Microbial agent for improving soil quality of subtropical secondary forest

Abstract

The invention relates to a microbial agent, in particular to a microbial agent for improving subtropical secondary forest soil quality, and belongs to the technical field of biology. The microbial agent comprises a component A, a component B and a component C, the component A is prepared from bacillus subtilis, bacillus amyloliquefaciens and bacillus mucilaginosus, the component B is prepared from bacillus subtilis, bacillus amyloliquefaciens and bacillus mucilaginosus, the component C is prepared from bacillus subtilis, bacillus amyloliquefaciens and bacillus mucilaginosus, and the component D is prepared from bacillus subtilis, bacillus amyloliquefaciens and bacillus mucilaginosus. The component B is prepared from shewanella putrefaciens, podosporium sp. And Burkholderia sp., and the component B is prepared from Swanella putrefaciens, Podosporium sp. And Burkholderia sp., and the component B is prepared from Swanella putrefaciens, Podosporium sp. And Burkholderia sp. The component C comprises calcium superphosphate, an adhesive, a soil swelling agent and water. According to the microbial agent, through microbial residual carbon and nutrients generated in the microbial growth-metabolism-death process, the organic matter content of subtropical secondary forest soil is increased in a green and efficient mode, phosphorus dissolving and nitrogen fixation are achieved, the soil microbial community structure is improved, and forward succession of secondary forests is promoted.

Description

Technical Field

[0001] The invention relates to a microbial agent, in particular to a microbial agent for improving soil quality in subtropical secondary forests, and belongs to the field of biotechnology. Background Art

[0002] Secondary forests account for about 57% of the total forest area in China and have become the main body of China's forest resources. The restoration and management of secondary forests are of great significance to the construction of national ecological security. Preliminary surveys have shown that subtropical secondary forests generally face problems such as nutrient imbalance (especially phosphorus limitation), lack of organic matter, and low soil enzyme activity, which have caused secondary forests to enter different degrees of "soil climax pattern", resulting in slow or even stopped succession, difficult recovery, and low quality of subtropical secondary forests at this stage.

[0003] In the existing technology, there are few technologies specifically aimed at improving forest soil quality. Most of them are conducted on farmland soil, and such soil improvement bacteria or reagents generally need to go through similar processes such as reactor pressurization, which are cumbersome to operate and costly. In addition, since farmland ecosystems and forest ecosystems have significant differences in biodiversity, material circulation, and energy flow, these differences lead to different microbial community structures and functions in the two soils. Therefore, using the same soil improvement bacteria product may not effectively promote microbial activity in the target soil, and thus fail to achieve the expected improvement effect.

[0004] Therefore, developing forest soil quality improvement technology to break the soil top pattern of subtropical secondary forests is a major need for forestry ecological construction and sustainable development in subtropical regions. Currently, there is no effective microbial agent that can improve forests with different soil types. Summary of the invention

[0005] In order to overcome the gaps in existing forest soil improvement technologies, as well as the problems of other soil types of improvers being cumbersome to operate, high in cost, and difficult to apply to forest soil improvement, the present invention proposes a microbial agent for improving the soil quality of subtropical secondary forests. It utilizes the microbial residual carbon and nutrients produced by the microbial growth-metabolism-death process to greenly and efficiently improve the soil organic matter content of subtropical secondary forests, solubilize phosphorus and fix nitrogen, improve the soil microbial community structure, and promote positive succession of secondary forests.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a microbial agent for improving the soil quality of subtropical secondary forests, comprising component A, component B and component C; the component A comprises Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus mucilaginosus; the component B comprises Shewanella putrefaciens, Podospora sp. and Burkholderia sp.; the component C comprises superphosphate, a binder, a soil bulking agent and water.

[0008] Preferably, in the component A, the weight ratio of Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus mucilaginosus is 3:3:2.

[0009] Preferably, in the B component, the weight ratio of Shewanella putrefaciens, Podospora sp. and Burkholderia sp. is 3:2:1.

[0010] Preferably, the B component further comprises a catalyst, and the catalyst is lactic acid bacteria, yeast and nitrifying bacteria.

[0011] Preferably, in the C component, the weight ratio of superphosphate, binder, soil bulking agent and water is 3:2:1:3.

[0012] Preferably, the weight ratio of components A, B and C is 1:1:1.

[0013] Preferably, the microbial agent also includes biochar.

[0014] The microbial agent provided by the present invention has the following beneficial effects:

[0015] It can significantly increase the content of soil organic matter in subtropical secondary forests, increase the activity of soil urease, phosphatase, etc., and at the same time significantly affect the relative abundance of protective bacteria and functional bacteria in the soil, increase the effective phosphorus content in the soil, and relieve phosphorus limitation.

[0016] The preparation method of the microbial agent is simple and easy to operate, has low cost, no secondary pollution, and has broad market value. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0018] Sources of raw materials used in the examples:

[0019] Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus mucilaginosus were obtained from Shandong Yihao Biotechnology Co., Ltd.; Shewanella putrefaciens was sourced from Wuhan Huizao Biotechnology Co., Ltd.; Podospora spp. was sourced from Shanghai Bohu Biotechnology Co., Ltd.; Burkholderia ovale was sourced from Shanghai Bo Ke Biotechnology Co., Ltd.; lactic acid bacteria were sourced from Henan Ruigao Biotechnology Co., Ltd.; yeast was sourced from Jinan Qiyue Chemical Technology Co., Ltd.; nitrifying bacteria were sourced from Guangzhou Ranyi Bio-Environmental Protection Technology Co., Ltd.; superphosphate was sourced from Shandong Weifeng Chemical Co., Ltd.; adhesive (i.e. bentonite) was sourced from Sishui County Changxing Smelting and Foundry Materials Co., Ltd.; soil bulking agent (i.e. loosening agent) was sourced from Renqiu Kewei Chemical Co., Ltd.; chemically pure hydrochloric acid and chemically pure sodium bicarbonate were sourced from Xilong Science.

[0020] The main components of the microbial agent are: the microbial agent includes component A (protective bacteria), component B (functional bacteria), component C (auxiliary item) and biochar; the component A includes Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus mucilaginosus; the component B includes Shewanella putrefaciens, Podospora sp. and Burkholderia sp. as well as lactic acid bacteria, yeast and nitrifying bacteria; the component C includes superphosphate, adhesive, soil bulking agent and water.

[0021] Preparation of microbial agent:

[0022] Component A is prepared at room temperature with Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus mucilaginosus in a weight ratio of 3:3:2;

[0023] Component B is prepared at room temperature by Shewanella putrefaciens, Podospora sp. and Burkholderia sp. in a weight ratio of 3:2:1, and then 3g of lactic acid bacteria, yeast and nitrifying bacteria are added; in practical applications, lactic acid bacteria, yeast and nitrifying bacteria are only used as catalysts for auxiliary activation, so there is no special requirement for the dosage, and the added amount can be 3-5g;

[0024] Component C is prepared at room temperature by superphosphate, adhesive, soil bulking agent and water in a weight ratio of 3:2:1:3, and the pH is adjusted to neutral with chemically pure dilute hydrochloric acid or sodium bicarbonate; wherein superphosphate is used as a stabilizer;

[0025] The prepared A, B, and C components are thoroughly blended at a weight ratio of 1:1:1 at room temperature to obtain a mixture, and biochar is added as a base to prepare a bacterial agent. The amount of the mixture and the biochar is such that the mixture can be completely distributed therein. In the present invention, the weight ratio of the mixture to the biochar is selected to be 1:20.

[0026] Various forest types including evergreen broad-leaved forest, mixed pine and broad-leaved forest and pine forest were selected for the experiment in Jiande City, Hangzhou, Jinyun County, Lishui and Yueqing City, Wenzhou. The specific locations and soil types are shown in Table 1.

[0027] Table 1 Soil types

[0028]

[0029]

[0030] The amount of microbial agent applied was determined according to the actual content of soil organic matter in the forest land (Table 2), and no additional maintenance was required after application. In particular, Examples 1-6 and 8-9 applied the microbial agent at an amount of 200 g per square meter, and Example 7 applied the microbial agent at an amount of 100 g per square meter.

[0031] Table 2 Standards for application of microbial agents

[0032]

[0033] The effect of the fungicide was determined 30 days after application. The soil from the forest surface with a depth of 0-20 cm was randomly drilled using the cross-five-point method, and the soil was brought back to the laboratory after removing debris.

[0034] A portion of the soil samples were dried at 70°C to constant weight for determination of soil organic matter and effective phosphorus content. Soil organic matter was determined by combustion method using an element analyzer (Multi N / C 3000, Analytik Jena AG, Germany), and effective phosphorus content was determined by a continuous flow analyzer (AA3, SEAL, Germany). The remaining soil samples were refrigerated at 4°C, and after hydrolysis with 6 mol / L HCl at 105°C, amino sugars were separated by GC / MS (8890-7000E, Agilent, USA) to calculate the carbon content of microbial residues. The results are shown in Table 3. The controls in Tables 3 to 6 refer to the content of the corresponding positions of the examples without the application of bacterial agents.

[0035] Table 3 Effects of microbial application on soil nutrients

[0036]

[0037]

[0038] The activities of soil urease and phosphatase were extracted and determined using a kit (Suzhou Keming Biotechnology Co., Ltd.). The results are shown in Table 4.

[0039] Table 4 Effects of microbial application on soil enzyme activity

[0040]

[0041]

[0042] High-throughput sequencing was used to determine the relative abundance of soil Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus mucilaginosus, Shewanella putrefaciens, Podospora, and Burkholderia. The results are shown in Tables 5 and 6.

[0043] Table 5 Effect of microbial application on the relative abundance of soil protective bacteria

[0044]

[0045]

[0046] Table 6 Effect of microbial inoculants on the relative abundance of soil functional bacteria

[0047]

[0048] It can be seen from Tables 3 to 6 that the application of the microbial agent provided by the present invention can significantly increase the organic matter content of the soil in subtropical secondary forests, increase the activity of soil urease, phosphatase, etc., and at the same time significantly affect the relative abundance of protective bacteria and functional bacteria in the soil, increase the effective phosphorus content in the soil, and relieve phosphorus limitation.

[0049] In terms of soil organic matter content, the yellow loam in the shrub forest increased significantly, by 22.11%; in terms of microbial residual carbon, the red loam in the pine forest increased most significantly, by 33.31%; in terms of available phosphorus content, the various types of soil increased significantly, with the bamboo forest soil increasing most significantly, reaching an increase rate of nearly 60%, with an average increase of 37.67%, effectively removing the restriction of phosphorus on soil nutrients (Table 3). At the same time, the application of bacterial agents also had a significant effect on soil enzyme activity, with urease activity increasing by up to 20.93% and phosphatase activity increasing by up to 29.75% (Table 4). In addition, the application of bacterial agents also significantly increased the relative abundance of protective bacteria such as Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus mucilaginosus in the soil, as well as functional bacteria such as Shewanella putrefaciens, Podosporium, and Burkholderia. It shows that the bacterial agent provided by the present invention not only promotes the growth and metabolism of beneficial bacteria in the soil, but also effectively removes the restriction of phosphorus on soil nutrients.

Claims

1. A microbial agent for improving soil quality in subtropical secondary forests, characterized in that: The invention comprises component A, component B and component C; the component A comprises Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus mucilaginosus; the component B comprises Shewanella putrefaciens, Podospora sp. and Burkholderia sp.; the component C comprises superphosphate, a binder, a soil bulking agent and water.

2. The microbial agent according to claim 1, characterized in that In the component A, the weight ratio of Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus mucilaginosus is 3:3:

2.

3. The microbial agent according to claim 1, characterized in that: In the B component, the weight ratio of Shewanella putrefaciens, Podospora sp. and Burkholderia sp. is 3:2:

1.

4. The microbial agent according to claim 1, characterized in that The B component also includes lactic acid bacteria, yeast and nitrifying bacteria.

5. The microbial agent according to claim 1, characterized in that: In the C component, the weight ratio of superphosphate, adhesive, soil bulking agent and water is 3:2:1:

3.

6. The microbial agent according to claim 1, characterized in that: The pH of the C component is neutral.

7. The microbial agent according to claim 1, characterized in that: The weight ratio of the components A, B and C is 1:1:

1.

8. The microbial agent according to claim 1, characterized in that: The microbial agent also includes biochar.

Images