ridge is difficult to meet the requirements when the rainfall is large. Therefore, a method for estimating and predicting non-point source pollution at the scale of the paddy field to be measured in paddy terraced fields under rainfall drive is needed to accurately predict and control the nitrogen and phosphorus emissions of the paddy field to be measured, so as to guide farmers to stagger the fertilizer application time from the emission risk period, which is beneficial to the scientific prevention and control of agricultural non-point source pollution in the future. Summary of the Invention

[0004] The main purpose of the present application is to provide a method for measuring the nitrogen and phosphorus emissions of paddy terraced fields, aiming to solve the problem of how to measure the nitrogen and phosphorus emissions in paddy terraced fields.

[0005] To achieve the above object, a method for measuring the nitrogen and phosphorus emissions of paddy terraced fields provided by the present application is applied to a ridge overflow measurement device. The ridge overflow measurement device includes a runoff collection plate with a switch-type drainage outlet at the bottom. One side of the runoff collection plate is communicated with a sedimentation tank. A drainage outlet is opened on the upper side of the sedimentation tank and drained through a water pipe. A water meter for collecting the drainage volume / overflow volume is arranged on the water pipe. The method includes the following steps:

[0006] (1) Measurement of overflow water volume and overflow nitrogen and phosphorus concentration

[0007] Record the water meter reading, the width of the runoff collection plate, and the length of the ridge of the paddy terraced field to be measured. According to the water meter reading, the width of the runoff collection plate, and the length of the ridge, calculate the overflow volume V 1 of the paddy terraced field to be measured, and measure the overflow nitrogen and phosphorus concentration C 1 in the sedimentation tank;

[0008] Wherein:

[0009]

[0010] In the formula, V 0 is the overflow water indication number in the ridge, W is the width of the runoff collection board, and L is the length of the ridge of the field plot;

[0011] (2) Measurement of drainage water volume and drainage nitrogen and phosphorus concentrations

[0012] When the paddy field needs to be drained, place the collection board at the bottom of the drainage outlet and 3 - 5 cm above the paddy field surface, open the switch - type drainage outlet, record the water meter reading at this time and calculate the drainage water volume V 2 , and measure the drainage nitrogen and phosphorus concentration C in the sedimentation tank 2 ;

[0013] (3) Calculation of nitrogen and phosphorus emission amounts

[0014] Calculate the nitrogen and phosphorus emission amount Load of the paddy field to be measured according to the overflow volume, the overflow nitrogen and phosphorus concentration, the drainage water volume and the drainage nitrogen and phosphorus concentration:

[0015]

[0016] In the formula, i is the i - th drainage of the ridge overflow, n is the number of times of ridge overflow in the rice growing season, j is the j - th artificial drainage of the paddy field to be measured, m is the number of times of drainage, C 1i is the overflow nitrogen and phosphorus concentration at the i - th overflow of the ridge, V 1i is the overflow volume at the i - th overflow of the ridge, C 2j is the drainage nitrogen and phosphorus concentration at the j - th drainage of the paddy field to be measured, V 2j is the drainage volume at the j - th drainage of the paddy field to be measured, and A is the area of the paddy field to be measured.

[0017] Optionally, the method further includes:

[0018] (4) Prediction of nitrogen and phosphorus emission amounts in rice terraces considering rainfall

[0019] (4.1) If there is no ridge overflow in the rice terrace to be measured, that is, the inflow volume I, rainfall R, paddy field water height h and ridge height H of the rice terrace satisfy I + R+h < H, use the following formula to predict the nitrogen and phosphorus emission amount L′ of the rice terrace:

[0020]

[0021] Among them, V tj = Δh * A

[0022] In the formula, j is the j - th artificial drainage of the paddy field to be measured, m is the number of drainage times, C tj is the average nitrogen and phosphorus emission concentration in the same month of the previous year during the drainage of the paddy field to be measured, V tjIt is the product of the difference in the depth of surface water in the paddy field before and after drainage, Δh, and the area of the paddy field to be measured, A.

[0023] (4.2) If there is an overflow from the ridge in the paddy field to be measured, measure the inflow I, rainfall R, surface water height h, and ridge height H of the paddy field, and use the following formula to predict the nitrogen and phosphorus emissions L′′ of the paddy field:

[0024]

[0025] Where:

[0026] V ti =(R ti +I ti -H ti +h ti )×A×a ave

[0027]

[0028] In the formula, I + R + h > H, V ti is the predicted water volume of the i-th overflow of the paddy field to be measured, C ti is the average value of the nitrogen and phosphorus concentrations in the surface water of the previous year in the month of the i-th overflow of the paddy field to be measured, C tj is the average value of the nitrogen and phosphorus concentrations in the drainage of the previous year in the month of the j-th drainage of the paddy field to be measured, V tj is the product of the predicted value of the difference in surface water depth Δh before and after the j-th drainage and the area A of the paddy field to be measured, a ave is the average value of the overflow coefficients, R ti is the rainfall before the i-th overflow, I ti is the inflow of the paddy field before the i-th overflow, H is the ridge height, h ti is the surface water height before the i-th overflow 。 According to the measured overflow volume V of the ridge in (1) 1i , R i is the cumulative rainfall before the i-th overflow of the paddy field to be measured, I i is the cumulative inflow of the paddy field to be measured during the i-th overflow of the paddy field, h i is the surface water height before the i-th overflow of the paddy field to be measured, calculate the single overflow coefficient a i of the paddy field to be measured, and the average value a ave of the multiple overflow coefficients.

[0029] Optionally, after the above (4), it further includes:

[0030] (5) Ridge height regulation

[0031] Regulate the ridge height H according to the following formula t :

[0032] H t (R * +50~60)*a ave

[0033] In the formula, R * is the maximum single rainfall, and a ave is the overflow coefficient.

[0034] Optionally, the determination method of the overflow nitrogen and phosphorus concentration C 1 and the drainage nitrogen and phosphorus concentration C 2 is to take a water sample from the sedimentation tank into a polyethylene bottle for determination.

[0035] Optionally, the water pipe includes a first water pipe and a second water pipe. One side of the first water pipe is communicated with the drainage port, and the other side is bent downward and communicated with one side of the second water pipe. The water meter is arranged on the second water pipe.

[0036] Optionally, the runoff collection plate includes a rectangular plate and a trapezoidal plate. One side of the rectangular plate is connected to the bottom edge of the trapezoidal plate, and the width is greater than or equal to 5-10 cm of the ridge width. The top angle of the trapezoidal plate inclines downward to be lower than the horizontal plane where the rectangular plate is located.

[0037] This application has at least the following beneficial effects:

[0038] Aiming at the problem that the nitrogen and phosphorus emissions of paddy terraces cannot be estimated and predicted, a ridge overflow device is designed to monitor the ridge overflow and drainage volume, combined with the detection of the drainage nitrogen and phosphorus concentration, to estimate the nitrogen and phosphorus emissions at the terrace plot scale. According to the ridge overflow volume, a ridge overflow coefficient is constructed to provide parameters for predicting the ridge overflow volume, and then the ridge height is regulated to provide support for effective fertilization of farmland and prevention of agricultural non-point source pollution. Description of the Drawings

[0039] Figure 1 is a schematic top view of the structure of the ridge overflow volume measuring device involved in the embodiment of the present application;

[0040] Figure 2 is a step flow chart of a method for calculating the nitrogen and phosphorus emissions of a paddy terrace in the present application;

[0041] Figure 3 is a schematic installation position diagram of the ridge overflow volume measuring device involved in the embodiment of the present application;

[0042] Figure 4 is a schematic front view of the structure of the ridge overflow volume measuring device involved in the embodiment of the present application;

[0043] Figure 5Schematic diagram of the positional relationship between the width of the rectangular plate of the runoff collection plate involved in the embodiments of the present application and the length of the ridge of the rice paddy terrace to be measured.

[0044] The realization of the purpose of the present application, functional features and advantages will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific embodiments

[0045] To better understand the above technical solutions, the exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0046] First embodiment

[0047] In this embodiment, referring to Figure 1 the top view of the structural schematic diagram of the ridge overflow measurement device shown, the ridge overflow measurement device includes a runoff collection plate 1 with a switch-type drain opening 2 provided at the bottom. One side of the runoff collection plate 1 is communicated with a sedimentation tank 3. A drain opening 4 is opened on the upper side of the sedimentation tank 3 and drained through a water pipe 5. A water meter 6 for collecting the drainage volume / overflow volume is provided on the water pipe 4.

[0048] Based on the architecture of this device, referring to Figure 2 , the steps of the method for measuring the nitrogen and phosphorus emissions of the rice paddy terrace in this embodiment are proposed:

[0049] Step S10, determination of the overflow water volume and the overflow nitrogen and phosphorus concentration

[0050] Record the water meter reading, the width W of the runoff collection plate, and the length L of the ridge of the rice paddy terrace to be measured. According to the water meter reading, the width of the runoff collection plate, and the length of the ridge, calculate the overflow volume V 1 of the rice paddy terrace to be measured, and measure the overflow nitrogen and phosphorus concentration C 1 in the sedimentation tank.

[0051] Where:

[0052]

[0053] In the formula, V 0 is the overflow water meter reading in the ridge, W is the width of the runoff collection plate, and L is the length of the ridge of the field block;

[0054] Step S20, determination of the drainage water volume and the drainage nitrogen and phosphorus concentration

[0055] Referring to Figure 3Schematic diagram of the installation position of the ridge overflow measurement device shown. When the paddy field needs to drain the surface water, dig a certain depth in the ridge to form a drainage channel, place the collection plate at the bottom of the drainage channel and 3 - 5 cm above the paddy field surface, that is, keep 3 - 5 cm deep surface water after drainage, open the switch - type drainage port, record the water meter reading at this time and calculate the drainage volume V 2 Measure the drainage nitrogen and phosphorus concentration C in the sedimentation tank 2 ;

[0056] Step S30, calculation of nitrogen and phosphorus emission

[0057] Calculate the nitrogen and phosphorus emission Load of the paddy field to be measured according to the overflow volume, the overflow nitrogen and phosphorus concentration, the drainage volume and the drainage nitrogen and phosphorus concentration:

[0058]

[0059] In the formula, i is the i - th drainage of the ridge overflow, n is the number of times of ridge overflow in the rice growing season, j is the j - th artificial drainage of the paddy field to be measured, m is the number of times of drainage, C 1i is the overflow nitrogen and phosphorus concentration at the i - th ridge overflow, V 1i is the overflow volume at the i - th ridge overflow, C 2j is the drainage nitrogen and phosphorus concentration at the j - th drainage of the paddy field to be measured, V 2j is the drainage volume at the j - th drainage of the paddy field to be measured, and A is the area of the paddy field to be measured.

[0060] Second embodiment

[0061] Based on the first embodiment, in this embodiment, referring to Figure 4 the front view of the ridge overflow measurement device shown, the water pipe 5 includes a first - section water pipe 51 and a second - section water pipe 52. One side of the first - section water pipe 51 is connected to the drainage port 4, and the other side bends downward and is connected to one side of the second - section water pipe 52. A water meter 6 is provided on the second - section water pipe 52.

[0062] Furthermore, the runoff collection plate 1 includes a rectangular plate 11 and a trapezoidal plate 12. Referring to Figure 5 the schematic diagram of the positional relationship between the width of the rectangular plate of the runoff collection plate and the length of the ridge of the paddy field to be measured shown, one side of the rectangular plate 11 is connected to the bottom edge of the trapezoidal plate 12, and the top angle of the trapezoidal plate 12 inclines downward to be lower than the horizontal plane where the rectangular plate 11 is located.

[0063] It should be noted that, in order to facilitate the fixation of the runoff collection plate on the ridge, the width of the rectangular plate should be greater than or equal to 5 - 10 cm of the ridge width, which is convenient for installing brackets on both sides of the rectangular plate.

[0064] Third embodiment

[0065] Based on the first embodiment, in this embodiment, the prediction of nitrogen and phosphorus emissions from paddy terraces with rainfall introduced is specifically as follows:

[0066] (4.1) If there is no overland flow on the ridge of the paddy terrace to be measured, the following formula is used to predict the nitrogen and phosphorus emissions L′ of the paddy terrace:

[0067]

[0068] V tj = Δh * A

[0069] In the formula, I + R + h < H, j is the jth artificial drainage of the paddy field to be measured, m is the number of drainage times, C tj is the average concentration of nitrogen and phosphorus in the drainage of the previous year in the month when the paddy field to be measured is drained, V tj is the product of the difference Δh in the water depth on the paddy field surface before and after drainage and the area A of the paddy field to be measured;

[0070] (4.2) If there is overland flow on the ridge of the paddy terrace to be measured, measure the inflow I, rainfall R, water depth h on the paddy field surface and ridge height H of the paddy terrace, and use the following formula to predict the nitrogen and phosphorus emissions L′′ of the paddy terrace:

[0071]

[0072] Among them:

[0073] V ti =(R ti + I ti - H ti + h ti ) × A × a ave

[0074]

[0075] In the formula, I + R + h > H, V ti is the predicted water volume of the ith overland flow of the paddy field to be measured, C ti is the average value of the nitrogen and phosphorus concentration in the water on the paddy field surface in the previous year in the month of the ith overland flow of the paddy field to be measured, C tj is the average value of the nitrogen and phosphorus concentration in the drainage of the previous year in the month of the jth drainage of the paddy field to be measured, V tj is the product of the predicted value Δh of the difference in the water depth on the paddy field surface before and after the jth drainage and the area A of the paddy field to be measured, a ave is the average value of the overland flow coefficient, R ti is the rainfall before the ith overland flow occurs, I ti is the inflow of the paddy field before the ith overland flow occurs, H is the ridge height, h ti is the water depth on the paddy field surface before the ith overland flow occurs. According to the measured overland flow volume V 1i of the ith ridge in (1), R iis the cumulative rainfall before the i-th overflow of the paddy field to be measured, I i is the cumulative water inflow of the paddy field to be measured during the i-th overflow of the paddy field to be measured, h i is the water level on the paddy field surface before the i-th overflow of the paddy field to be measured, and calculate the single overflow coefficient a of the paddy field to be measured i , and the average value of the multiple overflow coefficients a ave .

[0076] The third embodiment

[0077] Based on the second embodiment, in this embodiment, the ridge height is regulated based on the overflow coefficient constructed in the above scheme:

[0078] Regulate the ridge height H according to the following formula t :

[0079] H t (R * +50 - 60)*a ave

[0080] In the formula, R * is the single maximum rainfall, and a ave is the overflow coefficient.

[0081] The fourth embodiment

[0082] As an implementation scheme, this embodiment selects the Hani rice terraced fields area to estimate and regulate the nitrogen and phosphorus emissions of the fields.

[0083] (1) Estimation of nitrogen and phosphorus emissions at the field scale. The field area is 2 mu, the ridge length is 65 m, the ridge height is 10 cm, the water level on the paddy field surface is 5 cm, the width of the ridge runoff collection board is 30 cm, and a total of 6 times of ridge runoff are collected, and there is no drainage at the drainage outlet. The ridge overflow device monitors the ridge overflow, calculates the overflow volume of the field, and combines the drainage nitrogen and phosphorus concentrations to estimate the nitrogen and phosphorus emissions of the field. The results are shown in Table 1 below:

[0084] Table 1 Nitrogen and phosphorus emissions of the field during the rice season

[0085]

[0086] (2) Calculation of the ridge overflow coefficient of the rice terraced fields. The ratio of the monitored overflow volume to the theoretical overflow volume is the overflow coefficient, and the average value is 0.95. The obtained ridge overflow coefficients are shown in Table 2 below:

[0087]

[0088] (3) Prediction of the ridge overflow volume and nitrogen and phosphorus emissions

[0089] When harvesting in September, the water level on the paddy field surface drops from 5 cm to 3 cm, and the predicted drainage volume of the field is 40 m 3The nitrogen and phosphorus emissions of the field plot are the sum of the nitrogen and phosphorus emissions from the ridge overflow and the nitrogen and phosphorus emissions from drainage.

[0090] Table 3 Prediction of Ridge Overflow Volume

[0091] Month Inflow (mm) Rainfall (mm) Water depth on field surface (mm) Overflow coefficient Predicted overflow volume of field block (mm) 6 98.95 51.6 50 0.95 95.5 6 120.69 58.8 50 0.95 123.0 8 230.88 50.6 50 0.95 219.9 8 144.68 57.8 50 0.95 144.9 8 155.17 60.4 50 0.95 157.3

[0092] Table 4 Prediction of Nitrogen and Phosphorus Emissions of Field Plot

[0093]

[0094]

[0095] (4) Regulation of Ridge Height

[0096] When the maximum single rainfall is 60.4 mm, the water level on the field surface is controlled at 5 - 6 cm, and the overflow coefficient is 0.95, the ridge height is controlled at 10.5 - 11.4 cm to prevent rainfall-driven ridge overflow.

[0097] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments as well as all changes and modifications falling within the scope of the present application.

[0098] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method for calculating nitrogen and phosphorus emissions from rice terraces, characterized in that: Applied to the ridge overflow measurement device, the ridge overflow measurement device includes a runoff collection plate with a switch-type drain opening at the bottom. One side of the runoff collection plate is communicated with a sedimentation tank. A drain opening is provided on the upper side of the sedimentation tank and drained through a water pipe. A water meter for collecting the drainage volume / overflow volume is arranged on the water pipe. The method includes the following steps: (1) Measurement of overflow water volume and overflow nitrogen and phosphorus concentration Record the water meter reading, the width of the runoff collection plate, and the length of the ridge of the rice paddy terrace to be measured. According to the water meter reading, the width of the runoff collection plate, and the length of the ridge, calculate the overflow volume V1 of the rice paddy terrace to be measured, and measure the overflow nitrogen and phosphorus concentration C1 in the sedimentation tank; Wherein: In the formula, V0 is the water meter reading of the overflow water in the ridge, W is the width of the runoff collection plate, and L is the length of the ridge of the field; (2) Measurement of drainage water volume and drainage nitrogen and phosphorus concentration When the paddy field needs to be drained, place the collection plate at the bottom of the drain opening and 3-5 cm above the paddy field surface. Open the switch-type drain opening, record the water meter reading at this time as the drainage water volume V2, and measure the drainage nitrogen and phosphorus concentration C2 in the sedimentation tank; (3) Calculation of nitrogen and phosphorus emissions Calculate the nitrogen and phosphorus emissions Load of the paddy field to be measured according to the overflow volume, the overflow nitrogen and phosphorus concentration, the drainage water volume, and the drainage nitrogen and phosphorus concentration: In the formula, i is the i-th drainage of the ridge overflow, n is the number of ridge overflows during the rice growing season, j is the j-th artificial drainage of the tested rice field, m is the number of drainages, and C 1i is the overflow nitrogen and phosphorus concentration of the ridge at the i-th overflow, V 1i is the i-th overflow of the ridge, C 2j is the nitrogen and phosphorus concentration of the drainage water during the jth drainage of the tested paddy field, V 2j is the j-th drainage volume of the paddy field to be tested, and A is the area of ​​the paddy field to be tested.

2. The method according to claim 1, characterized in that The method further includes: (4) Prediction of nitrogen and phosphorus emissions in rice paddy terraces considering rainfall (4.1) If there is no ridge overflow in the rice paddy terrace to be measured, that is, the inflow volume I, rainfall R, water height h on the paddy field surface, and ridge height H of the rice paddy terrace satisfy I + R + h < H, use the following formula to predict the nitrogen and phosphorus emissions L′ of the rice paddy terrace: Where: V tj =Δh*A Where I + R + h < H, j is the j-th artificial drainage of the paddy field to be measured, m is the number of drainage times, C tj is the average concentration of nitrogen and phosphorus in the previous-year drainage in the month of the j-th drainage of the paddy field to be measured, V tj is the product of the difference Δh in the water depth on the paddy field surface before and after the j-th drainage and the area A of the paddy field to be measured; (4.2) If there is ridge overflow in the rice paddy terrace to be measured, measure the inflow volume I, rainfall R, water height h on the paddy field surface, and ridge height H of the rice paddy terrace, and use the following formula to predict the nitrogen and phosphorus emissions L′′ of the rice paddy terrace: Wherein: V ti =(R ti +I ti +h ti -H)×A×a ave In the formula, I+R+h>H, V ti is the predicted water volume of the i-th overflow of the tested paddy field, C ti is the average nitrogen and phosphorus concentration of the surface water in the rice field in the previous years in the month of the i-th overflow, C tj V is the average nitrogen and phosphorus concentration of the paddy field to be tested in the previous years during the month of drainage for the jth drainage. tj is the product of the predicted value of the difference in field water depth before and after the jth drainage, Δh, and the area of ​​the paddy field to be tested, A. ave is the mean overflow coefficient, R ti is the rainfall before the i-th overflow, I ti is the water inflow of the paddy field before the i-th overflow occurs, H is the height of the ridge, h ti is the water height of the field surface before the i-th overflow. According to the i-th overflow volume V of the field ridge measured in (1), 1i , R i is the cumulative rainfall before the i-th overflow of the tested paddy field, I i is the cumulative water inflow of the tested paddy field when it overflows for the i-th time, h i is the surface water height of the tested rice field before the i-th overflow, and the single overflow coefficient a of the tested rice field is calculated. i , and the mean value a of the multiple overflow coefficients ave .

3. The method according to claim 2, characterized in that After the step (4), it further includes: (5) Ridge height regulation The ridge height H is regulated according to the following formula: t : H t >(R * +50~60)*a ave In the formula, R * is the maximum single rainfall amount, a ave For the overflow coefficient, keep the water height on the field surface at 5-6cm.

4. The method according to claim 1, characterized in that The measurement methods of the overflow nitrogen and phosphorus concentration C1 and the drainage nitrogen and phosphorus concentration C2 are to take samples of the water in the sedimentation tank into polyethylene bottles for measurement.

5. The method according to claim 1, characterized in that The water pipe includes a first section of water pipe and a second section of water pipe. One side of the first section of water pipe is communicated with the drain opening, and the other side bends downward and is communicated with one side of the second section of water pipe. The water meter is arranged on the second section of water pipe.

6. The method according to claim 1, characterized in that The runoff collection plate includes a rectangular plate and a triangular plate. One side of the rectangular plate is connected to the bottom edge of the triangular plate and the width is greater than or equal to 5-10 cm of the ridge width. The top angle of the triangular plate inclines downward to be lower than the horizontal plane where the rectangular plate is located.

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