A selenium-rich straw composting agent and its application

Abstract

The present invention belongs to the technical field of straw composting agents, and specifically relates to a selenium-enriched straw composting agent and its application. A selenium-enriched straw composting agent, which is a mixture of Bacillus Velez, Paecilomyces lilacinus and Bacillus firmus, wherein the mass ratio of the Bacillus Velez, Paecilomyces lilacinus and Bacillus firmus is 1-20:1-9:1-10. The corn straw fermented composting liquid prepared by the composting agent of the present invention can effectively inhibit root-knot nematodes in the soil, and at the same time can increase the content of soluble sugar, vitamin C, lycopene and selenium in tomato fruits, thereby improving the quality of tomatoes.

Description

Technical Field

[0001] The invention belongs to the technical field of straw composting agents, and particularly relates to a selenium-enriched straw composting agent and application thereof. Background Art

[0002] Plant soil-borne diseases refer to diseases that are caused by pathogens, use soil as a transmission medium, and infect plants. There are many pathogens that cause soil-borne plant diseases, including the southern root-knot nematode that causes plant root-knot nematode disease. At present, the prevention and control measures for root-knot nematodes are mainly chemical control. Although chemical control has the advantages of good short-term effect, low cost, simple use, and a wide spectrum of insecticides and antibacterials, long-term and unreasonable application of chemical agents will seriously pollute the environment and cause insecticides and pathogens to develop resistance. Biological control uses harmless or beneficial microorganisms or antagonistic microorganisms and their metabolites to inhibit the hatching of nematode eggs and reduce the survival of larvae, induce plant resistance and promote growth, thereby achieving the purpose of disease prevention and control. It has the advantages of no pollution, low cost, and not easy to develop resistance, and has received more and more attention in recent years.

[0003] The biocontrol mechanism of biocontrol bacteria mainly includes competition, antagonism, hyperparasitism, induction of plant disease resistance and promotion of plant growth. my country has registered many types of Pseudomonas fluorescens, Bacillus subtilis, Bacillus amyloliquefaciens, Verticillium chlamysporum, Trichoderma harzianum and Bacillus firmus. However, the control spectrum of a single biocontrol bacteria is narrow and the control effect is limited. Mixing two or more biocontrol bacteria to cultivate rich metabolites may produce new chemical substances, which complement the ability to inhibit pathogens, improve the control effect and broaden the antibacterial spectrum. Studies have shown that the mixed use of Trichoderma, Bacillus and Pseudomonas has a synergistic effect on the prevention and control of plant diseases; Trichoderma pseudokoningii and Bacillus subtilis have significant effects on cucumber wilt; the fermentation mixture of Bacillus subtilis GLB191 and Bacillus brevis GLB197 has a significant control effect on grape gray mold; the mixed use or mixed fermentation of biocontrol bacteria and the use of synergistic effects between microorganisms to prevent and control plant diseases have gradually become an effective direction of biological control. However, the synergistic effects between different biocontrol bacteria are difficult to predict and may even reduce the control effect.

[0004] The inventors have found through a large number of experiments that when Bacillus Velezii, Paecilomyces lilacinus and Bacillus firmus are used in combination, their fermentation liquid can produce a synergistic effect on southern root-knot nematodes, thereby improving the control effect of soil-borne diseases of crops.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a selenium-rich straw composting agent and application thereof, wherein the straw fermentation composting liquid can not only improve the prevention and control effect of root-knot nematode disease, but also improve the quality of crops.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] The first object of the present invention is to provide a selenium-rich straw composting agent, which is a mixture of Bacillus Velez subtilis, Paecilomyces lilacinus and Bacillus firmus, wherein the mass ratio of Bacillus Velez subtilis, Paecilomyces lilacinus and Bacillus firmus is 1-20:1-9:1-10.

[0009] Preferably, the mass ratio of Bacillus Velezii, Paecilomyces lilacinus and Bacillus firmus is 15:5:7.

[0010] Preferably, the Bacillus Velez is Bacillus Velez CGMCC No. 14384 water dispersible granules with 20 billion live spores / g; the Paecilomyces lilacinus is Paecilomyces lilacinus granules with 500 million live spores / g; and the Bacillus firmus is Bacillus firmus wettable powder with 10 billion spores / g.

[0011] The second object of the present invention is to provide the application of the selenium-rich straw composting agent in improving the quality of crops.

[0012] The third object of the present invention is to provide the application of the selenium-rich straw composting agent in preventing and controlling soil-borne diseases and insect pests.

[0013] Preferably, the soil-borne pests and diseases include southern root-knot nematode disease.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] (1) The fermented and decomposed liquid of corn stalks prepared by the decomposing agent of the present invention can effectively inhibit the root-knot nematodes in the soil. The fermented and decomposed liquid mixed with Bacillus berras CGMCC No. 14384, Paecilomyces lilacinus and Bacillus firmus in a mass ratio of 15:5:7 has the best corrected control effect on the root-knot nematodes, reaching 78.97%. This shows that the decomposing agent of the present invention has a synergistic effect in inhibiting the tomato root-knot nematodes.

[0016] (2) The corn stalk fermented decomposition liquid prepared by the decomposition agent of the present invention can increase the content of soluble sugar, vitamin C, lycopene and selenium in tomato fruit, thereby improving the quality of tomatoes. DETAILED DESCRIPTION

[0017] The following is a clear and complete description of the technical solution of the patent of this invention.

[0018] Example

[0019] 1. Tested biocontrol bacteria

[0020] 20 billion viable spores / g of Bacillus Velezii CGMCC No.14384 water dispersible granules (Sichuan Baishi Dongwang Biotechnology Co., Ltd., registration number: PD20211360);

[0021] 500 million viable spores / g of Paecilomyces lilacinus granules (Deqiang Biological Co., Ltd., registration number: PD20110951);

[0022] Bacillus firmus wettable powder with 10 billion spores / g (Jiangxi Shunquan Biotechnology Co., Ltd., registration number: PD20184023).

[0023] 2. Preparation of fermented liquid

[0024] The corn stalks were crushed to 4.5-6 cm, the carbon-nitrogen ratio of the material was adjusted to 25:1 with chicken manure, the moisture content of the material was adjusted to 60%, and the composting agent was inoculated at a mass ratio of 1% (the composting agent formula is shown in Table 1 below), mixed evenly, and sealed and fermented at room temperature for 35 days, during which the material was turned over every 2 days. The fermented and decomposed material was mixed with water at a mass ratio of 1:6, sealed for 7 days, filtered with double-layer gauze, and the filtrate was collected to obtain the straw fermentation and decomposition liquid, which was stored at 4°C for later use.

[0025] 3. Inhibitory effect on root-knot nematodes

[0026] 3.1 Test soil: diseased soil with living culture of southern root-knot nematodes

[0027] 3.2 Test crops: Guihong No. 1 tomato

[0028] 3.2 Test methods

[0029] After mixing the test soil evenly, multiple portions were placed in pots with a height of 27 cm and a diameter of 36 cm. Tomato seedlings with consistent growth and two true leaves were selected and transplanted into the pots, with 2 plants per pot. 7 days after transplanting, the fermented straw decomposition liquid was applied, with an application amount of 150 mL / plant, and then applied once every 7 g. At the same time, the treatment with an equal amount of clean water was set as a blank control, and 10 repetitions were set for each treatment. During the period, routine management and watering were performed, and interference from other pests and diseases was prevented. Before transplanting, 5 points were randomly selected from each pot, and 50 g of soil samples were taken and mixed to detect the insect population density of root-knot nematodes (bars / 100 g soil).

[0030] After the first bunch of fruits entered the harvest period, 10 tomato plants were randomly selected from each treatment to collect rhizosphere soil samples, and the population density of root-knot nematodes (worms / 100g soil) was detected, and the nematode reduction rate-corrected control effect was calculated; 10 tomato fruits of the same maturity were selected from each treatment to determine the soluble sugar, lycopene, vitamin C and selenium contents, and the average values ​​were calculated.

[0031]

[0032] 3.3 Methods for determining nematodes in soil

[0033] Mix the soil sample thoroughly, take 100g and put it in a plastic bucket, add 1000mL of water, stir vigorously to disperse the soil lumps, let the upper liquid pass through 160-mesh to 400-mesh sieves after 1 minute, rinse with water continuously, collect the residue on the 400-mesh sieve, wash with clean water and make the volume to 50mL, draw 1mL into a petri dish and observe under a microscope. Calculate the number of nematodes per 100 soil.

[0034] 3.4 Test results

[0035] The reduction rates of root-knot nematodes in tomato rhizosphere soil under different treatments are shown in Table 1.

[0036] The effects of different treatments on tomato fruit quality are shown in Table 2.

[0037] Table 1 Reduction rate of 2nd instar larvae of root-knot nematodes in tomato rhizosphere soil under different treatments

[0038] Clean water treatment and treatment with different composting agent formulas Before watering (bars / 100g soil) Before watering (bars / 100g soil) Nematode reduction rate corrected control effect (%) Clean water treatment (CK) 543 936 -- Bacillus Velez CGMCC No.14384(A) 539 508 45.32 Paecilomyces lilacinus(B) 552 435 54.28 Bacillus firmus (C) 548 482 48.97 A+B (mixed in a mass ratio of 1:1) 556 386 59.72 A+C (mixed in a mass ratio of 1:1) 547 417 55.77 B+C (mixed in a mass ratio of 1:1) 550 362 61.82 A+B+C (mixed in mass ratio 1:1:1) 549 276 70.84 A+B+C (mixed in mass ratio of 15:5:7) 560 203 78.97

[0039] As shown in Table 1, after applying the fermented decomposition liquid of different decomposition agents, the corrected control effect of root-knot nematodes in each treatment was 45.32-78.97%, which showed a downward trend compared with the water treatment (CK). Among them, the fermented decomposition liquid mixed with Bacillus belas CGMCC No.14384, Paecilomyces lilacinus and Bacillus firmus in a mass ratio of 15:5:7 had the best corrected control effect, reaching 78.97%. This shows that the decomposition agent of the present invention has a synergistic effect in inhibiting tomato root-knot nematodes.

[0040] Table 2 Effects of different treatments on tomato fruit quality

[0041]

[0042]

[0043] As shown in Table 2, after applying the fermented decomposition liquid of different decomposition agents, the soluble sugar, vitamin C, lycopene and selenium in the tomato fruit increased to a certain extent. Among them, compared with the blank control treated with green water, the fermented decomposition liquid mixed with Bacillus belas CGMCC No.14384, Paecilomyces lilacinus and Bacillus firmus had the most significant improvement on the quality of tomato fruit. This shows that the decomposition agent of the present invention can increase the selenium content in tomato fruit and improve the quality of tomato fruit.

[0044] The exemplary embodiments are chosen and described in order to explain certain principles of the invention and their practical applications, thereby enabling those skilled in the art to make and utilize various exemplary embodiments of the invention as well as various alternatives and modifications.

Claims

1. A selenium-rich straw composting agent, characterized in that: The invention is prepared by mixing Bacillus velez, Paecilomyces lilacinus and Bacillus firmus, wherein the mass ratio of the Bacillus velez, Paecilomyces lilacinus and Bacillus firmus is 1-20:1-9:1-10; the Bacillus velez is Bacillus velez CGMCC No.14384 water dispersible granules with 20 billion live spores / gram; the Paecilomyces lilacinus is Paecilomyces lilacinus granules with 500 million live spores / gram; and the Bacillus firmus is Bacillus firmus wettable powder with 10 billion spores / gram.

2. The selenium-rich straw composting agent according to claim 1, characterized in that The mass ratio of the Bacillus Velezii, Paecilomyces lilacinus and Bacillus firmus is 15:5:

7.

3. Application of the selenium-rich straw composting agent according to any one of claims 1-2 in improving the quality of crops.

4. Use of the selenium-rich straw composting agent according to any one of claims 1-2 in preventing and controlling southern root-knot nematode disease.

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