Application of a green and efficient rice-frog and loach breeding system in farmland non-point source pollution

Abstract

This invention relates to the application of a green and efficient "rice-frog-loach" integrated farming system in addressing non-point source pollution in farmland. This system involves ecologically transforming rice paddies by constructing looped ditches around or within the paddies, creating an integrated water environment system connecting the ditches to the paddies. Simultaneously with rice cultivation, black-spotted frog tadpoles and loach fry are introduced, forming a "rice-frog-loach" composite ecological farming model. The black-spotted frogs prey on pests and control weeds, while the loach loosens the soil and promotes nitrogen and phosphorus conversion. Frog excrement and uneaten feed provide nutrients for the system, achieving ecological recycling. Furthermore, filtration and escape-prevention structures are installed at the inlet and outlet, and protective structures are built around the paddy field ridges. Through these synergistic effects, the application of chemical fertilizers and pesticides is effectively reduced, lowering the total nitrogen and total phosphorus content in farmland drainage, thus controlling non-point source pollution in farmland. This application combines ecological restoration, improved yield, and efficient resource utilization.

Description

Technical Field

[0001] This application relates to the fields of agricultural ecological engineering and environmental protection, and in particular to the application of a green and efficient "rice-frog-loach" farming system in the treatment of non-point source pollution in farmland. Background Technology

[0002] With the increasing scale and intensification of agricultural production, the use of agricultural inputs such as fertilizers and pesticides in rice cultivation has been steadily increasing. While this has improved grain yields to some extent, it has also brought about significant non-point source pollution problems in farmland. Large amounts of nutrients such as nitrogen and phosphorus, which are not absorbed and utilized by crops, enter surrounding water bodies through surface runoff or seepage, easily leading to eutrophication, water quality deterioration, and other environmental problems. This, in turn, adversely affects the stability of regional ecosystems and the safety of drinking water for residents. At the same time, pesticide residues also affect the structure of soil microbial communities, reduce soil fertility, and increase the risk to the quality and safety of agricultural products.

[0003] Current rice cultivation models are mostly monoculture structures with relatively simple ecosystems and a lack of effective biological regulation mechanisms. This makes them susceptible to pests and diseases, and pest control relies mainly on chemical pesticides, which not only increases production costs but also exacerbates environmental pollution. In addition, long-term high-intensity farming can lead to soil compaction, decreased organic matter content, and degradation of ecological functions, making it difficult to meet the needs of modern green and sustainable agricultural development.

[0004] To alleviate these problems, integrated rice-fish farming models, such as rice-fish and rice-shrimp farming, have gradually developed in recent years. These ecological agricultural technologies achieve a certain degree of ecological regulation and resource recycling by introducing aquatic animals. However, existing technologies still suffer from incomplete ecological chains, limited pollutant reduction effects, and insufficient system stability, especially in the synergistic removal of nitrogen and phosphorus and pesticide reduction, where there is still room for improvement. Furthermore, some farming models have inadequate structural modifications to paddy fields and lack standardized water circulation and escape prevention measures, affecting their practical application.

[0005] Regarding the aforementioned technologies, the inventors believe that the existing rice-farm farming model lacks ecological synergy, has limited nitrogen and phosphorus reduction efficiency, and is highly dependent on chemical fertilizers and pesticides, making it difficult to effectively achieve the unity of farmland non-point source pollution control and sustainable agricultural development. Summary of the Invention

[0006] To address the technical problems of insufficient ecological synergy, limited nitrogen and phosphorus removal efficiency, and high dependence on chemical fertilizers and pesticides in existing rice-frog-loach farming models, this application provides a green and efficient "rice-frog-loach" farming system for the application of agricultural non-point source pollution.

[0007] The application of a green and efficient "rice-frog-loach" farming system in agricultural non-point source pollution provided in this application adopts the following technical solution: Application of a green and efficient "rice-frog-loach" integrated farming system in agricultural non-point source pollution control. This system, constructed within rice-growing fields, includes the following technical measures: (1) Ecological transformation of paddy fields, setting up water ditches with a U-shaped structure around or inside the paddy fields, with the area of ​​the ditches accounting for 8% to 12% of the total area of ​​the paddy fields; (2) A connected water body is formed between the ditch and the paddy field, so that the paddy field area and the ditch area constitute an integrated water environment system; (3) While planting rice in paddy fields, black-spotted frog tadpoles and loach seedlings are released into the ditches and paddy field water bodies to construct a "rice-frog-loach" composite ecological farming system; (4) Utilize the predation of rice paddy pests and the control of weeds by the black-spotted frog to reduce the use of pesticides; (5) Utilize the activity of loach in water and soil to loosen the soil in paddy fields and promote the absorption and transformation of nitrogen and phosphorus nutrients in water. (6) Use the excrement and leftover food of the black-spotted frog as a nutrient source to provide nutrients for rice and loach, and realize ecological recycling; (7) A filter structure is installed at the water inlet of the paddy field, an escape prevention structure is installed at the drainage outlet, and a protective structure is installed around the field ridge to prevent the aquatic organisms from escaping. (8) Through the above-mentioned ecological synergy, the amount of fertilizer and pesticides used can be reduced, and the total nitrogen (TN) and total phosphorus (TP) content in farmland drainage can be reduced, thereby achieving farmland non-point source pollution control.

[0008] By adopting the above technical solutions, a three-dimensional ecological cycle system of "rice-frog-loach" multi-species synergy is constructed in the same paddy field, realizing the organic integration of planting and breeding and the efficient utilization of resources. The predation and suppression of pests and weeds in paddy fields by the black-spotted frog significantly reduces dependence on chemical pesticides. On the other hand, the loach's movement in water and soil effectively loosens the soil structure, enhances soil permeability, and promotes the conversion and absorption of nutrients such as nitrogen and phosphorus, thereby reducing nutrient loss. Frog excrement and uneaten food provide a continuous source of nutrients for rice and loach, forming a stable material cycle chain. Combined with the design of loop-shaped ditches and interconnected water bodies, the flow and exchange conditions of farmland water can be optimized, improving the ability to intercept and purify pollutants. Through inlet and outlet filtration and escape prevention structures, the stable operation of the system is ensured. Overall, the application of chemical fertilizers and pesticides is significantly reduced, effectively reducing the concentration of total nitrogen and total phosphorus in farmland drainage, achieving the comprehensive technical effects of controlling non-point source pollution, improving the agricultural ecological environment, enhancing the quality of agricultural products, and realizing "three harvests from one field".

[0009] Optionally, the width of the meandering ditch is 0.5 to 2 m and the depth is 0.3 to 1.2 m.

[0010] By adopting the above technical solution and limiting the width and depth of the meandering ditch, the water body's capacity for carrying and circulating water can be guaranteed while also taking into account the utilization rate of arable land. This provides a stable habitat for loaches and enhances the water exchange and pollutant sedimentation and purification effects.

[0011] Optionally, the ditch is arranged in a closed loop along the edge of the paddy field, or forms a ring or multiple ring structures inside the paddy field.

[0012] By adopting the above technical solutions, the connectivity and coverage of water circulation are enhanced, a stable ecological buffer zone is formed, and the activity space of aquatic organisms and the efficiency of pollutant interception and purification are improved.

[0013] Optionally, the stocking density of the black-spotted frog tadpoles is 50,000 to 80,000 per mu.

[0014] Optionally, the stocking density of the loach fry is 100,000 to 150,000 per mu.

[0015] Optionally, the filtration structure of the water inlet is a multi-layer filter structure, used to block foreign organisms and impurities from entering the paddy field system.

[0016] By adopting the above technical solutions, the incoming water is filtered in stages, effectively blocking foreign organisms and suspended impurities from entering the paddy field system, reducing the risk of diseases and pollution, and ensuring the stability of the water environment and the safe operation of the planting and breeding system.

[0017] Optionally, the escape prevention structure of the drain outlet is an escape prevention net or an interception device with a one-way flow guidance structure.

[0018] By adopting the above technical solution Optionally, the protective structure around the field ridge is an escape-proof fence with a height of 0.5 to 1.5 m and anti-climb features; The amount of chemical fertilizer used in the aforementioned planting and breeding system is reduced by more than 50% compared to conventional rice cultivation, and the amount of pesticide used is reduced by more than 80%. The total nitrogen (TN) concentration in the farmland drainage is controlled within the range of 0.5–1.0 mg / L, and the total phosphorus (TP) concentration is controlled within the range of 0.1–0.2 mg / L.

[0019] By adopting the above-mentioned technical solutions, the escape of black-spotted frogs and loaches from the fields is effectively prevented, ensuring the stability of the biological population and the continuous operation of the ecological cycle within the integrated farming system. In this integrated farming system, the synergistic effect of rice, frogs, and loaches significantly reduces the dependence on external chemical inputs, reducing fertilizer application by more than 50% and pesticide use by more than 80% compared to conventional rice cultivation. This reduces pollutant input at the source. Combined with water body ecological purification and biological transformation, the loss of nutrients such as nitrogen and phosphorus can be effectively reduced, keeping the total nitrogen (TN) concentration in farmland drainage stably controlled within the range of 0.5–1.0 mg / L and the total phosphorus (TP) concentration within the range of 0.1–0.2 mg / L. This significantly improves the quality of farmland water environment and pollution control capabilities, achieving a synergistic improvement in ecological security and agricultural production benefits.

[0020] Optionally, the rice provides shade and habitat for the black-spotted frog and the loach, and the black-spotted frog and the loach form a stable food chain relationship through complementary ecological niches.

[0021] Optionally, the farming system achieves "three harvests from one field", including rice production, black-spotted frog farming production, and loach farming production.

[0022] In summary, this application includes at least one of the following beneficial technical effects: 1. By constructing a "rice-frog-loach" integrated three-dimensional ecosystem, the organic synergy between rice cultivation and aquaculture is achieved, significantly improving the stability of farmland ecosystems and the efficiency of material cycling; 2. By utilizing the biological control of pests and weeds by the black-spotted frog, combined with the disturbance and purification effect of loach on water and soil, the dependence on chemical pesticides and fertilizers can be significantly reduced. The amount of pesticides used can be reduced by more than 80%, and the amount of fertilizer used can be reduced by more than 50%. 3. By optimizing water flow and retention conditions through the structure of loop-shaped ditches and interconnected water bodies, the adsorption, transformation and sedimentation capacity of nutrients such as nitrogen and phosphorus are enhanced, effectively reducing the concentration of total nitrogen and total phosphorus in farmland drainage, and achieving source reduction and process control of non-point source pollution; 4. By reusing frog excrement and uneaten feed, the system can achieve the recycling of nutrients, improve resource utilization, and reduce external inputs; 5. Through the inlet and outlet filtration structure and the escape prevention structure, the system's operational stability and the safety of aquatic organisms are ensured, maintaining the long-term sustainable operation of the ecosystem; 6. To realize the integrated production model of "one field, three harvests" for rice, black-spotted frog and loach, while significantly improving ecological benefits, it can also increase the economic benefits per unit of farmland, and is both environmentally friendly and economically feasible. Attached Figure Description

[0023] Figure 1This is a schematic diagram illustrating the application of a green and efficient "rice-frog-loach" farming system in agricultural non-point source pollution according to an embodiment of this application. Detailed Implementation

[0024] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0025] This application discloses an application of a green and efficient "rice-frog-loach" farming system in addressing agricultural non-point source pollution. (Refer to...) Figure 1 The integrated farming system is built within rice-growing fields and includes the following technical measures: (1) Ecological transformation of paddy fields, setting up water ditches with a U-shaped structure around or inside the paddy fields, with the area of ​​the ditches accounting for 8% to 12% of the total area of ​​the paddy fields; (2) A connected water body is formed between the ditch and the paddy field, so that the paddy field area and the ditch area constitute an integrated water environment system; (3) While planting rice in paddy fields, black-spotted frog tadpoles and loach seedlings are released into the ditches and paddy field water bodies to construct a "rice-frog-loach" composite ecological farming system; (4) Utilize the predation of rice paddy pests and the control of weeds by the black-spotted frog to reduce the use of pesticides; (5) Utilize the activity of loach in water and soil to loosen the soil in paddy fields and promote the absorption and transformation of nitrogen and phosphorus nutrients in water. (6) Use the excrement and leftover food of the black-spotted frog as a nutrient source to provide nutrients for rice and loach, and realize ecological recycling; (7) A filter structure is installed at the water inlet of the paddy field, an escape prevention structure is installed at the drainage outlet, and a protective structure is installed around the field ridge to prevent the aquatic organisms from escaping. (8) Through the above-mentioned ecological synergy, the amount of fertilizer and pesticides used can be reduced, and the total nitrogen (TN) and total phosphorus (TP) content in farmland drainage can be reduced, thereby achieving farmland non-point source pollution control.

[0026] The following section, in conjunction with the technical solution and technical disclosure of this invention, provides a more detailed explanation of the application of the green and efficient "rice-frog-loach" farming system in addressing agricultural non-point source pollution. The embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this invention. Example 1

[0027] This embodiment provides a "rice-frog-loach" integrated ecological farming system for controlling non-point source pollution in farmland. It is constructed in standard rice-growing farmland to achieve coordinated operation of rice cultivation and aquaculture and reduce pollution load. The construction of the ecological structure of paddy fields selected flat paddy fields with good irrigation and drainage conditions as experimental areas. Without changing the original irrigation system, the fields were ecologically transformed. Specifically, a loop-shaped closed water ditch structure was dug around and inside the paddy fields to form a connected water system with the main body of the paddy fields. The excavation area of ​​the U-shaped irrigation ditch accounts for 10% of the total area of ​​the paddy field. The width of the ditch is controlled at 1.0 m and the depth is controlled at 0.8 m. In some deep water areas, the depth can be increased to 1.0 m to provide overwintering and summer shelter space. The ditch is connected to the field surface by a gentle slope or shallow embankment to form a continuous water exchange channel, so that the water forms a micro-circulation flow state within the field, improving the efficiency of nitrogen and phosphorus migration and sedimentation. After completing the paddy field structure modification, rice seedlings were transplanted and managed according to conventional rice cultivation methods. A conventional rice variety with a medium growth cycle and strong resistance was selected. A shallow water layer (3-5 cm) was maintained in the field to meet the initial adaptation needs of frogs and loaches. After the rice turned green, a systematic biological release operation was carried out: black-spotted frog tadpoles and loach fry were released into the paddy field water and the meandering ditches. The release density of black-spotted frog tadpoles was 65,000 tadpoles / acre, and the release density of loach fry was 125,000 tadpoles / acre, ensuring that the ecosystem had sufficient initial biomass to establish a stable food chain structure. During system operation, multi-level ecological interactions are formed: Black-spotted frogs live in rice paddies and ditches. By preying on the larvae of pests such as rice planthoppers and rice leaf rollers, they effectively reduce the population density of pests. At the same time, they have an inhibitory effect on some weed seedlings, reducing the need for pesticides from the source and playing an ecological regulation role. Loaches move through the bottom of water bodies and the shallow soil of paddy fields, continuously disturbing the soil structure, increasing soil porosity and permeability, and promoting root respiration and nutrient absorption. At the same time, their feeding on benthic organic detritus and microbial communities helps reduce the organic load of water bodies, enhances the mineralization and conversion efficiency of nitrogen and phosphorus, and realizes the soil and water regulation function of loaches. The excrement and leftover food of the black-spotted frog are decomposed by microorganisms in the system and transformed into usable nitrogen and phosphorus nutrients, which are absorbed by the rice roots. At the same time, some of them enter the loach food chain, realizing a closed loop of "input-conversion-reuse" and forming a material recycling mechanism. The U-shaped ditch structure prolongs the water retention time, allowing suspended particulate matter and some nutrients to settle naturally, and achieves secondary purification through the combined action of aquatic plants and microorganisms; A three-layer filtration structure, including a coarse filter, a medium filter, and a fine filter, is installed at the system inlet to block external impurities, fish, and pathogens from entering the system. A one-way flow-guiding escape-proof structure is installed at the outlet to ensure that loaches and frogs in the system cannot be lost with the drainage. At the same time, an escape-proof fence with a height of 1.0 m and anti-climbing structure is installed around the perimeter of the paddy field to form a closed breeding environment in terms of physical space. The monitoring results of a complete rice growth cycle showed that the amount of chemical fertilizer applied was reduced by about 55% and the amount of pesticide applied was reduced by about 82% compared with traditional rice planting; the total nitrogen (TN) concentration in farmland drainage was stable at 0.63-0.85 mg / L; the total phosphorus (TP) concentration was stable at 0.13-0.18 mg / L; the rice yield remained basically stable and additional aquatic income was achieved, significantly reducing the non-point source pollution load of farmland while ensuring grain production. Example 2

[0028] Based on Example 1, this embodiment optimizes the structure of the water ditch and the water circulation method to adapt to regions with different water resource conditions.

[0029] The original single-loop irrigation ditches will be adjusted to a "multi-ring nested structure," that is, a double-ring or triple-ring irrigation ditch system will be set up within the field, extending the water flow path by 30% to 60%. The total area of ​​irrigation ditches will be adjusted to 8% to 11% to improve the utilization rate of arable land. The inner ring ditch is mainly used as a high-density loach activity area, while the outer ring ditch is mainly used as a habitat and predation area for black-spotted frogs, thus realizing ecological niche zoning in space and reducing competitive pressure between species; The extended water retention time increases nitrogen and phosphorus migration pathways within the system, leading to more complete microbial nitrification and denitrification processes. Simultaneously, the increased organic matter content in the sediment at the bottom of the ditch promotes the formation of a stable anaerobic microenvironment, thereby enhancing total nitrogen removal capacity. Monitoring results show that, under the same input conditions, the TN concentration decreased by approximately 8% to 12% compared to Example 1. TP concentration decreased by about 10%; water transparency improved significantly; the overall ecological stability of paddy fields was enhanced, and the incidence of pests and diseases was further reduced. Example 3

[0030] This embodiment provides a large-scale application model suitable for contiguous paddy field areas.

[0031] Multiple paddy field units are connected by a canal system to form a "field community water network structure". Water flow can be exchanged between the fields through control gates, so that pollutants can be reduced in stages at the regional scale. Differentiated release densities are set according to the location of different fields to form a biological density gradient control: Upstream fields: Loach density is high (130,000 to 150,000 fish / acre), so primary purification should be strengthened; Midstream fields: Frog density is high, so strengthen biological pest control; Downstream fields: Reduce stocking density for ecological stabilization and water quality improvement; After regional application, a multi-level purification chain is formed, which improves the quality of wastewater step by step. Overall monitoring results show that the average reduction rate of total nitrogen (TN) in the region is over 60%; the reduction rate of total phosphorus (TP) is over 55%; the amount of pesticides used has decreased by more than 80%; and the biodiversity of aquatic organisms in the region has been significantly improved.

[0032] As can be seen from the above embodiments, this application achieves the following comprehensive technical approach by constructing a "rice-frog-loach" multi-trophic-level complex ecosystem and combining it with a loop or multi-ring ditch structure, physical isolation, and water circulation regulation technology: Reduce pesticide use by using biological regulation to reduce pests, diseases, and weeds; By using loach disturbance and microorganisms to synergistically promote nitrogen and phosphorus transformation, nutrient reduction is achieved; Optimizing water body structure extends the migration path of pollutants and improves purification efficiency; Improve system resource utilization through material recycling; A closed escape prevention system ensures the long-term stable operation of the ecosystem.

[0033] The implementation principle of this application of a green and efficient "rice-frog-loach" integrated farming system for agricultural non-point source pollution is as follows: By constructing interconnected loop or ring-shaped ditches in rice paddies, the shallow water areas of the rice paddies and the deep water areas of the ditches form an integrated water environment system, extending the water retention time and enhancing water circulation and exchange. This provides a basic environment for the sedimentation, adsorption, and biotransformation of nutrients such as nitrogen and phosphorus from a hydrodynamic perspective. Based on this, black-spotted frogs and loaches are introduced to construct a multi-trophic-level complex ecosystem. The black-spotted frogs directly reduce the intensity of pests and weeds by preying on rice paddy pests and weed larvae, reducing pesticide dependence at the source. The loaches improve soil quality through their traversing and feeding activities in the water and topsoil. The soil pore structure and water flow promote the decomposition of deposited organic matter and the transformation and absorption of nitrogen and phosphorus nutrients, thereby reducing the accumulation and loss of pollutants. At the same time, frog excrement and uneaten food in the system serve as endogenous organic nutrient inputs, which are reused by rice roots and microbial communities, forming a closed material cycle pathway of "input-conversion-recycling", thereby reducing the demand for external fertilizers. Combined with multi-stage filtration at the inlet and escape prevention structure at the outlet, external pollution input is blocked and the escape of organisms within the system is prevented, maintaining the structural stability and functional sustainability of the ecosystem. Through the above-mentioned structural synergy and biological synergy, the technical goals of reducing nitrogen and phosphorus loads in farmland, reducing fertilizer and pesticide use, and comprehensively controlling non-point source pollution in farmland are achieved.

[0034] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. The application of a green and efficient "rice-frog-loach" farming system in agricultural non-point source pollution, characterized in that... The aforementioned farming system is constructed within rice-growing farmland and includes the following technical measures: (1) Ecological transformation of paddy fields, setting up water ditches with a U-shaped structure around or inside the paddy fields, with the area of ​​the ditches accounting for 8% to 12% of the total area of ​​the paddy fields; (2) A connected water body is formed between the ditch and the paddy field, so that the paddy field area and the ditch area constitute an integrated water environment system; (3) While planting rice in paddy fields, black-spotted frog tadpoles and loach fry are released into the ditches and paddy field water bodies to construct a "rice-frog-loach" composite ecological farming system; (4) Utilize the predation of rice paddy pests and the control of weeds by the black-spotted frog to reduce the use of pesticides; (5) Utilize the activity of loach in water and soil to loosen the soil in paddy fields and promote the absorption and transformation of nitrogen and phosphorus nutrients in water. (6) Use the excrement and leftover food of the black-spotted frog as a nutrient source to provide nutrients for rice and loach, and realize ecological recycling; (7) A filter structure is installed at the water inlet of the paddy field, an escape prevention structure is installed at the drainage outlet, and a protective structure is installed around the field ridge to prevent the aquatic organisms from escaping. (8) Through the above-mentioned ecological synergy, the amount of fertilizer and pesticide applied can be reduced, and the total nitrogen (TN) and total phosphorus (TP) content in farmland drainage can be reduced, thereby achieving farmland non-point source pollution control.

2. The application according to claim 1, characterized in that: The width of the meandering ditch is 0.5–2 m, and the depth is 0.3–1.2 m.

3. The application according to claim 1, characterized in that: The ditch is set up in a closed loop along the edge of the paddy field, or forms a ring or multiple ring structures inside the paddy field.

4. The application according to claim 1, characterized in that: The stocking density of the black-spotted frog tadpoles is 50,000 to 80,000 per acre.

5. The application according to claim 1, characterized in that: The stocking density of the loach fry is 100,000 to 150,000 per mu (approximately 667 square meters).

6. The application according to claim 1, characterized in that: The inlet has a multi-layer filter structure to prevent foreign organisms and impurities from entering the paddy field system.

7. The application according to claim 1, characterized in that: The escape prevention structure of the drainage outlet is an escape prevention net or an interception device with a one-way flow guidance structure.

8. The application according to claim 1, characterized in that: The protective structure surrounding the field ridge is an escape-proof fence, with a height of 0.5 to 1.5 m and anti-climb features; The amount of chemical fertilizer used in the aforementioned planting and breeding system is reduced by more than 50% compared to conventional rice cultivation, and the amount of pesticide used is reduced by more than 80%. The total nitrogen (TN) concentration in the farmland drainage is controlled within the range of 0.5–1.0 mg / L, and the total phosphorus (TP) concentration is controlled within the range of 0.1–0.2 mg / L.

9. The application according to claim 1, characterized in that: The rice paddies provide shade and habitat for the black-spotted frog and the loach, which form a stable food chain relationship through complementary ecological niches.

10. The application according to claim 1, characterized in that: The aforementioned farming system achieves "three harvests from one field," including rice production, black-spotted frog farming production, and loach farming production.

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