A hedgerow-based slope farmland segmentation erosion control method

Abstract

This invention relates to the field of ecological agriculture technology, specifically disclosing a segmented erosion control method for sloping farmland based on plant hedges. The method includes the following steps: dividing the sloping farmland into upper, middle, and lower planting areas according to the terrain from high to low; and then correspondingly installing upper, middle, and lower planting hedges, and constructing a plant community in the lower area. The installation of upper planting hedges includes inoculating the rhizosphere soil with nematodes, or with a combination of nematodes and microbial agents. The microbial agents include at least one of Bacillus, Arthrobacter, Neurospora, or Penicillium. This invention integrates "source control, reservoir enhancement, and potential tapping," effectively intercepting surface runoff and increasing soil moisture infiltration by altering the slope's micro-topography. This is of great significance for improving soil fertility and water and fertilizer resource utilization in dryland farmland, reducing fertilizer use and nitrogen and phosphorus loss, balancing nutrient distribution on the slope, increasing nutrient utilization, and ensuring ecological security.

Description

Technical Field

[0001] This invention relates to the field of ecological agriculture technology, and to a method for segmented erosion control on sloping farmland based on plant hedges. Background Technology

[0002] Due to obstacles such as erosion, infertility, acidity, and drought, over 80% of the agricultural production potential of sloping red soil dryland is difficult to realize. Increasing the input of chemical fertilizers (nitrogen and phosphorus fertilizers) has become the main means for farmers in red soil dryland to improve soil fertility and increase yields; however, according to statistics, the current fertilizer utilization rate is only about 43%. Because red soil has a high content of iron and aluminum oxides and is highly acidic, applied phosphorus is easily adsorbed and fixed by the soil, resulting in a severe deficiency of available phosphorus. At the same time, sloping farmland suffers from severe soil erosion, which not only wastes resources and results in low fertilizer economic efficiency, but also harms the environment through ammonia volatilization, runoff, erosion, and leaching.

[0003] Biomass mulching measures such as contour hedges, straw mulch, and green manure planting are effective in controlling soil erosion, reducing nitrogen and phosphorus loss, improving soil nutrients, and enhancing soil aggregate structure by increasing surface cover on sloping farmland. However, biomass mulching primarily uses organic materials, which provide soil microorganisms with abundant carbon sources and nutrients to regulate community structure. Simultaneously, microorganisms accelerate nutrient dissolution or increase the absorption of limiting nutrients by regulating the secretion of enzymes closely related to soil material cycling, leading to nitrogen and phosphorus stress. Furthermore, biomass mulching techniques often result in nutrient loss on the uphill slope and accumulation on the downhill slope, affecting nitrogen and phosphorus absorption and utilization. Existing technologies largely focus on single techniques such as fertilizer management, improving soil fertility, and controlling soil erosion. Temporally, the effects of fertilizer utilization improvement technologies are most pronounced in the current season, with weak long-term effects. Spatially, red soil drylands are mostly gentle slopes prone to severe soil erosion, and the abundant rainfall from April to June coincides with the planting season for dryland crops like peanuts and sweet potatoes, requiring less fertilizer. Nitrogen and phosphorus loss through rainwater is a significant pathway, and improper intercropping can further impact crop yields. In terms of diversification, existing technologies primarily focus on regulating exogenous factors affecting utilization efficiency, neglecting intrinsic factors influencing nitrogen and phosphorus retention and conversion capabilities, such as soil organic matter content, nitrogen-fixing and phosphorus-solubilizing biological activity, and crop symbiotic complementarity. Research on how to coordinate the relationships between soil, fertilizer, water, and crops with nitrogen and phosphorus nutrient utilization under biological cover, balance nutrient distribution on slopes, and enhance the nitrogen-fixing and phosphorus-solubilizing potential of sloping farmland (such as red soil drylands) and its economic benefits is scarce. Summary of the Invention

[0004] To address the shortcomings of existing technologies for controlling soil and water loss and reducing nitrogen and phosphorus loss on sloping farmland, this invention provides a segmented erosion control method for sloping farmland based on plant hedges. This method examines the effects of optimized layout of plant hedges, year-round balanced supply of cover crops on slopes, and construction of biological networks within the system on controlling soil and water loss, soil structure composition, nitrogen and phosphorus nutrient content and utilization rate on slope soils.

[0005] To achieve the above-mentioned objectives, the embodiments of the present invention employ the following technical solutions:

[0006] A segmented erosion control method for sloping farmland based on plant hedges, the construction of the segmented erosion control method includes the following steps: according to the terrain from high to low, the sloping farmland is divided into an upper slope planting area, a middle slope planting area and a lower slope planting area, and then plant hedges are set up on the upper slope, plant hedges are set up on the middle slope and plant communities are constructed on the lower slope.

[0007] Among them, at the same time or after the planting of the upper slope vegetation hedge, nematodes are inoculated into the rhizosphere soil of the upper slope vegetation hedge, or nematodes and microbial agents are inoculated.

[0008] The microbial preparation includes at least one of Bacillus, Arthrobacter, Leptospira, or Penicillium.

[0009] This invention addresses the unique characteristics of soil and nutrient loss caused by topographic differences in the upper, middle, and lower parts of a slope by strategically deploying plant hedges or communities for different terrains. By applying microbial agents and inoculating nematodes into the rhizosphere soil of the upper slope hedges, a targeted soil biological community is constructed, reducing nutrient migration from the upper slope, balancing nutrient distribution, and enhancing biological activity within the system. Constructing a plant community in the lower slope stimulates the activity of core functional microbial species, promotes organic nitrogen and phosphorus mineralization, and expands nutrient capacity within the system. Simultaneously, the soil enriched with key functional indigenous microbial species in the lower slope due to runoff and sediment transport from the upper slope and the interaction with the lower slope plant community can be backfilled into the upper slope, achieving system balance.

[0010] The selected Bacillus and Arthrobacterium in this invention can increase bacterial and fungal diversity and reduce organic carbon metabolism activity through competition with other microorganisms;

[0011] Zygomyces can accelerate the mineralization of organic nitrogen and phosphorus in the rhizosphere;

[0012] Penicillium can enhance its ability to decompose insoluble phosphorus in soil by competing with other microorganisms;

[0013] Nematodes can promote bacterial reproduction and activity to some extent by preying on key species such as Bacillus spp. and Arthrobacter. This increases the abundance of nitrogen-fixing and phosphate-solubilizing bacteria and promotes soil nitrogen mineralization.

[0014] Preferably, the microbial preparation includes Bacillus, Arthrobacter, Leptospira, and Penicillium;

[0015] The nematode in question is a bacteriophage of the genus *Smallbar*.

[0016] More preferably, the Gemmatimonas sp. strain number is DSM 14586T;

[0017] The strain number of the Arthrobacter sp. is CICC 10504;

[0018] The species number of *Catenulispora* sp. is NBRC 103397;

[0019] The species number of Penicillium sp. is CCTCC AF 209017;

[0020] The bacteriophages described herein were isolated from the dominant genus in the tested red soil, enriched, and cultured before use. The nematodes selected in this invention are more likely to survive.

[0021] Preferably, the viable count of the *Bacillus* bacteria in the microbial preparation is 1.0 × 10⁻⁶. 10 ~1.5×10 11 CFU / mL;

[0022] The viable count of the *Arthrobacter* was 1.5 × 10⁻⁶. 10 ~2.5×10 11 CFU / mL;

[0023] The viable cell count of the *Neurospora* was 1.5 × 10⁻⁶. 8 ~2.0×10 10 CFU / mL;

[0024] The viable count of the Penicillium was 1.5 × 10⁻⁶. 8 ~2.0×10 10 CFU / mL;

[0025] In this invention, the application rate of the microbial agent is 1-5% of the weight of the rhizosphere soil in the topsoil layer of the plant hedge per unit area;

[0026] Based on the weight of the topsoil layer (15-20cm), inoculate 60-80 small rod-shaped bacteriophages (Rhabditis sp.) per gram of dry soil.

[0027] By optimizing the types and dosage of microbial agents, the loss of nitrogen and phosphorus nutrients in sediment can be reduced, the content of available nitrogen, available phosphorus and organic matter in the soil can be increased, and the proportion of soil water-stable aggregates >2mm can be increased.

[0028] Preferably, when setting up the vegetation hedge on the upper part of the slope, the selected plant species include at least one of vetiver grass, daylily, alfalfa or pig manure bean;

[0029] When setting up the vegetation hedge in the middle of the slope, the selected plant species include at least one of vetiver grass, alfalfa or pig manure bean;

[0030] When constructing the plant community at the base of the slope, the selected plant species include at least one of peanut, cassava, or soybean.

[0031] More preferably, when setting up the upper slope plant hedge, daylily, vetiver grass and daylily are planted sequentially at the hedge construction location to form a daylily hedge, vetiver grass hedge and daylily hedge, respectively, to construct a set of plant hedge strips; the upper slope plant hedge includes at least one set of the plant hedge strips described above;

[0032] When setting up the vegetation hedge in the middle of the slope, including selecting to set up vetiver hedge, trenches can also be dug on both sides of the vegetation hedge in the middle of the slope and inoculated with earthworms.

[0033] The construction of the plant community on the lower slope includes intercropping peanuts and cassava.

[0034] More preferably, when setting up the plant hedges on the upper part of the slope, the row spacing between the daylily hedges and the vetiver hedges is 45-60cm;

[0035] The clump spacing of the vetiver or daylily is 10-15 cm;

[0036] When the upper slope vegetation hedge includes two or more sets of the aforementioned vegetation hedge strips, an inter-hedge crop planting strip is set between the two sets of vegetation hedge strips; and / or

[0037] When constructing the plant community at the bottom of the slope, the cassava plant spacing is 60-80cm, and the peanut and cassava row spacing is 45-55cm.

[0038] Preferably, a transverse slope planting area is set up between the upper slope hedge and the middle slope hedge, or between the middle slope hedge and the lower slope plant community.

[0039] Preferably, peanuts are planted at the same height in the transverse slope planting area, peanuts are rotated with peas, or peanuts are intercropped with cassava.

[0040] Preferably, the sloping farmland includes at least one of red soil sloping farmland, purple soil sloping farmland, or loess sloping farmland.

[0041] Compared with existing technologies, the segmented erosion control method for sloping farmland based on plant hedges provided by this invention has the following advantages:

[0042] (1) This invention optimizes the layout of plant hedges and constructs soil biological communities in the planting area on the upper slope, thereby cultivating a large aggregate structure of soil, reducing nutrient migration on the upper slope, balancing nutrient distribution on the slope, and improving biological activity within the system. Peanut-cassava intercropping at the lower slope stimulates the vitality of core indigenous functional microbial species, promotes organic nitrogen and phosphorus mineralization, and expands nutrient capacity within the system. At the same time, soil enriched with key functional indigenous microbial species due to runoff sediment from the upper slope and the interaction between the plant community at the lower slope can be backfilled on the slope, achieving dynamic balance of the system. This invention integrates "source control-storage increase-potential tapping," effectively intercepting surface runoff and increasing soil moisture infiltration rate by changing the micro-topography of the slope. It is of great significance for improving soil fertility and efficient utilization of water and fertilizer resources in dryland farmland, reducing fertilizer use and nitrogen and phosphorus loss, balancing nutrient distribution on the slope, increasing nitrogen and phosphorus nutrient utilization, and ensuring food and ecological security.

[0043] (2) Compared with conventional contour crops, the erosion control method for sloping farmland based on plant hedges provided by this invention can effectively reduce slope runoff and sediment yield by more than 60% on average over three years, reduce surface runoff by 50.4% to 96.2%, and reduce soil erosion modulus by 49.0% to 97.5%. In optimal conditions, it can reduce runoff nitrogen loss by up to 92.2%, runoff phosphorus loss by 94.9%, increase the proportion of soil water-stable aggregates >2mm by 8.3%, increase the content of available nitrogen and available phosphorus in the soil, maintain slope nutrients and make slope nutrients evenly distributed, effectively mitigating the phenomenon of nutrient depletion on the slope and enrichment on the lower slope in sloping farmland.

[0044] (3) In this invention, bacterogenic nematodes are inoculated into the rhizosphere soil of the plant hedges laid in the planting area on the slope, or microbial preparations made of Cyclospora, Arthrobacter, Bacillus and Penicillium are inoculated with bacterogenic nematodes. The four types of bacteria and bacterogenic nematodes preferred in this invention have a synergistic effect in increasing the content of available phosphorus, alkaline nitrogen, and organic matter in the soil, as well as increasing the activity of urease and acid phosphatase.

[0045] (4) In this invention, earthworms and organic materials are inoculated on both sides of the vetiver grass hedge in the middle of the slope. This not only enhances the stability of the aggregate and fixes nitrogen and phosphorus nutrients, but also alleviates the nutrient competition between the hedge and the farmer.

[0046] (5) In this invention, cassava is planted at the bottom of the slope, while peanuts, a conventional crop, are planted on the slope. The root interaction between peanuts and cassava stimulates the remodeling of the soil microbial network structure, promotes the mineralization of organic nitrogen and phosphorus nutrients in the soil, and increases the availability of nitrogen and phosphorus nutrients. After the peanut harvest, straw is used for mulching in the autumn and arrowhead peas are planted to regulate the carbon-nitrogen ratio of organic materials. Before planting peanuts in the second year, the soil is plowed back into the soil, reducing the input of chemical nitrogen fertilizer by 20% to 30% and increasing the utilization rate of nitrogen and phosphorus nutrients by 3.6% and 10.5%, respectively. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying 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.

[0048] Figure 1 This is a schematic diagram of the vegetation hedges on the upper part of the slope and the crop planting strips between the hedges in an embodiment of the present invention;

[0049] Figure 2 This shows the surface runoff data for different farming methods between 2021 and 2023.

[0050] Figure 3 These are the soil erosion moduli for different farming methods between 2021 and 2023;

[0051] Figure 4 This is a statistical chart showing peanut yield in a hillside planting area with different farming methods from 2021 to 2023.

[0052] Figure 5 The total nitrogen content of surface runoff under different farming methods during 2022;

[0053] Figure 6 The total phosphorus content in surface runoff under different farming methods during 2022;

[0054] Figure 7 These represent the total nitrogen and total phosphorus losses from surface runoff under different farming practices during 2022. Figure 7 a) represents the total nitrogen loss from surface runoff. Figure 7 b) Total phosphorus loss from surface runoff;

[0055] Figure 8 This is a statistical chart showing the variation of soil organic matter content with slope length under different farming methods;

[0056] Figure 9 This is a statistical graph showing the variation of hydrolyzable nitrogen content in soils with slope length under different farming methods;

[0057] Figure 10 This is a statistical chart showing the variation of available phosphorus content in soil with slope length under different farming methods;

[0058] Figure 11 This is a statistical chart showing the variation of available potassium content in soil with slope length under different farming methods;

[0059] Figure 12 This is a statistical chart showing the proportion of water-stable aggregates >2mm in soils with different farming methods. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are preferred examples of this invention and are only used to explain the invention and do not limit the invention.

[0061] To better illustrate the embodiments provided by the present invention, further examples are given below.

[0062] The present invention uses a sloping farmland located in Jinxian County, Nanchang City, Jiangxi Province, with red soil as the main soil type as an example for illustration. The slope angle of the sloping farmland in this study area is in the range of 8 to 25°.

[0063] Example 1

[0064] This embodiment selects 3.2 mu of sloping farmland as the technical demonstration area I, and provides a segmented erosion control method for sloping farmland based on plant hedges. The construction of the segmented erosion control method includes the following steps:

[0065] Step 1: Based on the terrain from high to low, and according to the slope angle and slope length, divide the sloping farmland into the upper slope planting area, the middle slope planting area, and the lower slope planting area.

[0066] Specifically, in this technical demonstration area I, the slope angle is 10°. The top area, which accounts for 1 / 3 of the total slope length, is designated as the upper slope planting area; the area below the upper slope planting area, which accounts for 1 / 3 of the total slope length, is designated as the middle slope planting area; and the area below the middle slope planting area, which accounts for 1 / 3 of the total slope length, is designated as the lower slope planting area.

[0067] Step 2: In the above-mentioned planting area, install vegetation hedges on the upper part of the slope, install vegetation hedges in the middle part of the slope, and construct a plant community at the lower part of the slope in sequence. The specific steps include the following:

[0068] (1) Layout of vegetation hedges on the upper part of the slope

[0069] When setting up a hedge on the upper part of a slope, choose vetiver grass and daylily.

[0070] At the location where the hedge is to be built in the planting area on the slope, plant daylilies, vetiver grass, and daylilies again in sequence at a row spacing of 50cm (i.e., vetiver grass + daylilies 1:2) to form a plant hedge belt. The vetiver grass and daylilies are spaced 12cm apart. Establish an 8-10m intercropping strip according to the slope; for example, peanuts are planted in the intercropping strip. A schematic diagram of the upper slope hedge and intercropping strip is shown below. Figure 1 As shown.

[0071] Simultaneously, microbial agents and nematodes are inoculated into the rhizosphere soil of the plant hedges. The microbial agent consists of four fungi: Bacillus, Arthrobacter, Zygomyces, and Penicillium, and is applied by irrigation at a rate of 1% of the weight of the topsoil per unit area after planting vetiver and daylily.

[0072] In the microbial preparation, the strain number of Gemmatimonas sp. is DSM 14586T, and its viable cell count is 1.0 × 10⁻⁶. 10 CFU / mL;

[0073] The strain of *Arthrobacter* sp. is designated CICC 10504, and its viable count is 1.5 × 10⁻⁶. 10 CFU / mL;

[0074] The strain number of *Catenulispora* sp. is NBRC 103397, and its viable count is 1.5 × 10⁻⁶. 8 CFU / mL;

[0075] The species identification number of Penicillium sp. is CCTCC AF 209017, and its viable count is 1.5 × 10⁻⁶. 8 CFU / mL.

[0076] The dominant bacteriophage nematode *Rhabditis* sp. isolated from red soil was cultured using conventional methods. Adult nematodes of similar size were obtained through centrifugation and stereomicroscopic examination for inoculation. These nematodes were then enriched and cultured. Because the selected nematodes were isolated from the dominant genus in the tested red soil, the resulting nematodes had a higher survival rate. The inoculation rate was 80 nematodes per gram of dry soil (based on the weight of the topsoil layer, 15-20 cm). It should be noted that the weight of the topsoil layer per unit area was calculated by multiplying its volume by its bulk density.

[0077] (2) Layout of vegetation hedges in the middle of the slope

[0078] When setting up a vegetation hedge in the middle of a slope, choose vetiver hedge. Place the vetiver hedge 60cm away from the grass hedge on both sides.

[0079] Dig a trench 70cm wide, and inoculate it with 20-30 earthworms per kilogram of dry soil. Add a mixture of straw and cow manure to the trench. In this example, the earthworm species selected is Eisenia foetida.

[0080] (3) Construction of plant communities in the lower part of the slope

[0081] When constructing the plant community on the lower slope, peanuts and cassava are selected for intercropping. The peanut-cassava ratio is 5:1 across the slope, with cassava plants spaced 60cm apart and peanut plants 50cm apart.

[0082] (4) Construction of vegetation communities on transverse slopes

[0083] A transverse slope planting area is established between the upper and middle slope hedges, and between the middle slope hedges and the lower slope plant community. Peanuts can be planted at the same height, rotated with peas, or intercropped with cassava in this transverse slope planting area.

[0084] For example, peanuts and cassava were planted starting in April of the same year. After the peanuts were harvested in August, arrowhead peas were planted after land preparation. Arrowhead pea seeds were sown in horizontal rows at a depth of 3-4 cm, covered with 2 cm of soil, with a row spacing of 30-40 cm and a sowing rate of 15.0-20.0 kg per acre. After sowing, 200-250 kg / acre of composted peanut stalks were covered. Arrowhead peas and cassava were harvested at the end of the same year. The arrowhead pea and cassava stalks were crushed and used as mulch. Peanuts and cassava were planted starting in April of the following year, at the same height as peanuts (nitrogen application of 120 kg / hm²). 2 Compared to other methods, the nitrogen application rate is reduced by 25 kg / hm² when using the method provided in this embodiment. 2 .

[0085] Example 2

[0086] This embodiment selects 3.5 mu of red soil sloping farmland as technical demonstration area II, and provides a segmented erosion control method for sloping farmland based on plant hedges. The construction of the segmented erosion control method includes the following steps:

[0087] Step 1: Based on the terrain from high to low, and according to the slope angle and slope length, divide the sloping farmland into the upper slope planting area, the middle slope planting area, and the lower slope planting area.

[0088] Specifically, the slope angle of this technical demonstration area is 25°. The top area, which accounts for 1 / 3 of the total slope length, is designated as the upper slope planting area; the area below the upper slope planting area, which accounts for 1 / 3 of the total slope length, is designated as the middle slope planting area; and the area below the middle slope planting area, which accounts for 1 / 3 of the total slope length, is designated as the lower slope planting area.

[0089] Step 2: In the above-mentioned planting area, install vegetation hedges on the upper part of the slope, install vegetation hedges in the middle part of the slope, and construct a plant community at the lower part of the slope in sequence. The specific steps include the following:

[0090] (1) Layout of vegetation hedges on the upper part of the slope

[0091] When setting up a hedge on the upper part of a slope, choose vetiver grass and daylily.

[0092] At the location where the hedge is to be built in the planting area on the upper part of the slope, daylilies and vetiver grass (i.e., vetiver grass + daylilies 1:1) are planted in sequence with a row spacing of 40cm to form a plant hedge. The clump spacing of vetiver grass and daylilies is 10cm. An 8-10m intercropping strip is set up according to the slope. For example, peanuts are planted in the intercropping strip.

[0093] Simultaneously, microbial agents and nematodes are inoculated into the rhizosphere soil of the plant hedges. The microbial agent consists of four fungi: Bacillus, Arthrobacter, Zygomyces, and Penicillium, and is applied by irrigation at a rate of 1% of the weight of the topsoil per unit area after planting vetiver and daylily.

[0094] In the microbial preparation, the strain number of Gemmatimonas sp. is DSM 14586T, and its viable cell count is 1.5 × 10⁻⁶. 11 CFU / mL;

[0095] The strain of *Arthrobacter* sp. is designated CICC 10504, and its viable count is 2.5 × 10⁻⁶. 11 CFU / mL;

[0096] The strain number of *Catenulispora* sp. is NBRC 103397, and its viable count is 2.0 × 10⁻⁶. 10 CFU / mL;

[0097] The species number of Penicillium sp. is CCTCC AF 209017, and its viable count is 2.0 × 10⁻⁶. 10 CFU / mL.

[0098] The nematodes were obtained in the same way as in Example 1, using the bacteriophage Rhabditis sp., with 60 nematodes per gram of dry soil, based on the weight of the topsoil (15-20 cm).

[0099] (2) Layout of vegetation hedges in the middle of the slope

[0100] When setting up a vegetation hedge in the middle of a slope, choose vetiver hedge. Place the vetiver hedge 60cm away from the grass hedge on both sides.

[0101] Dig a trench 70cm wide, and inoculate it with 20-30 earthworms per kilogram of dry soil. Add a mixture of straw and cow manure to the trench. In this example, the earthworm species selected is Eisenia foetida.

[0102] (3) Construction of plant communities in the lower part of the slope

[0103] When constructing the plant community on the lower slope, peanuts and cassava are selected for intercropping. The peanut-cassava ratio is 5:1 across the slope, with cassava plants spaced 80cm apart and peanut plants 45cm apart.

[0104] (4) Construction of vegetation communities on transverse slopes

[0105] A transverse slope planting area is established between the upper and middle slope hedges, and between the middle slope hedges and the lower slope plant community. Peanuts can be planted at the same height, rotated with peas, or intercropped with cassava in this transverse slope planting area.

[0106] Compared with conventional contour cropping, the application of the sloping farmland erosion control method based on plant hedges provided in this embodiment can achieve about 20% organic substitution of chemical fertilizers in the entire sloping farmland of the technical demonstration area II, reduce slope runoff and sand production by more than 60% on average, and reduce runoff nitrogen and phosphorus nutrient loss by 85.3% and 84.2%, respectively.

[0107] Example 3

[0108] This embodiment selects 3 mu of red soil sloping farmland as technical demonstration area III, and provides a segmented erosion control method for sloping farmland based on plant hedges. The construction of the segmented erosion control method includes the following steps:

[0109] Step 1: Based on the terrain from high to low, and according to the slope angle and slope length, divide the sloping farmland into the upper slope planting area, the middle slope planting area, and the lower slope planting area.

[0110] Specifically, the slope angle of this technical demonstration area is 8°. The top area, which accounts for 1 / 3 of the total slope length, is designated as the upper slope planting area; the area below the upper slope planting area, which accounts for 1 / 3 of the total slope length, is designated as the middle slope planting area; and the area below the middle slope planting area, which accounts for 1 / 3 of the total slope length, is designated as the lower slope planting area.

[0111] Step 2: In the above-mentioned planting area, install vegetation hedges on the upper part of the slope, install vegetation hedges in the middle part of the slope, and construct a plant community at the lower part of the slope in sequence. The specific steps include the following:

[0112] (1) Layout of vegetation hedges on the upper part of the slope

[0113] When setting up vegetation hedges on the upper part of the slope, choose alfalfa and pig manure beans;

[0114] At the hedge location on the upper part of the slope, plant alfalfa and dung bean (i.e., alfalfa + dung bean 1:1) in sequence with a row spacing of 60cm to form a plant hedge. The clump spacing of both alfalfa and dung bean is 15cm. Set up 8-10m intercropping strips according to the slope.

[0115] Simultaneously, microbial agents and nematodes are inoculated into the rhizosphere soil of the plant hedges. The microbial agent consists of four fungi: Bacillus, Arthrobacter, Zygomyces, and Penicillium, and is applied by irrigation at a rate of 5% of the weight of the topsoil per unit area after planting vetiver and daylily.

[0116] In the microbial preparation, the strain number of Gemmatimonas sp. is DSM 14586, and its viable cell count is 1.5 × 10⁻⁶. 10 CFU / mL;

[0117] The strain number of the *Arthrobacter* sp. is CCTCC AB 2010451, and its viable count is 1.5 × 10⁻⁶. 11 CFU / mL;

[0118] The species number of *Catenulispora* sp. is DSM 45250, and its viable count is 1.5 × 10⁻⁶. 9 CFU / mL;

[0119] The species number of Penicillium sp. is CCTCC AF 2020008, and its viable count is 2.0 × 10⁻⁶. 9 CFU / mL.

[0120] The nematodes were obtained in the same way as in Example 1, using the bacteriophage Rhabditis sp., with 70 nematodes per gram of dry soil, based on the weight of the topsoil (15-20 cm).

[0121] (2) Layout of vegetation hedges in the middle of the slope

[0122] When setting up a vegetation hedge in the middle of a slope, choose alfalfa hedge.

[0123] (3) Construction of plant communities in the lower part of the slope

[0124] When constructing the plant community at the lower part of the slope, soybeans and cassava are selected for intercropping; soybeans and cassava are planted at a ratio of 5:1 across the slope, with cassava plants spaced 70cm apart and soybeans 55cm apart from cassava plants.

[0125] (4) Construction of vegetation communities on transverse slopes

[0126] A transverse slope planting area is established between the upper and middle slope hedges, and between the middle slope hedges and the lower slope plant community. Peanuts can be planted at contour height, rotated with peas, or intercropped with cassava in this transverse slope planting area. For example, contour planting of peanuts begins in April of the current year.

[0127] Compared with conventional contour cropping, the application of the sloping farmland erosion control method based on plant hedges provided in this embodiment can achieve about 15% organic substitution of chemical fertilizers in the entire sloping farmland of the technical demonstration area III, reduce slope runoff and sand production by more than 70% on average, and reduce runoff nitrogen and phosphorus nutrient loss by 86.8% and 85.9%, respectively.

[0128] Example 4

[0129] In this embodiment, 2.8 mu of red soil sloping farmland was selected as the technical demonstration area IV, and a segmented erosion control method for sloping farmland based on plant hedges was provided. The steps of the segmented erosion control method are basically the same as those in embodiment 1, except that: in step two (1) when the plant hedges are laid on the upper part of the slope, only nematodes are inoculated in the rhizosphere soil of the plant hedges on the upper part of the slope. The method of obtaining the nematodes and the amount inoculated in the rhizosphere soil are the same as those in embodiment 1.

[0130] Example 5

[0131] This embodiment selects 3.4 mu of red soil sloping farmland as technical demonstration area V, and provides a segmented erosion control method for sloping farmland based on plant hedges. The steps of the segmented erosion control method are basically the same as those in embodiment 1. The difference is that when laying the plant hedges on the upper part of the slope, this embodiment selects to plant vetiver grass and daylily in a 1:1 ratio (i.e., vetiver grass + daylily 1:1). Apart from the above differences, the other parameters are the same as those in embodiment 1.

[0132] Example 6

[0133] This embodiment selects 3.8 mu of red soil sloping farmland as technical demonstration area VI, and provides a segmented erosion control method for sloping farmland based on plant hedges. The steps of the segmented erosion control method are basically the same as those in embodiment 1. The difference is that when laying the plant hedges on the upper part of the slope, a row of vetiver grass is selected to be planted to form a vetiver grass hedge. The row spacing and plant spacing are the same as those described in embodiment 1. Apart from the above differences, the other parameters are the same as those in embodiment 1.

[0134] Example 7

[0135] This embodiment selects 2.3 acres of red soil sloping farmland with a slope angle of 10° as the technical demonstration area VII, and provides a segmented erosion control method for sloping farmland based on plant hedges. The steps of the segmented erosion control method are basically the same as those in embodiment 1. The difference is that when setting up the plant hedges on the upper part of the slope, this embodiment sets the spacing between daylily hedges and vetiver grass at 40cm. Apart from the above differences, the other parameters are the same as those in embodiment 1.

[0136] Example 8

[0137] This embodiment selects 2.5 mu of red soil sloping farmland with a slope angle of 8° as the technical demonstration area VIII, and provides a segmented erosion control method for sloping farmland based on plant hedges. The steps of the segmented erosion control method are basically the same as those in Embodiment 1. The difference is that when setting up the plant hedges on the upper part of the slope, this embodiment sets the spacing between daylily hedges and vetiver grass at 60cm. Apart from the above differences, the other parameters are the same as those in Embodiment 1.

[0138] Comparative Example 1

[0139] In the study area described in Example 1, another sloping farmland was selected, which is similar to the technical demonstration area I in terms of area and slope angle. This comparative example provides a method for constructing biological structures on sloping farmland, which is basically the same as the method described in Example 1, except that: no vegetation hedges are laid on the upper part of the slope, no vegetation hedges are laid in the middle of the slope, and no peanut and cassava intercropping is laid on the lower part of the slope. In Comparative Example 1, peanuts are planted at the same height on the transverse slope, and the row spacing and plant spacing are 40cm and 20cm, respectively. Apart from the above differences, the other parameters are the same as those in Example 1.

[0140] Comparative Example 2

[0141] Based on Example 1, a split-zone experiment was conducted, in which an equal amount of sterile water was used to replace the microbial preparation, and no nematodes were inoculated. All other parameters were the same as in Example 1, serving as a blank control group.

[0142] The viable count of Bacillus spp. strain DSM 14586T in the microbial preparation was 1.5 × 10⁻⁶. 10 The viable count of Arthrobacter, strain number CICC 10504, was 2.5 × 10⁻⁶ CFU / mL. 10 The viable count of Penicillium with CFU / mL and strain number CCTCC AF209017 was 2.0 × 10⁻⁶. 8 CFU / mL, without inoculation with nematodes, and with all other parameters the same as in Example 1, served as control group 1;

[0143] The viable count of Bacillus subtilis strain DSM 14586T in the microbial preparation was 1.5 × 10⁻⁶. 10The viable count of Arthrobacter, strain number CICC 10504, was 2.5 × 10⁻⁶ CFU / mL. 10 The viable count of *Streptococcus pyogenes* strain DSM 44928 (CFU / mL) was 2.0 × 10⁻⁶. 8 The viable count of Penicillium with CFU / mL and strain number CCTCC AF 209017 was 2.0 × 10⁻⁶. 8 CFU / mL, without inoculation with nematodes, and with all other parameters the same as in Example 1, served as control group 2;

[0144] The viable count of Bacillus subtilis strain DSM 14586T in the microbial preparation was 1.5 × 10⁻⁶. 10 The viable count of Arthrobacter, strain number CICC 10504, was 2.5 × 10⁻⁶ CFU / mL. 10 The viable count of *Streptococcus pyogenes* strain DSM 44928 (CFU / mL) was 2.0 × 10⁻⁶. 8 The viable count of Penicillium with CFU / mL and strain number CCTCC AF 2020008 was 2.0 × 10⁻⁶. 8 CFU / mL, without inoculation with nematodes, and with all other parameters the same as in Example 1, served as control group 3;

[0145] The microbial preparation contains only 2.0 × 10⁻⁶ live bacteria. 8 The bacterial strain with CFU / mL was *Streptococcus pyogenes*, NBRC 103397, which was not inoculated with nematodes. All other parameters were the same as in Example 1, serving as control group 4.

[0146] Example of effect

[0147] (1) Detection of the effect of nitrogen and phosphorus loss control

[0148] Surface runoff, soil erosion modulus, total nitrogen and phosphorus content in surface runoff, and total nitrogen and phosphorus loss in surface runoff were monitored under different tillage methods in Examples 1, 5-6, and Comparative Example 1 from 2021 to 2023 using runoff monitoring ponds. Peanut yield in the transverse slope planting area was also statistically analyzed under different tillage methods. The surface runoff data for different tillage methods from 2021 to 2023 are as follows: Figure 2 As shown; Soil erosion moduli for different farming methods between 2021 and 2023 are as follows. Figure 3 As shown in the figure; a statistical chart of peanut yield in a hillside planting area with different farming methods from 2021 to 2023 is shown. Figure 4 As shown; the total nitrogen content of surface runoff under different farming methods in 2022 is as follows: Figure 5 As shown; Total phosphorus content in surface runoff under different farming methods during 2022 is as follows: Figure 6As shown; the total nitrogen and total phosphorus losses in surface runoff due to different farming methods in 2022 are as follows: Figure 7 As shown, where Figure 7 a) represents the total nitrogen loss from surface runoff. Figure 7 b) represents total phosphorus loss through surface runoff. It should be noted that... Figures 2-4 In this context, "slope crop cultivation" corresponds to the cultivation method in Example 1; "vetiver grass hedge" corresponds to the cultivation method in Example 6; "vetiver grass + daylily (1:1)" corresponds to the cultivation method in Example 5; and "vetiver grass + daylily (1:2)" corresponds to the cultivation method in Example 1.

[0149] Depend on Figures 2-7 It can be seen that, during the period of 2021 to 2023, compared with the method of planting peanuts on the upper slope of the sloping farmland with contour planting, and inoculating with microbial agents and nematodes in the upper slope of the sloping farmland selected in Example 1, the method of planting vetiver grass and daylily, and inoculating with microbial agents and nematodes can reduce surface runoff by 50.4% to 96.2% and reduce soil erosion modulus by 49.0% to 97.5%; among them, the ratio of vetiver grass + daylily 1:2 is better than that of vetiver grass + daylily 1:1 and vetiver grass hedge alone.

[0150] Monitoring results from the 2022 rainy season in the technical demonstration area showed that the total nitrogen content in surface runoff obtained using the segmented erosion control method provided in Example 1 was 0.02–0.48 mg / L (mean 0.109 mg / L), and the total phosphorus content was 0.20–15.88 mg / L (mean 3.519 mg / L). In Comparative Example 1, the total nitrogen content in contour farming on the transverse slope was 0.10–0.77 mg / L (mean 0.243 mg / L), and the total phosphorus content was 0.10–2 mg / L. 4.58 mg / L (mean 8.434 mg / L); The segmented erosion control method provided in Example 1 significantly reduced the loss of total nitrogen and total phosphorus nutrients in surface runoff by 92.2% and 94.9% respectively compared with Comparative Example 1. In Example 1, the optimized layout of vetiver grass + daylily hedges at a ratio of 1:2 on the upper slope was selected, which significantly reduced the loss of total nitrogen and total phosphorus nutrients in surface runoff by 47.5% and 55.9% respectively compared with the vetiver grass hedges on the upper slope in Example 6.

[0151] In summary, the optimized vetiver + daylily 1:2 layout significantly improves water retention and the segmented erosion control technology on sloping farmland effectively prevents nitrogen and phosphorus loss.

[0152] Depend on Figure 4 It can be seen that, during the three years from 2021 to 2023, although the peanut planting area in Example 1 was smaller than that in Comparative Example 1 due to the inclusion of grass hedges, the peanut yields were basically the same. Combined with... Figures 2-3 , Figures 5-11It is evident that the farming method provided in Comparative Example 1 has poorer environmental benefits in controlling nitrogen and phosphorus loss. If no measures are taken year after year, topsoil will be stripped away due to soil erosion, nutrient imbalance on the slope will occur, and the soil quality of the same sloping farmland will decrease year by year, affecting crop yield. In contrast, the farming method provided in Example 1 of this invention can balance environmental and economic benefits.

[0153] (2) Characteristics of nutrient distribution on slope and soil structure

[0154] Soil samples were collected every 1 meter from the slopes of a demonstration area established using conventional cross-slope tillage and the segmented erosion control method for sloping farmland based on vegetation hedges provided in this invention. The contents of soil organic matter, hydrolyzable nitrogen, available phosphorus, and available potassium were analyzed. Using the method specified in NY / T 1121.19--2008, the concentrations of water-stable aggregates >2 mm in the soil of the upper, middle, and lower parts of the slope under both conventional cross-slope tillage and the segmented erosion control method based on vegetation hedges were determined.

[0155] The following charts show the changes in organic matter content with slope length under different tillage methods in 2023: Figure 8 shows the changes in hydrolyzable nitrogen content with slope length; Figure 9 shows the changes in available phosphorus content with slope length; Figure 10 shows the changes in available potassium content with slope length; and Figure 11 shows the changes in the proportion of >2mm water-stable aggregates in soils under different tillage methods.

[0156] Depend on Figure 8-11 It is known that the erosion control method for sloping farmland based on plant hedges proposed in this invention is beneficial to maintaining the nutrients on the red soil sloping farmland and making the nutrients on the slope evenly distributed. In the cross-slope farming method, soil organic matter and available nutrients have strong spatial heterogeneity and are more likely to migrate with the slope to the bottom of the slope.

[0157] Depend on Figure 12 It can be seen that, compared with contour farming on transverse slopes, the erosion control method for sloping farmland based on plant hedges proposed in this invention increases the proportion of soil aggregates >2mm in diameter on average by 4.1 to 8.3 percentage points (especially in the lower part of the slope). The construction method proposed in this invention better retains nitrogen and phosphorus nutrients.

[0158] (3) The effect of the spacing between vetiver hedges and daylily hedges on the traits and yield of crops between the hedges

[0159] Field trials were conducted on Comparative Example 1, Example 1, and Examples 7-8 to investigate the effects of chlorophyll content, plant height, and yield of peanuts (intercropping crop) in the first row of adjacent hedges on the upper slope (Comparative Example 1 selected peanuts planted in the same row as those in other examples along contour lines). The results are shown in Table 1.

[0160] Table 1. Peanut maturity characteristics and yield under different spacings of vetiver hedges and daylily hedges.

[0161]

[0162] Table 1 shows that a spacing of 40cm between the vetiver hedge and peanuts leads to competition for light, water, and fertilizer, which is detrimental to peanut growth. When the spacing between the daylily hedge and vetiver is 50cm and 60cm, the peanut's stem height, chlorophyll content, and other growth traits are higher than in conventional horizontal slope planting, with the 50cm spacing being the optimal value. The peanuts are 25cm away from the daylily hedge; therefore, the distance between the peanuts and vetiver varies depending on the row spacing of the vetiver hedge and daylily hedge: 65cm at 40cm, 75cm at 50cm, and 85cm at 60cm.

[0163] (4) The effects of inoculated microbial preparations and inoculated bacteriophages on soil nutrients

[0164] Three months after inoculation with nematodes or different microbial agents, soil samples were collected from different groups in Examples 1, 4, or Comparative Example 2 within 2 m of the plant hedge. The available phosphorus, alkaline nitrogen, and soil urease and acid phosphatase activities were measured. The results are shown in Table 2.

[0165] Table 2. Effects of microbial agents and nematode treatment on soil nutrients and enzyme activity.

[0166]

[0167]

[0168] As shown in Table 1, compared with the blank control group, the soil available phosphorus content increased by 68.3%, available nitrogen content increased by 28.6%, urease activity increased by 83.8%, and acid phosphatase activity increased by 41.6% after treatment with the microbial agent and nematodes provided in Example 1 of this invention. Compared with Example 4 and control groups 1 or 4, the soil available phosphorus, available nitrogen, organic matter, urease activity, and acid phosphatase activity were all significantly increased after treatment with the microbial agent and nematodes provided in Example 1 of this invention (p<0.05); compared with control groups 2-3, the soil available phosphorus, available nitrogen, and acid phosphatase activity were significantly increased after treatment with the microbial agent combination and nematodes provided in Example 1 of this invention (p<0.05).

[0169] As can be seen from Table 1, the preferred Bacillus, Arthrobacter, Trichoderma, Penicillium, and bacteriophages in this invention have a synergistic effect in increasing the content of available phosphorus, alkaline nitrogen, and organic matter in the soil, as well as increasing the activity of urease and acid phosphatase. This may be because nematodes can inhibit the reproduction of certain harmful bacteria in the rhizosphere soil and increase the growth of fungi. Nematodes enhance their phosphorus solubilization and nitrogen fixation capabilities and the abundance of related microorganisms by preying on key species. In addition, the preferred microorganisms of this invention affect the mineralization of rhizosphere organic nitrogen and phosphorus through competition with other microorganisms, and the dynamic changes in soil physicochemical properties, in turn, affect the composition of the microbial community structure.

[0170] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A segmented erosion control method for red soil sloping farmland based on plant hedges, characterized in that: Includes the following steps: Step 1: Based on the terrain from high to low, divide the sloping farmland into planting areas at the top of the slope, planting areas in the middle of the slope, and planting areas at the bottom of the slope; Step 2: In the above-mentioned planting area, plant hedges are set up on the upper part of the slope, plant hedges are set up in the middle part of the slope, and plant communities are built on the lower part of the slope. When setting up the upper slope hedges, daylilies, vetiver grass, and daylilies are planted sequentially at the hedge construction locations to form daylily hedges, vetiver grass hedges, and daylily hedges, constructing a set of plant hedge belts. The row spacing between the daylily hedges and vetiver grass hedges is 45-60cm, and the clump spacing between the vetiver grass and daylilies is 10-15cm. The upper slope hedges include at least two sets of the aforementioned plant hedge belts. Nematodes and microbial agents are inoculated into the rhizosphere soil of the plant hedges. The microbial agents consist of Bacillus, Arthrobacter, Zygomyces, and Penicillium, and the nematodes are small-stem bacteriophages. The application rate of the microbial agents per unit area of ​​cultivated layer rhizosphere soil is 1-5%. Based on the weight of 15-20cm of cultivated soil, 60-80 small-stem bacteriophages are inoculated per gram of dry soil. An intercropping strip is set between the two sets of plant hedge belts. The vegetation hedge in the middle of the slope is a vetiver hedge. Ditches are dug on both sides of the vetiver hedge, 60cm-70cm away from the hedge, and 20-30 earthworms are inoculated per kilogram of dry soil. The plant community at the lower part of the slope is constructed by intercropping peanuts and cassava, with a peanut-cassava ratio of 5:1 on the cross slope. The cassava plant spacing is 60-80cm, and the peanut and cassava row spacing is 45-55cm. A transverse slope planting area is set up between the upper and middle slope hedges, and between the middle slope hedges and the lower slope plant community.

2. The method for segmented erosion control on red soil sloping farmland based on vegetation hedges as described in claim 1, characterized in that: The strain number of the Bacillus spp. is DSM 14586T; The strain number of the Arthrobacter is CICC 10504; The strain number of the *Neurospora* is NBRC 103397; The strain number of the Penicillium is CCTCC AF 209017.

3. The method for segmented erosion control on red soil sloping farmland based on plant hedges as described in claim 2, characterized in that: The viable count of the *Bacillus* was 1.0 × 10⁻⁶. 10 ~1.5×10 11 CFU / mL; The viable count of the *Arthrobacter* was 1.5 × 10⁻⁶. 10 ~2.5×10 11 CFU / mL; The viable cell count of the *Neurospora* was 1.5 × 10⁻⁶. 8 ~2.0×10 10 CFU / mL; The viable count of the Penicillium was 1.5 × 10⁻⁶. 8 ~2.0×10 10 CFU / mL.

4. The method for segmented erosion control on red soil sloping farmland based on vegetation hedges as described in any one of claims 1 to 3, characterized in that: Peanuts are planted in the intercropping strips between hedges.

5. The method for segmented erosion control on red soil sloping farmland based on vegetation hedges as described in any one of claims 1 to 3, characterized in that: The slope transverse planting area is planted with peanuts at contour height, peanuts and peas are rotated, or peanuts and cassava are intercropped.

Images