Straw covering application method and system for controlling nitrogen and phosphorus loss of slope cropland

Abstract

The invention discloses a straw covering application method and system for controlling nitrogen and phosphorus loss of slope cropland, and relates to the technical field of water and soil conservation. The method comprises the following steps: designing different straw coverage amounts based on a constructed field community according to the corn straw harvesting amount of the slope cropland and local farming habits, cutting straws according to a section of 20cm, cleaning the straws in clear water, taking out the straws, airing the straws, and uniformly covering the straws on the surface of soil according to the corn straw harvesting amount and the local farming habits; the method comprises the following steps: carrying out light rainfall intensity pre-rainfall by utilizing a rainfall device before test formal rainfall, so that the water content of soil in a plot is consistent, collecting surface flow and interflow, analyzing nitrogen and phosphorus loss amounts of the surface flow and the interflow, and determining an optimal coverage value for controlling nitrogen and phosphorus loss. According to the method, the slope cropland surface flow and interflow hydrographic paths can be considered, the nitrogen and phosphorus loss characteristics under straw coverage of the slope cropland are revealed, and the straw coverage dosage and the application method of the optimal benefit of preventing and controlling nitrogen and phosphorus loss are defined.

Description

Technical Field

[0001] This invention relates to the field of soil and water conservation technology, and in particular to a method and system for applying straw mulch to control nitrogen and phosphorus loss from sloping farmland. Background Technology

[0002] The loss of nutrients such as nitrogen and phosphorus carried during soil erosion leads to severe degradation of soil fertility. Soil erosion on sloping farmland has become a major cause of soil quality degradation. Simultaneously, large amounts of nitrogen and phosphorus are carried by runoff and sediment into downstream water bodies, exacerbating eutrophication in surrounding rivers and reservoirs and increasing the risk of agricultural non-point source pollution. Straw mulching, a common and efficient soil and water conservation measure, has been widely promoted on purple soil sloping farmland. Therefore, straw mulching can be applied to sloping farmland other than purple soil to observe its soil and water conservation effects. Straw mulching involves cutting harvested crop straw to a certain length and directly covering the soil surface to form a protective layer. In the short term, straw mulching can significantly increase surface roughness, reduce raindrop kinetic energy, delay runoff time, and enhance water infiltration. In the long term, straw mulching can alter soil physicochemical properties, enhance soil erosion resistance, and reduce runoff and sediment production. Therefore, through field runoff plot natural rainfall monitoring experiments, this study investigates the migration characteristics of nitrogen and phosphorus in surface runoff and interflow in sloping farmland under different straw mulch levels, clarifies the changes in soil physicochemical properties under different straw mulch levels, elucidates the impact mechanism of straw mulch on nitrogen and phosphorus migration in sloping farmland, proposes the optimal straw mulch application method to control nitrogen and phosphorus migration in sloping farmland, and realizes the research and demonstration of key technologies for controlling nitrogen and phosphorus migration in sloping farmland using straw mulch.

[0003] In summary, the problems with existing technologies are:

[0004] Given the widespread implementation of straw mulching, the optimal amount of straw mulching to control nitrogen and phosphorus loss from sloping farmland is still unclear, as is the optimal application method for straw mulching to control nitrogen and phosphorus loss from sloping farmland, thus making it difficult to implement. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for applying straw mulch to control nitrogen and phosphorus loss from sloping farmland, aiming to solve or improve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A method for applying straw mulch to control nitrogen and phosphorus loss from sloping farmland includes:

[0008] Constructing outdoor communities;

[0009] Based on the aforementioned field plots, different straw coverage amounts were designed according to the corn stalk harvest amount on sloping farmland and local farming habits. The straw was cut into 20cm sections, washed in clean water, dried, and then evenly covered on the soil surface according to the corn stalk harvest amount and local farming habits.

[0010] Before the actual rainfall, a light rainfall event was conducted using a rain gauge to ensure uniform soil moisture content in the plot. Surface runoff and interflow were collected, and the nitrogen and phosphorus loss from surface runoff and interflow were analyzed to determine the optimal cover value for controlling nitrogen and phosphorus loss.

[0011] Optionally, the method for constructing the field plot is as follows: select a piece of sloping farmland with consistent land use history and surrounding environment to establish a runoff plot.

[0012] The present invention also provides a straw mulching application system for controlling nitrogen and phosphorus loss on sloping farmland, which uses the method described above and includes: a water collection trough, a plastic pipe, a runoff bucket, a temperature and humidity sensor, and air-dried straw; wherein, the water collection trough includes a V-shaped water collection trough and an L-shaped water collection trough;

[0013] Excavation was carried out around the perimeter of the field plot down to the bedrock layer, and aluminum-plastic partitions were attached. The V-shaped water collection trough was inserted 5cm below the surface of the field plot outlet and connected to the first runoff bucket via a plastic pipe. The L-shaped water collection trough was inserted at the junction of the soil and bedrock at the field plot outlet and connected to the second runoff bucket via a plastic pipe. The temperature and humidity sensor was placed 15cm below the surface soil at the center of the field plot. The air-dried straw was evenly distributed on the soil surface according to the designed coverage amount.

[0014] Optionally, the air-dried straw is provided with different covering gradients, and each gradient is provided with two overlapping areas.

[0015] Optionally, the covering gradient of the air-dried straw includes a control area and four gradient areas.

[0016] Optionally, when filling the soil in the field plot, first fill 10cm of unsifted soil, then fill 20cm of sifted soil. The soil should be roughened in layers during filling, with each layer being 5cm thick.

[0017] Optionally, the aluminum-plastic partitions are all 15cm higher than the ground surface of the community to block water from the surrounding area.

[0018] Optionally, the width of the L-shaped water collection trough is narrower than the width of the field plot to prevent surface runoff from leaking out and to ensure that the runoff from the mobile phone in the second runoff bucket is interflow.

[0019] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0020] This invention discloses a method and system for controlling nitrogen and phosphorus loss from sloping farmland using straw mulch. The method includes: based on a constructed field plot, designing different straw mulch amounts according to the corn straw harvest and local farming practices; cutting the straw into 20cm sections, washing them in clean water, drying them, and then evenly covering the soil surface according to the corn straw harvest and local farming practices; using a rain gauge to conduct a pre-rainfall with a small intensity before the actual rainfall to ensure uniform soil moisture content in the plot; collecting surface runoff and interflow data; and analyzing the nitrogen and phosphorus loss from surface runoff and interflow to determine the optimal mulch value for controlling nitrogen and phosphorus loss. This invention considers the hydrological paths of surface runoff and interflow in sloping farmland, reveals the characteristics of nitrogen and phosphorus loss under straw mulch, and clarifies the optimal straw mulch amount and application method for controlling nitrogen and phosphorus loss.

[0021] This invention considers the hydrological pathways of surface runoff and interflow in sloping farmland, reveals the characteristics of nitrogen and phosphorus loss under straw mulch, and clarifies the optimal straw mulch application rate and method for controlling nitrogen and phosphorus loss. The research scheme and technical route of this invention are highly operable, capable of achieving the intended objectives, and possess excellent technical feasibility with low operational difficulty. After application, it will further clarify the response relationship between nitrogen and phosphorus loss characteristics and straw mulch amount, and the optimal straw mulch application rate for controlling nitrogen and phosphorus loss. This will realize the key technology development for controlling nitrogen and phosphorus loss through straw mulch in sloping farmland, providing scientific and technological support for the optimized utilization of straw mulch application measures in sloping farmland. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the straw mulching application method for controlling nitrogen and phosphorus loss on sloping farmland according to the present invention.

[0024] Figure 2 This is a schematic diagram of field rainfall monitoring in this embodiment;

[0025] Figure 3 This is a simulated rainfall map in the field in this embodiment. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The purpose of this invention is to provide a method and system for applying straw mulch to control nitrogen and phosphorus loss from sloping farmland, aiming to solve or improve at least one of the above-mentioned technical problems.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figures 1-3 As shown, the present invention provides a method for controlling nitrogen and phosphorus loss from sloping farmland by applying straw mulch, comprising:

[0030] S101: Conduct field plot monitoring experiments. Field plot monitoring experiments are conducted on the same sloping farmland with consistent land use history and surrounding environment (slope of about 15° and basic soil physical and chemical properties are consistent). The plot area is 5m×1m, and runoff plots are established.

[0031] S102: Based on the corn stalk harvesting amount on sloping farmland and local farming habits, design different stalk coverage amounts. Cut the stalks into 20cm sections, wash them in clean water, take them out and dry them, and then cover them evenly on the soil surface.

[0032] S103: Collect surface runoff and interflow, and analyze the nitrogen and phosphorus loss from surface runoff and interflow; identify the threshold, determine the optimal amount of straw mulch, and determine the straw mulch application method to control nitrogen and phosphorus loss from sloping farmland.

[0033] Based on the above method, an application system is constructed, including: a V-shaped water collection trough, an L-shaped water collection trough, a plastic pipe, a runoff bucket, a temperature and humidity sensor, and air-dried straw; an aluminum-plastic partition is placed on the bedrock layer of the plot to isolate it from the outside; the aluminum V-shaped water collection trough is inserted 5cm below the surface of the plot outlet; the plastic pipe connects the trough to the runoff bucket; at the same time, the aluminum L-shaped water collection trough is inserted at the junction of the soil and bedrock at the lower outlet of the plot; the trough is connected to another runoff bucket by a plastic pipe; an AV-EC5 soil moisture sensor (0-100%, ±0.1%) and an AV-10T soil temperature sensor (-40~140℃, ±0.1℃) are placed 15cm below the surface soil at the center of the plot.

[0034] As a specific implementation method, the amount of straw used for covering the experiment was set at different gradients according to the corn straw harvest and local farming practices, with two replicates for each gradient. When filling the soil troughs, 10cm of unsifted soil was filled first, followed by 20cm of sifted soil. The soil was roughened in layers during filling, with each layer being 5cm thick. The 20cm of air-dried corn straw was pre-soaked for 12 hours according to the experimental design, air-dried, and then evenly covered on the soil surface to remove any adhering debris. Rain gauges were used for pre-rainfall with light rainfall intensity to control the soil moisture content as closely as possible to the average moisture content of the field soil profile. The aluminum-plastic partitions in each plot were 15cm higher than the plot surface to block surrounding water inflow. The width of the interflow collection trough was slightly narrower than the plot width to prevent lateral leakage of surface runoff and to ensure that the collected runoff was interflow. Analyze the surface runoff and interflow collected from field plot experiments to determine the nitrogen and phosphorus loss from these runoffs; identify the optimal cover value for controlling nitrogen and phosphorus loss; and derive the optimal application method for straw mulching on sloping farmland.

[0035] The advantages and positive effects of this invention are as follows:

[0036] Field plot monitoring was conducted. During the design of runoff plots, catchment troughs were placed at key points of sediment production and nutrient loss to collect surface runoff and interflow. The amount of straw used for mulching was set at different gradients based on corn straw harvest and local farming practices, with two replicates for each gradient. One year after straw mulching, runoff and sediment samples were collected following a subsequent rainfall event. The data from the field plot monitoring were then analyzed to determine the optimal application method for straw mulching on sloping farmland, providing scientific and technological support for the optimized utilization of straw mulching measures on sloping farmland.

[0037] This technology reveals the surface runoff and soil runoff of sloping farmland through field simulated rainfall experiments and natural rainfall monitoring experiments. Based on data from field plot monitoring experiments, it determines the optimal amount of straw mulch and the optimal straw mulch application method for controlling nitrogen and phosphorus loss in sloping farmland, providing a scientific basis for establishing loss estimation models and optimizing straw mulch measures.

[0038] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0039] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for controlling nitrogen and phosphorus loss from sloping farmland by applying straw mulch, characterized in that, include: Constructing outdoor communities; Based on the aforementioned field plots, different straw coverage amounts were designed according to the corn stalk harvest amount on sloping farmland and local farming habits. The straw was cut into 20cm sections, washed in clean water, dried, and then evenly covered on the soil surface according to the corn stalk harvest amount and local farming habits. Before the actual rainfall, a light rainfall event was conducted using a rain gauge to ensure uniform soil moisture content in the plot. Surface runoff and interflow were collected, and the nitrogen and phosphorus loss from surface runoff and interflow were analyzed to determine the optimal cover value for controlling nitrogen and phosphorus loss.

2. The method for controlling nitrogen and phosphorus loss from sloping farmland by applying straw mulch according to claim 1, characterized in that, The method for constructing the field plots is as follows: select a piece of sloping farmland with consistent land use history and surrounding environment to establish a runoff plot.

3. A straw mulching system for controlling nitrogen and phosphorus loss from sloping farmland, using the method described in any one of claims 1-2, characterized in that, include: The system includes a water collection trough, plastic pipes, a runoff bucket, a temperature and humidity sensor, and air-dried straw; wherein the water collection trough includes a V-shaped water collection trough and an L-shaped water collection trough. Excavation was carried out around the perimeter of the field plot down to the bedrock layer, and aluminum-plastic partitions were attached. The V-shaped water collection trough was inserted 5cm below the surface of the field plot outlet and connected to the first runoff bucket via a plastic pipe. The L-shaped water collection trough was inserted at the junction of the soil and bedrock at the field plot outlet and connected to the second runoff bucket via a plastic pipe. The temperature and humidity sensor was placed 15cm below the surface soil at the center of the field plot. The air-dried straw was evenly distributed on the soil surface according to the designed coverage amount.

4. The straw mulching system for controlling nitrogen and phosphorus loss on sloping farmland according to claim 3, characterized in that, The air-dried straw is provided with different covering gradients, and each gradient has two overlapping areas.

5. The straw mulching system for controlling nitrogen and phosphorus loss on sloping farmland according to claim 4, characterized in that, The covering gradient of the air-dried straw includes a control area and four gradient areas.

6. The straw mulching system for controlling nitrogen and phosphorus loss on sloping farmland according to claim 3, characterized in that, When filling the soil in the field area, first fill with 10cm of unsifted soil, then fill with 20cm of sifted soil. The soil should be roughened in layers during filling, with each layer being 5cm thick.

7. The straw mulching system for controlling nitrogen and phosphorus loss on sloping farmland according to claim 3, characterized in that, The aluminum-plastic partitions are all 15cm higher than the ground surface of the community to block water from the surrounding area.

8. The straw mulching system for controlling nitrogen and phosphorus loss on sloping farmland according to claim 3, characterized in that, The width of the L-shaped water collection trough is narrower than the width of the field plot to prevent surface runoff from leaking out and to ensure that the runoff from the mobile phone in the second runoff bucket is interflow.

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