Biochar seed gel for saline-alkali soil vegetation restoration as well as preparation method and application of biochar seed gel

Abstract

The invention provides charcoal seed gel for saline-alkali soil vegetation restoration and a preparation method and application thereof, and belongs to the technical field of vegetation restoration. The biochar seed gel comprises water retention gel, effective nutritional ingredients and a structure maintenance agent, the water retention gel is polyacrylamide, the effective nutritional ingredients comprise a bacillus subtilis microbial agent, brassin, chitosan oligosaccharide, polyaspartic acid and a compound fertilizer, and the structure maintenance agent comprises biochar, clay, chitosan and saponin powder. The biochar seed gel forms a microenvironment on the surface of the soil, stress of a high-salt environment of the soil is reduced, and the gel is relatively high in water retention capacity, so that water is favorably maintained for growth of the seeds and seedlings, and a water shortage phenomenon caused by soil hardening is relieved.

Description

Technical Field

[0001] The invention belongs to the technical field of vegetation restoration, and in particular relates to a biochar seed gel for saline-alkali land vegetation restoration, and a preparation method and application thereof. Background Art

[0002] Saline-alkali land refers to land with high concentrations of salt and alkaline substances in the soil. This soil environment poses a serious threat to agricultural production and the ecosystem, resulting in a significant decrease in crop yields. In a saline-alkali environment, high concentrations of soil salt ions cause soil compaction, which in turn causes poor soil structure and reduced fertility; excessive soil salinity can easily interfere with the acquisition and transportation of plant nutrients, causing nutrient imbalance, resulting in reduced vegetation productivity, further causing the degradation of the surrounding ecological functions, and seriously threatening the local ecological environment. Vegetation restoration for saline-alkali land is currently the focus of saline-alkali land ecological restoration.

[0003] The amplification and propagation of vegetation seeds and propagules is a key link in the restoration of saline-alkali land vegetation. Especially for the most common annual plants in saline-alkali land, it is necessary to maintain a vegetation scale similar to that of the previous year. After the vegetation is degraded, there is a lack of sufficient seed sources and suitable soil environment to support the colonization of the community in the next year, and seeds and seedlings need to be passively supplemented. Common vegetation restoration measures are mainly sowing, plant species selection and transplanting. By amplifying and propagating plant seeds and propagules, the survival rate of saline-alkali land plants is effectively improved, thereby realizing the restoration of local vegetation communities. However, in the high-salt and drought stress environment of saline-alkali land, the growth and germination of vegetation are usually severely restricted, and even the settlement and growth of adverse plants will be affected to a certain extent, which brings huge challenges to the ecological restoration of saline-alkali land. Therefore, the development of low-cost and high-efficiency ecological restoration technologies that are adapted to the special stress environment of saline-alkali land is a key technical demand that needs to be urgently addressed.

[0004] The application of improved seed technology in the agricultural field has become relatively mature. Among them, seed coating technology is a widely used measure to improve seed tolerance and survival rate. By treating the outside of the seeds with coating agents, the germination rate, growth rate and stress resistance of the seeds are improved. With the continuous development of ecological restoration, facing the problems of insufficient natural germplasm resources and relatively low germination rate of natural seeds under stress environments, seed coating technology has gradually been introduced into the field of vegetation restoration. In view of the special stress environment of saline-alkali land, it is particularly important to improve and optimize seed coating technology, but related technologies are still lacking. Traditional coating technology is designed with farmland as the practice scene, but when it is practiced in saline-alkali land, high salt and drought limit the application of traditional coating technology. It is necessary to propose targeted overcoming technologies, and the effects of coating materials, especially salt reduction and water retention, are more stringent.

[0005] In addition, the addition of fungicides and pesticides in traditional agricultural coating technology is contrary to the principle of environmental friendliness. Excessive synthetic organic and inorganic compounds cause environmental pollution, leading to further degradation of the local fragile ecosystem. Therefore, the present invention is proposed to meet the requirements of low cost, pollution-free, salt reduction and drought resistance. Summary of the invention

[0006] The purpose of the present invention is to provide a biochar seed gel for saline-alkali land vegetation restoration and a preparation method and application thereof, so as to overcome the high-salt and drought stress environment of saline-alkali land and improve the seed germination rate and plant stress resistance.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a biochar seed gel for saline-alkali land vegetation restoration, comprising the following raw materials: water-retaining gel, effective nutrient components and a structure-maintaining agent;

[0009] The water-retaining gel is polyacrylamide; the effective nutrients include Bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer; and the structure-maintaining agent includes biochar, clay, chitosan and saponin powder.

[0010] Preferably, the weight ratio of the water-retaining gel, the effective nutrient component and the structure-maintaining agent is 1-10:1-5:1-10.

[0011] Preferably, the mass ratio of the Bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer is 3-5:1-2:5-10:1-2:3-5.

[0012] Preferably, the mass ratio of the biochar, clay, chitosan and sapodilla powder is 15-30:50-70:5-10:1-3.

[0013] Preferably, the concentration of the Bacillus subtilis inoculant is 5×10 10 ~1×10 12 cfu / g; the compound fertilizer is a high-phosphorus-potassium compound fertilizer; the biochar is reed biochar with a mesh size of ≥200 mesh; the clay is the in-situ soil in the ecological restoration area, which has been dried at 170-190°C for 20-24h and has a mesh size of ≥100 mesh.

[0014] The present invention also provides a method for preparing a biochar seed gel, comprising the following steps:

[0015] 1) mixing Bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer to obtain an effective nutrient agent;

[0016] 2) mixing biochar, clay, chitosan and sapodilla powder to obtain a structure maintaining agent;

[0017] 3) Mixing the water-retaining gel, the structure-maintaining agent and the effective nutrient agent to obtain the biochar seed gel.

[0018] Preferably, the biochar seed gel is sealed and stored in an environment of 3 to 5°C.

[0019] The present invention also provides an application of biochar seed gel in repairing vegetation in saline-alkali land.

[0020] Preferably, the biochar seed gel is suitable for halophytes with seed diameters less than 5 mm, and the halophytes include Suaeda salsa.

[0021] Preferably, the application comprises the following steps:

[0022] (1) soaking and germinating the seeds and mixing them with biochar seed gel at a mass ratio of 1:3 to 5 to obtain a seed and gel mixture;

[0023] (2) adding water in an amount of 8 to 12 times the mass of the mixture of seeds and gel in step (1), leaving it to stand for 20 to 28 hours, and then spraying it on the saline-alkali land.

[0024] Beneficial effects:

[0025] In the biochar seed gel provided by the present invention, polyacrylamide (PAM) is a high molecular water-absorbing material, which has good solubility in water and can form solutions of different concentrations, and has high water absorption and viscosity. It serves as the main material of the water-retaining gel, and mainly plays the role of water retention, thickening and fixing. By forming a gel to maintain moisture and isolate salt, the purpose of seed water retention and salt stress resistance is achieved.

[0026] Bacillus subtilis inoculant is a microbial inoculant, in which Bacillus subtilis is the main strain, which provides nutrients and growth-promoting substances for the life activities of the strain, and plays a role in improving the soil environment; the strain forms an antagonistic relationship with some harmful microorganisms, reduces the population density of harmful microorganisms, and plays a role in resisting diseases; the gas produced by the physiological activities of the strain changes the soil structure to a certain extent, helps to break up the compaction of saline-alkali soil, and plays a role in loosening the soil; the utilization of salt by the life activities of the strain effectively reduces the salt content in the soil, and plays a role in alleviating salt stress.

[0027] Brassinolide is a new type of plant endogenous hormone that promotes plant growth and alleviates plant salt stress. Compared with traditional plant growth regulators, brassinolide is more water-soluble, requires less dosage, and has weaker biological toxicity.

[0028] Chitosan oligosaccharides are low molecular weight oligosaccharides with excellent water solubility. The effects of chitosan oligosaccharides on plant growth include promoting plant growth, enhancing disease resistance and improving environmental adaptability. Chitosan oligosaccharides help to increase plant growth rate, reduce disease incidence, and enhance plant survival and yield stability under adverse environmental conditions by regulating plant internal hormones, inducing defense reactions and enhancing stress resistance.

[0029] Polyaspartic acid (PASP) as a biostimulant is beneficial to plant growth, mainly by promoting seed germination and root growth, improving plant water use efficiency and enhancing the plant's ability to absorb nutrients, thereby promoting plant growth, enhancing stress resistance and improving yield stability.

[0030] High-phosphorus-potassium compound fertilizer can artificially supplement various elements required for plant growth and development.

[0031] Reed biochar is a carbon material made from reed and other plant materials through high-temperature pyrolysis. It provides a carbon source for microbial agents, improves soil structure, increases soil organic matter content, and improves soil fertility and water retention. At the same time, its porous structure changes the physical and chemical properties of the soil and promotes the growth of soil flora by constructing a suitable soil microenvironment. The porous structure of biochar adsorbs and fixes nutrients, reduces nutrient loss and achieves a slow release of nutrients.

[0032] Clay is the original soil in the ecological restoration area, which mainly plays a role in maintaining the structure. The weight of the biochar seed gel is increased by adding clay. Clay has a strong ability to retain water, which can improve the permeability and water retention of the soil and provide certain inorganic substances required for plant growth; at the same time, the original soil ensures the adaptability of the biochar seed gel to the practice area and improves the survival rate of the seedlings.

[0033] Chitosan is a natural polymer material with good biocompatibility, biodegradability and biological activity. It plays a thickening role. At the same time, chitosan has a certain water retention capacity, which serves as an effective supplement to improve water retention capacity.

[0034] Gleditsia sinensis powder is a natural surfactant that can enhance the adhesion of the gel on the seed surface, thereby improving the mechanical properties of the biochar seed gel.

[0035] The biochar seed gel in the present invention forms a microenvironment on the soil surface, reducing the stress of the high-salt environment of the soil, and the gel has a strong water retention capacity, which helps to maintain moisture to supply seeds and seedlings for growth, and alleviate the water shortage caused by soil compaction. At the same time, the main raw materials of the biochar seed gel are mostly pure natural materials, which can reduce the negative environmental effects generated during the use of the gel. In addition. The biochar seed gel configuration method is simple, the materials are easy to obtain, and the cost is low; the gel is stored in solid form, which is convenient for storage and transportation. After adding water, it is sprayed on the surface of the object to be repaired, with high operating efficiency, which is conducive to the development of large-scale repair projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a sample diagram of gel seed in Example 2;

[0037] Figure 2 This is a diagram of the seed germination experiment results of Example 3. DETAILED DESCRIPTION

[0038] The invention provides a biochar seed gel for saline-alkali land vegetation restoration, comprising the following raw materials: water-retaining gel, effective nutrients and a structure-maintaining agent, wherein the water-retaining gel is polyacrylamide; the effective nutrients include Bacillus subtilis inoculant, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer; the structure-maintaining agent includes biochar, clay, chitosan and saponin powder.

[0039] In the present invention, the weight ratio of the water-retaining gel, the effective nutrients and the structure-maintaining agent is 1-10:1-5:1-10, and more preferably 10:2.5:7; the mass ratio of the Bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer is 3-5:1-2:5-10:1-2:3-5, and more preferably 3:1:6:2:3; the mass ratio of the biochar, clay, chitosan and saponin powder is 15-30:50-70:5-10:1-3, and more preferably 20:60:8:2.

[0040] In the present invention, the concentration of the Bacillus subtilis inoculant is 5×10 10 ~1×10 12 cfu / g, more preferably 1×10 11 cfu / g; the compound fertilizer is a high-phosphorus-potassium compound fertilizer, and more preferably a water-soluble compound fertilizer, with an NPK ratio of 12:33:21; the biochar is reed biochar, with a mesh size of ≥200 mesh; the clay is in-situ soil from an ecological restoration area, dried at 170-190°C for 20-24h, with a mesh size of ≥100 mesh, and more preferably dried at 180°C for 24h.

[0041] The present invention also provides a method for preparing a biochar seed gel, comprising the following steps:

[0042] 1) mixing Bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer to obtain an effective nutrient agent;

[0043] 2) mixing biochar, clay, chitosan and sapodilla powder to obtain a structure maintaining agent;

[0044] 3) Mixing the water-retaining gel, the structure-maintaining agent and the effective nutrient agent to obtain the biochar seed gel.

[0045] In the present invention, the biochar seed gel is sealed and stored in an environment of 3 to 5°C, more preferably 4°C.

[0046] The present invention also provides an application of biochar seed gel in repairing vegetation in saline-alkali land.

[0047] In the present invention, the biochar seed gel is suitable for halophytes with seed diameters less than 5 mm, and more preferably Suaeda salsa.

[0048] In the present invention, the application comprises the following steps:

[0049] (1) soaking and germinating the seeds and mixing them with biochar seed gel at a mass ratio of 1:3 to 5 to obtain a seed and gel mixture;

[0050] (2) adding water in an amount of 8 to 12 times the mass of the mixture of seeds and gel in step (1), leaving it to stand for 20 to 28 hours, and then spraying it on the saline-alkali land.

[0051] The mass ratio of the seeds to the biochar seed gel is further preferably 1:4, the amount of water added is further preferably 10 times the mass of the mixture of seeds and gel, and the standing time is further preferably 24 hours.

[0052] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0053] Example 1 Preparation of biochar seed gel

[0054] (1) Pretreatment of experimental materials

[0055] The clay collected from the site to be restored was dried in an oven at 180°C for 24 hours, and after cooling to 25°C, it was crushed and ground for 15 minutes, sieved, and the clay with a mesh size of ≥100 was retained;

[0056] The reed biochar was crushed and ground for 15 min, sieved, and the part with a mesh size ≥ 200 was retained.

[0057] (2) Preparation of effective nutrient ingredients

[0058] Bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid, and high phosphorus and potassium compound fertilizer are mixed in a mass ratio of 3:1:6:2:3 and stirred for 20 minutes until stirred evenly to obtain an effective nutrient agent.

[0059] (3) Preparation of structure-maintaining agent

[0060] Reed biochar, clay, chitosan, and sapodilla powder were mixed in a mass ratio of 10:30:4:1, and stirred in a blender (power of 550 W) for 20 min until uniformly stirred to obtain a structure maintaining agent.

[0061] (4) Preparation of biochar seed gel

[0062] The water-retaining gel, effective nutrient agent and structure-maintaining agent are mixed in a mass ratio of 10:2.5:7. The prepared biochar seed gel needs to be sealed and stored at a low temperature of 4°C.

[0063] Example 2 Mixing of seeds and biochar seed gel

[0064] In this embodiment, Suaeda salsa (L.) Pall. is used as the implementation object to be selected.

[0065] 1) The collected Suaeda salsa seeds are naturally dried and then air-selected to remove dust and straw, and sieved to retain seeds with a mesh size of 10 to 40.

[0066] 2) Rinse the Suaeda salsa seeds with 0.1% potassium permanganate solution for 3 minutes, then rinse with deionized water for 3 times, and soak the seeds in distilled water at 25° C. for 24 hours to accelerate germination.

[0067] 3) The seeds after soaking and germination were mixed with the biochar seed gel prepared in Example 1 at a mass ratio of 5:1 to obtain a seed and gel mixture. The state after mixing is as follows: Figure 1 As shown. Among them, Figure 1 The left picture shows the seed and gel mixture in a beaker. Figure 1 The picture on the right is a close-up shot of the seeds and gel mixture, the green ones are the seeds of the saltwort plant.

[0068] Example 3 Seed germination experiment under salt stress

[0069] Take the seeds of Suaeda salsa with full grains, set up two treatments, the control group is the Suaeda salsa seeds that have been air-selected, sieved and germinated (processed according to steps 1) to 2) in Example 2, and not mixed with biochar seed gel), and the experimental group is the Suaeda salsa seeds mixed with biochar seed gel (prepared according to the complete process in Example 2), each group has 9 parallel treatments, and each parallel treatment takes 100 (about 0.1g) Suaeda salsa seeds. The experiment was carried out indoors, the indoor temperature was 20℃±2℃, and the light was uniform throughout the day.

[0070] Natural slightly shade-dried soil (taken from the north bank of the Yellow River Delta National Nature Reserve) was filled into a 9cm diameter nutrient pot, and the soil layer thickness was 6cm. After adding 10 times the mass of the seed and gel mixture into the experimental group, it was stirred evenly after standing for 24 hours to form a turbid solution, which was sprayed onto the soil surface through a special instrument. Water was added to the control group to the same volume as the experimental group solution, and then sprayed onto the soil surface.

[0071] At 12 noon every day, 9 groups were irrigated with 10 mL of salt water with different salinities (a total of nine salinity gradients: 0 ppt, 2 ppt, 4 ppt, 8 ppt, 12 ppt, 16 ppt, 20 ppt, 24 ppt, and 28 ppt). The number of germinations was recorded at 4 p.m., and the emergence of seedlings was regarded as germination. The culture was continued for 8 days.

[0072] The results are as follows Figure 2 As shown in the figure, the test results show that under natural conditions, the seed germination rate decreases with the increase of salinity; the biochar seed gel breaks this rule, and its germination rate increases with the increase of salinity. In an environment with salinity>12ppt, the germination rate is higher than that of ordinary seeds, and a relatively higher germination rate level can be maintained. It proves that the gel has a promoting effect on seed germination in the high salt and drought stress environment of saline-alkali land.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A biochar seed gel for saline-alkali land vegetation restoration, It is characterized in that The raw materials include: water-retaining gel, effective nutrients and structure maintainers; The water-retaining gel is polyacrylamide; The effective nutrients include Bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer; The structure maintaining agent comprises biochar, clay, chitosan and sapodilla powder.

2. The biochar seed gel according to claim 1, It is characterized in that The weight ratio of the water-retaining gel, the effective nutrient component and the structure-maintaining agent is 1-10:1-5:1-10.

3. The biochar seed gel according to claim 2, It is characterized in that The mass ratio of the bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer is 3-5:1-2:5-10:1-2:3-5.

4. The biochar seed gel according to claim 3, It is characterized in that The mass ratio of the biochar, clay, chitosan and sapodilla powder is 15-30:50-70:5-10:1-3.

5. The biochar seed gel according to claim 4, It is characterized in that The bacterial concentration of the Bacillus subtilis agent is 5×10 10 ~1×10 12 cfu / g; The compound fertilizer is a high-phosphorus-potassium compound fertilizer; The biochar is reed biochar with a mesh size of ≥200 mesh; The clay is in-situ soil in the ecological restoration area, dried at 170-190° C. for 20-24 hours, and has a mesh size of ≥100 meshes.

6. A method for preparing the biochar seed gel according to claims 1 to 5, It is characterized in that The following steps are involved: 1) mixing Bacillus subtilis agent, brassinolide, chitosan oligosaccharide, polyaspartic acid and compound fertilizer to obtain an effective nutrient agent; 2) mixing biochar, clay, chitosan and sapodilla powder to obtain a structure maintaining agent; 3) Mixing the water-retaining gel, the structure-maintaining agent and the effective nutrient agent to obtain the biochar seed gel.

7. The preparation method according to claim 6, It is characterized in that The biochar seed gel is sealed and stored in an environment of 3-5°C.

8. Use of the biochar seed gel according to any one of claims 1 to 5 or the biochar seed gel obtained by the preparation method according to any one of claims 6 to 7 in restoring vegetation in saline-alkali land.

9. The use according to claim 8, It is characterized in that The biochar seed gel is suitable for halophytes with seed diameters less than 5 mm.

10. The use according to claim 9, It is characterized in that The following steps are involved: (1) soaking and germinating the seeds and mixing them with biochar seed gel at a mass ratio of 1:3 to 5 to obtain a seed and gel mixture; (2) adding water in an amount of 8 to 12 times the mass of the mixture of seeds and gel in step (1), leaving it to stand for 20 to 28 hours, and then spraying it on the saline-alkali land.

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