CN112094787A

CN112094787A - Preparation method and application of microbial agent for slope protection

Info

Publication number: CN112094787A
Application number: CN202011244009.9A
Authority: CN
Inventors: 刘海明; 李硕; 姜秀娟; 吕中文; 程淑琴; 杜蓉蓉
Original assignee: Beijing Hangtian Hengfeng Technology Co ltd
Current assignee: Beijing Hangtian Hengfeng Technology Co ltd
Priority date: 2020-11-10
Filing date: 2020-11-10
Publication date: 2020-12-18
Anticipated expiration: 2040-11-10
Also published as: CN112094787B

Abstract

The invention provides a preparation method and application of a microbial agent for slope protection, which relate to the technical field of ecological restoration, and are characterized in that after bacillus amyloliquefaciens and trichoderma harzianum strains are mixed, fermented and cultured, the bacillus amyloliquefaciens and trichoderma harzianum strains are mixed with a microbial agent formed by mycorrhizal fungi, so that the activity of rhizosphere microorganisms and soil enzymes can be improved, the number and the activity of harmful microorganisms in soil are inhibited, and the survival rate of slope protection plants is improved; and the cellulose can be rapidly degraded when being matched with a substrate of a straw board for use, and meanwhile, the formation of a soil aggregate structure is promoted, so that the survival rate of slope protection plants is improved.

Description

Preparation method and application of microbial agent for slope protection

Technical Field

The invention relates to the technical field of ecological restoration, in particular to a preparation method and application of a microbial agent for slope protection.

Background

The fragile phenomenon of the ecological environment in China is gradually expanded, according to statistics, the phenomena of loose soil quality of a grassland and landslide are frequent due to wind and sand activities, secondary salinization, overloading and grazing of the grassland and the like, the sand content of a river is increased, and the livestock manure directly enters river water, so that the environmental development of the grassland is influenced, and the ecological balance of the water environment around the grassland is threatened. Vegetation slope protection is the first-selected ecological slope protection technology.

But after the soil of the slope is degraded, desertification occurs and the water storage capacity is weakened; and the slope protection plant is at the initial stage of planting, and root system growth is slow, and the soil after the degeneration is unfavorable for plant seed implantation and plant rooting germination, and then leads to the survival rate to reduce, has increased the bank protection degree of difficulty, has weakened the ecological effect of bank protection.

If the survival rate of slope protection plants is improved by applying a large amount of compound fertilizer, the problems of serious leaching loss of fertilizer nutrients and further damage to the water environment around the grassland exist; although the organic fertilizer mainly comprising farmyard manure can improve the physicochemical properties of soil, the organic matters in the organic fertilizer have different properties, and the contained germs, ova of pests and the like are easy to cause soil pollution, and the organic fertilizer is not suitable for grassland soil bodies after soil degradation.

Therefore, a microbial agent capable of improving the survival rate of slope-protected plants is needed.

Disclosure of Invention

In view of the above problems, the invention provides a preparation method and application of a microbial combined bacterial agent, which are not antagonistic among strains and are synergistic with each other, and the main purpose of the preparation method is to facilitate grass seed growth and straw degradation.

In order to achieve the purpose, the invention also provides a preparation method of the microbial agent for slope protection, which comprises the steps of activating the bacillus amyloliquefaciens, inoculating the activated bacillus amyloliquefaciens into a liquid seed culture medium of the bacillus amyloliquefaciens, and culturing to obtain a bacillus amyloliquefaciens fermentation seed solution; wherein the bacterial content of the bacillus amyloliquefaciens is 1

10⁸cfu/ml；

Activating trichoderma harzianum, and inoculating the activated trichoderma harzianum to a trichoderma harzianum liquid seed culture medium for culture to obtain trichoderma harzianum fermented seed liquid; wherein, the spore concentration of the Trichoderma harzianum bacterial liquid is adjusted to 1

10⁶Per ml;

weighing 51% of straw, 25.5% of wheat bran, 1.5% of rice bran, 21.5% of shell powder and 0.5% of (NH)₄)₂SO₄Mixing to obtain fermented material, adding water to make water content of the fermented material reach 75%, stirring, packaging into polypropylene fungus bags, sterilizing at 121 deg.C for 20min, 150g per bag to obtain sterilized fermented material;

adding 3ml of bacillus amyloliquefaciens fermentation seed liquid and 5ml of trichoderma harzianum fermentation seed liquid into the sterilized fermentation material, and fermenting for 12 days at room temperature; after culturing for 12 days, drying the fermentation product, separating the fermentation material from conidia by screening, collecting spore powder and storing at 4 ℃ to obtain a mixed microbial inoculum of bacillus amyloliquefaciens and trichoderma harzianum;

the method comprises the following steps of planting and breeding the bursa of moccasia micraccoon in advance through corn, taking a mixture of spores, extra-root hyphae and root soil of infected corn root segments of the bursa of moccasia micraccoon as a bursa of moccasia micraccoon microbial inoculum, wherein each gram of the bursa of moccasia micraccoon microbial inoculum contains 25-35 spores;

and mixing the mixed microbial inoculum of the bacillus amyloliquefaciens and the trichoderma harzianum with the moscilla bursa microbial inoculum to obtain the microbial agent for slope protection.

Further, preferably, the dry basis weight ratio of the mixed bacterial preparation of bacillus amyloliquefaciens and trichoderma harzianum to the moscilla bursa bacterial preparation is 1: 5 to 9.

Further, preferably, the bacillus amyloliquefaciens is bacillus amyloliquefaciens FZB42 strain; the Trichoderma harzianum is Trichoderma harzianum T-E5 strain.

Further, preferably, Bacillus amyloliquefaciens and Trichoderma harzianum stored at 4 ℃ are respectively activated by NA and PDA plates, and cultured in a constant temperature incubator at 28 ℃ for 2 days and 5 days, respectively; inoculating bacillus amyloliquefaciens into a BYP liquid culture medium, and culturing for 2 days in a constant-temperature oscillation incubator at 28 ℃ and 180 r/min; adding 10ml of sterilized normal saline into each plate of the Trichoderma harzianum strain full of spores, hanging sporangium by using an applicator, inoculating into PDB culture medium, and culturing for 5 days in a constant-temperature shaking incubator at 28 ℃ and 180 r/min.

The invention also protects the application of the microbial agent prepared by the preparation method in slope protection.

The application comprises the following steps:

preparing a mixture of a straw board and a substrate in advance; punching the straw plate to form the straw plate with through holes; stirring and mixing 60-82 parts of local soil, 25-35 parts of humic acid, 12-22 parts of decomposed cow dung, 6-8 parts of water-retaining agent, 15-35 parts of microbial agent and 15-21 parts of grass seeds to form a matrix mixture;

slope surface finishing; digging grooves at the top and the bottom of the slope;

fixing the straw board; anchoring the upper end of the straw plate in the groove on the top of the slope by using a rivet, filling the groove with soil and compacting; anchoring the bottom end of the straw board in the groove of the toe by using a rivet, and filling and compacting soil;

filling the substrate mixture into the through holes of the straw board;

covering soil and maintaining; soil is covered on the surface of the straw board, and then watering is carried out regularly, preferably until the upper layer of soil and the straw board are thoroughly wetted.

Further, the grass seeds are preferably a mixture of 40-60 parts of Chinese zoysia japonica seeds, 25-45 parts of oat seeds and 10-20 parts of alfalfa seeds.

The invention has the following beneficial effects:

the microbial agent provided by the invention takes the mixture of bacillus amyloliquefaciens, trichoderma harzianum and marshmallow cystocellus as the microbial agent, not only can improve the activity of rhizosphere microorganisms and soil enzymes, but also can inhibit the quantity and activity of harmful microorganisms in soil and improve the survival rate of slope protection plants; the composite material is matched with a straw board substrate for use, can quickly degrade cellulose, promotes the formation of a soil aggregate structure, and further promotes the survival rate of slope protection plants;

the plant growth promotion of the mixture of the bacillus amyloliquefaciens agent, the mucedingly occus moscillus agent and the trichoderma harzianum is superior to that of the mixture which is inoculated with the bacillus amyloliquefaciens alone or with the mycorrhizal fungi;

after the bacillus amyloliquefaciens and the trichoderma harzianum strains are mixed, fermented and cultured, the bacillus amyloliquefaciens and the trichoderma harzianum strains form a mixed microbial inoculum with mycorrhizal fungi; compared with the mixture of the bacillus amyloliquefaciens microbial inoculum, the pipewort mossambica microbial inoculum and the trichoderma harzianum microbial inoculum which are respectively cultured and mixed, the straw degradation and the grass seed growth promoting capability are stronger;

therefore, the synergistic effect of the mycorrhizal fungi, the trichoderma harzianum and the bacillus amyloliquefaciens in the aspect of slope protection plant growth promotion is proved; has better ecological benefit.

Drawings

FIG. 1 is a graph showing the cohesion of soil bodies with different matrix mixtures according to an embodiment of the present invention.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The examples do not show specific techniques or conditions, and the reagents or apparatuses used are not shown in the specifications of the products, and the conventional products are available from normal distributors.

In the prior art, Arbuscular Mycorrhizal (AM) fungi are beneficial soil microorganisms that can infect most higher plants in the terrestrial ecosystem and form a "mycorrhizal" symbiotic structure, and are one of the important functional flora of the ecosystem. AM fungi, Trichoderma and plant root growth-promoting bacteria (PGPR) are typical plant root symbiotic microorganisms.

The AM fungus can have the function of promoting the utilization of nitrogen and phosphorus of crops, can secrete the sacchricin to improve the content of soil organic matters and improve the conditions of soil air exhaust, water supply and the like, and the sacchricin can promote the formation of soil aggregates through the binding capacity with soil particles to protect soil organic carbon from being decomposed by microorganisms; meanwhile, the fertilizer can also be used as a soil active organic carbon source, supplement a carbon source for other microorganisms and stimulate functional microorganism colonization, so that the utilization of nitrogen and phosphorus of crops is promoted; the bursa of Moses fungus (AMF) is one of mycorrhizal fungi, can reduce the content of malondialdehyde in plants, and is favorable for enhancing the drought stress resistance of seedlings.

The trichoderma has the dissolving capacity on the insoluble inorganic phosphate and the insoluble potassium in the soil, and can promote the seed germination and seedling growth of various plants; the bacillus amyloliquefaciens has the functions of promoting the growth of plants and improving the drought and salt stress resistance of the plants. And the lignin of the straw can be degraded by the generated lignocellulose degrading enzymes such as lignin catalase.

The AM fungi, the trichoderma and the bacillus amyloliquefaciens have interaction, so that the soluble sugar content, the relative water content and the chlorophyll content of leaves of seedlings can be improved, the hypha density is higher, the root length and the branching number of slope protection plants are increased, the coverage area of the hyphae is enlarged after the hyphae is combined with the fungal hyphae, and the absorption of water and mineral elements is enhanced; promoting the growth of plants, in particular roots, among them, Trichoderma harzianum (Trichoderma) T-E5 strain, Bacillus amyloliquefaciens (Bacillus amyloliquefaciens) strain FZB42 and Glomus mosseae (Glomus mosseae) were all commercially available.

Preparation example 1

PDA culture medium: 21.0g of sucrose, 20.0g of agar and 200g of potato; 1000ml of distilled water, and the PH value is 7.0-7.5;

PDB culture medium: (28 ℃, 180r/min, 72 h): 20.0g of cane sugar and 200g of potatoes; 1000ml of distilled water, and the PH value is 7.0-7.5;

nutrient agar medium (NA): 5.0g of beef extract, 10.0g of peptone, 5.0g of sodium chloride, 20.0g of agar, 1000ml of distilled water and pH 7.0-7.2;

NB medium: 10.0g of peptone, 5.0g of beef extract, 5.0g of sodium chloride, 20.0g of agar, 1000ml of distilled water and pH 7.0-7.5;

BPY medium: 5.0g of beef extract, 5.0g of sodium chloride, 10.0g of glucose, 10.0g of peptone, 5.0g of yeast powder, 1000ml of distilled water and 7.0-7.5 of PH;

all media were sterilized at 121 ℃ for 30min for use.

Activating Bacillus amyloliquefaciens FZB42 strain and Trichoderma harzianum strain stored at 4 ℃ by using NA and PDA plates respectively, and culturing in a constant temperature incubator at 28 ℃ for 2 days and 5 days respectively; inoculating bacillus amyloliquefaciens into a BYP liquid culture medium, and culturing for 2 days in a constant-temperature oscillation incubator at 28 ℃ and 180 r/min; adding 10ml of sterilized normal saline into each plate of the Trichoderma harzianum strain full of spores, hanging sporangium by using an applicator, inoculating into PDB culture medium, and culturing for 5 days in a constant-temperature shaking incubator at 28 ℃ and 180 r/min.

Wherein the bacterial content of the bacillus amyloliquefaciens is 1

10⁸cfu/ml, adjusting the spore concentration of Trichoderma harzianum liquid to 1

10⁶Per ml;

specifically, the propagating step comprises: takes the spores, hyphae and soil samples of infected plant root segments of the Muscosculus tussississimus as an initial inoculant and takes corn or Sudan grass as host plants.

Use the mixture of farmland soil and fertilizer as expanding numerous matrix, dry farmland soil and fertilizer respectively and cross 2mm sieve, sieve the back, with farmland soil and fertilizer according to volume ratio 2: 1, uniformly mixing, and sterilizing before or after mixing the farmland soil and the organic fertilizer to obtain the propagation expanding matrix. Wherein the sterilization method of the propagation matrix comprises steam sterilization at 121 ℃, sterilization for 1-2 hours, taking out and cooling to room temperature.

Adding water into the propagation matrix, wherein the adding amount of the water is 15-20% of the total mass of the propagation matrix and the initial inoculant; after the host plant is sowed and in the growth process, the host plant is managed conventionally to ensure the normal growth of the host plant, the host plant is cultured for 3-4 months, the overground part of the host plant is cut off, the cut root section is uniformly mixed with a substrate, and the air-dried substrate containing the root section of the host plant, the spores of the mycosphaerella pusilla and the hyphae outside the root is the single mycosphaerella pusilla fungicide.

Mixing a mixed microbial inoculum of bacillus amyloliquefaciens and trichoderma harzianum with a moscilla ductus agent according to a mass ratio of 1: 5 mixing to form mixed bacterial powder, and mixing the mixed bacterial powder with filtered diatomite to obtain the microbial agent I for slope protection.

Preparation example 2

Wherein the bacterial content of the bacillus amyloliquefaciens is 1

10⁶Per ml;

mixing a mixed microbial inoculum of bacillus amyloliquefaciens and trichoderma harzianum with a moscilla ductus agent according to a mass ratio of 1: 9 to form mixed bacterial powder, and mixing the mixed bacterial powder with filtered diatomite to obtain the microbial agent II for slope protection.

Preparation example 3

Wherein the bacterial content of the bacillus amyloliquefaciens is 1

10⁶Per ml;

mixing a mixed microbial inoculum of bacillus amyloliquefaciens and trichoderma harzianum with a moscilla ductus agent according to a mass ratio of 1: 4.5 mixing to form mixed bacterial powder, and mixing the mixed bacterial powder with filtered diatomite to obtain the microbial agent III for slope protection.

Preparation example 4

Inoculating the bacillus amyloliquefaciens FZB42 strain on an LB solid plate culture medium for streak culture, and activating the strain; inoculating the activated bacterial colony to an LB liquid culture medium to prepare a first-level seed liquid of the bacillus amyloliquefaciens; the first-stage seed liquid of the bacillus amyloliquefaciens is subcultured in an LB liquid culture medium to prepare a second-stage seed liquid of the bacillus amyloliquefaciens; inoculating the second-stage seed liquid of Bacillus amyloliquefaciens to a fermentation culture medium, performing shake culture at 32 deg.C for 48h, washing with sterile water, centrifuging at 4 deg.C and 5000r/min for 10min, collecting thallus, resuspending in sterile double distilled water, and adjusting the concentration of suspension to 6.5 × 10 with sterile water⁹cfu/ml, and spray drying to obtain the bacillus amyloliquefaciens microbial inoculum; wherein, the components of the fermentation medium comprise: 38 parts of corn flour, 24 parts of cottonseed meal, 24 parts of bran and KH₂PO 5 parts, Na₂HPO₄6 parts and 1000 parts of sterile water, and the pH of the fermentation medium is 7.0.

The method comprises the following steps of planting and breeding the bursa of moccasia micraccoon in advance through corn, taking a mixture of spores, extra-root hyphae and root soil infected with corn root segments of the bursa of moccasia micraccoon as a bursa of moccasia micraccoon microbial inoculum, wherein each gram of the bursa of moccasia micraccoon microbial inoculum contains 25-35 spores;

mixing a bacillus amyloliquefaciens microbial inoculum with the Moxidou Tunica microbial inoculum and the Trichoderma harzianum wettable powder according to the mass ratio of 3: 8: 95 to form mixed bacterial powder, and mixing the mixed bacterial powder with filtered diatomite to obtain the microbial agent IV for slope protection.

Effect example 1

Selecting an experimental site from Shanxi Yingzi village in the oceanic river of Anshan city, Liaoning province, selecting 5 blocks of A1-A5 from the experimental field, harvesting the corn straws, and then crushing the corn straws to 3-5 cm before paving the corn straws in 5 experimental fields; wherein the A1 plot contains a first microbial agent, the A2 plot contains a second microbial agent, the A3 plot contains a third microbial agent, the A4 plot contains a fourth microbial agent, and the A5 plot does not contain a microbial agent; 2.4kg of the microbial inoculum prepared in the examples 1 to 4 is applied to each mu of the experimental field, the microbial inoculum for slope protection is not used in a control group A5 plot, then irrigation is carried out, the straw decomposition is observed, and the change condition of the experimental result is shown in table 1:

the results show that the degradation and decomposition time of the straws can be advanced to 6-7 days by applying the microbial agents 1-4 in the test fields A1-A4 compared with the control group A5 without adding the microbial agents.

Effect example 2

Selecting corn straws, crushing the corn straws into 3-5 cm, and then placing the straw fragments in an oven at 85 ℃ for drying until the water content is about 18%, so as to obtain dry straw fragments.

Weighing 50g (N)₀) The dried straw pieces were put into nylon mesh bags for a total of 50. Each 10 nylon bags are used as a group and form five groups B1-B5; wherein, the nylon bags of group B1 are filled with microbial inoculum and mixed with the straw fragments, the nylon bags of group B2 are filled with microbial inoculum II and mixed with the straw fragments, the nylon bags of group B3 are filled with microbial inoculum III and mixed with the straw fragments, and the nylon bags of group B4 are filled with microbial inoculum IV and mixed with the straw fragments; no microbial agent was placed in the nylon bag of group B5. And 50 samples of the nylon bags are simultaneously embedded into a 10 cm soil layer, after 10 days, 20 days and 30 days, 5 samples of each group are randomly taken out, stored in a refrigerator at 4 ℃, and dried within 3 days. Before the sample is dried, the sample is washed by tap water until the dropping water is colorless(indicating that foreign matters such as soil are washed clean), then the sample is dried at 85 ℃ for 6 hours, accurately weighed and the weight of each bag is recorded (N)_X) Straw weight loss ratio (W)_X) The calculation formula of (2): w_X=100 (N₀-N_X) /N₀And the weight loss rate of the straws in a certain decomposition period (10, 20 and 30 days) can be calculated. The comparative analysis is carried out on the treatment weight loss ratios of the five groups B1-B5, and the experimental results are shown in Table 2.

The weight loss ratios of 5 groups of experimental treatments of 10, 20 and 30 days in table 2 show that the decomposition degrees of the straw fragments added with the microbial agent are obviously different from those of the straw fragments without the microbial agent. The results show that the microbial agent for slope protection, which is formed by combining the bacillus amyloliquefaciens microbial agent, the bursa of mosaicensis microbial agent and the Trichoderma harzianum wettable powder, has a stronger degradation effect on lignocellulose, wherein after three groups of bacillus amyloliquefaciens and Trichoderma harzianum strains from B1-B3 are mixed, fermented and cultured, compared with the mixed microbial agent formed by mycorrhizal fungi, the microbial agent has stronger straw degradation capability compared with a mixture of the bacillus amyloliquefaciens microbial agent, the bursa of mosaicensis microbial agent and the Trichoderma harzianum microbial agent, which are respectively cultured and mixed in the group B4.

Example 1

Stirring and mixing 70 parts of local soil, 30 parts of humic acid, 15 parts of decomposed cow dung, 7 parts of water-retaining agent, 25 parts of microbial agent I and 17 parts of grass seeds to form a first matrix mixture;

the method for obtaining humic acid comprises the following steps: extracting humic acid from weathered coal by an alkali-soluble acid precipitation method, and drying and granulating to obtain the humic acid particles. Humic acid is added into the matrix mixture, and the humic acid has quick-acting and slow-acting effects; the soil structure can be changed, and the soil permeability is increased; the pH value of the soil can be adjusted by changing the pH value of the soil; it also stimulates the proliferation and growth of beneficial microorganisms in the soil.

Wherein the grass seeds are a mixture of 60 parts of Chinese zoysia japonica seeds, 45 parts of oat seeds and 20 parts of alfalfa seeds. In practice, the grass seed may be one or more of zoysia sinensis, oat seed, alfalfa, green bristlegrass, fescue, buffalo grass, and the like. The root system of the Chinese zoysia japonica is more developed than that of the green bristlegrass, and the root systems and the soil of the Chinese zoysia japonica, the alfalfa and the oat can form a root-soil complex, so that the root system complex can reinforce the soil and improve the shear strength of the soil body. Therefore, in order to adapt to the northern environment and improve the overall slope protection effect in the experiment, the mixed planting of the Chinese zoysia, the oat and the alfalfa is selected.

Example 2

60 parts of local soil, 25 parts of humic acid, 12 parts of decomposed cow dung, 6 parts of water-retaining agent, 15 parts of microbial agent II and 15 parts of grass seeds are stirred and mixed to form a matrix mixture II;

wherein the grass seeds are a mixture of 40 parts of Chinese zoysia japonica seeds, 25 parts of oat seeds and 10 parts of alfalfa seeds.

Example 3

Stirring and mixing 82 parts of local soil, 35 parts of humic acid, 22 parts of decomposed cow dung, 8 parts of water-retaining agent, 35 parts of microbial agent and 21 parts of grass seeds to form a third matrix mixture;

wherein the grass seeds are a mixture of 50 parts of Chinese zoysia japonica seeds, 35 parts of oat seeds and 15 parts of alfalfa seeds.

Example 4

Stirring and mixing 82 parts of local soil, 35 parts of humic acid, 22 parts of decomposed cow dung, 8 parts of water-retaining agent, 35 parts of microbial agent and 21 parts of grass seeds to form a matrix mixture IV;

Example 5

Stirring and mixing 78 parts of local soil, 33 parts of humic acid, 20 parts of decomposed cow dung, 7 parts of water-retaining agent and 18 parts of grass seeds to form a matrix mixture V;

Application example 1

Selecting five sloping fields with the same inclination angle at the northern Yingzi village section of the ocean river of Anshan city in Liaoning province to carry out an on-site slope protection test; selecting 4 months of a dry period as test time; the inclination angle of the selected sloping field is 34 degrees; the straw board structure revetment is used in the five sloping fields of C1-C5.

Wherein, C1 plot uses a first matrix mixture containing a first microbial agent, C2 plot uses a second matrix mixture containing a second microbial agent, C3 plot uses a third matrix mixture containing a third microbial agent, C4 plot uses a fourth matrix mixture containing a fourth microbial agent, C5 plot uses a fifth matrix mixture containing no microbial agent, and the dosage of the matrix mixture in each square slope is the same for five slopes.

Preparing a straw plate provided with through holes; the thickness of the straw board is 9cm, the diameter of the through holes is 9cm, and the hole spacing is 15 cm; the density of the straw board is 0.6g/cm³And the Shore hardness of the straw board is 61A.

Constructing the straw board structure slope protection in a C1-C5 land, constructing according to slope surface arrangement, straw board fixing, grass seed-containing matrix mixture filling and soil covering and curing processes, and specifically excavating grooves at the top and the bottom of the slope; anchoring the upper end of the straw plate in the groove on the top of the slope by using a rivet, filling the groove with soil and compacting; anchoring the bottom end of the straw board in the groove of the toe by using a rivet, and filling and compacting soil; filling the substrate mixture containing grass seeds into the holes of the straw board; soil is covered on the surface of the straw board, particularly, soil is filled in the groove of the straw board, and then watering is carried out periodically, so that the upper layer of soil and the straw board are preferably thoroughly wetted.

During the test period, the slope surface experiences rainfall with different intensities for many times, and after the rainfall is finished, the slope surface under the straw board is basically kept dry, so that in the rainfall process, the vegetation on the slope surface reduces the scouring of raindrops on the soil of the slope surface to a certain extent, and the protection effect of the method on the slope surface is verified.

In month 10, the field soil strength was tested by using an American Iowa borehole shear tester.

Firstly, adopting a large soil sampler to sample soil on the surface layer to a depth of more than 50 cm, installing a shear tester at a hole opening, lowering a shear head to a test height, loading initial consolidation pressure and keeping for 15min, keeping the rest pressures at all levels for 5min respectively, measuring the shear strength of a soil body under the action of normal pressure at each level after consolidation is finished, and drawing a curve according to the strengths at all levels to obtain the cohesive force of the soil body. The graph of the change of the soil mass cohesive force along with the soil mass depth is shown in figure 1; figure 1 shows the cohesion of the soil mass for different mixtures of matrices.

As can be seen from FIG. 1, the soil mass cohesion of the C1-C4 plots is greater than that of the C5 plots at the same depth when the C1-C4 plots adopting the microbial agent for slope protection of the invention are compared with the C5 plots not adopting the microbial agent. Therefore, the vegetation using the microbial agent has high survival rate, and the fine reticular roots are formed in the soil body, so that the reinforcement effect on the soil body of the slope body is good, and therefore, the slope body of the C1-C4 plot has good overall stability, the soil body slippage phenomenon is avoided, and the windproof and slope protection effects are good. Wherein, after C1-C3 three groups of bacillus amyloliquefaciens and trichoderma harzianum strains are mixed, fermented and cultured, compared with a mixed microbial inoculum formed by mycorrhizal fungi, and a mixture of the bacillus amyloliquefaciens microbial inoculum, the ascochyta mossambica microbial inoculum and the trichoderma harzianum microbial inoculum which are respectively cultured and mixed in the C4 group, the method has stronger wind prevention and slope protection capability.

In conclusion, the preparation method and the application of the microbial agent for slope protection can improve the proline content of slope protection plants in damaged soil, improve the soil structure of damaged slopes, the nutrient element circulation, the plant drought resistance and the plant individual nutrient absorption by applying the mixed microbial agent containing the bacillus amyloliquefaciens microbial agent, the sorangium mossambica microbial agent and the trichoderma harzianum microbial agent, and further improve the ecological benefit of slope protection; and the microbial agent for slope protection has better straw degradation effect. After the bacillus amyloliquefaciens and the trichoderma harzianum strains are mixed, fermented and cultured, the mixed bacterial agent formed by the mycorrhizal fungi has better windproof and slope protection effects compared with a mixture of the bacillus amyloliquefaciens bacterial agent, the pipewort mossambica bacterial agent and the trichoderma harzianum bacterial agent which are respectively cultured and mixed.

Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements do not depart from the spirit of the invention and are intended to be included within the scope of the invention.

Claims

1. A preparation method of microbial agent for slope protection is characterized in that,

activating bacillus amyloliquefaciens, and inoculating the activated bacillus amyloliquefaciens into a liquid seed culture medium of the bacillus amyloliquefaciens for culture to obtain a bacillus amyloliquefaciens fermentation seed solution; wherein the bacterial content of the bacillus amyloliquefaciens is 1

10⁸cfu/ml；

10⁶Per ml;

2. The method for preparing a microbial agent for slope protection according to claim 1, wherein the weight ratio of the mixed agent of bacillus amyloliquefaciens and trichoderma harzianum to the ascomyces mosilicalis on a dry basis is 1: 5 to 9.

3. The method for preparing a microbial agent for slope protection according to claim 2, wherein the bacillus amyloliquefaciens is bacillus amyloliquefaciens FZB42 strain; the Trichoderma harzianum is Trichoderma harzianum T-E5.

4. The method for preparing a microbial agent for slope protection according to claim 1, wherein bacillus amyloliquefaciens and trichoderma harzianum stored at 4 ℃ are activated by NA and PDA plates, respectively, and cultured in a constant temperature incubator at 28 ℃ for 2 days and 5 days, respectively; inoculating bacillus amyloliquefaciens into a BYP liquid culture medium, and culturing for 2 days in a constant-temperature oscillation incubator at 28 ℃ and 180 r/min; adding 10ml of sterilized normal saline into each plate of the Trichoderma harzianum strain full of spores, hanging sporangium by using an applicator, inoculating into PDB culture medium, and culturing for 5 days in a constant-temperature shaking incubator at 28 ℃ and 180 r/min.

5. The use of the microbial inoculum prepared by the preparation method of any one of claims 1-4 in slope protection.

6. Use according to claim 5, characterized in that it comprises the following steps:

filling a matrix mixture into the through holes of the straw board;

7. The use according to claim 6, wherein the grass seeds are a mixture of 40-60 parts of zoysia sinensis seeds, 25-45 parts of oat seeds and 10-20 parts of alfalfa seeds.