A delayed microbial activation soil amendment method for frozen immature soil
By spreading a delayed-release microbial activator during the freezing period of frost-prone soils and utilizing the components released by snow avalanche, the problem of unclear scope of frost-prone soil improvement was solved, achieving low-cost and efficient vegetation restoration and soil improvement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 中国雅江集团有限公司
- Filing Date
- 2026-03-09
- Publication Date
- 2026-06-05
AI Technical Summary
The scope of improvement for frozen basal soils is unclear during the seasons suitable for artificial intervention, making it difficult to determine which areas require intervention. Furthermore, existing technologies for improving frozen basal soils are costly and difficult to implement effectively in areas with poor transportation.
During the freezing period of the nascent soil, a delayed-release microbial activating amendment was prepared, which included water-absorbing clay, film-producing bacteria, dried moss, and decomposed organic fertilizer. After mixing and granulating, the amendment was spread on the soil surface and disintegrated under the action of snow water. The released components enhanced soil aggregation and vegetation cover. An anti-cracking agent was used to prevent the amendment from breaking apart.
During the short, moist window of spring, vegetation cover and soil wind erosion resistance can be rapidly increased, improvement costs can be reduced, and materials can be ensured not to germinate or be damaged prematurely during the freezing period, thereby improving the soil improvement effect of frozen nascent soil.
Smart Images
Figure CN122146306A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of soil conditioning materials or soil stabilizing materials, and in particular to a delayed microbial activation method for soil improvement in frozen nascent soils. Background Technology
[0002] Frozen nascent soil is a typical primary soil. Primary soil refers to soils with weak development, indistinct soil profile layers, significant parent material characteristics, and a relatively young stage, which is clearly different from some zonal soils.
[0003] Unlike tundra regions where the parent material has existed for many years and is highly weathered, the parent material of frost-formed soils is generally still pristine glacial till and weathered debris. Therefore, frost-formed soils are extremely detrimental to vegetation growth, with the main adverse effects including: 1. Extremely barren, with a severe lack of nutrient supply: Low temperatures result in extremely low activity of soil microorganisms (such as nitrogen-fixing bacteria, nitrifying bacteria, and decomposing bacteria), and the organic matter mineralization process (converting organic matter into inorganic salts for plant absorption) is exceptionally slow. Similarly, due to the simple mineral composition and lack of adsorption carriers, trace elements are also generally deficient. At the same time, due to the lack of nutrients and water and the harsh physical environment, the number and activity of microorganisms and animals (such as earthworms) in the soil are extremely low, which is not conducive to the decomposition of organic matter, nutrient cycling, and improvement of soil structure.
[0004] 2. The soil's ability to retain fertilizer is almost zero: Under low-temperature conditions, the decomposition rate of plant residues is far lower than their accumulation rate. Large amounts of semi-decomposed organic matter, rich in lignin and cellulose, accumulate in the soil. This semi-decomposed organic matter, under the action of microorganisms, produces and releases large amounts of organic acids. Seasonal snowmelt or rainfall infiltrates the soil. These acidic solutions, rich in organic acids, displace and carry away usable fertilizers such as ammonium and potassium salts adsorbed on soil colloids as they flow through the soil.
[0005] 3. Water stress Even in summer, the lower layer of soil may remain frozen (permafrost), forming an impermeable layer. The meltwater from the upper layer cannot seep down, leading to surface marshland; at the same time, plant roots cannot penetrate the permafrost to absorb deeper water, making the soil more susceptible to drought due to surface evaporation when the weather is sunny.
[0006] 4. Mechanical stress The hard permafrost or bedrock close to the ground restricts the space for roots to extend downwards, resulting in plants with shallow root systems that are prone to lodging and have poor resistance to adverse conditions. At the same time, the high content of gravel further hinders the roots from penetrating and extending.
[0007] The above factors result in only shallow-rooted herbaceous plants or mosses typically growing on frost-covered soils. Even without vegetation destruction, the vegetation cover is low, and the soil has poor resistance to wind erosion. This has less impact in summer and winter because summer rainfall is abundant and the soil is relatively moist, while in winter the soil is frozen. However, the impact is particularly severe during spring droughts. During spring droughts, the topsoil thaws and becomes less resistant to wind erosion. At the same time, with little rainfall in spring, the topsoil, dried by the freeze-thaw cycle, becomes sandy, and the most valuable topsoil is eroded away by the wind. This not only worsens the local soil conditions but also causes the wind-blown sand to erode normal soil along its path.
[0008] Like other soils, frost-prone soils can have their vegetation cover increased through soil improvement and vegetation restoration, thereby enhancing their resistance to wind erosion during spring droughts. However, there is a significant constraint on the management of frost-prone soils: during seasons suitable for artificial intervention, the extent of these soil types is unclear. Both soil improvement and vegetation restoration require a sufficient water supply. If rainfall cannot be utilized, frequent artificial irrigation is necessary, drastically increasing costs. Therefore, seasonally introduced windblown sand is best addressed during the rainy and warm summer months. However, even permafrost thaws in summer, forming an active layer, while seasonally frozen soil thaws completely, blurring the differences between the surrounding soils. In many parts of northern my country, the topsoil freezes in winter, resulting in seasonally frozen soil. In winter, there are significant differences in vegetation cover between fertile farmland and less fertile land, and the exposed soil, especially the exposed sand and gravel on the less fertile land, makes the differences quite noticeable. However, these differences diminish in summer. In plateau regions, the difference between the nascent frozen soil and the surrounding normal soil is already smaller than in plains, and this difference becomes even smaller in summer.
[0009] Taking the research project on the mechanism and prevention strategies of soil erosion of various types under complex mountain conditions, as an example, this project requires the improvement of aeolian sandy soil in Pai Town, Milin County, Nyingchi City. The project area is located in the Yarlung Tsangpo Grand Canyon, with extremely inconvenient transportation and high labor costs for field operations. The local precipitation reaches 650 mm, but the seasonal distribution of precipitation is uneven, with relatively dry winter and spring. From October to March of the following year, strong winds blow through the Yarlung Tsangpo River valley in the afternoon (especially after 3-4 pm), forming sandstorms by stirring up exposed sand particles from the riverbed. At this time, the temperature has recovered and the seasonal permafrost has thawed, but there is almost no precipitation. During the spring drought, the seasonal permafrost composed of basal permafrost on the nearby Sejila Mountain, which is already very loose after the freeze-thaw cycle, will be directly eroded and carried away downwind under such dry and windy conditions. However, in summer, the temperature is high and there is more rainfall, and the boundary between the basal permafrost and the surrounding normal soil becomes blurred. Summary of the Invention
[0010] This invention provides a method for delayed microbial activation of soil amendment for frozen nascent soil.
[0011] The technical problem to be solved is that the impact range of the frozen nascent soil is ambiguous during the season when artificial intervention is appropriate, and it is unclear which areas require artificial intervention.
[0012] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a delayed-action microbial activation soil improvement method for frost-prone soil, used to inhibit the formation of windblown sand in the topsoil of seasonally frozen soil during spring drought, wherein the topsoil of seasonally frozen soil is frost-prone soil, and the soil improvement method includes the following steps: Step 1: During the freezing period of the frost-prone soil, investigate the extent of the frost-prone soil. Step 2: Preparation of delayed-action microbial activation modifier; The delayed-release microbial activator modifier is a dry granule made by mixing and granulating a water-absorbing clay for rapidly improving soil aggregation, a film-forming microbial agent for secreting extracellular polymers to aggregate soil particles, a dry moss in a cryptogenic state, a well-rotted organic fertilizer for providing nutrients to the film-forming microbial agent and the moss, and an anti-cracking agent to prevent the delayed-release microbial activator modifier from prematurely breaking due to thermal stress. The binder used in granulation is hydrolyzable. The crack-resistant agent is porous carbon particles; Step 3: Before the frozen soil thaws, spread the delayed microbial activation modifier on the surface of the frozen soil. Step 4: After the frozen soil thaws, the delayed-action microbial activator disintegrates under the action of snow water, distributing water-absorbing clay, cryptic dried moss, and film-forming bacteria into the frozen soil. The water-absorbing clay initially aggregates soil particles to provide a growth substrate for the film-forming bacteria. The film-forming bacteria secrete extracellular polymers to further aggregate soil particles, while the moss recovers and increases vegetation cover.
[0013] Furthermore, in step one, the following methods were used to investigate the extent of the frozen basalt formation: Step 1.1: Identify areas in the remote sensing image that are permafrost and have a vegetation cover of no more than 20%, and mark them as areas prone to wind erosion. Step 1.2: Sampling of topsoil in wind-erosion-prone areas, with the topsoil of plots having a chemical alteration index not exceeding 60 being classified as frost-prone soil.
[0014] Furthermore, in step three, the area ratio of the frozen nascent soil covered by the sown delayed microbial activating modifier to the vegetation cover shall not be less than 30%.
[0015] Furthermore, the decomposed organic fertilizer is decomposed cow or sheep manure; The easily absorbent clay is attapulgite. The crack-resistant agent is bone char particles with a particle size of no more than 2 mm; The dried moss was *Bryophytum esculentum*, which was collected, sprayed with sodium carboxymethyl cellulose solution, and then air-dried. The film-forming bacterial agent is a freeze-dried bacterial powder of Pseudomonas psychrophilus.
[0016] Furthermore, the delayed-action microbial activation modifier comprises the following components in parts by weight: Well-rotted organic fertilizer: 35-45 parts; Dried moss: 25-35 parts; Absorbent clay: 15-25 parts; Crack-resistant agent: 8-12 parts; Furthermore, the content of film-producing bacteria in the delayed microbial activation modifier is not less than 100 million CFU / gram, calculated in CFU.
[0017] Furthermore, in step two, sodium alginate solution or potassium alginate solution is used as a binder, and a delayed microbial activation modifier is prepared using a disc granulation process. Then, the microbial activation modifier is dried in a convection dryer using dry air.
[0018] Furthermore, the particle size of the delayed microbial activator modifier is 5-10 mm; during the drying process, the temperature of the drying air does not exceed 30°C in the falling-rate drying stage, and does not exceed 35°C in the other stages.
[0019] Compared with existing technologies, the delayed-action microbial activation method for soil improvement in frozen nascent soils of this invention has the following advantages: In this invention, a film-producing microbial agent is used to improve the soil, and dried moss in a dormant state is used to restore vegetation. This allows for the use of locally sourced materials in areas with poor transportation to manage wind-blown sandy soil (all materials except the microbial agent can be sourced locally, and the amount of microbial agent is very small). However, the materials are applied to the soil during the winter when the area of the frozen, nascent soil is clearly defined, and the materials take effect during the snowmelt period.
[0020] During winter, both the film-producing bacteria and the dried moss are encapsulated in a dried, delayed-release microbial activator, remaining in a dormant state. They do not germinate prematurely or become damaged due to exposure to the environment. The integrity of the delayed-release microbial activator is ensured by an anti-cracking agent, thus maintaining a stable dormant state.
[0021] After snowmelt, the delayed-release microbial activators that maintain their shape through hydrolytic binders break down under the action of snowmelt, releasing water-absorbing clay, biofilm-producing bacteria, dried moss, and decomposed organic fertilizer. The water-absorbing clay initially aggregates soil particles, providing a growth substrate for the biofilm-producing bacteria. The biofilm-producing bacteria secrete extracellular polymers to further aggregate soil particles. At the same time, the moss revives (meaning it doesn't need to grow to be effective; it only needs to revive, which takes a very short time), increasing vegetation cover. Thus, during the brief window of relatively moist soil in spring snowmelt, vegetation cover and soil wind erosion resistance are rapidly improved, enabling the nascent frozen soil to cope with wind erosion during the subsequent spring drought. Attached Figure Description
[0022] Figure 1 This is a flowchart of a delayed microbial activation method for soil improvement in frozen nascent soil, according to the present invention. Detailed Implementation
[0023] Taking the research project on the mechanism and prevention and control of soil erosion of various types under complex mountain conditions, which proposes to use the present invention for soil improvement, as an example, the present invention is used to protect the frost-free soil on the nearby Sejila Mountain. This frost-free soil will be windblown and blown downwind during the spring drought.
[0024] A delayed-action microbial activation method for soil improvement in nascent frozen soil is used to inhibit the formation of windblown sand in the topsoil of seasonally frozen soil during spring droughts. The topsoil of seasonally frozen soil is nascent frozen soil. The soil improvement method includes the following steps: Step 1: During the freezing period of the frost-prone soil, investigate the extent of the frost-prone soil. When frozen, the soil itself has sufficient resistance to wind erosion and requires no additional treatment. At the same time, the exposed soil and vegetation conditions during this period differ significantly from the surrounding area, which is helpful for remote sensing and sampling.
[0025] Step 2: Preparation of delayed-action microbial activation modifier; The delayed-release microbial activator is a dry granule made by mixing and granulating a mixture of easily absorbent clay for rapidly improving soil aggregation, a film-forming microbial agent for secreting extracellular polymers to aggregate soil particles, a dry moss in a cryptogenic state, well-rotted organic fertilizer for providing nutrients to the film-forming microbial agent and moss, and an anti-cracking agent to prevent the delayed-release microbial activator from prematurely breaking due to thermal stress. The binder used in granulation is hydrolyzable, which causes the delayed-release microbial activator to disintegrate and release its internal components during snowmelt in spring. The crack-resistant agent itself is an easily overlooked component. In our experiments, we found that the thermal expansion coefficients of the various components of the delayed-action microbial activator modifier differed significantly. The prepared particles easily cracked prematurely at low temperatures, exposing their internal structure and losing their protective function. Therefore, it is necessary to add some porous particles for crack resistance. These particles form a graded mixture with the other components and also act as a buffer, mitigating uneven expansion and contraction under thermal stress.
[0026] In this embodiment, the crack-resistant agent is porous carbon particles, which allows for the full utilization of locally available materials.
[0027] Step 3: Before the frozen soil thaws, spread the delayed microbial activation modifier on the surface of the frozen soil. Step 4: After the frozen soil thaws, the delayed-action microbial activator disintegrates under the action of snow water, distributing water-absorbing clay, cryptic dried moss, and film-forming bacteria into the frozen soil. The water-absorbing clay initially aggregates soil particles to provide a growth substrate for the film-forming bacteria. The film-forming bacteria secrete extracellular polymers to further aggregate soil particles, while the moss recovers and increases vegetation cover.
[0028] The components that improve the soil here include absorbent clay, biofilm-forming bacteria, and dried moss. The biofilm-forming bacteria, using decomposed organic fertilizer as a substrate, produce various extracellular polymers to aggregate the soil. However, its growth requires a specific substrate and it does not thrive in windy, sandy conditions. Therefore, absorbent clay is used first to quickly aggregate soil particles. Simultaneously, the dried moss rapidly recovers upon contact with water, expanding vegetation cover without requiring further growth, thus fully utilizing the short window of soil moisture during the early spring floods. Subsequently, as the snowmelt gradually depletes, the biofilm-forming bacteria and moss return to a dormant state.
[0029] In step one, the following methods were used to investigate the extent of the frozen basalt formation: Step 1.1: Identify areas in the remote sensing image that are permafrost and have a vegetation cover of no more than 20%, and mark them as areas prone to wind erosion. The 20% threshold here is a well-known threshold in this field; areas with vegetation cover below 20% are highly susceptible to wind erosion. If a piece of land has such low vegetation cover without human interference, it indicates that its barrenness is too high, which is not conducive to vegetation growth, and therefore it is likely to be a nascent frost-prone soil.
[0030] Step 1.2: Sampling of topsoil in wind-erosion-prone areas, with the topsoil of plots having a chemical alteration index not exceeding 60 being classified as frost-prone soil.
[0031] This is a precise method of identification. Specifically, if the soil is a nascent soil, then its parent material must have a very low degree of weathering. The quantitative factor for measuring this indicator is the chemical alteration index. The higher the index, the more fully developed the soil is, and the lower the index, the lower the degree of weathering of the parent material. Under normal circumstances, the chemical alteration index of frost-prone nascent soil does not exceed 60, while in normal soil, this index rarely falls below 85.
[0032] Of course, for most areas, the nascent soil formed by winter freezing can be visually identified by its appearance, as a large amount of exposed sand and gravel can be seen on its surface. This sampling mainly targets a small number of areas that are considered wind-eroded areas in remote sensing but do not show obvious exposed sand and gravel on their surface. In practice, sampling can be done once per 50×50 meter plot, and these problematic areas can be sampled in smaller blocks.
[0033] In step three, the area ratio of the frozen nascent soil covered by the sown delayed microbial activator and the vegetation cover shall not be less than 30%.
[0034] There is no need to cover the surface of the frozen nascent soil with a delayed-action microbial activator, as that would be too costly. It is sufficient to use a microbial activator that covers a proportion of the land area of the plot that is not less than 30% of the sum of the microbial activator and the vegetation cover of the plot.
[0035] In this embodiment, the decomposed organic fertilizer is decomposed cow and sheep manure; thus, it is possible to use local materials as much as possible. Attapulgite is a type of clay that readily absorbs water. It can be sourced locally and is a type of clay that does not crumble after drying. As it absorbs water, it gradually becomes softer. Its water absorption capacity is relatively high among clays, capable of absorbing 100% to 300% of its own weight in water.
[0036] The crack-resistant agent is bone char particles with a particle size of no more than 2 mm; The reason for using bone char pellets here is to make it convenient to use local waste materials such as yak bones, and bone char itself is also a high-quality phosphate fertilizer.
[0037] The dried moss is *Bryum dentata*, which was collected, sprayed with sodium carboxymethyl cellulose solution, and then air-dried. *Bryum dentatum* is a very fast-recovering moss; however, like other recovering plants, it suffers from the problem of failing to properly enter the cryptobiotic state when it loses too much water, and instead dies directly. Before being harvested, its water loss rate is limited and controllable, but this invention requires a large quantity of moss material, making it impractical to specifically collect moss already in the cryptobiotic state. Directly harvested moss may fail to enter the cryptobiotic state due to excessive water loss; therefore, surface protection with sodium carboxymethyl cellulose solution and air-drying are necessary to control the water loss rate.
[0038] Note that the collected moss should be shaken apart first (it should not be in large clumps), then sprayed with sodium carboxymethyl cellulose solution and air-dried. This not only speeds up the drying process but also facilitates subsequent granulation.
[0039] The biofilm-producing agent is a freeze-dried bacterial powder of *Pseudomonas psychrophila*. The strain selected in this example is *Pseudomonas psychrophila*. This is a species that can still grow normally and secrete extracellular polymers in low-temperature environments; after all, temperatures are not high during the spring flood season, so a relatively cold-resistant strain is needed.
[0040] The delayed-action microbial activation modifier comprises the following components in parts by weight: Well-rotted organic fertilizer: 35-45 parts; Dried moss: 25-35 parts; Absorbent clay: 15-25 parts; Crack-resistant agent: 8-12 parts; In this embodiment, the ratio of the above components is 40:30:20:10. This is a formula that has shown to be effective in experiments. However, in actual operation, the ratio cannot be made completely precise, so a certain amount of fluctuation must be left.
[0041] Furthermore, the content of film-producing bacteria in the delayed-action microbial activation modifier is no less than 100 million CFU / g. This concentration ensures that there are still enough germinating bacteria after the dormancy period.
[0042] In step two, sodium alginate solution or potassium alginate solution is used as a binder, and a delayed microbial activation modifier is prepared using a disc granulation process. Then, the microbial activation modifier is dried in a convection dryer using dry air.
[0043] The reason for using a disc granulation process similar to rolling glutinous rice balls is to minimize mechanical compression that could damage the dried moss. Sodium or potassium alginate solution is used as a binder because it reacts with calcium ions and other components in the soil solution to form calcium alginate, which then solidifies, preventing premature curing. Potassium alginate can be used as a potassium fertilizer here, but it is more expensive. The dosage should only be sufficient to meet the granulation requirements; lower concentrations and smaller dosages are better. In this example, a 1% wt sodium alginate solution is used for granulation and added via spraying.
[0044] The particle size of the delayed microbial activation modifier is 5-10 mm. If the particles are too large, granulation and drying will be difficult. If the particles are too small, the protective effect on the internal structure will not be obvious, and the microbial agent may be killed by exposure to ultraviolet light.
[0045] During the drying process, the temperature of the drying air should not exceed 30°C during the falling-rate drying stage. In this stage, the surface of the particles is unsaturated with moisture, and the interior of the particles gradually dries. If the temperature is too high at this point, it can kill the bacterial agent; therefore, temperature control is necessary to ensure it does not exceed the upper limit of the maximum growth concentration of *Pseudomonas psychrophilus*. In the remaining stages, the temperature of the drying air should not exceed 35°C. During these stages, the surface of the particles is saturated with moisture, and due to the influence of water, the internal temperature of the particles will be lower than 35°C. Since the particles prepared by the disc granulation process have a low moisture content, drying can be completed quickly using these relatively low temperatures. Of course, vacuum freeze-drying can also be used if conditions permit, but the cost is much higher.
[0046] The drying equipment should preferably be a chamber dryer or a fluidized bed dryer. Of course, when using a fluidized bed dryer, it is important to ensure that the particle strength is sufficient to prevent excessive breakage in the fluidized bed. If neither of the above conditions is met, you can use an electric fan to blow on the particles in a room with heating or other heating equipment, or place the particles near the air outlet of an air conditioner in heating mode.
[0047] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A delayed-action microbial activation method for soil improvement in nascent frozen soil, used to inhibit the formation of windblown sand in the topsoil of seasonally frozen soil during spring drought, wherein the topsoil of seasonally frozen soil is nascent frozen soil, characterized in that: The soil improvement method includes the following steps: Step 1: During the freezing period of the frost-prone soil, investigate the extent of the frost-prone soil. Step 2: Preparation of delayed microbial activation modifier; the delayed microbial activation modifier is a dry granule made by mixing and granulating a water-absorbing clay for rapidly improving soil aggregation, a film-forming bacteria agent for secreting extracellular polymers to aggregate soil particles, dried moss in a cryptogenic state, well-rotted organic fertilizer for providing nutrients to the film-forming bacteria agent and moss, and an anti-cracking agent to prevent the delayed microbial activation modifier from prematurely breaking due to thermal stress, and the binder used for granulation is hydrolyzable; The crack-resistant agent is porous carbon particles; Step 3: Before the frozen soil thaws, spread the delayed microbial activation modifier on the surface of the frozen soil. Step 4: After the frozen soil thaws, the delayed-action microbial activator disintegrates under the action of snow water, distributing water-absorbing clay, cryptic dried moss, and film-forming bacteria into the frozen soil. The water-absorbing clay initially aggregates soil particles to provide a growth substrate for the film-forming bacteria. The film-forming bacteria secrete extracellular polymers to further aggregate soil particles, while the moss recovers and increases vegetation cover.
2. The method for delayed microbial activation of soil amendment for frozen nascent soil as described in claim 1, characterized in that: In step one, the following methods were used to investigate the extent of the frozen basalt formation: Step 1.1: Identify areas in the remote sensing image that are permafrost and have a vegetation cover of no more than 20%, and mark them as areas prone to wind erosion. Step 1.2: Sampling of topsoil in wind-erosion-prone areas, with the topsoil of plots having a chemical alteration index not exceeding 60 being classified as frost-prone soil.
3. The method for delayed microbial activation of soil amendment for frozen nascent soil as described in claim 2, characterized in that: In step three, the area ratio of the frozen nascent soil covered by the sown delayed microbial activator and the vegetation cover shall not be less than 30%.
4. The method for delayed microbial activation of soil amendment for frozen nascent soil as described in claim 1, characterized in that: The decomposed organic fertilizer is decomposed cow and sheep manure; The easily absorbent clay is attapulgite. The crack-resistant agent is bone char particles with a particle size of no more than 2 mm; The dried moss was *Bryophytum esculentum*, which was collected, sprayed with sodium carboxymethyl cellulose solution, and then air-dried. The film-forming bacterial agent is a freeze-dried bacterial powder of Pseudomonas psychrophilus.
5. The method for delayed microbial activation of soil amendment for frozen nascent soil as described in claim 4, characterized in that: The delayed-action microbial activation modifier comprises the following components in parts by weight: Well-rotted organic fertilizer: 35-45 parts; Dried moss: 25-35 parts; Absorbent clay: 15-25 parts; Crack-resistant agent: 8-12 parts; Furthermore, the content of film-producing bacteria in the delayed microbial activation modifier is not less than 100 million CFU / gram, calculated in CFU.
6. The method for delayed microbial activation of soil amendment for frozen nascent soil as described in claim 1, characterized in that: In step two, sodium alginate solution or potassium alginate solution is used as a binder, and a delayed microbial activation modifier is prepared using a disc granulation process. Then, the microbial activation modifier is dried in a convection dryer using dry air.
7. The method for delayed microbial activation of soil amendment for frozen nascent soil as described in claim 6, characterized in that: The particle size of the delayed microbial activator modifier is 5-10 mm; during the drying process, the temperature of the drying air does not exceed 30℃ in the falling-rate drying stage, and does not exceed 35℃ in the other stages.