Application of nano-copper oxide, degrading agent and method for reducing quinclorac in soil and improving crop yield

Abstract

The application discloses application of nano copper oxide, a degradation agent and a method for reducing 2,4-dichlorophenoxyacetic acid in soil and improving crop yield. The degradation agent comprises nano copper oxide, Bacteroides and green curved bacteria. The method comprises the following steps: (1) adding Bacteroides and green curved bacteria into acidic wet soil polluted by 2,4-dichlorophenoxyacetic acid; (2) adding nano copper oxide into the soil; and (3) planting crops. The nano copper oxide is added into the soil, and is used in cooperation with Bacteroides and green curved bacteria, so that the 2,4-dichlorophenoxyacetic acid is efficiently and sustainably degraded, the crop yield is increased, and the dual benefits of pesticide degradation and crop yield increase are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil remediation, and in particular relates to an application of nano copper oxide, a pesticide degrader, and a method for reducing pesticides in soil and increasing crop yields. Background Art

[0002] Herbicides, a crucial tool in modern agricultural production, have significantly improved weed control efficiency. However, their extensive use has led to increasingly serious problems, including residual contamination, ecotoxicity, and the development of resistance. The long-term, high-volume spraying of traditional herbicides not only disrupts soil microbial balance and contaminates groundwater, but also threatens human health through bioaccumulation. Some herbicide ingredients have been linked to endocrine disruption and cancer risk. Currently, over 500 weed species worldwide have developed resistance to mainstream herbicides, forcing farmers to increase their frequency of use, creating a vicious cycle of "dose escalation and contamination spread." Furthermore, only approximately 20% of the active ingredient in conventional formulations is absorbed by the target organism, while 80% enters the environment through runoff and drift, threatening non-target organisms and food safety. Against this backdrop, the development of a synergistic nano-biotechnology-based green control system is urgently needed to mitigate the resistance crisis and ensure food security.

[0003] In intensive agricultural production, the widespread use of pesticides protects crops but also leads to pesticide accumulation and environmental pollution. Quinclorac, in particular, has been widely used in recent years, and the accumulation and environmental pollution of quinclorac have become increasingly significant. Nanomaterials can reshape soil health through a physical-chemical-biological synergistic pathway, activate plant antioxidant enzyme systems, and enhance their tolerance to adverse stresses. However, there are few studies on the effects of nano-copper oxide on quinclorac residues. Therefore, systematically analyzing the multi-level mechanism of action of nano-copper oxide on the degradation of quinclorac residues in soil and the improvement of crop yields has become a key scientific proposition for solving the problem of sustainable agricultural development. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the above background technology, and provide an application of nano-copper oxide in reducing dichloroquine in soil, a degradation agent for reducing dichloroquine in soil, and a method for using the degradation agent to reduce dichloroquine in soil and increase crop yield. The method uses nano-copper oxide to reduce dichloroquine in soil and promote the growth of crops.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] Application of nano copper oxide in reducing quinclorac in soil.

[0007] In the above application, preferably, the soil is acidic moist soil contaminated by quinclorac, to which Bacteroides and Chloroflexus are added, such as acidic paddy soil from Hunan area.

[0008] As a general technical concept, the present invention also provides a degradation agent for reducing quinclorac in soil, comprising nano copper oxide, Bacteroides and Chloroflexus, wherein the nano copper oxide is applied at a concentration of 250-500 mg / kg based on dry soil, and the total concentration of Bacteroides and Chloroflexus is 10 7 -10 8 CFU / g, where Bacteroides and Chloroflexus are mixed at a cell ratio of 1-2:1. That is, for every 1kg of dry soil, the dosage of nano copper oxide is 250-500mg, and for every 1g of dry soil, the total amount of Bacteroides and Chloroflexus is 10 7 -10 8 CFU.

[0009] Among the above degradation agents, preferably, the nano copper oxide has a particle size of 40-50 nm. Nano copper oxide with the above particle size is more conducive to its degradation of dichloroquine in soil.

[0010] As a general technical concept, the present invention also provides a method for reducing quinclorac in soil and increasing crop yield using the above-mentioned degradation agent, comprising the following steps:

[0011] (1) Adding Bacteroides and Chloroflexus to acidic moist soil contaminated with quinclorac;

[0012] (2) Add nano copper oxide to the soil;

[0013] (3) Planting crops.

[0014] In the above method, preferably, before planting crops, first inoculate Bacteroides and Chloroflexus into acidic moist soil contaminated with quinclorac, and culture until the total concentration of Bacteroides and Chloroflexus reaches 10 7 -10 8 CFU / g. During this process, the nutrients in the soil can be monitored. If the necessary nutrients required by Bacteroides and Chloroflexus are lacking, they can be supplemented appropriately.

[0015] In the above method, preferably, the culture is carried out at 25-30°C under normal light conditions for 7-14 days to make the total concentration of Bacteroides and Chloroflexus reach 10 7 -10 8 CFU / g.

[0016] In the above method, preferably, the content of quinclorac in the soil is 15-30 mg / kg based on dry soil, that is, the content of quinclorac in every 1 kg of dry soil is 15-30 mg.

[0017] In the above method, preferably, the acidic moist soil has a water content of 55-65 wt.% and a pH of 5-6. Acidic moist soil under the above conditions is conducive to the synergistic effect of nano-copper oxide, Bacteroides and Chloroflexus.

[0018] In the above method, preferably, the crop is lettuce.

[0019] Currently, there is little research on the process and mechanism of nano-copper oxide promoting pesticide degradation. In the remediation of organic pollution in agricultural soil, microorganisms and biostimulation are the core targets of in situ bioremediation strategies. This technology also has environmental benefits such as improving nutrient utilization, which helps to provide an effective ecological solution to major environmental problems such as pesticide pollution, soil remediation and sustainable agriculture. The present invention adopts an innovative nanomaterial strategy to reduce plant herbicide residues in the soil, comprehensively promoting the degradation of dichloroquine and increasing crop yields. Nano-copper oxide is used as a nanomaterial in conjunction with Bacteroides and Chloroflexus to achieve the metabolic degradation of dichloroquine through biostimulation and microbial mediation. At the same time, the synergistic use of nano-copper oxide with Bacteroides and Chloroflexus can also increase the yield of lettuce crops. The present invention adopts interdisciplinary and comprehensive technical means to innovatively combine nanomaterials with microorganisms at a higher and more complex system level, achieving the goal of efficient and sustainable degradation of dichloroquine while simultaneously increasing crop yields.

[0020] This invention is the first to use nano-copper oxide as a soil remediation agent. While providing essential copper to plants, it also collaborates with microorganisms to mediate the degradation of quinclorac, achieving a synergistic "yield-increasing and toxicity-reducing" effect. By incorporating nano-copper oxide, Bacteroides, and Chloroflexus, the researchers demonstrate the metabolic potential for efficient quinclorac degradation, enabling the degradation of quinclorac.

[0021] When using nano-copper oxide, Bacteroides, and Chloroflexus, first adding Bacteroides and Chloroflexus to acidic, moist soil and culturing them to the desired concentration before adding nano-copper oxide resulted in a better degradation effect on quinclorac. This may be because Bacteroides and Chloroflexus first proliferate and acclimate in the acidic, moist soil while acting on quinclorac, which facilitates the degradation effect after the addition of nano-copper oxide.

[0022] It should be noted that the dosage of nano copper oxide itself needs to be reasonably controlled to match the pollution level of dichloroquinoline. The research of the present invention shows that, based on dry soil, 250-500 mg / kg of nano copper oxide can effectively inhibit the growth of Bacteroides and Chloroflexus (total amount of 10 7 -10 8The optimal concentration range is the combined effect of the two groups of chloroquine and chloroquine, which can significantly reduce the residual of dichloroquine and avoid the toxicity of the nanomaterial itself.

[0023] The market application prospects of the present invention are illustrated as follows:

[0024] 1. It is suitable for agricultural production scenarios where rice fields are converted to vegetable crops, and can effectively solve the problems of vegetable contamination and continuous cropping caused by herbicide residues such as quinclorac.

[0025] 2. Increase yields by reducing plant pesticide residues and promote the development of green agriculture.

[0026] 3. Improve soil ecological environment quality, increase nutrient utilization efficiency, and achieve sustainable agricultural management.

[0027] 4. It complies with the environmental protection policy orientation of pesticide residue prevention and control, and has broad space for promotion and application.

[0028] Compared with the prior art, the advantages of the present invention are:

[0029] The present invention adds nano-copper oxide to the soil and uses it in conjunction with Bacteroides and Chloroflexus to achieve efficient and sustainable degradation of quinclorac and simultaneously increase crop yields, thus achieving the dual benefits of pesticide degradation and crop yield increase.

[0030] Through the multifunctional coordinated design of nano-copper oxide, this invention reveals the key mechanism for regulating pesticide degradation, breaks through the "degradation-yield reduction" contradiction in traditional technology, and achieves a win-win situation for farmland restoration and agricultural production.

[0031] The present invention provides an effective ecological solution to major environmental issues such as pesticide pollution, soil remediation, and sustainable agriculture. Furthermore, the technical approach is clear and feasible, requiring only conventional application for implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1The figure is a growth diagram of lettuce in the embodiment (in the figure, 15QNC represents a quinclorac concentration of 15 mg / kg, without the addition of nano-copper oxide; 30QNC represents a quinclorac concentration of 30 mg / kg, without the addition of nano-copper oxide; 15QNC+500cuo represents a quinclorac concentration of 15 mg / kg, with the addition of 500 mg / kg of nano-copper oxide; 30QNC+500cuo represents a quinclorac concentration of 15 mg / kg, with the addition of 500 mg / kg of nano-copper oxide). DETAILED DESCRIPTION

[0034] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0035] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0036] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0037] Example:

[0038] A degrader for reducing quinclorac in soil, comprising nano copper oxide, Bacteroides and Chloroflexus, wherein the applied concentration of nano copper oxide is 250-500 mg / kg based on dry soil, and the total concentration of Bacteroides and Chloroflexus is 10 7 -10 8 CFU / g, where Bacteroides and Chloroflexus were mixed at a cell number ratio of 1-2:1.

[0039] A method for reducing quinclorac in soil and increasing crop yield using the above-mentioned degradation agent comprises the following steps:

[0040] (1) Adding Bacteroides and Chloroflexus to acidic moist soil contaminated with quinclorac;

[0041] (2) Add nano copper oxide to the soil;

[0042] (3) Planting lettuce.

[0043] The specific steps and performance verification are as follows:

[0044] 1. Test soil:

[0045] Experimental soil samples were collected from farmland in Chunhuahua Town, Changsha, Hunan Province, China. Topsoil samples (0–20 cm depth) were air-dried and sieved to <2 mm. Basic soil properties were: 52.2% silt, 25.5% clay, 22.3% sand, pH 5.6, available potassium 0.175 g / kg dry soil, and organic matter 33.86 g / kg dry soil.

[0046] 2. Chemical reagents:

[0047] Quinclorac (50% active ingredient) was produced by Tianyi Biotechnology Co., Ltd. (Zhejiang, China), and quinclorac standard (CAS: 84087-01-4, purity >98%) was purchased from Aladdin (Shanghai, China). CuO-NPs (40 nm in diameter, spherical, purity >99.5%) were from MacLean (Shanghai, China).

[0048] 3. Test instruments:

[0049] High performance liquid chromatography (HPLC) (Agilent Technologies, Germany), high-speed and low-speed centrifuges, oil bath, drying oven, etc.

[0050] 4. The specific technical solutions are as follows:

[0051] 4.1 Experimental Design

[0052] This study included two levels of quinclorac concentration and nano copper oxide-bacterial addition, calculated on a dry soil basis, as follows:

[0053] Quinclorac concentration: 15 mg / kg, 30 mg / kg;

[0054] Bacteroides and Chloroflexus: Mix at a cell ratio of 1:1.5;

[0055] Nano copper oxide addition amount: 0, 250 mg / kg, 500 mg / kg.

[0056] A completely randomized experimental design was designed based on two factors. 1 kg of sieved dry soil was first placed in each pot. Dichloroquine wettable powder was dissolved in distilled water and evenly applied to each treatment group at concentrations of 15 mg / kg and 30 mg / kg (evenly sprayed into the soil to simulate soil contaminated by dichloroquine). The above-mentioned Bacteroides and Chloroflexi were inoculated into the soil and cultured under normal light conditions at a soil moisture content of approximately 60% and 25-30°C until the total amount of Bacteroides and Chloroflexi reached 10 7 -10 8CFU / g dry soil; 250mg / kg and 500mg / kg of copper oxide nanoparticles (CuO-NPs) were applied as a mixed treatment. Lettuce seeds were sterilized and washed in a dark and warm environment, and nine germinated lettuce seeds (16 cm long, 12 cm wide, and 11.5 cm high) were placed in each pot. After the seedlings grew their second true leaves, three lettuces were retained per pot. When the seedlings grew to approximately 5-7 cm in height, they were further thinned to one plant per pot. Lettuce was grown in a glasshouse at natural temperature and sufficient light, irrigated with distilled water. At the end of the experiment, mature lettuce samples were collected, washed, dried, and weighed to quantify their biomass. Soil samples were collected for analysis of quinclorac residues in the soil.

[0057] For comparison, this example also omitted the addition of Bacteroides and Chloroflexus, and directly added 250 mg / kg of nano-copper oxide to the soil containing 15 mg / kg of quinclorac. The same lettuce cultivation experiment was conducted while keeping other conditions unchanged.

[0058] For comparison, this example also changes the method of using Bacteroides and Chloroflexus, and directly uses a concentration of 10 7 -10 8 CFU / g dry soil of Bacteroides and Chloroflexus, along with 250mg / kg of nano-copper oxide, were added to soil containing 15mg / kg of quinclorac without prior culture. Other conditions remained unchanged, and the same lettuce culture experiment was conducted.

[0059] For comparison, this example also replaces the aforementioned 250 mg / kg nano copper oxide particles with 250 mg / kg nano ferric oxide particles, and conducts the same lettuce culture test at a quinclorac concentration of 15 mg / kg, without changing the bacterial dosage and usage.

[0060] As a comparison, this example also replaces the aforementioned Bacteroides and Chloroflexus with 10 7 -10 8 The same lettuce culture test was carried out with a Bacillus subtilis inoculant of 100 CFU / g (dry soil) at a concentration of 15 mg / kg of quinclorac, the same method of use of the bacteria, and the same dosage of 250 mg / kg of nano-copper oxide particles.

[0061] 4.2. Quinclorac Residues

[0062] The method for determining the quinclorac content in soil and lettuce involved freeze-drying the soil and lettuce samples. 3–5 g of the soil and lettuce were then extracted with a boric acid-methanol solution. The extract was then centrifuged, and the supernatant was collected and concentrated using a rotary evaporator. The extract was then filtered through a 0.22 μm nylon filter membrane. The accumulation of quinclorac was analyzed using high-performance liquid chromatography (HPLC; Agilent 1260, USA). The results are shown in Tables 1 and 2.

[0063] Table 1: Reduction of quinclorac residues in soil

[0064]

[0065] Table 2: Reduction of quinclorac residues in lettuce

[0066]

[0067] In the above table, treatment group A represents no addition of nano-copper oxide, but addition of Bacteroides + Chloroflexus; treatment group B represents 250 mg / kg nano-copper oxide + Bacteroides + Chloroflexus; treatment group C represents 500 mg / kg nano-copper oxide + Bacteroides + Chloroflexus; treatment group D represents 250 mg / kg nano-copper oxide, but no Bacteroides and Chloroflexus are added; compared with treatment group B, treatment group E changes the method of using Bacteroides and Chloroflexus, and adds them together with nano-copper oxide; compared with treatment group B, treatment group F uses nano-iron oxide instead of nano-copper oxide; compared with treatment group B, treatment group G uses Bacteroides + Chloroflexus instead of Bacteroides + Chloroflexus.

[0068] As shown in Table 1 above, when the concentration of quinclorac in soil was 15 mg / kg, the residue of quinclorac in soil showed the largest decrease in treatment group C, and the nano-copper oxide dosage was smaller in treatment group B, with a decrease less than that in treatment group C. Treatment group A and treatment group D did not adopt nano-copper oxide and microbial agent respectively, and the decrease in quinclorac in soil was less than that in treatment group B and treatment group C. In treatment group E, microbial agent and nano-copper oxide were added simultaneously, and the decrease in quinclorac in soil was less than that in treatment group B, which shows that adding microbial agent in soil in advance is conducive to the degradation of quinclorac in soil. Treatment group F and treatment group G did not adopt specific nano-copper oxide and microbial agent in treatment group B respectively, and the decrease in quinclorac in soil was also less than that in treatment group B. The concentration of quinclorac in soil is 30mg / kg when presenting and the concentration of quinclorac in soil is 15mg / kg when roughly the same trend, but because the concentration of quinclorac is high, the residual range of decline numerical value is also obviously higher.The above-mentioned test result shows, there is obvious synergy between the nano copper oxide, Bacteroides and Chloroflexus that the present invention adopts, can promote the degraded of quinclorac in soil.As shown in Table 2, the residual range of decline of quinclorac in lettuce and the residual range of decline of quinclorac in soil are roughly the same trend.

[0069] 4.3. Increased lettuce production

[0070] The combined use of nano-copper oxide, Bacteroides spp., and Chloroflexus spp. increased plant (lettuce) yield to a certain extent under different quinclorac concentrations. The results are shown in Table 3 below.

[0071] Table 3: Lettuce yield improvement rate

[0072]

[0073] In the above table, treatment group A represents no addition of nano-copper oxide, but addition of Bacteroides + Chloroflexus; treatment group B represents 250 mg / kg nano-copper oxide + Bacteroides + Chloroflexus; treatment group C represents 500 mg / kg nano-copper oxide + Bacteroides + Chloroflexus; treatment group D represents 250 mg / kg nano-copper oxide, but no Bacteroides and Chloroflexus are added; compared with treatment group B, treatment group E changes the method of using Bacteroides and Chloroflexus, and adds them together with nano-copper oxide; compared with treatment group B, treatment group F uses nano-iron oxide instead of nano-copper oxide; compared with treatment group B, treatment group G uses Bacillus subtilis instead of Bacteroides + Chloroflexus.

[0074] As shown in Table 3 above, when the concentration of quinclorac in the soil was 15 mg / kg, the lettuce yield increase rate showed the greatest improvement in treatment group C. Treatment group B, which used a smaller amount of nano-copper oxide, had a smaller increase than treatment group C. Treatment groups A and D, which did not use nano-copper oxide and a microbial agent, respectively, saw a smaller increase in lettuce yield than treatment groups B and C. Treatment group E, which added both the microbial agent and nano-copper oxide, saw a smaller increase in lettuce yield than treatment group B, suggesting that adding a microbial agent to the soil in advance is beneficial for degrading quinclorac in the soil and increasing lettuce yield. Treatment groups F and G, which did not use the specific nano-copper oxide and microbial agent used in treatment group B, also saw a smaller increase in lettuce yield than treatment group B. A soil concentration of 30 mg / kg quinclorac showed a similar trend to that of 15 mg / kg quinclorac. The above test results show that the nano copper oxide, Bacteroides and Chloroflexus used in the present invention have obvious synergistic effects, which can promote the degradation of dichloroquine in the soil and increase lettuce yield.

[0075] At the same time, by Figure 1 It can also be seen from the lettuce growth chart that under the same number of days and the same growth environment, the lettuce growth in the treatment group with nano-copper oxide is significantly better.

Claims

1. Application of nano copper oxide in reducing quinclorac in soil.

2. The use according to claim 1, characterized in that The soil is acidic moist soil contaminated by quinclorac, to which Bacteroides and Chloroflexus are added.

3. A degradation agent for reducing quinclorac in soil, characterized in that, The nano copper oxide, Bacteroides and Chloroflexus are included. Based on dry soil, the concentration of the nano copper oxide is 250-500 mg / kg, and the total concentration of Bacteroides and Chloroflexus is 10 7 -10 8 CFU / g, where Bacteroides and Chloroflexus were mixed at a cell number ratio of 1-2:

1.

4. The degradation agent according to claim 3, characterized in that The particle size of the nano copper oxide is 40-50 nm.

5. A method for reducing quinclorac in soil and increasing crop yield using the degradation agent according to claim 3 or 4, characterized in that: The following steps are involved: (1) Adding Bacteroides and Chloroflexus to acidic moist soil contaminated with quinclorac; (2) Add nano copper oxide to the soil; (3) Planting crops.

6. The method according to claim 5, characterized in that Before planting crops, inoculate Bacteroides and Chloroflexus into acidic moist soil contaminated with quinclorac and culture until the total concentration of Bacteroides and Chloroflexus reaches 10 7 -10 8 CFU / g.

7. The method according to claim 6, characterized in that Culture at 25-30℃ under normal light conditions for 7-14 days until the total concentration of Bacteroides and Chloroflexus reaches 10 7 -10 8 CFU / g.

8. The method according to claim 5, characterized in that Calculated on the basis of dry soil, the content of quinclorac in the soil is 15-30 mg / kg.

9. The method according to claim 5, characterized in that In acidic moist soil, the soil moisture content is 55-65wt.% and the pH value is 5-6.

10. The method according to claim 5, characterized in that The crop is lettuce.

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