Application of difenoconazole as fungal denitrification inhibitor in controlling release of nitrous oxide in soil

Abstract

The invention discloses application of difenoconazole as a fungus denitrification inhibitor in controlling release of nitrous oxide in soil, and relates to the technical field of medicine application. According to the method, the difenoconazole is used for regulating and controlling the fungus denitrification process in a targeted manner, so that the emission amount of greenhouse gas N2O after a nitrogen fertilizer is applied to a farmland (namely the soil environment of the waterlogged farmland) can be effectively reduced, and the specific effects are that under the laboratory condition, the difenoconazole can be used for reducing the release amount of the N2O in the soil by 75-93%; under the experimental condition of the paddy field, the release amount of N2O in the paddy field is reduced by 54% by difenoconazole.

Description

Technical Field

[0001] The invention relates to the technical field of drug application, and in particular to the application of difenoconazole as a fungal denitrification inhibitor in controlling the release of nitrous oxide in soil. Background Art

[0002] Nitrous oxide (N2O) is a greenhouse gas with a strong radiative effect, contributing up to 6.2% to the global temperature rise. Therefore, in order to reduce the greenhouse effect, the regulation and reduction of N2O emissions are imminent.

[0003] Human agricultural activities have aggravated N2O emissions from farmland soil. The microbial-mediated denitrification process in farmland soil is an important source of N2O emissions, of which fungal denitrification releases about 20-25% of the total N2O emissions. The principle of N2O production in the microbial-mediated denitrification process is that fungi lack N2O reductase (NOS) in their cells, so fungal denitrification usually uses N2O as the final product of the reaction. It can be seen that the microbial-mediated denitrification process in farmland soil has seriously increased the emission flux of greenhouse gases from farmland. Studies have shown that flooded farmland soil has a higher fungal denitrification N2O emission rate. According to data from previous studies, fungal denitrification accounts for 51-63% of the total N2O emissions from rice fields across the country. Therefore, how to reduce the release of N2O by fungal denitrification is of great significance for reducing greenhouse gas emissions from farmland and mitigating global climate change.

[0004] At present, the means to control the release of N2O from farmland soil is to regulate nitrification. The main way to regulate nitrification is to apply nitrification inhibitors DMPP (3,4-dimethylpyrazole phosphate), DCD (dicyandiamide) and Nitrapyrin (2-chloro-6-(trichloromethyl)pyridine). However, the existing nitrification inhibitors can only regulate nitrification, but it is difficult to inhibit the denitrification process that actually produces more N2O. In the flooded farmland soil environment, the N2O emissions produced by denitrification are still very high. Therefore, in order to further control the release of N2O in agricultural activities, it is necessary to study the inhibitors of the denitrification process. Summary of the invention

[0005] The invention discloses the application of difenoconazole as a fungal denitrification inhibitor in controlling the release of nitrous oxide in soil. Difenoconazole regulates the fungal denitrification process in a targeted manner to reduce the problem of increased emission of greenhouse gas N2O after nitrogen fertilizer is applied to farmland (i.e., flooded farmland soil environment).

[0006] The technical solution adopted by the present invention is as follows:

[0007] Application of difenoconazole as a fungal denitrification inhibitor in controlling soil nitrous oxide release.

[0008] Furthermore, the soil is flooded farmland soil.

[0009] Furthermore, the soil is paddy field soil.

[0010] A soil fungal denitrification inhibitor comprising difenoconazole.

[0011] In summary, compared with the prior art, the present invention has the following advantages and beneficial effects:

[0012] 1. The present invention discloses the use of difenoconazole as a fungal denitrification inhibitor in controlling the release of nitrous oxide in soil: difenoconazole can target and regulate the fungal denitrification process, thereby effectively reducing the emission of greenhouse gas N2O after nitrogen fertilizer is applied to farmland (i.e., flooded farmland soil environment), which is specifically embodied in that: under laboratory conditions, difenoconazole can reduce the release of soil N2O by 75-93%; under experimental conditions in rice fields, difenoconazole reduces the release of N2O in rice fields by 54%;

[0013] 2. The present invention discloses a soil fungal denitrification inhibitor in farmland soil, which effectively inhibits the denitrification process mediated by microorganisms in farmland soil;

[0014] 3. Compared with traditional nitrification inhibitors, the present invention provides a new idea of ​​using denitrification inhibitors to reduce N2O emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a bar graph of N2O release in each treatment group of the laboratory soil culture experiment in Example 1, wherein a is the control situation of the blank group and the difenoconazole alone treatment group, b is the control situation of the bacterial denitrification treatment group and the difenoconazole + bacterial denitrification treatment group, c is the control situation of the fungal denitrification treatment group and the difenoconazole + fungal denitrification treatment group, and d is the control situation of the abiotic denitrification treatment group and the difenoconazole + abiotic denitrification treatment group;

[0016] Figure 2 This is a layout diagram of the experimental device for monitoring the N2O release in farmland using the static dark box method in Example 2, where a is a physical diagram of the box, and b is a layout diagram of the box placed in rice;

[0017] Figure 3 Graph showing the N2O release of the fenpropimorph group and the blank group in the rice field cultivation experiment in Example 2, wherein a is a line graph showing the N2O release at different times after the application of urea and fenpropimorph, and b is a statistical bar graph showing the N2O release. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with various embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments.

[0019] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this method adopt conventional test methods in the art. The terms described in the present invention are only for describing specific implementation methods and are not intended to limit the content disclosed in the present invention.

[0020] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which the invention belongs; other raw materials, reagents, experimental methods and technical means not specifically specified in the present invention refer to the raw materials and reagents commonly used by ordinary technicians in the field, as well as the commonly used experimental methods and technical means.

[0021] Example 1

[0022] This example provides a laboratory soil culture experiment of difenoconazole regulating fungal denitrification process:

[0023] 1. Set up a blank group, a bacterial denitrification treatment group, a fungal denitrification treatment group, and a non-biological denitrification treatment group

[0024] (1) Blank control group

[0025] 1 g (dry weight) of soil sample was placed in a 12 mL Labco test tube, and 1 mL of solution was added, the solution containing glucose (carbon source) and sodium nitrate (nitrogen source), with specific concentrations of glucose 180 mg / kg (soil) and sodium nitrate 100 mg / kg (soil).

[0026] (2) Bacterial denitrification treatment group

[0027] 1 g (dry weight) of soil sample was placed in a 12 mL Labco test tube, and 1 mL of solution was added, which contained glucose (carbon source), sodium nitrate (nitrogen source), and cycloheximide (fungal inhibitor). The specific concentrations were glucose 180 mg / kg (soil), sodium nitrate 100 mg / kg (soil), and cycloheximide 10 mg / g (soil).

[0028] (3) Fungal denitrification treatment group

[0029] 1 g (dry weight) of soil sample was placed in a 12 mL Labco test tube, and 1 mL of solution was added, which contained glucose (carbon source), sodium nitrate (nitrogen source), and streptomycin (bacterial inhibitor). The specific concentrations were glucose 180 mg / kg (soil), sodium nitrate 100 mg / kg (soil), and streptomycin 6 mg / g (soil).

[0030] (4) Abiotic denitrification treatment group

[0031] 1 g (dry weight) of soil sample was placed in a 12 mL Labco test tube, and 1 mL of solution was added, which contained glucose (carbon source), sodium nitrate (nitrogen source), cycloheximide (fungal inhibitor), and streptomycin (bacterial inhibitor). The specific concentrations were glucose 180 mg / kg (soil), sodium nitrate 100 mg / kg (soil), cycloheximide 10 mg / g (soil), and streptomycin 6 mg / g (soil).

[0032] (5) Difenoconazole alone treatment group

[0033] 1 g (dry weight) of soil sample was placed in a 12 mL Labco test tube, and 1 mL of solution was added, which contained glucose (carbon source), sodium nitrate (nitrogen source), and difenoconazole. The specific concentrations were glucose 180 mg / kg (soil), sodium nitrate 100 mg / kg (soil), and difenoconazole 1 mg / kg (soil).

[0034] (6) Difenoconazole + bacterial denitrification treatment group

[0035] 1 g (dry weight) of soil sample was placed in a 12 mL Labco test tube, and 1 mL of solution was added, which contained glucose (carbon source), sodium nitrate (nitrogen source), cycloheximide (fungal inhibitor), and difenoconazole. The specific concentrations were glucose 180 mg / kg (soil), sodium nitrate 100 mg / kg (soil), cycloheximide 10 mg / g (soil), and difenoconazole 1 mg / kg (soil).

[0036] (7) Difenoconazole + fungal denitrification treatment group

[0037] 1 g (dry weight) of soil sample was placed in a 12 mL Labco test tube, and 1 mL of solution was added, which contained glucose (carbon source), sodium nitrate (nitrogen source), streptomycin (bacterial inhibitor), and difenoconazole. The specific concentrations were glucose 180 mg / kg (soil), sodium nitrate 100 mg / kg (soil), streptomycin 6 mg / g (soil), and difenoconazole 1 mg / kg (soil).

[0038] (8) Difenoconazole + abiotic denitrification treatment group

[0039] 1 g (dry weight) of soil sample was placed in a 12 mL Labco test tube, and 1 mL of solution was added, which contained glucose (carbon source), sodium nitrate (nitrogen source), cycloheximide (fungal inhibitor), streptomycin (bacterial inhibitor), and difenoconazole. The specific concentrations were glucose 180 mg / kg (soil), sodium nitrate 100 mg / kg (soil), cycloheximide 10 mg / g (soil), streptomycin 6 mg / g (soil), and difenoconazole 1 mg / kg (soil).

[0040] 2. Determine the N2O release of each treatment group

[0041] The above Labco test tube was passed with nitrogen to fill the upper space of the test tube. Subsequently, the test tube was placed in an anaerobic glove box for incubation for 72 hours, the moisture content was controlled at 70%, the temperature was 25±0.5°C, and the N2O concentration in the bottle was measured. The gas chromatograph was used for measurement, and the electron capture detector (ECD) was used. The carrier gas was high-purity He, the flow rate was 40mL / min, the column temperature was 60°C, the injection port temperature was 120°C, and the detector temperature was 300°C.

[0042] The results are as follows Figure 1 As shown in the results, under laboratory conditions, fenpropimorph can significantly reduce the total N2O release from the soil by 76.9%, of which the inhibition rate of N2O release from fungal denitrification is as high as 93.3%. However, it has no significant effect on the N2O release in the soil of the bacterial denitrification treatment group and the abiotic denitrification treatment group, indicating that fenpropimorph can target and regulate the fungal denitrification process, thereby reducing the release of N2O in the soil.

[0043] Example 2

[0044] This example provides a rice field cultivation experiment of difenoconazole regulating the fungal denitrification process:

[0045] In Ansheng Town, Liangping District, Chongqing City (30°41'46”N, 107°44'25”E), at an altitude of 453 meters, two rice fields (rice variety: Weiliang Youyuzhan) with equivalent soil conditions (total organic matter content 17.47±2.90g / kg, total nitrogen content 1.17±0.02g / kg, total phosphorus content 0.72±0.02g / kg, pH value 6.83±0.10) were selected and named A (fenpropimorph group) and B (blank group).

[0046] Urea (30 kg / mu) and difenoconazole (15 g / mu, 0.05% urea application rate) were applied to field A. Figure 2 As shown in the figure, the static dark box method is used to monitor the N2O release from farmland: the box is made of 6mm thick polyvinyl chloride material with a bottom area of ​​0.09m 2The volume is 27L. The outside of the box is wrapped with sponge and tin foil to prevent drastic changes in temperature in the box due to sunlight during sampling. On the day of transplanting rice seedlings, a square base was buried in the center of each plot. The base was embedded in the soil 5cm deep as a sampling point. The upper end of the base was composed of a groove about 3cm deep for placing the static box body. It was sealed during sampling to prevent the surrounding air from exchanging with the gas in the box. The N2O content was measured 0.5, 1, 2, 4, 8, 12, 24, 48, 72, 96, 120, 144, 168, 216, 164, 336, 408, and 504h after applying urea.

[0047] In site B, only urea (30 kg / mu) was applied, and the static dark box method was also used to monitor the N2O release from the farmland.

[0048] The results are as follows Figure 3 As shown, under rice field conditions, the difenoconazole group reduced N2O release in rice fields by 54% compared with the blank group.

[0049] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. Application of difenoconazole as a fungal denitrification inhibitor in controlling soil nitrous oxide release.

2. The use according to claim 1, characterized in that The soil is flooded farmland soil.

3. The use according to claim 2, characterized in that The soil is paddy field soil.

4. A soil fungal denitrification inhibitor, characterized in that: Contains difenoconazole.

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