A non-uniform fertilization method for controlling ground-source pollution in sloping farmland

Abstract

This invention discloses a non-uniform fertilization method for controlling non-point source pollution in sloping farmland, comprising: determining the type of cultivated crop and fertilization spacing based on the slope of the target treatment area; dividing the target treatment area into several plots of the same size, determining the slope length based on the slope of each plot, and dividing each plot into three slope positions: the foot, the middle, and the top; determining the fertilization amount at the top of the corresponding plot based on the soil nutrient background value; fertilizing each plot in the target treatment area, with the fertilization amount decreasing proportionally at the top, middle, and foot of the slope; collecting surface runoff samples generated after rainfall at the lower part of each plot, measuring pollutant indicators in the collected water samples to obtain non-point source pollution results; and after the crops on the sloping farmland are harvested, measuring and calculating the crop's fertilizer absorption and utilization efficiency, and obtaining the crop output under non-uniform fertilization. This invention can effectively reduce non-point source pollution in sloping farmland while ensuring crop yield, and has the advantage of low cost.

Description

Technical Field

[0001] This invention relates to methods for controlling non-point source pollution in farmland, specifically to a non-uniform fertilization method for controlling non-point source pollution in sloping farmland. Background Technology

[0002] Sloping farmland accounts for 17.5% of my country's arable land, playing a vital role in ensuring grain production. However, due to its unique topography, sloping farmland is susceptible to nitrogen and phosphorus migration and agricultural non-point source pollution due to rainfall erosion and infiltration. In particular, the application of large amounts of chemical fertilizers to increase crop yields undoubtedly exacerbates nutrient loss from sloping farmland and causes even more severe non-point source pollution in nearby waterways. Currently, methods to address non-point source pollution from sloping farmland include artificial wetlands, ecological interception ditches, vegetation barriers, and chemical soil conditioners. These methods are costly, and some may alter soil properties or compete with crops for nutrients, leading to reduced yields. Furthermore, these methods are process interception technologies and do not control non-point source pollution at its source. Source reduction primarily involves optimizing production processes to reduce the generation and emission of agricultural non-point source pollution.

[0003] In summary, while ensuring the yield and quality of grain on sloping farmland, it is an urgent problem to explore low-cost solutions that are suitable for the unique topographical conditions of sloping farmland and can effectively reduce non-point source pollution generated by agricultural activities on sloping farmland from the source. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to address the problems pointed out in the background art by providing a low-cost non-uniform fertilization method for controlling agricultural non-point source pollution on sloping farmland. By applying unequal amounts of fertilizer at different locations along the slope direction, the total amount of fertilizer applied to sloping farmland can be reduced while ensuring grain yield and quality, thereby achieving source control of agricultural non-point source pollution on sloping farmland.

[0005] Technical solution: The non-uniform fertilization method for controlling ground-source pollution on sloping farmland as described in this invention includes:

[0006] (1) Determine the slope and topographic conditions of the target treatment area, and determine the types of cultivated crops and fertilization intervals according to the slope. The slope range is 5° to 25°.

[0007] (2) Divide the target treatment area into several fields of the same size, determine the slope length according to the slope of the field, and divide each field into three slope positions: the foot of the slope, the middle of the slope, and the top of the slope.

[0008] (3) Analyze the soil nutrient background values ​​of each field in the target treatment area, and determine the amount of fertilizer to be applied to the top of the slope of each field based on the soil nutrient background values;

[0009] (4) Apply fertilizer to each field in the target treatment area, and reduce the amount of fertilizer applied at the top, middle and bottom of the slope by 20% to 40%.

[0010] Furthermore, in step (1), when the slope of the sloping farmland is 5° to 15°, grain crops including corn and wheat are planted, and the distance between fertilization points is small; when the slope of the sloping farmland is 15° to 25°, economic fruit forests including fruit trees and tea trees are planted, and the distance between fertilization points is large.

[0011] Furthermore, in step (2), when the slope is 5°, the slope length is controlled to be 10 meters; when the slope is 25°, the slope length is controlled to be 5 meters; the slope lengths corresponding to other slopes are linearly interpolated in this way.

[0012] Furthermore, the three slope positions—the foot, middle, and top—are divided at equal distances upwards along the slope direction according to the length of the field.

[0013] Furthermore, in step (3), the soil nutrient background values ​​include total nitrogen content, total phosphorus content, and total potassium content. The soil nutrient background values ​​of each field are divided into three levels: low, medium, and high. When total nitrogen < 0.35 g·kg -1 Total phosphorus <0.3 g·kg -1 Total potassium <12g·kg -1 At that time, it was at a low level; when total nitrogen was 0.35–0.65 g·kg⁻¹. -1 Total phosphorus 0.3–0.5 g·kg -1 Total potassium 12-20 g / kg -1 When the total nitrogen level is >0.65 g·kg⁻¹, it is considered a medium level; when the total nitrogen level is >0.65 g·kg⁻¹, it is considered a medium level. -1 Total phosphorus >0.5 g·kg -1 Total potassium >20g·kg -1 At that time, it was at a high level;

[0014] Under low, medium, and high soil nutrient background levels, the amount of fertilizer applied to the top of the slope corresponds to three levels: high, medium, and low, respectively.

[0015] Furthermore, in step (4), hole application or surface application is selected according to the growth of different crops.

[0016] Furthermore, the fertilization method for controlling ground-source pollution in sloping farmland also includes:

[0017] (5) Collect surface water and soil loss samples generated after rainfall at the foot of the slope of each field, stir the runoff water samples within a preset time period to obtain water and soil samples; analyze and measure the pollutants carried by the water and soil samples to obtain the results of non-point source pollution generated under non-uniform fertilization on sloping farmland.

[0018] Furthermore, in step (5), surface water and soil erosion samples are collected through a surface runoff collection device; the pollutant indicators to be analyzed include total phosphorus, total nitrogen, ammonium nitrogen and nitrate nitrogen, and the non-point source pollution results are determined based on the content of these nutrients in the erosion samples.

[0019] Furthermore, the fertilization method for controlling ground-source pollution in sloping farmland also includes:

[0020] (6) After the crops are harvested on sloping farmland, the efficiency of crop absorption and utilization of fertilizer is measured and calculated, and the crop output under non-uniform fertilization is obtained.

[0021] Furthermore, in step (6), the crop’s fertilizer absorption and utilization efficiency includes the crop’s roots, stems and leaves’ absorption and utilization efficiency of nitrogen and phosphorus. The crop output is mainly dry matter output. The crop’s fertilizer absorption and utilization efficiency and crop output are calculated and accumulated according to the three slope positions of the slope foot, middle and top of each field to obtain the fertilizer utilization rate and crop output of each field.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0023] (1) The present invention determines the type of cultivated crop, the spacing between fertilization points and the slope length of the field to be treated based on the terrain slope, which effectively reduces the nutrient loss caused by the terrain slope.

[0024] (2) Based on the nutrient background value of the target cultivated area, the present invention determines the amount of fertilizer to be applied, adapts to local conditions, and strictly controls the application of fertilizer in the cultivation of sloping farmland, thereby effectively controlling agricultural non-point source pollution.

[0025] (3) This invention can reduce the amount of chemical fertilizer applied to sloping farmland while ensuring crop growth and output, thereby reducing non-point source pollution generated from the source in agricultural cultivation on sloping farmland.

[0026] (4) This invention utilizes the characteristics of soil and water loss along the slope under the unique topographic conditions of sloping farmland to apply fertilizer in a decreasing manner along the slope, which more effectively redistributes nutrients in sloping farmland, thereby improving the absorption and utilization efficiency of fertilizer by crops on sloping farmland.

[0027] (5) It effectively reduces the amount of fertilizer used and is inexpensive. Attached Figure Description

[0028] Figure 1 This is a flowchart of a non-uniform fertilization method for treating ground-source pollution on sloping farmland, provided in an embodiment of this application.

[0029] Figure 2 The examples in this application are three groups of six fields grouped according to the background values ​​of soil nutrients. Detailed Implementation

[0030] The invention will now be further described with reference to the accompanying drawings.

[0031] like Figure 1 As shown in the figure, this application provides a method for non-uniform fertilization to control ground-source pollution on sloping farmland, including the following steps:

[0032] (1) Determine the slope and topographic conditions of the target treatment area, and determine the types of cultivated crops and the spacing of fertilization according to the slope. The slope range is 5° to 25°. Specifically, when the slope of the sloping farmland is 5° to 15°, grain crops such as corn and wheat are planted, and the spacing of fertilization points is small; when the slope of the sloping farmland is 15° to 25°, economic fruit forests such as fruit trees and tea trees are planted, and the spacing of fertilization points is large.

[0033] (2) Divide the target treatment area into several plots of the same size. Determine the slope length according to the slope of the plot. When the slope is 5°, the slope length is controlled at 10 meters; when the slope is 25°, the slope length is controlled at 5 meters; the slope length for other slopes is linearly interpolated accordingly. Divide each plot into three slope positions: slope foot, slope middle, and slope top, at equal distances along the slope direction according to the slope length of the plot.

[0034] (3) Analyze the soil nutrient background values ​​of each field in the target treatment area, and determine the amount of fertilizer to be applied to the top of the slope of each field based on the soil nutrient background values;

[0035] Soil nutrient background values ​​include total nitrogen, total phosphorus, and total potassium content. The soil nutrient background values ​​of each field were categorized as low (total nitrogen <0.35 g·kg⁻¹). -1 Total phosphorus <0.3 g·kg -1 Total potassium <12g·kg -1 Medium level (total nitrogen 0.35–0.65 g·kg⁻¹) -1 Total phosphorus 0.3–0.5 g·kg -1 Total potassium 12-20 g / kg -1 ) and high levels (total nitrogen >0.65 g·kg -1 Total phosphorus >0.5 g·kg -1 Total potassium >20g·kg -1 The soil nutrient background values ​​are classified into three levels: low, medium, and high. The amount of compound fertilizer (nitrogen, phosphorus, and potassium ratio of 30:12:8) applied to the top of the slope corresponds to three levels: high (140 kg / mu), medium (120 kg / mu), and low (100 kg / mu).

[0036] (4) Apply fertilizer to each field in the target treatment area, with the amount of fertilizer applied at the top, middle and bottom of the slope decreasing by 20% to 40%. When applying fertilizer, choose hole application or surface application according to the growth of different crops.

[0037] (5) Collect surface water and soil loss samples generated after rainfall at the foot of the slope of each field using a surface runoff collection device. Stir the runoff water samples within a preset time period to obtain water and soil samples. Analyze and determine the pollutants carried by the water and soil samples. The pollutant indicators analyzed include total phosphorus, total nitrogen, ammonium nitrogen and nitrate nitrogen. Based on the content of these nutrients in the lost samples, determine the non-point source pollution results generated under non-uniform fertilization on sloping farmland.

[0038] (6) After the crops are harvested on sloping farmland, the efficiency of crop absorption and utilization of fertilizer is measured and calculated, and the crop output under non-uniform fertilization is obtained.

[0039] The efficiency of crop fertilizer absorption and utilization includes the efficiency of crop roots, stems and leaves in absorbing and utilizing nitrogen and phosphorus. Crop output is mainly dry matter yield. The efficiency of crop fertilizer absorption and utilization and crop output are calculated and accumulated according to the three slope positions of each field: the foot of the slope, the middle of the slope and the top of the slope, to obtain the fertilizer utilization rate and crop yield of each field.

[0040] Here is a specific example.

[0041] This example selects an agricultural planting area with concentrated yellow clay soil in the south as the target treatment area. The area is no less than 50m away from the agricultural activity area, and there are no obstructions of preset height within the set range of the agricultural activity area, so that the soil type, fertility level, farming method, irrigation and drainage conditions, planting system, slope and aspect can represent the local conventional agricultural production conditions.

[0042] (1) The slope of the target treatment area was measured to be 8°. Taiyu 339 summer maize was selected as the test variety. It was planted for one season, with a spacing of 0.4m along the slope and 0.6m across the slope. It was planted evenly in late May.

[0043] (2) The target treatment area was divided into 6 plots of the same size. The slope length was obtained by linear interpolation based on the slope of 8°. The slope length was 9.25m. Each plot was divided into three slope positions at equal intervals along the slope direction: top, middle and bottom.

[0044] (3) The soil nutrient background values ​​of the six plots were analyzed, and the plots were classified as high, medium, and low. Two plots were identified as high, two as medium, and two as low. One plot from each level was used as a control (using uniform fertilization). Figure 2 As shown, the entire field in the blank treatment was fertilized uniformly according to the fertilizer application rate at the top of the slope.

[0045] (4) In a field with a medium soil nutrient background value, when planting corn, apply Stanley compound fertilizer (nitrogen, phosphorus and potassium ratio of 30:12:8) 120 kg / mu at the top of the slope, apply fertilizer 84 kg / mu in the middle of the slope, and apply fertilizer 48 kg / mu in the foot of the slope.

[0046] In a field with high soil nutrient background levels, when planting corn, apply 100 kg / mu of Stanley compound fertilizer (nitrogen, phosphorus and potassium ratio of 30:12:8) in the hole at the top of the slope, 70 kg / mu of fertilizer in the hole in the middle of the slope, and 40 kg / mu of fertilizer in the hole at the foot of the slope.

[0047] In one field with low soil nutrient background, apply Stanley compound fertilizer (NPK ratio of 30:12:8) at the top of the slope at the time of rice sowing, apply fertilizer at the middle of the slope at 98 kg / mu, and apply fertilizer at the location at 56 kg / mu.

[0048] (5) The chemical composition of total phosphorus, total nitrogen, ammonium nitrogen and nitrate nitrogen was analyzed and calculated from the runoff samples of the six fields to obtain the results of non-point source pollution, as shown in Table 1.

[0049] Table 1

[0050]

[0051] As shown in Table 1, under the same soil nutrient background level, the nutrient loss from non-uniform fertilization was less than that from uniform fertilization in the control treatment.

[0052] (6) After the corn is harvested in the field, the efficiency of corn absorption and utilization of fertilizer and the yield of corn dry matter are measured and calculated, as shown in Table 2.

[0053] Table 2

[0054]

[0055] As shown in Table 2, under the same soil nutrient background level, the nitrogen and phosphorus absorption and utilization efficiency of non-uniform fertilization was higher than that of uniform fertilization in the control treatment, while the maize yield was similar under the two fertilization methods. This indicates that non-uniform fertilization can improve the absorption of nitrogen and phosphorus by maize and maintain a good yield. Combined with Table 1, it can be seen that non-uniform fertilization reduces non-point source pollution while ensuring crop yield.

Claims

1. A non-uniform fertilization method for controlling ground-source pollution in sloping farmland, characterized in that, include: (1) Determine the slope and topographic conditions of the target treatment area, and determine the types of cultivated crops and fertilization intervals according to the slope. The slope range is 5°~25°. (2) Divide the target treatment area into several fields of the same size, determine the slope length according to the slope of the field, and divide each field into three slope positions: the foot of the slope, the middle of the slope, and the top of the slope. (3) Analyze the soil nutrient background values ​​of each field in the target treatment area, and determine the amount of fertilizer to be applied to the top of the slope of each field based on the soil nutrient background values; the soil nutrient background values ​​include the total nitrogen content, total phosphorus content and total potassium content of the soil, and divide the soil nutrient background values ​​of each field into three levels: low level, medium level and high level. When the total nitrogen content is <0.35g·kg -1 Total phosphorus <0.3 g·kg -1 Total potassium <12g·kg -1 At that time, it was at a low level; when total nitrogen was 0.35~0.65 g·kg⁻¹. -1 Total phosphorus 0.3~0.5 g·kg -1 Total potassium 12~20g·kg -1 When the total nitrogen level is >0.65 g·kg⁻¹, it is considered a medium level; when the total nitrogen level is >0.65 g·kg⁻¹, it is considered a medium level. -1 Total phosphorus >0.5 g·kg -1 Total potassium >20g·kg -1 At that time, it was considered a high level; under low, medium, and high soil nutrient background values, the amount of fertilizer applied to the top of the slope corresponded to three orders of magnitude: high, medium, and low, respectively. (4) Apply fertilizer to each field in the target treatment area, and reduce the amount of fertilizer applied at the top, middle and bottom of the slope by 20% to 40%.

2. The non-uniform fertilization method for controlling ground-source pollution on sloping farmland according to claim 1, characterized in that, In step (1), when the slope of the sloping farmland is 5°~15°, grain crops including corn and wheat are planted, and the distance between fertilization points is small; when the slope of the sloping farmland is 15°~25°, economic fruit forests including fruit trees and tea trees are planted, and the distance between fertilization points is large.

3. The non-uniform fertilization method for controlling ground-source pollution on sloping farmland according to claim 1, characterized in that, In step (2), when the slope is 5°, the slope length is controlled to be 10 meters; when the slope is 25°, the slope length is controlled to be 5 meters; the slope lengths for other slopes are linearly interpolated in this way.

4. The non-uniform fertilization method for controlling ground-source pollution on sloping farmland according to claim 3, characterized in that, The slope is divided into three sections: the foot of the slope, the middle of the slope, and the top of the slope, at equal distances along the slope direction and according to the length of the field.

5. The non-uniform fertilization method for controlling ground-source pollution on sloping farmland according to claim 1, characterized in that, In step (4), depending on the growth of different crops, hole application or surface application can be selected.

6. The non-uniform fertilization method for controlling ground-source pollution on sloping farmland according to any one of claims 1 to 5, characterized in that, Also includes: (5) Collect surface water and soil erosion samples generated after rainfall at the foot of the slope of each field, and collect samples of runoff water within a preset time period by stirring and sampling to obtain water and soil samples; The pollutants carried by the soil and water samples were analyzed and measured to obtain the results of non-point source pollution caused by uneven fertilization on sloping farmland.

7. The non-uniform fertilization method for controlling ground-source pollution on sloping farmland according to claim 6, characterized in that, In step (5), surface water and soil erosion samples are collected through a surface runoff collection device; the pollutant indicators to be analyzed include total phosphorus, total nitrogen, ammonium nitrogen and nitrate nitrogen.

8. The non-uniform fertilization method for controlling ground-source pollution on sloping farmland according to claim 6, characterized in that, Also includes: (6) After the crops on sloping farmland have been harvested, the efficiency of crop absorption and utilization of fertilizers was measured and calculated, and the crop output under non-uniform fertilization was obtained.

9. The non-uniform fertilization method for controlling ground-source pollution on sloping farmland according to claim 8, characterized in that, In step (6), the crop’s fertilizer absorption and utilization efficiency includes the crop’s roots, stems and leaves’ absorption and utilization efficiency of nitrogen and phosphorus. The crop output is mainly dry matter output. The crop’s fertilizer absorption and utilization efficiency and crop output are calculated and accumulated according to the three slope positions of the slope foot, middle and top of each field to obtain the fertilizer utilization rate and crop output of each field.

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