A method for efficient rapid propagation and transplanting of shrub seedlings in high-altitude cold and arid regions

Abstract

This invention belongs to the field of forestry asexual propagation technology, specifically involving a method for efficient and rapid propagation and transplanting of shrub seedlings in high-altitude, cold, and arid regions. The method includes the following steps: 1) preparing the land by creating ridges, opening holes in the furrows, covering the ridge surface with black PE film, and the furrow surface with white PE film, then burying seedling cups with built-in mesh bags in the holes; 2) taking shrub branches, cutting one end horizontally near the bud and the other end obliquely, then storing them in sand for low-temperature stress induction, hormone activation, and antioxidant treatment, finally inserting them into the seedling cups from step 1) after thorough rain; 3) constructing an arched shed after cutting, fertilizing and hardening off the seedlings after 15-25 days, and then transplanting. This invention achieves the dual effects of rainwater harvesting and moisture retention, as well as warming and cold protection, through optimized ridge and furrow structure design combined with differentiated mulch film laying technology; simultaneously, by combining specialized seedling cup design, customized cultivation substrate, and cutting pretreatment technology, it effectively overcomes the technical bottleneck of low seedling survival rate under multiple stresses of high altitude, cold, and drought.

Description

Technical Field

[0001] This invention belongs to the field of forestry asexual reproduction technology, specifically involving a method for efficient and rapid propagation and transplanting of shrub seedlings in high-altitude cold and arid areas. Background Technology

[0002] High-altitude, cold, and arid regions are characterized by high altitude, low temperatures, low rainfall, and frequent strong winds. Coupled with a lack of necessary irrigation, this makes shrub seedling propagation in these areas extremely difficult. Currently, ecological restoration often uses seedlings cultivated at low altitudes for transplanting. However, these seedlings often sprout prematurely by the time the transplanting area reaches planting conditions, resulting in low survival rates after transplanting. While temporary planting can alleviate this problem to some extent, it is difficult to manage, and even slight negligence can easily lead to mass seedling mortality. This results in the predicament of annual afforestation efforts failing to produce lush forests.

[0003] Based on long-term production practices, the core bottleneck in the current propagation of shrub seedlings in high-altitude cold and arid regions lies in the cutting propagation stage, specifically manifested in four aspects: First, the land preparation methods are monotonous, failing to fully utilize scarce rainfall resources, resulting in insufficient soil water retention capacity, and seedlings are prone to reduced survival rates and weakened growth vigor due to physiological drought; Second, cuttings are directly inserted into the bare ground without effective heat preservation measures, leading to insufficient accumulation of effective temperature during the growing season and forcing a prolonged seedling cultivation period; Third, the seedling cultivation process lacks systematic stress-induction and precise microenvironment control technologies, resulting in seedling survival rates generally below 30%; Fourth, cuttings are mostly transplanted bare-root, making it difficult to keep the roots in soil, severely restricting post-transplant survival and recovery. Therefore, it is urgent to construct a high-efficiency and rapid propagation technology system for shrub seedlings that is suitable for the habitat characteristics of high-altitude cold and arid regions, to support the sustainable development of ecological restoration in these areas. Summary of the Invention

[0004] To achieve the above objectives, this invention provides a method for the efficient and rapid propagation and transplanting of shrub seedlings in high-altitude cold and arid regions, comprising the following steps: 1) Prepare the land by making ridges, dig holes in the furrows, cover the ridges with black PE film, cover the furrows with white PE film, and then bury the seedling cups with net bags inside into the holes. 2) Take shrub branches, make a horizontal cut at one end near the bud and a slanted cut at the other end, then store them in sand, induce low temperature stress resistance, activate with hormones, treat with antioxidants, and finally insert them into the seedling cups of step 1) after thorough rain. 3) After the cuttings are taken, build an arched shed. Fertilize and harden off the seedlings after 15-25 days, and then transplant them.

[0005] Furthermore, in step 1), the land is tilled to a depth of 25-35cm during preparation, and weeds and stones with a diameter of 8cm or more are removed; the furrows are 25-35cm wide, 15-25cm high, and 10-20cm wide.

[0006] Furthermore, in step 1), a 2cm high mound is set between the holes with a depth of 18-22cm.

[0007] Further, in step 1), the thickness of the PE film is 0.01~0.02 mm; the seedling cup is a plastic seedling cup with a depth of 15~20 cm and a diameter of 5~10 cm, and a drainage hole on the side wall 5~8 cm from the mouth of the cup; the diameter of the drainage hole is 2~4 mm, and the number is 8~12. The mesh bag is a nylon mesh bag containing a substrate; the substrate is prepared by mixing clay, sand, perlite and peat in a volume ratio of 2:5:2:1, and 0.5% acrylamide water-retaining agent is added.

[0008] Furthermore, the shrub branches mentioned in step 2) are branches of Willow simonii, Scaly Water Juniper, or Tamarix chinensis; the branches are 18-22 cm long and retain more than 3 buds.

[0009] Furthermore, the sand storage time in step 2) is 15 to 20 days, during which the sand moisture is maintained.

[0010] Further, the method for inducing low-temperature stress resistance in step 2) is as follows: for the first 0-12 hours, the branches are rapidly cooled to 3 ℃; for the first 12-60 hours, the temperature is maintained at 3 ℃, with a 1 ℃ fluctuation every 30 minutes during this period; for the first 60-72 hours, the temperature is slowly increased to 10 ℃.

[0011] Further, the method for hormone activation in step 2) is as follows: the base of the branches is soaked in 500 mg·L⁻¹ water. -1 After 12 hours in IAA, immediately transfer to hormone solution IAA 500 mg / L. -1 + NAA 300 mg·L -1 + IBA 400 mg·L -1 In the process, the base of the cuttings should be vertically immersed 5–8 cm away from light. Gently shake for 5 seconds every 2 hours to prevent oxygen deficiency. After 12 hours, remove and air dry.

[0012] Further, the antioxidant treatment method in step 2) is as follows: the branches are treated with 0.2 mmol·L⁻¹ -1 Ascorbic acid + 0.5 mmol·L -1 Soak glutathione for 30 minutes, turning it over every 10 minutes during this period; When taking cuttings, dip the roots of the cuttings in carbendazim, insert them into the seedling cup with the bud above the root and the root below the root, to a depth of 3 / 4 of the cutting length, and retain 1-2 buds at the top.

[0013] Furthermore, the arched shed described in step 3) is constructed using bamboo strips and PE film, and is covered with cotton quilts at night; The fertilization method is as follows: when the cuttings have grown new roots and the terminal buds have begun to sprout or unfold new leaves, apply 10 kg of NPK20-20-20 water-soluble fertilizer per mu; when the seedlings grow to the 4-leaf stage, apply 0.1% potassium dihydrogen phosphate + 10% micronutrient water-soluble fertilizer as foliar fertilizer every 10 days, for a total of 2 times, with 5 ml per seedling each time; During the first week of seedling hardening, the cotton quilt was removed at night; during the second and third weeks, the PE film at both ends of the greenhouse was opened with a gap of 8-13 cm during the day; after the third week, the film was completely removed. When transplanting, the seedlings should be 50-80 cm tall, with a ground diameter of ≥0.5 cm, ≥5 roots, and a root length of ≥8 cm. Add 20-30 g / plant of water-retaining agent and 50 g / plant of NPK20-20-20 water-soluble fertilizer to the bottom of the transplanting hole. After transplanting, set up a 30 cm high straw mat for wind protection. Do not apply fertilizer in the first year. Apply 50 g of P:N:K=3:1:1 compound fertilizer in the spring of the following year.

[0014] This invention presents a method for the efficient and rapid propagation and transplanting of shrub seedlings in high-altitude, cold, and arid regions. Through optimized furrow structure design and differentiated mulch film laying technology, it achieves the dual effects of rainwater harvesting and moisture retention, as well as warming and cold protection. At the same time, by combining specialized seedling cup design, customized cultivation substrate, and cutting pretreatment technology, it effectively overcomes the technical bottleneck of low seedling survival rate under multiple stresses of high altitude, cold, and drought. It provides a practical and feasible technical solution for ecological restoration in high-altitude, cold, and arid regions and has significant value for promotion and application.

[0015] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention.

[0016] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention. Attached Figure Description

[0017] Figure 1 Schematic diagram of the cross-section of the furrow micro-rain harvesting system. Detailed Implementation

[0018] Example 1: High-efficiency and rapid propagation of shrub seedlings in high-altitude cold and arid regions 1. Furrow micro-rainwater collection and insulation system The target plot is tilled to a depth of 30cm, removing stones and weeds with a diameter of more than 8cm, and the land is prepared into a ridge-furrow pattern with a ridge width of 30cm, a ridge height of 20cm, and a furrow width of 15cm. A cutting point is set every 20cm in the trench, and a 2cm high soil mound is set between the cutting points to form a "concave" shape to facilitate rainwater collection. A hole is dug at the cutting point, with a depth of 20cm. The ridge surface is covered with a black PE film (0.01 mm) and the furrow surface is covered with a white PE film (0.01 mm), forming a microenvironment of "black film absorbing heat - white film collecting rain". The relative temperature inside the film increases by 3-4℃, the relative air humidity increases by 15-20%, and the soil moisture content increases by more than 25%. 2. Pre-bury seedling cups and net bags at the bottom of the trench. a) Place a plastic seedling cup with a depth of 18cm and a diameter of 8cm into the cutting hole. The upper edge of the seedling cup should be 2cm lower than the surface of the trench. Set 10 drainage holes with a diameter of 3mm on the side wall of the seedling cup 6cm away from the mouth of the cup to collect water and remove excess water at the same time. b) Insert a nylon mesh bag that is the same size as the seedling cup but slightly higher than the seedling cup into the seedling cup. When transplanting, simply lift the mesh bag to achieve transplanting with zero root damage, which also promotes the free growth of the seedling roots. c) Place the substrate in the nylon mesh bag. The substrate formula is clay, sand, perlite and peat in a volume ratio of 2:5:2:1, and add 0.5% acrylamide water-retaining agent (particle size 2-3 mm, water absorption ratio 200-300 times).

[0019] d) Cover the top of the seedling cups and the grooves with white plastic film to help rainwater collect in the seedling cups.

[0020] 3. Preparations before scion planting e) Plant selection: Salix oritrepha Schneid, Myricaria squamosa Desv., Tamarix austromongolica Nakai.

[0021] f) Cutting preparation: In March, take 1-2 year old fully lignified branches from the mother plants of *Salix matsudana*, *Myrica rubra*, and *Tamarix chinensis* as cuttings. The branches should be 20 cm long and retain more than 3 buds. Make a horizontal cut at the top (near the bud) and a V-shaped cut on both sides at the bottom. Tie 50 branches together and store them in sand. Water them as needed to maintain the humidity of the sand. Store them in sand for 15-20 days.

[0022] 4. Pretreatment of cuttings for stress resistance g) Low-temperature stress induction: Taking advantage of the low nighttime temperatures on the plateau, which are below 0°C, the cuttings were covered with insulation blankets during the day to maintain a temperature of 3-10°C for 72 hours. Specifically, the cuttings treated with sand storage were rapidly cooled to 3°C from 0-12 hours; maintained at a constant 3°C ​​from 12-60 hours, with a 1°C fluctuation every 30 minutes from 12 hours; and slowly increased to 10°C from 60-72 hours.

[0023] h) Hormone activation: The base of the cuttings (i.e., the lower cut of the cuttings) after low-temperature stress induction was immersed in 500 mg·L⁻¹ water. -1 IAA for 12 hours; then immediately transfer to hormone solution IAA 500 mg / L. -1 + NAA 300 mg·L -1 + IBA 400mg·L -1 In the process, the base of the cuttings should be vertically immersed 5–8 cm away from light. Gently shake for 5 seconds every 2 hours to prevent oxygen deficiency. After 12 hours, remove and air dry.

[0024] i) Antioxidant treatment: The hormone-activated cuttings were treated with 0.2 mmol·L⁻¹ antioxidant. -1 Ascorbic acid (AsA) + 0.5 mmol·L -1 Soak the cuttings in glutathione (GSH) solution for 30 minutes, turning them over every 10 minutes to ensure even penetration; then wrap the base of the cuttings with damp newspaper and insert them into the soil within 10 minutes to prevent them from drying out.

[0025] j) Cutting time: It must be after the first thorough rain in April.

[0026] k) Cutting process: Make holes in the seedling cups in step d), then dip the roots of the antioxidant-treated cuttings in carbendazim, and finally insert the treated cuttings into the holes of the seedling cups, keeping the cuttings perpendicular to the ground, with the buds above the roots, at a depth of 3 / 4 of the cutting length, and retaining 1-2 buds at the top. 5. Management of the microenvironment for cuttings l) Double-layer covering for heat preservation and root promotion (0-20 days): After the cuttings are completed, a small arched shed (bamboo strips + 0.05 mm PE film) is built with white transparent plastic to keep the temperature inside the shed above 20℃ during the day and cover the outside of the shed with cotton quilt at night to keep the temperature >2℃ and prevent moisture evaporation.

[0027] m) Gradually uncover the greenhouse to cool down and harden the seedlings (21–42 days): Starting from day 21, remove the cotton quilt at night during the first week, leaving the greenhouse film on, so that the temperature inside the greenhouse drops to 15–20℃; during the second and third weeks, open the PE film at both ends of the arched greenhouse by 10 cm during the day; after the third week, completely remove the film.

[0028] n) Routine management 35 days after cuttings: Water management: Relying on natural rainfall, the seedling cups naturally store water during light rain, while excess water leaks out through the drainage holes during moderate and heavy rain.

[0029] Fertilizer management: When it is confirmed that the cuttings have grown new roots and the terminal buds have begun to sprout or unfold new leaves, start applying water-soluble fertilizer (NPK20-20-20 water-soluble fertilizer for macronutrients) at 10 kg / mu; when the seedlings grow to the 4-leaf stage, apply foliar fertilizer of 0.1% potassium dihydrogen phosphate + 10% micronutrient water-soluble fertilizer (Guoguang Luowei) once every 10 days, for a total of 2 times, with 5 ml per seedling each time.

[0030] 6. Gradual transplanting of seedlings in substrate net bags Nursery exit standards: seedling height 50-80 cm, ground diameter ≥0.5 cm, root system ≥5 roots, root length ≥8 cm; Transplanting holes should be 30 cm × 30 cm. Add 20-30 g / plant of water-retaining agent and 50 g / plant of NPK20-20-20 water-soluble fertilizer to the bottom of the hole. After transplanting, set up a 30 cm high windbreak with straw mats. Do not apply fertilizer in the first year. Apply 50 g of compound fertilizer (P:N:K = 3:1:1) in the spring of the following year.

[0031] Following the above method (see diagram), Figure 1 To achieve efficient and rapid propagation of seedlings: I. High-efficiency and rapid propagation of wild willow seedlings Location: Sanjiaocheng Sheep Breeding Farm, Gangcha County, Haibei Prefecture, Qinghai Province Experimental area: 0.6 mu (0.3 mu in furrow area, 0.3 mu in bare land CK) Trial period: April 10, 2023 to May 10, 2024 Tested tree species: Salix oritrepha Schneid (1-2 year old lignified branches) 1. Land preparation Furrow parameters: ridge width 30cm, ridge height 20cm, furrow width 15cm, black film (0.01 mm) / white film (0.01 mm) covering.

[0032] Seedling cup: 18 cm × 8 cm, 10 holes on the side wall, nylon mesh bag inside the cup.

[0033] Matrix: 20% clay + 50% sand + 20% perlite + 10% peat, 0.5% acrylamide water-retaining agent.

[0034] 2. Cutting treatment Branches were collected on April 10th → stored in sand → low-temperature stress resistance induction for 72 h → hormone activation (500 mg·L⁻¹) -1 IAA 12h, then IAA 500 mg·L-1 +NAA 300 mg·L -1 + IBA 400 mg·L -1 → Antioxidant treatment (AsA 0.2 mmol·L⁻¹) -1 +GSH 0.5 mmol·L -1 30 min.

[0035] 3. Cuttings and maintenance The first thorough rain fell on May 7th, and the cuttings were completed on May 8th, totaling 2400 plants; After the cuttings were taken out, a small arched shed (bamboo strips + 0.05 mm PE film) was built using white transparent plastic for 30 days, and the film was removed on June 8th. Apply 10 kg / mu of water-soluble fertilizer (NPK20-20-20) before the rain on July 15 and August 20. When the seedlings grow to the 4-leaf stage, apply foliar fertilizer of 0.1% potassium dihydrogen phosphate + 10% micronutrient water-soluble fertilizer (Guoguang Luowei) every 10 days for a total of 2 times, with 5 ml per seedling each time.

[0036] 4. Results The annual growth indicators were measured on October 15, 2023, and the overwintering rate was measured on May 10, 2024.

[0037] Table 1. Measurement of growth indicators of *Salix matsudana* seedlings II. High-efficiency and rapid propagation of scaly juniper seedlings Location: Sanjiaocheng Sheep Breeding Farm, Gangcha County, Haibei Prefecture, Qinghai Province Experimental area: 0.8 mu (0.5 mu in furrow area, 0.3 mu in bare land control area CK) Trial period: April 10, 2023 to May 10, 2024 Tested tree species: *Myricaria scabra* (Scaly juniper) Myricaria squamosa Desv. (1-2 year old lignified branches) 1. Land preparation The parameters for furrows, seedling cups, and substrate are the same as those for "1. Land preparation" under the section "I. High-efficiency and rapid propagation of willow seedlings".

[0038] 2. Cuttings and stalks Same as "2. Cutting treatment" and "3. Cutting and management" under "I. High-efficiency and rapid propagation of willow seedlings".

[0039] 3. Results The annual growth indicators were measured on October 15, 2023, and the overwintering rate was measured on May 10, 2024.

[0040] Table 2. Determination of growth indicators for scaly juniper seedlings III. High-efficiency and rapid propagation of Gansu-Mongolia tamarisk seedlings Location: Sanjiaocheng Sheep Breeding Farm, Gangcha County, Haibei Prefecture, Qinghai Province Experimental area: 0.5 mu (0.3 mu in furrow area, 0.2 mu in bare land control area CK) Trial period: April 10, 2023 to May 10, 2024 Tested tree species: Tamarix austromongolica Nakai (1-2 year old lignified branches) 1. Land preparation The parameters for furrows, seedling cups, and substrate are the same as those for "1. Land preparation" under the section "I. High-efficiency and rapid propagation of willow seedlings".

[0041] 2. Cuttings and stalks Same as "2. Cutting treatment" and "3. Cutting and management" under "I. High-efficiency and rapid propagation of willow seedlings".

[0042] 3. Results The annual growth indicators were measured on October 15, 2023, and the overwintering rate was measured on May 10, 2024.

[0043] Table 3. Determination of growth indicators of Tamarix chinensis seedlings The above breeding results show that the furrow rainwater harvesting-cup seedling system increases soil moisture content by 25-30%; stress-resistant pretreatment and microenvironment management significantly improve survival rate and overwintering survival rate; under the experimental conditions, the average survival rate of seedlings in the current year can reach over 85%, with a ground diameter > 0.6 cm, a plant height > 80 cm, and an overwintering survival rate increased by 39.7-61.8%, which is significantly higher than the control (P<0.05), and can be directly used for ecological afforestation in the following spring.

[0044] The following experimental examples further illustrate the beneficial effects of the present invention: Experiment 1: Verification of Factors Affecting the High-Efficiency and Rapid Propagation of Shrub Seedlings in High-Altitude Cold and Arid Regions Preliminary experiments revealed that each step in the integrated propagation process of "rain collection-heat preservation-root promotion-transplanting" affects the survival rate of seedlings after transplanting. In particular, different types of mulch and the mesh bags in the seedling cups have a significant impact on the propagation of shrub seedlings in high-altitude cold and arid areas. Therefore, the following experiments were conducted to further verify this. I. The regulatory effect of mulch film color configuration on microenvironment and seedling survival Experimental location: Sanjiaocheng Sheep Breeding Farm, Gangcha County, Haibei Prefecture, Qinghai Province Test period: April 15, 2024 to May 15, 2025 Tree species tested: Mountain willow Experimental design: randomized block design, 3 replicates, each plot area 20m² (10m² for furrows and 10m² for bare ground (CK)). Land preparation and materials: The specifications of furrows, seedling cups (18cm×8cm), substrate ratio (clay:sand:perlite:peat = 2:5:2:1 + 0.5% water-retaining agent) and cutting pretreatment (low temperature induction + hormone activation + antioxidant treatment) are completely consistent with those in Example 1.

[0045] 1. Monitoring data on microenvironmental effects (average from May to August 2024) Treatment T2 resulted in strong reflection from the white film on the ridge surface, reducing the daytime heat absorption of the ridge by 63% and reversing the direction of heat flux (the ridge absorbs heat from the furrow instead of supplying heat). This led to an average daily temperature in the furrow that was 6.5°C lower than in T1, with the lowest nighttime temperature reaching freezing point, resulting in an extremely high risk of frost damage to the cuttings. Although the black film in the furrow could absorb heat slightly, its rainwater collection efficiency decreased by 50%, resulting in insufficient dew condensation.

[0046] 2. Seedling growth and survival rate determination (October 15, 2024) The T2 treatment, with its black film covering the furrows, reduced soil moisture content, causing water stress on the cuttings during the critical rooting period (0-20 days). The hormone-activated cuttings suffered increased cambium necrosis due to water shortage, and nighttime low temperatures caused freeze-thaw damage to the base of the cuttings, leading to the accumulation of rooting inhibitors. The CK control was superior to T2: while bare soil lacked the warming effect of rainwater harvesting, it avoided the "negative effects" of T2.

[0047] 3. Overwintering survival rate and water use efficiency (measured on May 15, 2025) Treatment T1, through the synergistic coupling of "heat absorption by black ridges and rain collection by white film," created a microenvironment of "high temperature, high humidity, and high energy" within the furrow, reducing the root system's winter frost damage index by 73%. Treatment T2, due to slow spring warming and a 3-week lag in root activity, resulted in insufficient lignification and a winter mortality rate as high as 71.6%.

[0048] 4. Analysis of Economic Benefits and Promotion Value T2 treatment not only failed to improve the survival rate, but also caused a surge in costs and a halving of the survival rate due to misconfiguration. The alignment of the film color is an "asymmetric key factor" for the rapid propagation of seedlings in high-altitude cold and arid areas, and reverse configuration will produce irreversible negative effects.

[0049] in conclusion: 1. The irreplaceable nature of the synergistic mechanism. There is a physical coupling effect between the heat absorption of the black film on the ridge surface (average daily temperature of 8°C) and the rainwater collection of the white film in the furrow (improving water collection efficiency by 85%). The reverse configuration leads to the decoupling of the heat-water process and the deterioration of the microenvironment.

[0050] 2. This invention is not a simple “film-covered cutting”, but a systematic regulation that achieves “energy capture-water enrichment-stress resistance induction” through color alignment. Misalignment of any link will lead to the collapse of the technical system, which is especially rare in high-altitude and arid regions.

[0051] 3. This experiment adopted a completely randomized block design with a sample size of n=900 and a significance level of P<0.001, confirming that "black film on the ridge surface + white film in the furrow" is a necessary condition for achieving a survival rate of ≥85%. The survival rate of the reverse configuration (T2) (38.6%) was even lower than that of the bare field control (42.1%), which confirms the irreplaceable nature of the technical solution.

[0052] II. Screening and Adaptability Verification Tests of Lightweight Matrix Mesh Bag Materials Experimental location: Sanjiaocheng Sheep Breeding Farm, Gangcha County, Haibei Prefecture, Qinghai Province Test period: April 15, 2024 to May 15, 2025 Tree species tested: Mountain willow Experimental design: 4 treatments × 3 replicates, completely randomized block design, 200 cuttings per plot. Controlled variables: All treatments adopted a uniform furrow rainwater harvesting system (black ridges and white film), substrate formula (clay:sand:perlite:peat = 2:5:2:1 + 0.5% water-retaining agent), cutting pretreatment (low temperature induction + hormone activation + antioxidant treatment), and microenvironment management measures.

[0053] 1. Root development and container effect determination (October 15, 2024) T1 Nylon mesh bag: 0.5 mm pore size precisely restricts the root system, resulting in a loose root structure with numerous branches, and fibrous roots accounting for 76%. T2 Non-woven fabric: Pores too small (0.2 mm) hinder root respiration and water permeability. T3 Biodegradable bag: Premature disintegration leads to loss of root restraint, and water stress results in a mortality rate of 58%. CK: Roots are in direct contact with the sidewalls of the seedling cup, with severe ring-like tangling.

[0054] 2. Comparison of transplanting effects and root damage rate (30 days after transplanting on April 20, 2025) When transplanting seedlings using T1 nylon mesh bags, the substrate clump remained nearly 99% intact after removal from the cup, with a root damage rate of only 2.1%, significantly improving seedling survival rates. In contrast, the CK control group lacked the soil-holding effect of the nylon mesh bags, making the substrate easily detach during transplanting, resulting in a root damage rate as high as 76.3%, and substrate scattering leading to an 82% loss of absorbing roots.

[0055] Root-soil bonding mechanism: After transplanting with T1 nylon mesh bags, the fine roots (0.2-0.5 mm in diameter) inside the original bag quickly penetrate the mesh (0.5 mm) and form an "anchoring-bridging" structure with the soil outside the bag. The root-soil bonding degree is as high as 0.94, and the wind pull-out resistance is increased by 3.2 times (measured value: T1 is 28.5 N, CK is only 7.8 N).

[0056] in conclusion 1. Material Uniqueness: In extreme environments with altitude ≥3000 m and freeze-thaw cycles >120 times / year, nylon mesh bags (0.5 mm aperture) are the only core material that meets the following triple standards: good tensile strength retention rate >90%, transplanting non-damage: root damage rate <3%, and seedling recovery period <10 days.

[0057] 2. Advantages compared with the traditional bagless control: Although the CK control has no material costs, the high root damage rate during transplanting (76.3%) and low overwintering survival rate (26.5%) ultimately resulted in a afforestation-grade seedling rate of only 22.4%, less than 1 / 3 of the nylon mesh bag treatment. Moreover, the labor efficiency was only 40% of the bagless treatment, and it could not achieve the "zero root damage, zero seedling slowdown" technical effect described in the patent.

[0058] 3. Long-term effects: One year after transplanting, the rate of afforestation-grade seedlings treated with nylon mesh bags reached 85.7%, which is 3.8 times higher than the average of other materials. Moreover, the overwintering survival rate remained stable at over 89%, ensuring the goal of "survival in the same year and forest formation in the following year" for ecological restoration in high-altitude areas.

[0059] In summary, this invention achieves the dual effects of rainwater harvesting and moisture retention, as well as warming and cold protection, through optimized furrow structure design and differentiated mulch film laying technology. At the same time, by combining specialized seedling cup design, customized cultivation substrate and cutting pretreatment technology, it effectively breaks through the technical bottleneck of low seedling survival rate under multiple stresses of high altitude, cold and drought, and provides a practical technical solution for ecological restoration in high-altitude cold and arid areas.

Claims

1. A method for efficient and rapid propagation and transplanting of shrub seedlings in high-altitude cold and arid regions, characterized by: Includes the following steps: 1) Prepare the land by making ridges, dig holes in the furrows, cover the ridges with black PE film, cover the furrows with white PE film, and then bury the seedling cups with net bags inside into the holes. 2) Take shrub branches, make a horizontal cut at one end near the bud and a slanted cut at the other end, then store them in sand, induce low temperature stress resistance, activate with hormones, treat with antioxidants, and finally insert them into the seedling cups of step 1) after thorough rain. 3) After the cuttings are taken, build an arched shed. Fertilize and harden off the seedlings after 15-25 days, and then transplant them.

2. The method according to claim 1, characterized in that: Step 1) When preparing the land, the soil should be deeply tilled to a depth of 25-35cm, and weeds and stones with a diameter of 8cm or more should be removed; the width of the furrows should be 25-35cm, the height of the furrows should be 15-25cm, and the width of the furrows should be 10-20cm.

3. The method according to claim 1, characterized in that: Step 1) The depth of the hole is 18~22cm, and a 2cm high soil mound is set between the holes.

4. The method according to claim 1, characterized in that: Step 1) The thickness of the PE film is 0.01~0.02 mm; the seedling cup is a plastic seedling cup with a depth of 15~20 cm and a diameter of 5~10 cm, and a drainage hole on the side wall 5~8 cm from the mouth of the cup; the diameter of the drainage hole is 2~4 mm, and the number is 8~12; The mesh bag is a nylon mesh bag containing a substrate; the substrate is prepared by mixing clay, sand, perlite and peat in a volume ratio of 2:5:2:1, and 0.5% acrylamide water-retaining agent is added.

5. The method according to claim 1, characterized in that: Step 2) The shrub branches are branches of Willow simonii, Scaly Water Berry, or Tamarix chinensis; the branches are 18-22cm long and have more than 3 buds.

6. The method according to claim 1, characterized in that: Step 2) The sand storage time is 15 to 20 days, during which the sand moisture is maintained.

7. The method according to claim 1, characterized in that: Step 2) The method for inducing low-temperature stress resistance is as follows: from 0 to 12 h, the branches are rapidly cooled to 3 ℃; from 12 to 60 h, the temperature is maintained at 3 ℃, with a 1 ℃ fluctuation every 30 min every 12 h; from 60 to 72 h, the temperature is slowly increased to 10 ℃.

8. The method according to claim 1, characterized in that: Step 2) The method for hormone activation is as follows: the base of the branches is soaked in 500 mg·L⁻¹ water. -1 IAA for 12 hours, then immediately transfer to hormone solution IAA 500 mg / L -1 + NAA 300 mg·L -1 + IBA 400 mg·L -1 In the process, the base of the cuttings should be vertically immersed 5–8 cm away from light. Gently shake for 5 seconds every 2 hours to prevent oxygen deficiency. After 12 hours, remove and air dry.

9. The method according to claim 1, characterized in that: Step 2) The method for treating the branches with the antioxidant is as follows: use 0.2 mmol·L⁻¹ -1 Ascorbic acid + 0.5 mmol·L -1 Soak glutathione for 30 minutes, turning it over every 10 minutes during this period; When taking cuttings, dip the roots of the cuttings in carbendazim, insert them into the seedling cup with the bud above the root and the root below the root, to a depth of 3 / 4 of the cutting length, and retain 1-2 buds at the top.

10. The method according to claim 1, characterized in that: Step 3) The arched shed is constructed using bamboo strips and PE film, and is covered with cotton quilts at night; The fertilization method is as follows: when the cuttings have grown new roots and the terminal buds have begun to sprout or unfold new leaves, apply 10 kg of NPK20-20-20 water-soluble fertilizer per mu; when the seedlings grow to the 4-leaf stage, apply 0.1% potassium dihydrogen phosphate + 10% micronutrient water-soluble fertilizer as foliar fertilizer every 10 days, for a total of 2 times, with 5 ml per seedling each time; During the first week of seedling hardening, the cotton quilt was removed at night; during the second and third weeks, the PE film at both ends of the greenhouse was opened with a gap of 8-13 cm during the day; after the third week, the film was completely removed. When transplanting, the seedlings should be 50-80 cm tall, with a ground diameter of ≥0.5 cm, ≥5 roots, and a root length of ≥8 cm. Add 20-30 g / plant of water-retaining agent and 50 g / plant of NPK20-20-20 water-soluble fertilizer to the bottom of the transplanting hole. After transplanting, set up a 30 cm high straw mat for wind protection. Do not apply fertilizer in the first year. Apply 50 g of P:N:K=3:1:1 compound fertilizer in the spring of the following year.

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