Organic rice film mulching green cultivation method

Abstract

The invention discloses an organic rice film mulching green cultivation method, and further discloses preparation and application of a high-efficiency bactericide. According to the method disclosed by the invention, an efficient bactericide is used in a rice seedling stage, and a film covering and wetting cultivation mode is combined, so that the occurrence rate of rice sheath blight disease is reduced, and the sheath blight control effect is 67.9-85.4%; the film mulching machine has a remarkable weed suppression effect, the weed plant control effect and the fresh weight control effect are both greater than 95%, and weeding modes such as manual weeding are not needed in the whole process; according to the organic rice biodegradable plastic film mulching green cultivation method provided by the invention, 30% of water is saved in rice production, one to two times of prevention and control of biopesticide are saved, and the yield and quality of rice are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rice cultivation, and in particular relates to a green cultivation method of organic rice covered with film. Background Art

[0002] Since the film mulching technology was introduced into my country in 1978, it has been widely used in rice, corn and various vegetable crops. It has many advantages such as suppressing weeds, increasing temperature and moisture retention, and increasing yield and quality. In recent years, the wet cultivation of rice covered with film has the advantages of reducing fertilizer, pesticides and carbon, improving yield and quality, and has received widespread attention from the industry. In the process of organic rice cultivation, since chemical pesticides cannot be used, rice field weeding is mainly done by manual weeding, which is difficult to employ and costly. At the same time, in the case of frequent diseases and insect pests, the current application of conventional biological agents is difficult to guarantee the yield and quality of organic rice. In the process of organic rice cultivation, biodegradable film mulching cultivation technology can achieve efficient weed suppression, and replaces manual weeding by film mulching to solve the problem of difficult weeding in organic rice fields.

[0003] Sheath blight is a common fungal disease of rice caused by Rhizoctonia solani. It is the top rice disease in the south and can occur throughout the entire growth period of rice. The occurrence of rice sheath blight requires high humidity, especially in the case of improper irrigation or continuous rain, the disease spreads rapidly, endangering the yield and quality of rice. Due to the rapid effect, low cost and simple prevention and control methods of chemical pesticides, the current prevention and control of sheath blight of ordinary rice is still mainly based on chemical pesticides. In the cultivation of organic rice, agricultural prevention and control methods such as reasonable dense planting, removing the source of fungi, and frequent shallow water irrigation, as well as biological agent prevention and control methods are mainly used, and the pest control effect needs to be further improved. Rice film mulching cultivation technology changes conventional flooding to a moist cultivation mode. By avoiding deep flooding, keeping the site moist, and paying attention to clearing ditches and drainage on rainy days, the occurrence of sheath blight can be reduced to a certain extent. If film-covered moist cultivation can be combined with new high-efficiency fungicides, it can effectively solve the problems of difficult weeding in organic rice fields and serious occurrence of sheath blight in traditional cultivation models. It is an ideal choice for the green transformation and development of the organic rice industry. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a green cultivation method of organic rice covered with film.

[0005] Technical solution: In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for preparing a high-efficiency fungicide comprises the following steps:

[0006] (1) preparing a chitosan solution with glacial acetic acid as solvent, dissolving it by ultrasonication, adjusting the pH to 4-6, adding an emulsifier to the chitosan solution, and stirring to obtain a uniform chitosan solution;

[0007] (2) dissolving tea saponin and mustard oil in anhydrous ethanol, dripping the mixed alcohol solution into the chitosan solution prepared in step (1), and stirring to obtain a chitosan-tea saponin / mustard oil solution;

[0008] (3) dissolving sodium tripolyphosphate in distilled water to obtain a sodium tripolyphosphate solution; dropping the sodium tripolyphosphate solution into the chitosan-tea saponin / mustard oil solution obtained in step (2), and stirring to obtain a tea saponin / mustard oil microcapsule dispersion;

[0009] (4) centrifuging the microcapsule dispersion, washing, and vacuum freeze-drying to obtain tea saponin / mustard oil microcapsules;

[0010] (5) preparing a cuprous oxide suspension, adding tea saponin / mustard oil microcapsules to the cuprous oxide suspension to obtain a highly effective fungicide for spraying on seedlings.

[0011] Wherein, the concentration of the chitosan solution in step (1) is 1.0-2.5 mg / mL. Preferably, the emulsifier in step (1) includes Span80 or Tween80 with a mass fraction of 0.15%.

[0012] Wherein, the mass ratio of tea saponin to chitosan in step (2) is 0.5-0.9:1.0, and the mass ratio of mustard oil to chitosan is 0.3-0.8:1.0. Preferably, the stirring speed in step (2) is 200-400 rpm, and the stirring time is 0.5-1.0 h.

[0013] Wherein, in step (3), the mass ratio of chitosan to sodium tripolyphosphate is 4-8:1. Preferably, the stirring speed is 200-400 rpm, and the stirring time is 0.5-1.0 h.

[0014] Wherein, in step (4), the centrifugal speed is 6000-8000 rpm, the centrifugal time is 15-20 min, and preferably, the vacuum degree is 0.2 mbar, the shelf temperature is 30° C., and the cold trap temperature is -85° C.

[0015] Wherein, in step (5), the mass fraction of cuprous oxide suspension is 0.3-0.5%, and the mass fraction of microcapsules is 0.4-1.5%.

[0016] The present invention also includes a high-efficiency fungicide prepared by the preparation method.

[0017] The present invention also includes the application of the high-efficiency fungicide in organic rice cultivation.

[0018] Wherein, the spraying amount of the high-efficiency fungicide per mu is 10 to 15L.

[0019] The present invention also includes a green cultivation method of organic rice covered with film, comprising the following steps:

[0020] (1) Select rice varieties with good taste that have been approved or registered for introduction in a unified ecological zone, and soak the selected seeds in 1-2% lime water for 40-50 hours at room temperature;

[0021] 2) Sowing and raising seedlings, spray the high-efficiency fungicide evenly on the seedlings before transplanting;

[0022] 3) 3-5 days before transplanting, land preparation should be carried out, and the residues of the previous crop should be removed by salvaging the field. The land preparation should be leveled and raked to ensure that the height difference of the field surface is between 0 and 5 cm.

[0023] 4) Use a mulching and transplanting machine to lay biodegradable mulch. Drain excess water from the field before transplanting. Complete the transplanting operation within 12 hours after drainage.

[0024] 5) Field water management adopts full-process wet irrigation, including covering and transplanting to jointing stage, keeping the field soil moist, replenishing water when the field water holding capacity of the 0-10cm tillage layer is less than 75%, and the depth of the field irrigation water layer is ≤1cm; when the number of seedlings in the group reaches 80% of the expected number of ears, the water can be cut off and the field can be left idle for multiple times; from jointing to grain filling and fruiting stage, intermittent wet irrigation is carried out, alternating between dry and wet, with wet as the main method, to ensure that the field water holding capacity of the soil should reach more than 80%; stop irrigation at the end of rice grain filling and maturity;

[0025] 6) For fertilization, use decomposed organic fertilizer and apply it with dry harrow; for topdressing, use certified organic foliar fertilizer, organic bacterial fertilizer and other commercial fertilizers according to the growth of rice.

[0026] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0027] 1. The present invention provides a method for preparing a high-efficiency fungicide for spraying seedlings. The microcapsules formed by chitosan and sodium tripolyphosphate have many advantages such as good biocompatibility, degradability, adhesion, and no use of organic reagents. After tea saponin and mustard oil are encapsulated, the stability and persistence are improved. The tea saponin / mustard oil microcapsules are dispersed in a cuprous oxide suspension to prepare a high-efficiency fungicide, realizing the combination of inorganic fungicides and plant-derived antibacterial substances, comprehensively exerting antibacterial effects, and further improving the disease prevention effect.

[0028] 2. The application of high-efficiency fungicides in the seedling stage, combined with the film-covered moist cultivation mode, reduced the incidence of rice sheath blight, and the control effect of sheath blight was 67.9-85.4%;

[0029] 3. The weed control effect of the mulching machine is remarkable, with the weed control efficiency and fresh weight control efficiency both exceeding 95%, and there is no need to use manual weeding or other weed control methods throughout the process;

[0030] 4. The present invention provides a green cultivation method of organic rice covered with film, which can save 30% of water in rice production, save 1 to 2 times of biological pesticide control, and improve rice yield and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Scanning electron micrograph of tea saponin / mustard oil microcapsules prepared in Example 1;

[0032] Figure 2 The weed control effect of organic rice cultivated with biodegradable mulch film in Example 1. DETAILED DESCRIPTION

[0033] Example 1

[0034] The preparation method of the high-efficiency bactericide of the present embodiment is as follows:

[0035] ① Prepare a 1.5 mg / mL chitosan solution (Shanghai MacLean Biochemical Technology Co., Ltd., C766659-2.5 kg) with 1.0% glacial acetic acid as solvent, dissolve by ultrasonication (50w, 5h), adjust the solution pH to 5 with 1 mol / L NaOH, add emulsifier Span80 (mass fraction 0.15%) to the chitosan solution, and stir to obtain a uniform chitosan solution;

[0036] ② Dissolve tea saponin (Shanghai Yuanye Biotechnology Co., Ltd., S30575-500g) and mustard oil (Beijing Ruida Henghui Technology Development Co., Ltd., HE-3277-100mL) in anhydrous ethanol, drop the mixed alcohol solution into the chitosan solution prepared in step ①, and stir at 300 rpm for 0.8h. The mass ratio of tea saponin / chitosan is 0.7:1.0, and the mass ratio of mustard oil / chitosan is 0.5:1.0;

[0037] ③ Dissolve sodium tripolyphosphate (Sinopharm Chemical Reagent Co., Ltd., XW77582945) in distilled water and drip into the chitosan-tea saponin / mustard oil solution obtained in step ②. The mass ratio of chitosan / sodium tripolyphosphate is 6:1, and stir at 300 rpm for 0.7 h to obtain a tea saponin / mustard oil microcapsule dispersion;

[0038] ④ The microcapsule dispersion was centrifuged at 7000 rpm for 18 min, washed 4 times, and vacuum freeze-dried to obtain tea saponin / mustard oil microcapsules. Figure 1 This is a scanning electron micrograph of tea saponin / mustard oil microcapsules;

[0039] ⑤ Prepare a cuprous oxide water suspension with a mass concentration of 0.4%, add tea saponin / mustard oil microcapsules into the cuprous oxide suspension, wherein the mass fraction of the microcapsules accounts for 0.25% of the total water suspension, and prepare a highly effective fungicide for spraying seedlings.

[0040] A green cultivation method for organic rice covered with film, specifically comprising the following steps:

[0041] 1) The variety selected was Jiangsu fine variety Nanjing 46, and the seeds were soaked and disinfected in 1% lime water at room temperature for 48 hours;

[0042] 2) Sowing and raising seedlings. Before transplanting the seedlings, spray the prepared high-efficiency fungicide evenly on the seedlings. The application rate per mu is 13L. The amount should be such that the leaves and stems of the seedlings are moist without dripping.

[0043] 3) 3-5 days before transplanting, land preparation should be carried out, and the residues of the previous crop should be removed by salvaging the field. The land preparation should be leveled and raked to ensure that the height difference of the field surface is between 0 and 5 cm.

[0044] 4) Use a mulching and transplanting machine to lay biodegradable mulch. Drain excess water from the field before transplanting. Complete the transplanting operation within 12 hours after drainage.

[0045] 5) Field water management adopts full-process wet irrigation;

[0046] 6) Apply 30,000 kg of decomposed organic fertilizer per hectare, combined with dry harrowing; topdress with certified organic foliar fertilizer, organic bacterial fertilizer and other commercial fertilizers according to the growth of rice;

[0047] 7) Other field management refers to the local organic rice planting management, and no weeding measures such as manual weeding are adopted.

[0048] The test results of weed control effect, weed fresh weight control effect, sheath blight control effect, rice yield, rice quality and other indicators are shown in Table 1. The weed control effect and weed fresh weight control effect were calculated by setting up a double blank control of local organic rice conventional cultivation without film covering and no weeding measures such as manual weeding; the sheath blight control effect was calculated by the conventional cultivation method of local organic rice (seedlings were not sprayed with high-efficiency fungicides and film covering and moist cultivation mode) according to the national sheath blight investigation standards. The appearance and taste of rice were measured by the rice taste meter (STA 1A) produced by Japan's Satake Co., Ltd.

[0049] Table 1 Test results of weed control effect, weed fresh weight control effect, sheath blight control effect, rice yield and rice quality index

[0050] index Measurement results Weed control effect / % 99.1 Fresh weight weed control effect / % 99.3 Effect of sheath blight control / % 85.3 Yield / (kg / mu) 561.2 Appearance 9.7 Taste value 91.8

[0051] The present invention also provides multiple groups of comparative examples, as follows:

[0052] Comparative Example 1:

[0053] An organic rice film-covered green cultivation method is similar to Example 1, except that in step 2), no high-efficiency fungicide is used before transplanting the seedlings.

[0054] Comparative Example 2:

[0055] An organic rice film-covered green cultivation method is similar to Example 1, except that in step 2), a cuprous oxide suspension with a concentration of 0.4% is used as a high-efficiency fungicide for spraying the seedlings.

[0056] Comparative Example 3:

[0057] An organic rice film-covered green cultivation method is similar to Example 1, except that in step 2), tea saponin and mustard oil in the high-efficiency fungicide for spraying the seedlings are directly added without being wrapped.

[0058] Comparative Example 4:

[0059] An organic rice film-covered green cultivation method is similar to Example 1, except that the high-efficiency fungicide for spraying the seedlings in step 2) does not contain tea saponin.

[0060] Comparative Example 5:

[0061] An organic rice film-covered green cultivation method is similar to Example 1, except that the high-efficiency fungicide for spraying the seedlings in step 2) does not contain mustard oil.

[0062] Comparative Example 6:

[0063] Similar to Example 1, except that no biodegradable mulch film is used in step 4), conventional flooding irrigation is used in step 5), and manual weeding is used in step 7).

[0064] In Comparative Examples 1 to 6, the test results of weed control effect, weed fresh weight control effect, sheath blight control effect, rice yield, rice quality and other indicators are shown in Table 2.

[0065] Table 2 Test results of weed control effect, weed fresh weight control effect, sheath blight control effect, rice yield, and rice quality index of comparative examples 1 to 6

[0066]

[0067] Embodiment 2:

[0068] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, stirring at a speed of 200 rpm for 0.5 h in ②, and the mass ratio of tea saponin / chitosan is 0.9:1.0.

[0069] Embodiment 3:

[0070] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ②, stirring at a rotation speed of 400 rpm for 1.0 h, and the mass ratio of tea saponin / chitosan is 0.8:1.0.

[0071] Embodiment 4:

[0072] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ②, stirring at a rotation speed of 200 rpm for 1.0 h, and the mass ratio of tea saponin / chitosan is 0.8:1.0.

[0073] Embodiment 5:

[0074] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ②, stirring at a rotation speed of 200 rpm for 1.0 h, and the mass ratio of mustard oil / chitosan is 0.3:1.0.

[0075] Embodiment 6:

[0076] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ②, stirring at a speed of 400 rpm for 0.5 h, and the mass ratio of mustard oil / chitosan is 0.8:1.0.

[0077] Embodiment 7:

[0078] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ②, stirring at a speed of 300 rpm for 0.7 h, and the mass ratio of mustard oil / chitosan is 0.6:1.0.

[0079] Embodiment 8:

[0080] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ③, stirring at a rotation speed of 200 rpm for 1.0 h, and the chitosan / sodium tripolyphosphate mass ratio is 4:1.

[0081] Embodiment 9:

[0082] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ③, stirring at a speed of 400 rpm for 0.5 h, and the mass ratio of chitosan / sodium tripolyphosphate is 8:1.

[0083] Embodiment 10:

[0084] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ③, stirring at a speed of 300 rpm for 0.8 h, and the mass ratio of chitosan / sodium tripolyphosphate is 5:1.

[0085] Embodiment 11:

[0086] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ③, stirring at a speed of 300 rpm for 0.8 h, and the mass ratio of chitosan / sodium tripolyphosphate is 7:1.

[0087] Embodiment 12:

[0088] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ①, an emulsifier Tween 80 (mass fraction 0.15%) is added;

[0089] Embodiment 13:

[0090] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ①, adjusting pH=4.

[0091] Embodiment 14:

[0092] An organic rice film-covered green cultivation method is similar to Example 1, except that the preparation steps of the high-efficiency fungicide are different, specifically, in ①, adjusting the pH to 6.

[0093] Embodiment 15:

[0094] An organic rice film-covered green cultivation method is similar to Example 1, except that in the organic rice film-covered green cultivation method, in step 2), the application rate of the high-efficiency fungicide per mu is 10 L.

[0095] Embodiment 16:

[0096] A green cultivation method for organic rice with film covering is similar to Example 1, except that in the green cultivation method for organic rice with film covering, in step 2), the application rate of the high-efficiency fungicide per mu is 15 L.

[0097] Examples 2 to 16 also have the effects of improving weed control and prevention of sheath blight in rice fields, increasing rice yield and improving rice quality. The test results are shown in Table 3:

[0098] Table 3 Test results of weed control effect, weed fresh weight control effect, sheath blight control effect, rice yield, and rice quality index of Examples 2 to 16

[0099]

[0100] From the above results, it can be seen that the film-mulching rice cultivation method of the present invention has a significant weed control effect; the application of high-efficiency fungicides during the rice seedling stage combined with the film-mulching moist cultivation mode has an excellent effect in reducing the incidence of rice sheath blight, and the rice yield and taste value are improved.

Claims

1. A method for preparing a highly effective fungicide, characterized in that: The following steps are involved: (1) Prepare chitosan solution with glacial acetic acid as solvent, dissolve by ultrasonication, adjust pH to 4-6, add emulsifier to chitosan solution, and stir to obtain uniform chitosan solution; (2) dissolving tea saponin and mustard oil in anhydrous ethanol, dropping the mixed alcohol solution into the chitosan solution prepared in step (1), and stirring to obtain a chitosan-tea saponin / mustard oil solution; (3) Sodium tripolyphosphate is dissolved in distilled water to obtain a sodium tripolyphosphate solution; Dropping the sodium tripolyphosphate solution into the chitosan-tea saponin / mustard oil solution obtained in step (2), stirring to obtain a tea saponin / mustard oil microcapsule dispersion; (4) centrifuging the microcapsule dispersion, washing, and vacuum freeze-drying to obtain tea saponin / mustard oil microcapsules; (5) Prepare a cuprous oxide suspension, add tea saponin / mustard oil microcapsules to the cuprous oxide suspension, and obtain a highly effective fungicide for spraying on seedlings.

2. The method for preparing a high-efficiency fungicide according to claim 1, characterized in that: The concentration of the chitosan solution in step (1) is 1.0-2.5 mg / mL. Preferably, the emulsifier in step (1) includes Span80 or Tween80 with a mass fraction of 0.15%.

3. The method for preparing a high-efficiency fungicide according to claim 1, characterized in that: In step (2), the mass ratio of tea saponin to chitosan is 0.5-0.9:1.0, and the mass ratio of mustard oil to chitosan is 0.3-0.8:1.

0. Preferably, in step (2), the stirring speed is 200-400 rpm, and the stirring time is 0.5-1.0 h.

4. The method for preparing a high-efficiency fungicide according to claim 1, characterized in that: In step (3), the mass ratio of chitosan to sodium tripolyphosphate is 4-8:

1. Preferably, the stirring speed is 200-400 rpm and the stirring time is 0.5-1.0 h.

5. The method for preparing a high-efficiency fungicide according to claim 1, characterized in that: In step (4), the centrifugal speed is 6000-8000 rpm, the centrifugal time is 15-20 min, and preferably, the vacuum degree is 0.15-0.20 mbar, the shelf temperature is 30° C., and the cold trap temperature is -85° C.

6. The method for preparing a high-efficiency fungicide according to claim 1, characterized in that: In step (5), the mass fraction of the cuprous oxide suspension is 0.3-0.5%, and the mass fraction of the microcapsules is 0.4-1.5%.

7. A high-efficiency fungicide prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the high-efficiency fungicide according to claim 7 in organic rice cultivation.

9. The use according to claim 8, characterized in that: The spraying rate of the high-efficiency fungicide per mu is 10-15L, and the best amount is to wet the leaves and stems of the seedlings without dripping.

10. An organic rice film-covered green cultivation method, characterized in that: The following steps are involved: 1) Select rice varieties with good taste that have been approved or introduced in a unified ecological zone, and soak the selected seeds in 1-2% lime solution for 40-50 hours at room temperature; 2) Sowing and raising seedlings, spray the high-efficiency fungicide evenly on the seedlings before transplanting them; 3) 3-5 days before transplanting, land preparation should be carried out, and the residues of the previous crop of straw should be removed by salvaging the field. The land preparation should be leveled and raked to ensure that the height difference of the field surface is between 0 and 5 cm; 4) Use a mulching and transplanting machine to lay biodegradable mulch. Drain excess water from the field before transplanting. Complete the transplanting operation within 12 hours after drainage. 5) Field water management adopts full-process wet irrigation, including covering and transplanting to jointing stage, keeping the field soil moist, replenishing water when the field water holding capacity of the 0-10cm tillage layer is less than 75%, and the depth of the field irrigation water layer is ≤1 cm; when the number of seedlings in the group reaches 80% of the expected number of ears, the water can be cut off and the field can be left idle for multiple times; from jointing to filling and fruiting stage, intermittent wet irrigation is used, alternating between dry and wet, with wet irrigation as the main method, to ensure that the field water holding capacity of the soil should reach more than 80%; Stop irrigation when rice grains are at the end of filling and ripening stage; 6) For fertilization, use decomposed organic fertilizer and apply it with dry harrow; for topdressing, use certified organic foliar fertilizer, organic bacterial fertilizer and other commercial fertilizers according to the growth of rice.

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