Method for promoting mycorrhizal fungi infection to improve afforestation survival rate based on electrically-driven earthworms

Abstract

The invention relates to a method for promoting ectomycorrhizal fungi infection and further improving the afforestation survival rate of difficult sites based on electrically driving earthworms, which comprises the following steps: (1) selecting mycorrhizal fungi and earthworms which can form a stable symbiotic relationship to construct a mycorrhizal-earthworm coupling system; (2) constructing an electric power system: arranging the electric power system around a trunk, loading the mycorrhiza-earthworm coupling system in the step (1) into the electric power system, and electrifying. Compared with the prior art, the method has the advantages that the infection rate of ectomycorrhizal fungi of tree root tips can be increased, and the growth, health and afforestation survival rate of trees in difficult sites are promoted, so that the purposes of carbon sequestration and carbon sink increase of soil are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of forestry, and in particular to a method for promoting mycorrhizal fungal infection and improving afforestation survival rate based on electrically driven earthworms. Background Art

[0002] Difficult sites have poor soil, low organic matter content, and lack of nutrients, which is not conducive to tree growth. Afforestation in difficult sites also has to deal with the poor soil structure of secondary forest sites, such as salinization, compaction, organic matter and heavy metal pollution. The development of the root system of secondary forest trees is severely restricted, resulting in difficulty in soil carbon storage and low tree survival rate.

[0003] my country has a large area of ​​difficult sites and a low afforestation survival rate, which seriously restricts the growth of forest resources and the improvement of the ecological environment. Afforestation in difficult sites is an important requirement for the construction of forest cities. How to consolidate the survival rate of trees in secondary forests and promote soil carbon storage is a bottleneck problem in the restoration of ecosystems in difficult sites. Existing auxiliary technologies for afforestation in difficult sites mainly include imported soil afforestation, water collection afforestation, mixed afforestation, and enhanced fertilization. Traditional technologies have the following problems: (1) The soil improvement effect is not obvious and slow, and cannot meet the needs of tree growth; (2) A large amount of chemical fertilizers pollute the environment; (3) There is a lack of comprehensive technology that promotes soil properties and tree growth in difficult sites at the same time.

[0004] Patent application CN202211550483.3 discloses a method for biological improvement of urban green space soil, which specifically includes the following steps: S1. Determination of soil properties; S2. Placement and inoculation of earthworm bait; S3. Inoculation of bacterial strains; S4. Simultaneous inoculation of earthworms and bacterial strains; S5. Data statistics and formulation of soil improvement plans, by inoculating the soil with different bacterial strains and earthworms, and then testing the soil in turn, and formulating the best soil improvement plan based on the statistics and analysis of the test data. This plan can formulate soil improvement plans more accurately and specifically based on the results of actual data, thereby ensuring the improvement of the soil environment, improving soil properties, and increasing the survival rate of seedlings, thereby reducing the replanting and replacement of seedlings during the warranty maintenance period, and reducing the economy of landscaping construction units. However, this technology does not take into account the characteristics of ectomycorrhizal fungi, that is, such microorganisms must infect the root tips of trees to form ectomycorrhizae. In this technology, earthworms move slowly and do not necessarily move to deep soil layers, which can easily lead to problems such as ectomycorrhizal fungi not adapting to the surface soil environment, sinking slowly, or losing their activity before reaching deep soil layers. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a method for promoting mycorrhizal fungal infection and improving afforestation survival rate based on electrically driven earthworms, thereby increasing the infection rate of ectomycorrhizal fungi at the root tips of trees, promoting the growth, health and afforestation survival rate of trees in difficult sites, and achieving the purpose of soil carbon fixation and sink.

[0006] The purpose of the present invention can be achieved by the following technical solution: A method for promoting mycorrhizal fungal infection and improving afforestation survival rate based on electrically driven earthworms, comprising the following steps:

[0007] (1) Select mycorrhizal fungi and earthworms with a symbiotic relationship to construct a mycorrhizal-earthworm coupling system;

[0008] (2) Building an electric power system: Setting up an electric power system around the tree trunk, installing the mycorrhizal-earthworm coupling system described in step (1) into the electric power system, and powering it on.

[0009] Furthermore, in the mycorrhizal-earthworm coupling system described in step (1), 5 to 30 earthworms are added per kilogram of mycorrhizal fungal agent, and (1 to 100)*10 of ectomycorrhizal fungi are contained in each kilogram of mycorrhizal fungal agent. 9 indivual.

[0010] Furthermore, the earthworms are selected from earthworm species that are adapted to difficult site environments;

[0011] The mycorrhizal fungi are ectomycorrhizal fungi.

[0012] Furthermore, the earthworm is Earthworm lumbricoides; and the mycorrhizal fungus is the ectomycorrhizal fungus Lactarius aquosus.

[0013] Furthermore, the electric power system is a tubular electric power system, including a tube, a conductive rod attached to the inner wall of the tube, a battery, the positive and negative electrodes of the battery are respectively connected to the conductive rod, and the mycorrhiza-earthworm coupling system is loaded in the tube.

[0014] Furthermore, the battery is a 24V dry cell with a maximum current of 4A.

[0015] Furthermore, a nylon mesh is provided at the bottom of the tube, and the battery is placed at the top of the tube.

[0016] Furthermore, the power-on time in step (2) is 1-3 hours.

[0017] In step (2), the electric power system is 1-5m away from the tree trunk.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0019] (1) The present invention utilizes the principle of accelerating earthworm movement by electric field and promoting the diffusion of ectomycorrhizal fungi. Mycorrhizal fungi with symbiotic relationships and earthworms adapted to difficult site environments are selected to increase the diffusion rate of mycorrhizal fungi and the infection rate of tree root tips. Electric power and isolation devices are added to speed up the movement of earthworms and the movement speed of ectomycorrhizal fungi inoculum.

[0020] (2) The mycorrhizal-earthworm coupling technology used in the present invention is used to improve the survival rate of afforestation in difficult sites. By selecting mycorrhizal fungi with a symbiotic relationship and earthworms adapted to the difficult site environment, a mycorrhizal-earthworm coupling system is constructed and applied to afforestation in difficult sites. The infection rate of ectomycorrhizal fungi at the root tips of trees can be increased, and the growth, health and survival rate of trees in difficult sites can be promoted, so as to achieve the purpose of soil carbon sequestration and sink.

[0021] (3) Compared with the traditional method of directly increasing water and fertilizer, the present invention has the advantages of low cost, strong operability, environmental friendliness, high added value, etc. It has good environmental, economic and social benefits, and provides a new method for reducing afforestation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0023] Description of the markings in the figure:

[0024] 1- tube, 2- nylon mesh, 3- conductive rod, 4- battery. DETAILED DESCRIPTION

[0025] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0027] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0028] In the following embodiments, if there is no special description of raw materials or processing technology, it means that they are all conventional commercially available raw materials or conventional processing technologies in the field. If there is no special description of functional components or structures, it means that they are all conventional components or conventional structures used in the field to achieve corresponding functions.

[0029] The present invention selects mycorrhizal fungi with symbiotic relationship and earthworms adapted to difficult site environment, based on the principle of electric field promoting earthworm activity, promotes the diffusion and inoculation of ectomycorrhizal fungi, improves the infection rate of ectomycorrhizal fungi at the root tip of trees, and is applied to afforestation in difficult sites, including the following steps:

[0030] (1) Selection of mycorrhizal fungi: Select ectomycorrhizal fungi that can form a symbiotic relationship with the tree roots.

[0031] (2) Select earthworm species that are adapted to difficult site environments.

[0032] (3) Build a tubular electric power system.

[0033] (4) The mycorrhizal fungi and earthworms obtained in (1) and (2) are mixed in a certain proportion, placed in (3), and used in secondary forest sites.

[0034] Example 1

[0035] Due to long-term iron ore mining in the Shilu Iron Mine Area of ​​Hainan Province, the soil in the mining area is seriously polluted by heavy metals (iron, nickel, etc.), the soil in the mining area is degraded, the vegetation is destroyed, and the ecological environment is damaged.

[0036] In this embodiment, mycorrhiza-earthworm coupled electrodynamic technology is used to restore the ecology of the Shilu iron ore area in Hainan Province. The specific method is as follows:

[0037] (1) Selection of mycorrhizal fungi and earthworms:

[0038] The ectomycorrhizal fungi adapted to the local tropical climate are selected. In this embodiment, the ectomycorrhizal fungi Lactarius aquosus commonly found in tropical trees and plants is selected.

[0039] The earthworm species adapted to the local climate and soil conditions were selected. In this embodiment, Pheretima aspergillum was selected.

[0040] (2) Cultivation of mycorrhizal fungi and earthworms

[0041] Ectomycorrhizal fungi suitable for tropical environments were screened and propagated in the laboratory, and a liquid inoculant of ectomycorrhizal fungi was prepared by fermentation under anaerobic conditions at 30°C using a liquid culture medium of potato dextrose agar (PDA) (12 g / L potato extract, 20 g / L glucose, pH 5.6±0.2). The liquid inoculant was mixed with a soil matrix that had been through a high-temperature aerobic composting product (70°C aerobic composting for one week and matured for three months) at a mass ratio of 1:10 (inoculant: matrix) to form an inoculant of ectomycorrhizal fungi.

[0042] Cultivate earthworms at earthworm breeding bases to ensure their health and reproduction.

[0043] (3) Construction of mycorrhiza-earthworm coupling system

[0044] The ectomycorrhizal fungi inoculant cultivated in step (2) was mixed with earthworms in the following proportions to form a mycorrhizal-earthworm coupling system: 20 earthworms + 1 kg of the ectomycorrhizal fungi inoculant in step (2) (the concentration of the ectomycorrhizal fungi Macrospora is about 10 9 / g).

[0045] (4) Build a tubular electric power system

[0046] like Figure 1 As shown: the electric power system is randomly arranged within the interval of 1-5 meters from the tree trunk: a PVC pipe 1 with a diameter of 20 cm and a length of 20 cm is selected, and a nylon mesh 2 with a pore size of 0.5 cm is provided at the bottom, which is used for filtering and protection. The nylon mesh has the characteristics of high toughness, good elasticity, corrosion resistance, and oil resistance. Therefore, the nylon mesh of this pore size can be used to prevent the leakage of larger particles of materials, while allowing earthworms and mycorrhizal materials to pass through. A conductive rod 3 is attached to the inner wall of the PVC pipe, and the mycorrhizal-earthworm coupling system constructed in step (3) is added. A battery 4 is directly placed on the PVC pipe 1, and the positive and negative poles are connected to dry batteries (24V, maximum current 4A) respectively. The power is turned on for 2 hours, and the dry batteries are placed in the pipe 1 to prevent the earthworms from escaping upwards.

[0047] (5) Implementation Effect

[0048] 1. Soil remediation:

[0049] In the above-mentioned difficult site seriously polluted by heavy metals such as iron and nickel in the Shilu iron ore area of ​​Hainan Province, 5-year-old Pinus latteri seedlings were planted, and a tubular electric power system was arranged 1 meter away from the tree trunk. Earthworms and ectomycorrhizal fungi inoculants were added. The added amount was 20 earthworms + 1 kg of the ectomycorrhizal fungi inoculant of step (2) (the concentration of ectomycorrhizal fungi giant cysts was about 10 9 / g), and the inoculation process was completed after 2 hours of power on. In order to detect the inoculation effect, soil and root tips were collected one year later. The root tip infection rate was determined by electron microscopy, the soil organic matter content was determined by incineration method, and the activity of mycorrhizal fungi and earthworms through inoculation was analyzed.

[0050] Ectomycorrhizal fungal infection rate = number of mycorrhizal segments / number of observed root segments

[0051] 2. Vegetation restoration:

[0052] Afforestation survival rate (%) = (number of surviving trees / total number of afforestation trees) × 100%

[0053] Comparative Example 1

[0054] A difficult site in the Shilu Iron Mine area of ​​Hainan Province which is seriously polluted by heavy metals such as iron and nickel was selected without any treatment as Comparative Example 1.

[0055] Comparative Example 2

[0056] The rest is the same as Example 1, except that only earthworms and mycorrhizae are added, and no electricity is applied, that is, no electricity is applied in step (4).

[0057] The results are shown in Table 1 below:

[0058] Table 1. Changes in soil organic matter, tree survival rate and mycorrhizal infection rate in different treatment groups

[0059]

[0060] As can be seen from Table 1 above, the treatment method of Example 1 has a higher soil organic matter content, and this method can increase the organic matter content of the mining area soil by more than 10% compared with Comparative Example 1. Compared with Comparative Example 1, the afforestation survival rate and mycorrhizal infection rate of Example 1 are also higher. Compared with Comparative Example 2, the soil organic matter and afforestation survival rate are also higher.

[0061] Embodiment 2-5

[0062] The rest is the same as Example 1, except that: in the control step (3), the amount of earthworms added per kilogram of ectomycorrhizal fungi inoculant is 5, 10, 20 and 30 respectively. The effect of adding different amounts of earthworms on the mycorrhizal infection rate was tested, and the results are shown in Table 2 below:

[0063] Table 2. Effect of adding different numbers of earthworms on mycorrhizal infection rate (calculated per kg inoculant)

[0064]

[0065] As can be seen from Table 2 above, adding earthworms is beneficial to the improvement of mycorrhizal infection rate. When 5-30 earthworms are added, the ectomycorrhizal infection rate is significantly promoted by 3.2-14%.

[0066] In summary, the "addition of electrodynamics + mycorrhizae and earthworms" treatment can increase soil organic matter content by more than 10%, improve forest survival rate by more than 30%, and increase the root tip infection rate of ectomycorrhizal fungi by more than 50%. In addition, the best infection rate can be achieved by adding 20 earthworms per kilogram of inoculant.

[0067] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for promoting mycorrhizal fungal infection and improving afforestation survival rate based on electrically driven earthworms, characterized in that: The following steps are involved: (1) Select mycorrhizal fungi and earthworms with a stable symbiotic relationship to construct a mycorrhizal-earthworm coupling system; (2) Building an electric power system: Setting up an electric power system around the tree trunk, installing the mycorrhiza-earthworm coupling system described in step (1) into the electric power system, and powering it on.

2. The method according to claim 1, characterized in that: In the mycorrhizal-earthworm coupling system described in step (1), 5 to 30 earthworms are added per kilogram of mycorrhizal fungal agent, and (1 to 100)*10 of ectomycorrhizal fungi are contained in each kilogram of mycorrhizal fungal agent. 9 indivual.

3. The method of claim 1, wherein the method is characterized in that: The earthworms are selected from earthworm species that are adapted to difficult site environments; and the mycorrhizal fungi are ectomycorrhizal fungi.

4. The method according to claim 3, characterized in that: The earthworm is Earthworm lumbricoides; the mycorrhizal fungus is the ectomycorrhizal fungus Lactarius aquosus.

5. The method of claim 1, wherein the method is characterized in that: The electric power system is a tubular electric power system, comprising a tube, a conductive rod attached to the inner wall of the tube, a battery, the positive and negative electrodes of the battery are respectively connected to the conductive rod, and the mycorrhiza-earthworm coupling system is loaded in the tube.

6. The method of claim 5, wherein the method is characterized in that: The battery is a 24V dry cell with a maximum current of 4A.

7. The method of claim 5, wherein the method is characterized in that: The bottom of the tube is provided with a nylon mesh, and the battery is placed on the top of the tube.

8. The method of claim 1, wherein the method is characterized in that: The power-on time of step (2) is 1-3 hours.

9. The method of claim 1, wherein the method is characterized in that: In step (2), the electric power system is 1-5m away from the tree trunk.

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