A pelleting technology for calcium silicate-enhanced biochar-based feed oat seeds and its application in desert remediation.

Abstract

This invention relates to the field of vegetation restoration in desertified areas of the Qinghai-Tibet Plateau, and particularly to a pelleting technology for calcium silicate-enhanced biochar-based feed oat seeds and its application in desertification remediation. The invention includes the following steps: S1: Preparation and functional modification of raw materials; a: Preparation of modified biochar carrier; b: Preparation of activated calcium silicate reinforcing agent; c: Preparation of a special composite binder; S2: Component design of the seed pelleting powder; S3: Multi-layered pelleting process; S4: Application in desertification remediation in high-altitude and cold regions. Based on the synergistic principle of rhizosphere microecological regulation and plant calcium silicate nutrient enhancement, this invention uses modified yak manure biochar as a carrier to construct a water- and fertilizer-retaining framework, and activated calcium silicate as a reinforcing agent to improve seedling mechanical strength. A multi-layer coating process achieves the spatiotemporal orderly release of functions. This invention increases the germination rate and survival rate of oats, improves stress resistance, and realizes the resource utilization of waste and soil improvement.

Description

Technical Field

[0001] This invention relates to the field of vegetation planting and restoration technology in desertified areas of the Qinghai-Tibet Plateau, and in particular to a calcium silicate-enhanced biochar-based feed oat seed pelleting technology and its application in desert restoration. Background Technology

[0002] With the booming development of animal husbandry and the in-depth implementation of national ecological policies such as "returning grazing land to grassland," the energy structure and grazing methods in the Qinghai-Tibet Plateau region have undergone significant changes. Livestock manure, traditionally the main fuel, especially yak manure, has been replaced by clean energy, leading to a substantial decrease in its collection. This indicates that a large amount of yak manure will remain on grasslands in the future. While a moderate amount of manure deposits can improve local soil nutrients, excessive accumulation of yak manure can cause grassland vegetation to yellow or even die due to lack of oxygen and shading, posing a potential threat to the fragile ecological environment of the Qinghai-Tibet Plateau. Therefore, how to achieve the resource-based and harmless utilization of waste yak manure has become a pressing environmental and agricultural issue that needs to be addressed in the region.

[0003] In ecological restoration, forage oats, as a pioneer grass species for ecological restoration in the Qinghai-Tibet Plateau and high-altitude desertified areas, possess excellent characteristics such as cold resistance, drought resistance, strong tillering ability, and well-developed root system, and are widely used in the improvement of degraded grasslands and the construction of artificial grasslands. However, in high-altitude, arid, and semi-arid desertified soil environments, oats face severe survival challenges due to loose soil structure, poor water and fertilizer retention capacity, severe wind erosion, and large diurnal temperature variations: low seed germination rate, low seedling survival rate, and slow root establishment, making them highly susceptible to seedling death due to wind erosion or drought. Therefore, how to improve its planting rate and stress resistance in harsh environments is a key technical challenge in the current field of ecological restoration.

[0004] Current soil improvement technologies have many limitations. For degraded and sandy soils on the Qinghai-Tibet Plateau, existing measures mainly rely on engineering sand fixation, topsoil covering, or the application of chemical fertilizers, which are costly and prone to causing soil compaction or secondary pollution. While biochar technology is considered a potential direction for soil improvement, especially the use of yak manure to produce biochar, which can combine waste utilization with soil improvement, current biochar applications are mostly direct application or simple physical mixing. In the wind-swept plateau regions, powdered biochar is highly susceptible to wind erosion and loss, and it is difficult to accurately target the rhizosphere microenvironment during the early stages of seed germination, resulting in low utilization efficiency.

[0005] Furthermore, plant nutrition and physiology studies have shown that silicon is an important beneficial element for gramineous plants. Applying silicon fertilizer can significantly enhance the mechanical strength of plant epidermal cell walls, reduce transpiration water loss, and improve stress resistance. However, existing silicon fertilizer technologies are insufficient to meet the needs of high-altitude sandy land remediation: water-soluble silicon fertilizers are highly alkaline, easily disrupting soil pH balance and are prone to leaching; while insoluble silicon fertilizers, although mild in nature and containing calcium, have extremely low solubility in neutral or slightly alkaline sandy soils, making them difficult for roots to absorb directly. Traditional broadcasting methods cannot solve the activation problem of insoluble silicon fertilizers, resulting in extremely low conversion efficiency and failing to provide effective support during the critical window of seed germination and seedling growth.

[0006] Furthermore, existing seed pelleting technologies mostly use inert materials such as clay and talc as fillers, primarily serving to increase weight and act as a carrier, lacking biological activity and nutrient regulation functions. Although some technologies attempt to incorporate fertilizers, for plants like oats that require strong root systems for sand fixation, there is currently a lack of composite material technologies that can simultaneously achieve multiple functions such as waste resource utilization, improvement of the rhizosphere microenvironment, and induction of the release of insoluble nutrients.

[0007] In summary, the existing technology lacks a systematic technical solution that can closely integrate the resource utilization of yak manure with the restoration of vegetation in high-altitude sandy areas, utilize the microporous structure and rhizosphere regulation capabilities of biochar to synergistically activate insoluble calcium silicate, and precisely apply it around oat seeds. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by proposing a calcium silicate-enhanced biochar-based feed oat seed pelleting technology and its application in sandy land restoration.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A pelleting technology for calcium silicate-reinforced biochar-based feed oat seeds and its application in desert remediation includes the following steps:

[0011] S1: Preparation and Functional Modification of Raw Materials

[0012] a: Preparation of modified biochar carrier:

[0013] Raw material selection: Yak dung, a typical organic waste from the pastoral areas of the Qinghai-Tibet Plateau, was selected as a biochar precursor;

[0014] Pyrolysis and carbonization: After the yak dung is naturally air-dried and crushed, it is placed in a carbonization furnace. Under limited oxygen conditions, nitrogen is introduced to seal or the furnace is directly sealed. The heating rate is controlled at 5-10℃ / min, and the temperature is raised to 450℃. The furnace is then kept at a constant temperature for 1-2 hours for pyrolysis.

[0015] Physical pulverization: After the carbonization product is cooled to room temperature, it is subjected to airflow ultrafine pulverization and passed through an 80-120 mesh sieve to obtain basic biochar powder;

[0016] Chemical modification: Immerse biochar powder in a 3%-5% hydrogen peroxide solution and oxidize it at room temperature for 2-4 hours. After treatment, wash with deionized water until the filtrate is neutral and dry at 80℃.

[0017] b: Preparation of activated calcium silicate reinforcing agent:

[0018] Raw material mixing: Select industrial or agricultural grade calcium silicate powder with a fineness of 200-300 mesh, add organic acid activator, and the mass ratio of calcium silicate to organic acid is 10:1 to 20:1;

[0019] Mechanochemical activation: Place the mixture in a ball mill and perform high-energy ball milling for 30-60 minutes;

[0020] c: Preparation of special composite adhesive: Weigh 1%-2% polyvinyl alcohol, 0.5%-1% sodium carboxymethyl cellulose, and the remainder water by weight percentage. Slowly add PVA and CMC to hot water at 80℃-90℃ and stir continuously until completely dissolved to form a homogeneous and transparent colloidal solution. Cool to room temperature for later use.

[0021] S2: Component design of seed pellet powder: by weight, it consists of the following components: modified biochar powder: 40-60 parts, activated calcium silicate powder: 20-35 parts, filler: 10-20 parts, compound microbial agent: 1-3 parts, plant growth regulator: 0.01-0.05 parts;

[0022] S3: Multi-layer granulation process: Using a rotary coating method, a three-layer structure is constructed on the seed surface through step-by-step powder supply and liquid spraying: inner layer for nutrient enhancement, middle layer for ecological buffering, and outer layer for protection and regulation.

[0023] a: Pretreatment and feeding: Select plump oat seeds, disinfect, wash and dry them with 0.1%-0.5% potassium permanganate, and then place them in the rotating pot of the coating machine;

[0024] The first inner layer is constructed as a calcium silicate-reinforced layer: Start the coating machine at a speed of 30-50 r / min, spray to moisten the seeds, and apply 20%-30% of the total powder dosage. This part of the powder is mainly composed of activated calcium silicate powder and a small amount of biochar powder.

[0025] The second middle layer is a micro-ecological buffer layer: a binder is sprayed and 40%-50% of the total powder dosage is spread. This part of the powder is mainly composed of modified biochar powder, filler and compound microbial agent.

[0026] The third outer layer is a protective and regulating layer: a binder is sprayed and the remaining powder is spread. This powder contains filler, remaining biochar and plant growth regulators.

[0027] Shaping and post-processing: After the powder coating is completed, increase the rotation speed to 60-80 r / min and polish for 3-5 minutes to make the surface of the pellets smooth and firm. Dry at a low temperature of 35℃-40℃ until the moisture content is <12%, sieve, and select pelleted seeds with a particle size of 2-4 times that of the original seeds.

[0028] Preferably, in S1, the organic acid activator includes at least one of citric acid or humic acid.

[0029] Preferably, in step S2, the filler includes at least one of bentonite or talc, the compound microbial agent includes Bacillus subtilis with an effective viable count of ≥200 million / g, and the plant growth regulator includes gibberellin.

[0030] Preferably, in step S1, the solid-liquid ratio of the hydrogen peroxide solution is 1:5 to 1:10.

[0031] Preferably, in S1, the degree of polymerization of polyvinyl alcohol is 1700-1799.

[0032] The application of a calcium silicate-reinforced biochar-based feed oat seed pelleting technology in sandy land remediation includes the following steps:

[0033] S1: Sowing time: After the soil thaws in spring or before the rainy season;

[0034] S2: In-situ repair mechanism:

[0035] Water absorption and disintegration and micro-region construction: When the pellets come into contact with rainwater or soil water, the outer binder absorbs water and swells, causing the pellets to disintegrate and form loose and porous micro-regions around the seeds. The modified biochar quickly absorbs water, forming a micro-reservoir to ensure the water required for seed germination.

[0036] Slow-release of silicon and calcium and the formation of stress resistance: As the root system grows, the inner layer of activated calcium silicate continuously releases monosilicic acid. After the seedling absorbs silicon, it is deposited under the cell wall of the stem and leaf epidermis to form a cuticle-silicon bilayer structure.

[0037] Waste utilization and carbon sequestration: using yak dung to make charcoal for returning to the fields. Attached Figure Description

[0038] Figure 1 This is a comparison diagram of root morphology characteristics between the control group and Examples 1 and 2.

[0039] The beneficial effects of this invention are as follows:

[0040] This invention is based on the synergistic principle of rhizosphere microecological regulation and plant silicon-calcium nutrient enhancement. It uses modified yak manure biochar as a carrier to construct a water- and fertilizer-retaining framework, and activated calcium silicate as a reinforcing agent to improve seedling mechanical strength. A multi-layer coating process achieves the spatiotemporal orderly release of these functions. This invention increases oat germination rate and survival rate, improves stress resistance, and realizes the resource utilization of waste and soil improvement. Detailed Implementation

[0041] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0042] Reference Figure 1 A pelleting technology for calcium silicate-reinforced biochar-based feed oat seeds includes the following steps:

[0043] S1: Preparation and Functional Modification of Raw Materials

[0044] a: Preparation of modified biochar carrier:

[0045] Raw material selection: Yak dung, a typical organic waste from the pastoral areas of the Qinghai-Tibet Plateau, was selected as a biochar precursor;

[0046] Pyrolysis carbonization: After the yak dung is naturally air-dried and crushed, it is placed in a carbonization furnace. Under limited oxygen conditions, nitrogen gas is introduced and the furnace is sealed or directly sealed. The heating rate is controlled at 5-10℃ / min, and the temperature is raised to 450℃. The pyrolysis is carried out at a constant temperature for 1-2 hours. This temperature range is conducive to the preservation of some volatiles and pore structure in biochar, while forming a stable aromatic structure.

[0047] Physical pulverization: After the carbonization product is cooled to room temperature, it is subjected to airflow ultrafine pulverization and passed through an 80-120 mesh sieve to obtain basic biochar powder;

[0048] Chemical modification: Immerse biochar powder in a 3%-5% hydrogen peroxide solution and oxidize it at room temperature for 2-4 hours. After treatment, wash with deionized water until the filtrate is neutral and dry at 80℃.

[0049] Among them, the hydrogen peroxide oxidation treatment introduces a large number of oxygen-containing functional groups such as carboxyl-COOH and hydroxyl-OH on the surface of biochar, which significantly improves the hydrophilicity and cation exchange capacity (CEC) of biochar, and enhances its ability to adsorb and retain subsequently added calcium silicate and soil moisture.

[0050] b: Preparation of activated calcium silicate reinforcing agent:

[0051] Raw material mixing: Select industrial or agricultural grade calcium silicate powder with a fineness of 200-300 mesh, add organic acid activator, and the mass ratio of calcium silicate to organic acid is 10:1 to 20:1;

[0052] Mechanochemical activation: Place the mixture in a ball mill and perform high-energy ball milling for 30-60 minutes;

[0053] This process utilizes mechanochemical effects. On one hand, ball milling reduces the particle size of calcium silicate, disrupting its crystal structure and decreasing its crystallinity. On the other hand, organic acids micro-etch and complex the surface of calcium silicate during ball milling. This treatment significantly improves the dissolution rate of calcium silicate in the weakly acidic environment of soil, enabling it to release monosilicic acid (H4SiO4) and calcium ions (Ca²⁺) more quickly for plant absorption.

[0054] c: Preparation of special composite adhesive: Weigh 1%-2% polyvinyl alcohol, 0.5%-1% sodium carboxymethyl cellulose, and the remainder water by weight percentage. Slowly add PVA and CMC to hot water at 80℃-90℃ and stir continuously until completely dissolved to form a homogeneous and transparent colloidal solution. Cool to room temperature for later use.

[0055] PVA provides mechanical strength after drying, preventing pellets from breaking during transportation and sowing; CMC has extremely strong water absorption and swelling properties, ensuring that the pellets disintegrate rapidly when exposed to water, without hindering seed germination.

[0056] S2: Component design of seed pellet powder: by weight, it consists of the following components: modified biochar powder: 40-60 parts, activated calcium silicate powder: 20-35 parts, filler: 10-20 parts, compound microbial agent: 1-3 parts, plant growth regulator: 0.01-0.05 parts;

[0057] S3: Multi-layer granulation process: Using a rotary coating method, a three-layer structure is constructed on the seed surface through step-by-step powder supply and liquid spraying: inner layer for nutrient enhancement, middle layer for ecological buffering, and outer layer for protection and regulation.

[0058] a: Pretreatment and feeding: Select plump oat seeds, disinfect, wash and dry them with 0.1%-0.5% potassium permanganate, and then place them in the rotating pot of the coating machine;

[0059] The first inner layer is a silicon-calcium reinforced layer: Start the coating machine at 30-50 r / min, spray to moisten the seeds, and apply 20%-30% of the total powder dosage. This powder mainly consists of activated calcium silicate powder mixed with a small amount of biochar powder; this layer adheres closely to the seed coat. When the seed germinates and shows white sprouts, the radicle first comes into contact with this layer, enabling it to absorb a high concentration of available silicon and calcium immediately, promoting thickening of the root cell walls and enhancing the primary root's adaptability to drought and physical resistance.

[0060] The second middle layer constructs a micro-ecological buffer layer: a binder is sprayed, and 40%-50% of the total powder dosage is applied. This powder mainly consists of modified biochar powder, fillers, and composite microbial agents. This layer utilizes the pores of the biochar to absorb moisture and nutrients, providing a sanctuary for microorganisms. Bacillus subtilis colonizes this layer, secreting organic acids to further activate the mineral silica and produce plant growth hormones, forming a rhizosphere microenvironment conducive to root expansion.

[0061] The third outer layer forms a protective and regulating layer: a binder is sprayed, and the remaining powder is sprinkled on top. This powder contains filler, remaining biochar, and plant growth regulators. The outermost layer is relatively dense and provides physical protection. Gibberellin is located in the outermost layer. Upon contact with water, it dissolves first and penetrates the seed coat, breaking seed dormancy and simultaneously initiating the germination process.

[0062] Shaping and post-processing: After the powder coating is completed, increase the rotation speed to 60-80 r / min and polish for 3-5 minutes to make the surface of the pellets smooth and firm. Dry at a low temperature of 35℃-40℃ until the moisture content is <12%, sieve, and select pelleted seeds with a particle size of 2-4 times that of the original seeds.

[0063] In S1, the organic acid activator includes at least one of citric acid or humic acid. In S2, the filler includes at least one of bentonite or talc, the compound microbial agent includes Bacillus subtilis with an effective viable count ≥200 million / g, and the plant growth regulator includes gibberellin. In S1, the solid-liquid ratio of the hydrogen peroxide solution is 1:5-1:10. In S1, the degree of polymerization of polyvinyl alcohol is 1700-1799.

[0064] The application of a calcium silicate-reinforced biochar-based feed oat seed pelleting technology in sandy land remediation includes the following steps:

[0065] S1: Sowing time: after the soil thaws in spring or before the rainy season; among the advantages of sowing: pelleting significantly increases the weight and sphericity of oat seeds, improves aerodynamic characteristics, makes the landing point of mechanical aerial seeding more precise, and enhances the ability to resist wind drift; good flowability and no clogging during row sowing.

[0066] S2: In-situ repair mechanism:

[0067] Water absorption and disintegration and micro-region construction: When the pellets come into contact with rainwater or soil water, the outer binder absorbs water and swells, causing the pellets to disintegrate and form loose and porous micro-regions around the seeds. The modified biochar quickly absorbs water, forming a micro-reservoir to ensure the water required for seed germination.

[0068] Slow-release silicon and calcium and stress resistance: As the root system grows, the inner layer of activated calcium silicate continuously releases monosilicic acid. After the seedling absorbs silicon, it is deposited under the cell wall of the stem and leaf epidermis to form a cuticle-silica double-layer structure. This structure effectively reduces non-stomatal transpiration of leaf water, thus resisting drought and significantly improving the mechanical hardness of the stem, enabling it to resist the physical impact of wind and sand flow and resist wind erosion.

[0069] Waste utilization and carbon sequestration: Using yak dung to make charcoal and returning it to the fields realizes the resource utilization of pastoral waste, and also introduces stable organic carbon into sandy soil, improving soil structure.

[0070] In this invention, calcium silicate activated by ball milling with organic acids is introduced into the inner layer of the pelletized product, working synergistically with the modified biochar in the outer layer. The activated calcium silicate releases monosilicic acid (H4SiO4), which is absorbed by the roots and deposited in the cell walls of the stem and leaf epidermis, forming a cuticle-silica bilayer structure. This not only reduces the non-stomatal transpiration rate of oat leaves, improving drought resistance, but also significantly increases the mechanical strength and hardness of the stems, enabling seedlings to effectively resist the physical impact of wind and sandstorms and resist wind erosion. Simultaneously, the high water absorption of the modified biochar provides the necessary moisture environment for the dissolution of calcium silicate, while the organic acids produced by the microbial agent further promote the release of mineral silicon, achieving a closed-loop synergistic effect of water retention, silicon dissolution, and absorption.

[0071] Simultaneously, hydrogen peroxide-modified yak dung biochar was used as the main matrix, combined with a multi-layer coating process. The modified biochar surface exhibited increased oxygen-containing functional groups and significantly enhanced hydrophilicity. In arid sandy environments, after pellet disintegration, a highly water-retaining and nutrient-rich microzone was formed around the seed, effectively buffering the damage to the seed caused by drastic changes in soil moisture. Furthermore, dormancy was broken by gibberellin in the outer layer, and auxin was secreted by Bacillus subtilis in the middle layer, achieving chemical and biological regulation of the entire seed germination process. Compared to traditional direct seeding, this invention significantly improves the germination rate of oats under low-temperature and drought conditions.

[0072] Furthermore, biochar prepared from yak dung, a major waste product in the pastoral areas of the Qinghai-Tibet Plateau, solves the environmental pollution problem caused by the accumulation of manure in pastoral areas and realizes ecological cycle. At the same time, biochar is stable in nature. When applied to sandy land, it can not only improve the soil aggregate structure, but also serve as a stable carbon sink that is fixed in the soil for a long time, thus having significant ecological benefits.

[0073] Furthermore, a special binder combining PVA and CMC is used, along with a polishing process to control the particle size. The pelleted seeds have a smooth surface, moderate hardness, and excellent flowability and precise landing point in aerial seeding and mechanical row seeding. The increased seed weight also effectively prevents the seeds from being blown away by the wind, solving the problem of irregular grass seeds being difficult to mechanize.

[0074] Experiments were conducted using standard pelleted seeds and stress-resistant pelleted seeds:

[0075] Experimental location and environment: Simulating the high-altitude desertification environment of the Qinghai-Tibet Plateau (day / night temperature 20℃ / 5℃, light 14h), the soil was selected from desertified soil collected from the western Sichuan Plateau. The desertified soil was sieved to remove impurities, pH=8.2, organic matter content <5 g / kg, and extremely barren.

[0076] Tested seeds: oats, 1000-grain weight 8.5g, initial germination rate 86%.

[0077] Experimental design: A pot experiment was conducted, with 3 treatment groups:

[0078] Control group (CK): naked oats, without any treatment.

[0079] Example 1 group: Standard pelleted seeds.

[0080] Example 2 group: using stress-resistant pelleted seeds.

[0081] Water management: Simulate drought stress conditions and control soil moisture content at 40%~45% of field capacity.

[0082] Measurement period: Destructive sampling was conducted 45 days after sowing.

[0083] Example 1: Standard pelleted seeds: Effects of calcium silicate-reinforced biochar-based pelleting on oat germination and transplanting

[0084] This embodiment focuses on verifying the effect of pelleting technology on improving seed germination rate and seedling establishment ability in harsh desertified environments.

[0085] 1.1 Germination and Survival Indicators

[0086] Emergence was recorded daily after sowing, and the seedling survival rate was calculated after 25 days. The results showed that naked seeds (CK) had an extremely low germination rate in arid sandy soil due to rapid water loss; while the pelleted seeds using the technology of this invention, utilizing the water-absorbing and moisture-retaining effects of biochar and the inducing effect of gibberellin, significantly improved germination performance.

[0087] Table 1: Results of germination and colonization indicators in Example 1 (n=5)

[0088] detection indicators Control group (CK) Example 1 (Standard Type) Example 2 (Resistant Type) Improvement compared to CK (Example 2) Significance (P<0.05) Germination rate (%) 38.5 ± 4.2 80.2 ± 3.5 77.4 ± 2.8 +101.0% yes Seedling survival rate (%) 25.4 ± 3.1 72.6 ± 4.1 75.8 ± 3.6 +198.4% yes Average emergence time (d) 12.5 ± 1.5 7.2 ± 0.8 8.1 ± 0.9 Shortened by 35.2% yes

[0089] Note: Group 2 of Example 2 had a slightly slower germination rate than Group 1 of Example 1 due to its thicker coating layer and higher adhesive viscosity, but it had the highest final seedling survival rate, indicating that it had stronger stress resistance.

[0090] 1.2 Seedling growth indicators: Biomass was measured after 25 days of cultivation. The results showed that pelleting treatment significantly promoted oat growth, especially the accumulation of underground biomass.

[0091] Table 2: Comparison of seedling biomass indicators in Example 1 group (n=15)

[0092] detection indicators Control group (CK) Example 1 (Standard Type) Example 2 (Resistant Type) Growth rate (Example 2 vs CK) Aboveground dry weight (mg / plant) 42.5 ± 3.2 78.4 ± 4.5 85.6 ± 5.1 +101.41% Dry weight of underground parts (mg / plant) 28.1 ± 2.5 65.2 ± 3.8 79.4 ± 4.2 +182.56% Root-to-crown ratio 0.66 0.83 0.93 -- Plant height (cm) 12.8 ± 1.2 18.5 ± 1.4 19.2 ± 1.1 +50.00%

[0093] Example 2: Stress-resistant pelleted seeds: Mechanism verification of pelleting technology enhancing oat stress resistance (drought resistance and wind erosion resistance)

[0094] To verify the stress resistance mechanism brought about by the synergistic effect of activated calcium silicate and modified biochar in this invention, this embodiment focuses on measuring the root morphology, stem mechanical strength and physiological stress resistance indicators of the plant.

[0095] 2.1 Root microenvironment and morphological construction

[0096] The results showed that the pelleting technology of the present invention successfully constructed a benign rhizosphere microenvironment by introducing Bacillus subtilis / Bacillus colloidis and biochar, inducing the roots to grow into the deep sandy soil.

[0097] Table 3: Root morphology and microenvironment indicators of Group 2 in Example 2 (n=15)

[0098] detection indicators Control group (CK) Example 1 (Standard Type) Example 2 (Resistant Type) Remark Total root length (cm) 45.2 ± 5.1 88.4 ± 6.2 112.5 ± 8.4 Example 2: Roots penetrate to the deepest point Average root diameter (mm) 0.22 ± 0.02 0.31 ± 0.03 0.35 ± 0.02 Thicker root system Rhizosphere soil moisture content (%) 4.2% 8.5% 9.8% Micro-reservoir effect of biochar layer Rhizosphere microbial biomass carbon (mg / kg) 125.4 348.2 410.5 Successful colonization with microbial agent

[0099] Comparison of root morphology characteristics in Example 2 (compared with the control group, the total root length and root surface area of ​​both Example 1 and Example 2 increased, with Example 2 showing a longer total root length and a larger root surface area).

[0100] 2.2 Silicon-Calcium Reinforcing Effect and Mechanical Strength

[0101] This is the core innovation of this invention. The absorption and utilization of activated calcium silicate are verified by measuring the silicon content in the leaves and the bending strength of the stems.

[0102] Table 4: Results of silicon and calcium nutrition and mechanical strength determination of plants in Example 2 group

[0103] detection indicators Control group (CK) Example 1 (Standard Type) Example 2 (Resistant Type) Increase in magnitude (Example 2 vs CK) Technical effect analysis Leaf silicon content (g / kg) 4.12 ± 0.3 8.56 ± 0.5 11.24 ± 0.8 +172.8% Activated calcium silicate is absorbed efficiently. Stem bending strength (N) 1.52 ± 0.1 2.85 ± 0.2 3.48 ± 0.3 +128.9% Increased stem hardness enhances resistance to wind and sand lodging. Leaf proline (μg / g) 452 ± 2.1 285 ± 4 210 ± 5 -53.4% The lower the proline content, the less susceptible the organism is to drought stress. Leaf cuticle thickness (μm) 2.1 3.5 4.2 +100.0% Reduce water non-stomatal transpiration

[0104] Based on the data from both Example 1 and Example 2, it can be concluded that:

[0105] The calcium silicate-enhanced biochar-based pelleted seeds prepared by this invention have a seedling survival rate nearly three times that of naked seeds in arid and sandy soils (75.8% vs 25.4%), effectively solving the problem of sowing failure.

[0106] Meanwhile, in Example 2, the stress-resistant pelleted seeds, through the organic acid activation of calcium silicate technology, significantly improved the silicon content of plant leaves and the bending strength of stems. Specifically, the silicon content of plant leaves increased by 172.8%, and the bending strength of stems increased by 128.9%, while significantly reducing the drought stress index proline, demonstrating that this technology can effectively improve the drought resistance and wind erosion resistance of oats.

[0107] The pelleted material formed a highly water-retaining and microbial-rich microzone around the seeds, promoting a 182.56% increase in root biomass and laying the foundation for the long-term survival of plants in sandy areas.

[0108] Example 1 and Example 2 are applicable to general degraded grassland and severely wind-eroded sandy land, respectively, demonstrating that the technical solution of the present invention has good flexibility and application potential.

[0109] This invention is based on the synergistic principle of rhizosphere microecological regulation and plant silicon and calcium nutrition enhancement. It uses modified yak manure biochar as a carrier to construct a water-retaining and fertilizer-retaining framework, and activated calcium silicate as a reinforcing agent to improve the mechanical strength of seedlings. The invention achieves the spatiotemporal orderly release of functions through a multi-layer coating process.

[0110] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A pelleting technology for calcium silicate-reinforced biochar-based feed oat seeds, characterized in that, Includes the following steps: S1: Preparation and Functional Modification of Raw Materials a: Preparation of modified biochar carrier: Raw material selection: Yak dung, a typical organic waste from the pastoral areas of the Qinghai-Tibet Plateau, was selected as a biochar precursor; Pyrolysis and carbonization: After the yak dung is naturally air-dried and crushed, it is placed in a carbonization furnace. Under limited oxygen conditions, nitrogen is introduced to seal or the furnace is directly sealed. The heating rate is controlled at 5-10℃ / min, and the temperature is raised to 450℃. The furnace is then kept at a constant temperature for 1-2 hours for pyrolysis. Physical pulverization: After the carbonization product is cooled to room temperature, it is subjected to airflow ultrafine pulverization and passed through an 80-120 mesh sieve to obtain basic biochar powder; Chemical modification: Immerse biochar powder in a 3%-5% hydrogen peroxide solution and oxidize it at room temperature for 2-4 hours. After treatment, wash with deionized water until the filtrate is neutral and dry at 80℃. b: Preparation of activated calcium silicate reinforcing agent: Raw material mixing: Select industrial or agricultural grade calcium silicate powder with a fineness of 200-300 mesh, add organic acid activator, and the mass ratio of calcium silicate to organic acid is 10:1 to 20:1; Mechanochemical activation: Place the mixture in a ball mill and perform high-energy ball milling for 30-60 minutes; c: Preparation of special composite adhesive: Weigh 1%-2% polyvinyl alcohol, 0.5%-1% sodium carboxymethyl cellulose, and the remainder water by weight percentage. Slowly add PVA and CMC to hot water at 80℃-90℃ and stir continuously until completely dissolved to form a homogeneous and transparent colloidal solution. Cool to room temperature for later use. S2: Component design of seed pellet powder: by weight, it consists of the following components: modified biochar powder: 40-60 parts, activated calcium silicate powder: 20-35 parts, filler: 10-20 parts, compound microbial agent: 1-3 parts, plant growth regulator: 0.01-0.05 parts; S3: Multi-layer granulation process: Using a rotary coating method, a three-layer structure is constructed on the seed surface through step-by-step powder supply and liquid spraying: inner layer for nutrient enhancement, middle layer for ecological buffering, and outer layer for protection and regulation. a: Pretreatment and feeding: Select plump oat seeds, disinfect, wash and dry them with 0.1%-0.5% potassium permanganate, and then place them in the rotating pot of the coating machine; The first inner layer is constructed as a calcium silicate-reinforced layer: Start the coating machine at a speed of 30-50 r / min, spray to moisten the seeds, and apply 20%-30% of the total powder dosage. This part of the powder is mainly composed of activated calcium silicate powder and a small amount of biochar powder. The second middle layer is a micro-ecological buffer layer: a binder is sprayed and 40%-50% of the total powder dosage is spread. This part of the powder is mainly composed of modified biochar powder, filler and compound microbial agent. The third outer layer is a protective and regulating layer: a binder is sprayed and the remaining powder is spread. This powder contains filler, remaining biochar and plant growth regulators. Shaping and post-processing: After the powder coating is completed, increase the rotation speed to 60-80 r / min and polish for 3-5 minutes to make the surface of the pellets smooth and firm. Dry at a low temperature of 35℃-40℃ until the moisture content is <12%, sieve, and select pelleted seeds with a particle size of 2-4 times that of the original seeds.

2. The pelleting technology for calcium silicate-reinforced biochar-based feed oat seeds according to claim 1, characterized in that, In S1, the organic acid activator includes at least one of citric acid or humic acid, with a mass ratio of calcium silicate to organic acid of 10:1 to 20:

1.

3. The pelleting technology for calcium silicate-reinforced biochar-based feed oat seeds according to claim 1, characterized in that, In S2, the filler includes at least one of bentonite or talc, the compound microbial agent includes Bacillus subtilis with an effective viable count of ≥200 million / g, and the plant growth regulator includes gibberellin.

4. The pelleting technology for calcium silicate-reinforced biochar-based feed oat seeds according to claim 1, characterized in that, In S1, the solid-liquid ratio of the hydrogen peroxide solution is 1:5-1:

10.

5. The pelleting technology for calcium silicate-reinforced biochar-based feed oat seeds according to claim 1, characterized in that, In S1, the degree of polymerization of polyvinyl alcohol is 1700-1799.

6. The application of the calcium silicate-reinforced biochar-based feed oat seed pelleting technology according to any one of claims 1-5 in sandy land remediation, characterized in that, Includes the following steps: S1: Sowing time: After the soil thaws in spring or before the rainy season; S2: In-situ repair mechanism: Water absorption and disintegration and micro-region construction: When the pellets come into contact with rainwater or soil water, the outer binder absorbs water and swells, causing the pellets to disintegrate and form loose and porous micro-regions around the seeds. The modified biochar quickly absorbs water, forming a micro-reservoir to ensure the water required for seed germination. Slow-release of silicon and calcium and stress resistance: As the root system grows, the inner layer of activated calcium silicate continuously releases monosilicic acid. After the seedlings absorb silicon, it is deposited under the cell walls of the stem and leaf epidermis to form a cuticle-silicon double-layer structure. This not only reduces the non-stomatal transpiration rate of the leaves and improves drought resistance, but also significantly increases the mechanical strength and hardness of the stem, enabling the seedlings to effectively resist the physical impact of wind and sand. Waste utilization and soil carbon sequestration: Using yak dung to make biochar and returning it to the fields solves the environmental pollution problem caused by manure accumulation in pastoral areas and achieves ecological cycle. Biochar is stable in nature. When applied to sandy land, it can not only improve the soil aggregate structure, but also serve as a stable carbon sink that is sequestered in the soil for a long time, with significant ecological benefits.

Images