Seedling raising method for shiny-leaved yellowhorn trees

Abstract

The invention relates to the technical field of tree seedling raising, and discloses a shiny-leaved yellowhorn tree seedling raising method which comprises the following steps: S1, seed screening and grading: selecting mature shiny-leaved yellowhorn seeds, and grading through physical screening, specific gravity screening and quality detection to obtain primary and secondary seeds; s2, seed pretreatment: performing gradient temperature soaking, composite enzymolysis, magnetic field activation and variable temperature stratification treatment on the graded seeds; s3, preparing a seedling substrate, namely mixing leaf mold, garden soil, river sand, decomposed organic fertilizer and ceramsite in parts by weight, and adding a bactericide, a rooting agent and a slow-release fertilizer; s4, intelligent seeding: selecting a seedling raising tray of a corresponding specification according to the seed grade, and performing accurate seeding by adopting automatic seeding equipment; s5, seedling stage management: regulating and controlling the temperature, humidity, illumination and carbon dioxide concentration of a seedling raising environment by utilizing an intelligent environment control system, and combining precise water and fertilizer management, comprehensive pest control and staged seedling hardening treatment.

Description

Technical Field

[0001] The invention relates to the technical field of tree seedling cultivation, and in particular to a Xanthoceras sorbifolia tree seedling cultivation method. Background Art

[0002] Xanthoceras sorbifolia, a deciduous shrub or small tree of the genus Xanthoceras in the Sapindaceae family, is a rare woody oil plant endemic to my country. Its seeds are high in oil content and excellent in quality, possessing both edible and medicinal value. Furthermore, Xanthoceras sorbifolia is highly adaptable and tolerant of drought and barrenness, making it an excellent species for preventing wind and sandstorms and improving the ecological environment. Therefore, its cultivation holds significant economic and ecological significance. However, Xanthoceras sorbifolia seeds have a hard seed coat, a long dormancy period, and a low natural germination rate. Traditional seedling cultivation methods suffer from low germination rates, slow seedling growth, and low survival rates, hindering the large-scale cultivation and industrial development of Xanthoceras sorbifolia. Therefore, developing an efficient seedling cultivation method for Xanthoceras sorbifolia trees is of great practical significance. Summary of the Invention

[0003] (1) Technical problems solved In view of the deficiencies in the prior art, the present invention provides a method for raising seedlings of Xanthoceras sorbifolia trees.

[0004] (2) Technical solution To achieve the above object, the present invention provides the following technical solution: a method for raising seedlings of Xanthoceras sorbifolia, comprising the following steps: S1. Seed screening and grading: Select mature Xanthoceras sorbifolia seeds and grade them through physical screening, specific gravity screening, and quality testing to obtain first- and second-grade seeds; S2. Seed pretreatment: The graded seeds are subjected to gradient temperature soaking, compound enzymatic hydrolysis, magnetic field activation and variable temperature stratification treatment; S3. Seedling medium preparation: Mix leaf mold, garden soil, river sand, decomposed organic fertilizer, and ceramsite according to weight, and add fungicide, rooting agent, and slow-release fertilizer; S4. Intelligent sowing: Select seedling trays of corresponding specifications according to seed grade, and use automated sowing equipment for precise sowing; S5. Seedling management: Use intelligent environmental control systems to regulate the temperature, humidity, light and carbon dioxide concentration of the seedling environment, combined with precise water and fertilizer management, integrated pest and disease control and phased seedling hardening.

[0005] Furthermore, in step S1, the physical screening is performed by screening with a sieve with an aperture of 5 mm to remove seeds with a particle size of less than 5 mm; the specific gravity screening is performed by placing the seeds in a salt solution with a concentration of 10-12%, soaking for 10-15 minutes, and removing floating seeds; the quality inspection includes measuring the thousand-grain weight, plumpness, seed coat integrity and pest and disease conditions of the seeds. The thousand-grain weight of the first-class seeds is ≥80 g, the plumpness is ≥98%, the seed coat is intact and free of pests and diseases; the thousand-grain weight of the second-class seeds is 70-80 g, the plumpness is 90-98%, the seed coat is basically intact and there is no obvious pest and disease.

[0006] Furthermore, the gradient temperature soaking in step S2 is specifically as follows: the first-level seeds are first soaked in warm water at 55~60℃ for 0.5~1 h, and then soaked in warm water at 30~35℃ for 4~8 h; the second-level seeds are first soaked in warm water at 50~55℃ for 1.5~2 h, and then soaked in warm water at 25~30℃ for 16~20 h, during which the water is changed every 2~4 h, and the water temperature during the water change is consistent with the current soaking water temperature.

[0007] Furthermore, in step S2, the composite enzymatic hydrolysis is to place the seeds soaked in the gradient temperature into a composite enzyme solution, the primary seeds are soaked at 30-35°C for 2-3 hours, and the secondary seeds are soaked at 35-38°C for 5-6 hours; the composite enzyme solution is composed of cellulase, hemicellulase, and pectinase in a mass ratio of 3:2:1, the enzyme concentration is 0.8-1.2%, and the pH value of the solution is adjusted to 4.5-5.5; the magnetic field activation is to place the seeds after enzymatic hydrolysis in a pulsed magnetic field with a magnetic field strength of 40-60 mT, the primary seeds are treated for 10-15 minutes, the secondary seeds are treated for 20-25 minutes, and the pulse frequency is 50-60 Hz.

[0008] Furthermore, in step S2, the variable temperature stratification treatment is to mix the seeds activated by the magnetic field with the stratification matrix in a volume ratio of 1:3~5. The stratification procedure of the first-level seeds is: 5°C low temperature treatment for 7 days, 25°C high temperature treatment for 3 days, 5°C low temperature treatment for 7 days, and 25°C high temperature treatment for 3 days; the stratification procedure of the second-level seeds is: 5°C low temperature treatment for 10 days, 25°C high temperature treatment for 5 days, 5°C low temperature treatment for 10 days, and 25°C high temperature treatment for 5 days; the stratification matrix is a mixture of peat soil, wet sand, and activated carbon in a mass ratio of 5:4:1, and the matrix humidity is maintained at 60~65%.

[0009] Furthermore, in step S3, the volume ratio of each component of the seedling matrix is: 30-35 parts of leaf mold, 20-25 parts of garden soil, 15-20 parts of river sand, 10-15 parts of decomposed organic fertilizer, and 5-10 parts of ceramsite; the fungicide is carbendazim or thiophanate-methyl, and the addition amount is 0.2-0.3% of the total mass of the matrix; the rooting agent is a mixture of naphthaleneacetic acid and indolebutyric acid in a mass ratio of 1.5-2:1, and the addition amount is 0.02-0.03% of the total mass of the matrix; the slow-release fertilizer is a nitrogen-phosphorus-potassium composite slow-release fertilizer, the mass ratio of nitrogen, phosphorus and potassium is 3:1:2, and the addition amount is 1-2% of the total mass of the matrix.

[0010] Furthermore, in step S4, a 32-hole seedling tray is used for the first-level seeds, one seed is sown in each hole, and the sowing depth is 1 cm; a 50-hole seedling tray is used for the second-level seeds, one seed is sown in each hole, and the sowing depth is 1.5 cm; after sowing, a layer of vermiculite with a thickness of 0.5~1 cm is covered.

[0011] Furthermore, the parameters regulated by the intelligent environmental control system in step S5 are: the temperature during the germination period is maintained at 25-28°C, the relative humidity is 80-85%, the light intensity is 2000-3000 lux, the light duration is 8-12 h / day, and the carbon dioxide concentration is 800-1000 ppm; the temperature during the seedling period is maintained at 20-25°C, the relative humidity is 70-75%, the light intensity is 4000-6000 lux, the light duration is 10-14 h / day, and the carbon dioxide concentration is 600-800 ppm; the temperature during the seedling period is maintained at 18-22°C, the relative humidity is 60-65%, the light intensity is 6000-8000 lux, the light duration is 12-16 h / day, and the carbon dioxide concentration is 500-600 ppm.

[0012] Furthermore, the precise water and fertilizer management in step S5 is as follows: mist spraying is used during the germination period to keep the substrate moist; watering is performed every 3 to 5 days during the seedling period, and watering is performed each time until the substrate moisture content reaches 60 to 65%, and at the same time, 0.2 to 0.3% amino acid foliar fertilizer is sprayed once every 7 to 10 days; watering is performed every 5 to 7 days during the seedling period, and watering is performed each time until the substrate moisture content reaches 55 to 60%, and nitrogen-phosphorus-potassium compound fertilizer is applied once every 10 to 15 days, with a nitrogen, phosphorus, and potassium mass ratio of 2:1:2 and a fertilizer amount of 10 to 15 g per square meter of substrate, and watering is carried out in time after fertilization.

[0013] Furthermore, the staged hardening treatment in step S5 is as follows: starting 20 days before transplanting the seedlings, in the first stage of 10 days, the temperature is reduced by 2-3°C, the humidity is reduced by 5-10%, and the light intensity is increased by 1000-2000 lux; in the second stage of 10 days, the temperature is further reduced by 2-3°C, the humidity is further reduced by 5-10%, and the light intensity is further increased by 1000-2000 lux, while the natural ventilation time is gradually increased.

[0014] (3) Beneficial technical effects The Xanthoceras sorbifolia seedling cultivation process of the present invention achieves significant technical advantages through multi-link collaborative optimization: By adopting a composite pretreatment method of graded screening combined with gradient temperature immersion, enzymatic hydrolysis, magnetic field activation, and variable temperature stratification, the germination rate of first-level seeds reached over 95%, and the germination rate of second-level seeds reached 90%, which is a significant improvement compared with traditional methods and solves the problem of long dormancy period and uneven germination of Xanthoceras sorbifolia seeds. The synergistic effect of the seedling medium and precise water and fertilizer increases the height of the seedlings, increases the length of the taproot, improves the quality of the seedlings, and increases the survival rate, laying the foundation for later stress resistance. Through intelligent environmental regulation, the cycle from seed germination to seedling formation is shortened to meet the timeliness requirements of large-scale seedling cultivation. Staged seedling hardening and adversity induction treatment improve the survival rate of seedlings in drought and temperature fluctuation environments, adapting to the planting conditions in the arid and semi-arid regions of Northwest China. The process of the present invention is compatible with automated sowing and intelligent management, reduces labor costs, and the materials are recyclable, which is in line with the development direction of green agriculture and provides key technical support for the large-scale development of the Xanthoceras sorbifolia industry. DETAILED DESCRIPTION

[0015] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0016] The components of the seedling culture medium formula of the present invention are all commercially available unless otherwise specified; Example 1 A method for raising Xanthoceras sorbifolia seedlings comprises the following steps: S1. Seed screening and grading: Select mature Xanthoceras sorbifolia seeds and grade them through physical screening, specific gravity screening, and quality testing to obtain first- and second-grade seeds; S2. Seed pretreatment: The graded seeds are subjected to gradient temperature soaking, compound enzymatic hydrolysis, magnetic field activation and variable temperature stratification treatment; S3. Seedling medium preparation: Mix leaf mold, garden soil, river sand, decomposed organic fertilizer, and ceramsite according to weight, and add fungicide, rooting agent, and slow-release fertilizer; S4. Intelligent sowing: Select seedling trays of corresponding specifications according to seed grade, and use automated sowing equipment for precise sowing; S5. Seedling management: Use intelligent environmental control systems to regulate the temperature, humidity, light and carbon dioxide concentration of the seedling environment, combined with precise water and fertilizer management, integrated pest and disease control and phased seedling hardening.

[0017] In step S1, the physical screening is performed by screening with a sieve with an aperture of 5 mm to remove seeds with a particle size of less than 5 mm; the specific gravity screening is performed by placing the seeds in a 10% salt solution, soaking for 10 minutes, and removing floating seeds; the quality inspection includes measuring the thousand-grain weight, plumpness, seed coat integrity, and pest and disease conditions of the seeds. The thousand-grain weight of the first-class seeds is ≥80 g, the plumpness is ≥98%, the seed coat is intact and free of pests and diseases; the thousand-grain weight of the second-class seeds is 70-80 g, the plumpness is 90-98%, the seed coat is basically intact and there is no obvious pest and disease.

[0018] The gradient temperature soaking in step S2 is specifically as follows: the first-level seeds are first soaked in warm water at 55°C for 0.5 h, and then soaked in warm water at 30°C for 4 h; the second-level seeds are first soaked in warm water at 50°C for 1.5 h, and then soaked in warm water at 25°C for 16 h. During this period, the water is changed every 2 h, and the water temperature during the water change is consistent with the current soaking water temperature.

[0019] In step S2, the composite enzymatic hydrolysis is to place the seeds soaked in the gradient temperature into a composite enzyme solution, the first-level seeds are soaked at 30°C for 2 hours, and the second-level seeds are soaked at 35°C for 5 hours; the composite enzyme solution is composed of cellulase, hemicellulase, and pectinase in a mass ratio of 3:2:1, the enzyme concentration is 0.8%, and the pH value of the solution is adjusted to 4.5; the magnetic field activation is to place the seeds after enzymatic hydrolysis in a pulsed magnetic field with a magnetic field intensity of 40 mT, the first-level seeds are treated for 10 minutes, the second-level seeds are treated for 20 minutes, and the pulse frequency is 50 Hz.

[0020] In step S2, the variable temperature stratification treatment is to mix the seeds activated by the magnetic field with the stratification matrix in a volume ratio of 1:3. The stratification procedure of the first-level seeds is: 5°C low temperature treatment for 7 days, 25°C high temperature treatment for 3 days, 5°C low temperature treatment for 7 days, and 25°C high temperature treatment for 3 days; the stratification procedure of the second-level seeds is: 5°C low temperature treatment for 10 days, 25°C high temperature treatment for 5 days, 5°C low temperature treatment for 10 days, and 25°C high temperature treatment for 5 days; the stratification matrix is a mixture of peat soil, wet sand, and activated carbon in a mass ratio of 5:4:1, and the matrix humidity is maintained at 60%.

[0021] The volume ratio of each component of the seedling culture medium in step S3 is: 30 parts of leaf mold, 20 parts of garden soil, 15 parts of river sand, 10 parts of decomposed organic fertilizer, and 5 parts of ceramsite; the fungicide is carbendazim, and the addition amount is 0.2% of the total mass of the matrix; the rooting agent is a mixture of naphthaleneacetic acid and indolebutyric acid in a mass ratio of 1.5:1, and the addition amount is 0.02% of the total mass of the matrix; the slow-release fertilizer is a nitrogen-phosphorus-potassium composite slow-release fertilizer, the mass ratio of nitrogen, phosphorus and potassium is 3:1:2, and the addition amount is 1% of the total mass of the matrix.

[0022] In step S4, a 32-hole seedling tray was used for the first-level seeds, and one seed was sown in each hole at a sowing depth of 1 cm; a 50-hole seedling tray was used for the second-level seeds, and one seed was sown in each hole at a sowing depth of 1.5 cm; after sowing, a layer of vermiculite with a thickness of 0.5 cm was covered.

[0023] The parameters regulated by the intelligent environmental control system in step S5 are: the temperature during the germination period is maintained at 25°C, the relative humidity is 80%, the light intensity is 2000 lux, the light duration is 8 h / day, and the carbon dioxide concentration is 800 ppm; the temperature during the seedling period is maintained at 20°C, the relative humidity is 70%, the light intensity is 4000 lux, the light duration is 10 h / day, and the carbon dioxide concentration is 600 ppm; the temperature during the seedling period is maintained at 18°C, the relative humidity is 60%, the light intensity is 6000 lux, the light duration is 12 h / day, and the carbon dioxide concentration is 500 ppm.

[0024] The precise water and fertilizer management in step S5 is as follows: mist spraying is used during the germination period to keep the substrate moist; watering is done once every 3 days during the seedling stage, and watering is done each time until the substrate moisture content reaches 60-65%, and 0.2% amino acid foliar fertilizer is sprayed once every 7 days; watering is done once every 5 days during the seedling stage, and watering is done each time until the substrate moisture content reaches 55-60%, and nitrogen-phosphorus-potassium compound fertilizer is applied once every 10 days, with a nitrogen, phosphorus, and potassium mass ratio of 2:1:2 and a fertilizer amount of 10 g per square meter of substrate, and watering is done in time after fertilization.

[0025] The integrated pest control in step S5 includes agricultural control, physical control, biological control and chemical control; agricultural control is to regularly clean the seedling environment and maintain ventilation and light transmission; physical control is to set up yellow boards and blue boards in the seedling shed to lure and kill pests; biological control is to release natural enemies and apply biological pesticides; chemical control is to spray low-toxic, low-residue chemical pesticides at the early stage of the occurrence of pests and diseases.

[0026] The staged seedling hardening treatment in step S5 is as follows: starting 20 days before transplanting the seedlings, in the first stage of 10 days, the temperature is reduced by 2°C, the humidity is reduced by 5%, and the light intensity is increased by 1000 lux; in the second stage of 10 days, the temperature is further reduced by 2°C, the humidity is further reduced by 5%, and the light intensity is further increased by 1000 lux, while the natural ventilation time is gradually increased.

[0027] Example 2 A method for raising Xanthoceras sorbifolia seedlings comprises the following steps: S1. Seed screening and grading: Select mature Xanthoceras sorbifolia seeds and grade them through physical screening, specific gravity screening, and quality testing to obtain first- and second-grade seeds; S2. Seed pretreatment: The graded seeds are subjected to gradient temperature soaking, compound enzymatic hydrolysis, magnetic field activation and variable temperature stratification treatment; S3. Seedling medium preparation: Mix leaf mold, garden soil, river sand, decomposed organic fertilizer, and ceramsite according to weight, and add fungicide, rooting agent, and slow-release fertilizer; S4. Intelligent sowing: Select seedling trays of corresponding specifications according to seed grade, and use automated sowing equipment for precise sowing; S5. Seedling management: Use intelligent environmental control systems to regulate the temperature, humidity, light and carbon dioxide concentration of the seedling environment, combined with precise water and fertilizer management, integrated pest and disease control and phased seedling hardening.

[0028] In step S1, the physical screening is performed by screening with a sieve with a pore size of 5 mm to remove seeds with a particle size of less than 5 mm; the specific gravity screening is performed by placing the seeds in a salt solution with a concentration of 11%, soaking for 12 minutes, and removing floating seeds; the quality inspection includes measuring the thousand-grain weight, plumpness, seed coat integrity and pest and disease conditions of the seeds. The thousand-grain weight of the first-class seeds is ≥80 g, the plumpness is ≥98%, the seed coat is intact and free of pests and diseases; the thousand-grain weight of the second-class seeds is 70~80 g, the plumpness is 90~98%, the seed coat is basically intact and there is no obvious pest and disease.

[0029] The gradient temperature soaking in step S2 is specifically as follows: the first-level seeds are first soaked in warm water at 58°C for 0.6 h, and then soaked in warm water at 32°C for 6 h; the second-level seeds are first soaked in warm water at 52°C for 1.8 h, and then soaked in warm water at 28°C for 18 h. During this period, the water is changed every 3 h, and the water temperature during the water change is consistent with the current soaking water temperature.

[0030] In step S2, the composite enzymatic hydrolysis is to place the seeds soaked in the gradient temperature into the composite enzyme solution, the first-level seeds are soaked at 32°C for 2.5 hours, and the second-level seeds are soaked at 36°C for 5.5 hours; the composite enzyme solution is composed of cellulase, hemicellulase, and pectinase in a mass ratio of 3:2:1, the enzyme concentration is 1%, and the pH value of the solution is adjusted to 5; the magnetic field activation is to place the seeds after enzymatic hydrolysis in a pulsed magnetic field with a magnetic field intensity of 50 mT, the first-level seeds are treated for 10 minutes, the second-level seeds are treated for 22 minutes, and the pulse frequency is 55 Hz.

[0031] In step S2, the variable temperature stratification treatment is to mix the seeds activated by the magnetic field with the stratification matrix in a volume ratio of 1:4. The stratification procedure of the first-level seeds is: 5°C low temperature treatment for 7 days, 25°C high temperature treatment for 3 days, 5°C low temperature treatment for 7 days, and 25°C high temperature treatment for 3 days; the stratification procedure of the second-level seeds is: 5°C low temperature treatment for 10 days, 25°C high temperature treatment for 5 days, 5°C low temperature treatment for 10 days, and 25°C high temperature treatment for 5 days; the stratification matrix is a mixture of peat soil, wet sand, and activated carbon in a mass ratio of 5:4:1, and the matrix humidity is maintained at 65%.

[0032] The volume ratio of each component of the seedling culture medium in step S3 is: 32 parts of leaf mold, 23 parts of garden soil, 18 parts of river sand, 12 parts of decomposed organic fertilizer, and 8 parts of ceramsite; the fungicide is carbendazim, and the addition amount is 0.2% of the total mass of the matrix; the rooting agent is a mixture of naphthaleneacetic acid and indolebutyric acid in a mass ratio of 1.8:1, and the addition amount is 0.02% of the total mass of the matrix; the slow-release fertilizer is a nitrogen-phosphorus-potassium composite slow-release fertilizer, the mass ratio of nitrogen, phosphorus and potassium is 3:1:2, and the addition amount is 1.5% of the total mass of the matrix.

[0033] In step S4, a 32-hole seedling tray was used for the first-level seeds, and one seed was sown in each hole at a sowing depth of 1 cm; a 50-hole seedling tray was used for the second-level seeds, and one seed was sown in each hole at a sowing depth of 1.5 cm; after sowing, a layer of vermiculite with a thickness of 0.8 cm was covered.

[0034] The parameters regulated by the intelligent environmental control system in step S5 are as follows: the temperature during the germination period is maintained at 26°C, the relative humidity is 85%, the light intensity is 2500 lux, the light duration is 10 h / day, and the carbon dioxide concentration is 900 ppm; the temperature during the seedling period is maintained at 22°C, the relative humidity is 72%, the light intensity is 5000 lux, the light duration is 12 h / day, and the carbon dioxide concentration is 700 ppm; the temperature during the seedling period is maintained at 20°C, the relative humidity is 62%, the light intensity is 7000 lux, the light duration is 14 h / day, and the carbon dioxide concentration is 550 ppm.

[0035] The precise water and fertilizer management in step S5 is as follows: mist spraying is used during the germination period to keep the substrate moist; watering is performed once every 4 days during the seedling period, and each watering is performed until the substrate moisture content reaches 60-65%, and 0.2% amino acid foliar fertilizer is sprayed once every 8 days; watering is performed once every 6 days during the seedling period, and each watering is performed until the substrate moisture content reaches 55-60%, and nitrogen-phosphorus-potassium compound fertilizer is applied once every 12 days, with a nitrogen, phosphorus, and potassium mass ratio of 2:1:2 and a fertilizer amount of 12 g per square meter of substrate, and watering is carried out in time after fertilization.

[0036] The integrated pest control in step S5 includes agricultural control, physical control, biological control and chemical control; agricultural control is to regularly clean the seedling environment and maintain ventilation and light transmission; physical control is to set up yellow boards and blue boards in the seedling shed to lure and kill pests; biological control is to release natural enemies and apply biological pesticides; chemical control is to spray low-toxic, low-residue chemical pesticides at the early stage of the occurrence of pests and diseases.

[0037] The staged hardening treatment in step S5 is as follows: starting 20 days before transplanting the seedlings, in the first stage for 10 days, the temperature is reduced by 2°C, the humidity is reduced by 8%, and the light intensity is increased by 1500 lux; in the second stage for 10 days, the temperature is further reduced by 2°C, the humidity is further reduced by 5%, the light intensity is further increased by 1500 lux, and the natural ventilation time is gradually increased.

[0038] Example 3 A method for raising Xanthoceras sorbifolia seedlings comprises the following steps: S1. Seed screening and grading: Select mature Xanthoceras sorbifolia seeds and grade them through physical screening, specific gravity screening, and quality testing to obtain first- and second-grade seeds; S2. Seed pretreatment: The graded seeds are subjected to gradient temperature soaking, compound enzymatic hydrolysis, magnetic field activation and variable temperature stratification treatment; S3. Seedling medium preparation: Mix leaf mold, garden soil, river sand, decomposed organic fertilizer, and ceramsite according to weight, and add fungicide, rooting agent, and slow-release fertilizer; S4. Intelligent sowing: Select seedling trays of corresponding specifications according to seed grade, and use automated sowing equipment for precise sowing; S5. Seedling management: Use intelligent environmental control systems to regulate the temperature, humidity, light and carbon dioxide concentration of the seedling environment, combined with precise water and fertilizer management, integrated pest and disease control and phased seedling hardening.

[0039] In step S1, the physical screening is performed by screening with a sieve with an aperture of 5 mm to remove seeds with a particle size of less than 5 mm; the specific gravity screening is performed by placing the seeds in a 12% salt solution, soaking for 15 minutes, and removing floating seeds; the quality inspection includes measuring the thousand-grain weight, plumpness, seed coat integrity, and pest and disease conditions of the seeds. The thousand-grain weight of the first-class seeds is ≥80 g, the plumpness is ≥98%, the seed coat is intact and free of pests and diseases; the thousand-grain weight of the second-class seeds is 70-80 g, the plumpness is 90-98%, the seed coat is basically intact and there is no obvious pest and disease.

[0040] The gradient temperature soaking in step S2 is specifically as follows: the first-level seeds are first soaked in warm water at 60°C for 1 hour, and then soaked in warm water at 35°C for 8 hours; the second-level seeds are first soaked in warm water at 55°C for 2 hours, and then soaked in warm water at 30°C for 20 hours. During this period, the water is changed every 4 hours, and the water temperature during the water change is consistent with the current soaking water temperature.

[0041] In step S2, the composite enzymatic hydrolysis is to place the seeds soaked in the gradient temperature into a composite enzyme solution, the first-level seeds are soaked at 35°C for 3 hours, and the second-level seeds are soaked at 38°C for 6 hours; the composite enzyme solution is composed of cellulase, hemicellulase, and pectinase in a mass ratio of 3:2:1, the enzyme concentration is 1.2%, and the pH value of the solution is adjusted to 5.5; the magnetic field activation is to place the seeds after enzymatic hydrolysis in a pulsed magnetic field with a magnetic field intensity of 60 mT, the first-level seeds are treated for 15 minutes, the second-level seeds are treated for 25 minutes, and the pulse frequency is 60 Hz.

[0042] In step S2, the variable temperature stratification treatment is to mix the seeds activated by the magnetic field with the stratification matrix in a volume ratio of 1:5. The stratification procedure of the first-level seeds is: 5°C low temperature treatment for 7 days, 25°C high temperature treatment for 3 days, 5°C low temperature treatment for 7 days, and 25°C high temperature treatment for 3 days; the stratification procedure of the second-level seeds is: 5°C low temperature treatment for 10 days, 25°C high temperature treatment for 5 days, 5°C low temperature treatment for 10 days, and 25°C high temperature treatment for 5 days; the stratification matrix is a mixture of peat soil, wet sand, and activated carbon in a mass ratio of 5:4:1, and the matrix humidity is maintained at 65%.

[0043] The volume ratio of each component of the seedling matrix in step S3 is: 35 parts of leaf mold, 25 parts of garden soil, 20 parts of river sand, 15 parts of decomposed organic fertilizer, and 10 parts of ceramsite; the fungicide is chlorothalonil, and the addition amount is 0.3% of the total mass of the matrix; the rooting agent is a mixture of naphthaleneacetic acid and indolebutyric acid in a mass ratio of 2:1, and the addition amount is 0.03% of the total mass of the matrix; the slow-release fertilizer is a nitrogen-phosphorus-potassium composite slow-release fertilizer, the mass ratio of nitrogen, phosphorus and potassium is 3:1:2, and the addition amount is 2% of the total mass of the matrix.

[0044] In step S4, a 32-hole seedling tray is used for the first-level seeds, and one seed is sown in each hole at a sowing depth of 1 cm; a 50-hole seedling tray is used for the second-level seeds, and one seed is sown in each hole at a sowing depth of 1.5 cm; after sowing, a layer of vermiculite with a thickness of 1 cm is covered.

[0045] The parameters regulated by the intelligent environmental control system in step S5 are: the temperature during the germination period is maintained at 28°C, the relative humidity is 85%, the light intensity is 3000 lux, the light duration is 12 h / day, and the carbon dioxide concentration is 1000 ppm; the temperature during the seedling period is maintained at 25°C, the relative humidity is 75%, the light intensity is 6000 lux, the light duration is 14 h / day, and the carbon dioxide concentration is 800 ppm; the temperature during the seedling period is maintained at 22°C, the relative humidity is 65%, the light intensity is 8000 lux, the light duration is 16 h / day, and the carbon dioxide concentration is 600 ppm.

[0046] The precise water and fertilizer management in step S5 is as follows: mist spraying is used during the germination period to keep the substrate moist; watering is performed once every 5 days during the seedling stage, and watering is performed each time until the substrate moisture content reaches 60-65%. At the same time, 0.3% amino acid foliar fertilizer is sprayed once every 10 days; watering is performed once every 7 days during the seedling stage, and watering is performed each time until the substrate moisture content reaches 55-60%. Nitrogen-phosphorus-potassium compound fertilizer is applied once every 15 days, with a nitrogen, phosphorus, and potassium mass ratio of 2:1:2 and a fertilizer amount of 15 g per square meter of substrate. Watering is carried out in time after fertilization.

[0047] The integrated pest control in step S5 includes agricultural control, physical control, biological control and chemical control; agricultural control is to regularly clean the seedling environment and maintain ventilation and light transmission; physical control is to set up yellow boards and blue boards in the seedling shed to lure and kill pests; biological control is to release natural enemies and apply biological pesticides; chemical control is to spray low-toxic, low-residue chemical pesticides at the early stage of the occurrence of pests and diseases.

[0048] The staged hardening treatment in step S5 is as follows: starting 20 days before transplanting the seedlings, in the first stage for 10 days, the temperature is reduced by 3°C, the humidity is reduced by 10%, and the light intensity is increased by 2000 lux; in the second stage for 10 days, the temperature is further reduced by 3°C, the humidity is further reduced by 10%, the light intensity is further increased by 2000 lux, and the natural ventilation time is gradually increased.

[0049] Comparative Example 1: In step S2, only immersion in 30°C warm water for 8 h (no gradient temperature treatment) was performed, and no composite enzymatic hydrolysis and magnetic field activation treatment were performed. The remaining steps were consistent with Example 1.

[0050] Comparative Example 2: In step S3, the seedling culture medium is garden soil and river sand, with a mass ratio of 3:1, and the remaining steps are consistent with Example 1.

[0051] Comparative Example 3: In step S5, natural environment regulation is adopted without intelligent control system, temperature, humidity and light change naturally with the outside world, and no staged hardening treatment is performed. The remaining steps are consistent with Example 1.

[0052] Experimental testing: 1. Germination rate test: Sample preparation: 100 first-level seeds and 100 second-level seeds were selected from Examples 1 to 3 and Comparative Examples 1 to 3, respectively, with 3 replicates set for each group. Test conditions: The seeds were placed in an intelligent germination box and the environmental parameters during the germination period were controlled according to the respective examples. For comparative example 3, the average parameters of the natural environment were used: temperature 20-25°C, humidity 60-70%, and light intensity 8-10 h / day. Observation records: Observe the seed germination every day, and take the radicle breaking through the seed coat ≥2 mm as the germination standard. Stop recording when there are no new germinated seeds for 7 consecutive days, and calculate the germination rate. Germination rate = (number of germinated seeds / number of test seeds) × 100% Table 1 Test results of first-level seed germination rate (%)

[0053] Table 2 Secondary seed germination rate test results (%)

[0054] As shown in the table, compared with Comparative Example 1, Examples 1-3 showed a significant effect of the synergistic treatments of gradient temperature immersion, composite enzymatic hydrolysis, and magnetic field activation on germination rates. Compared with Comparative Example 2, the addition of a seedling culture medium increased the germination rates of both primary and secondary seeds, demonstrating that the composite matrix composed of leaf mold and decomposed organic fertilizer can provide sufficient nutrition and a suitable microenvironment for seed germination. Compared with Comparative Example 3, intelligent environmental control and seedling hardening significantly improved germination rates.

[0055] 2. Seedling height: On the 30th day after seed germination, the height of the seedlings from the substrate surface to the growth point was measured with a ruler. Thirty seedlings were randomly selected from each group and the average value was taken. 3. Taproot length: The taproot length of the seedlings was measured at the same time, as the straight-line distance from the radicle breakthrough point to the root tip. Thirty plants were randomly selected from each group and the average value was taken. 4. Survival rate: When the seedlings grow to 60 days old, the ratio of surviving seedlings to the total number of seedings is counted.

[0056] Survival rate = (number of surviving seedlings / number of test seeds) × 100% Table 3. Test results of first-level seeds

[0057] Table 4 Secondary seed test results

[0058] As can be seen from the table, the seedling raising method of the present invention can not only improve the germination rate, but also ensure the quality of the seedlings, improve the survival rate, and lay a good foundation for subsequent transplanting.

[0059] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for raising seedlings of Xanthoceras sorbifolia, characterized in that: The following steps are involved: S1. Seed screening and grading: Select mature Xanthoceras sorbifolia seeds and grade them through physical screening, specific gravity screening, and quality testing to obtain first- and second-grade seeds; S2. Seed pretreatment: The graded seeds are subjected to gradient temperature soaking, compound enzymatic hydrolysis, magnetic field activation and variable temperature stratification treatment; S3. Seedling medium preparation: Mix leaf mold, garden soil, river sand, decomposed organic fertilizer, and ceramsite according to weight, and add fungicide, rooting agent, and slow-release fertilizer; S4. Intelligent sowing: Select seedling trays of corresponding specifications according to seed grade, and use automated sowing equipment for precise sowing; S5. Seedling management: Use intelligent environmental control systems to regulate the temperature, humidity, light and carbon dioxide concentration of the seedling environment, combined with precise water and fertilizer management, integrated pest and disease control and phased seedling hardening.

2. A method for raising seedlings of Xanthoceras sorbifolia according to claim 1, characterized in that, In step S1, the physical screening is performed by screening with a sieve with an aperture of 5 mm to remove seeds with a particle size of less than 5 mm; the specific gravity screening is performed by placing the seeds in a salt solution with a concentration of 10-12%, soaking for 10-15 minutes, and removing floating seeds; the quality inspection includes measuring the thousand-grain weight, plumpness, seed coat integrity, and pest and disease conditions of the seeds. The thousand-grain weight of the first-class seeds is ≥80 g, the plumpness is ≥98%, the seed coat is intact and free of pests and diseases; the thousand-grain weight of the second-class seeds is 70-80 g, the plumpness is 90-98%, the seed coat is basically intact and there is no obvious pest and disease.

3. A method for raising seedlings of Xanthoceras sorbifolia according to claim 1, characterized in that, The gradient temperature soaking in step S2 is specifically as follows: the first-level seeds are first soaked in warm water at 55-60°C for 0.5-1 h, and then soaked in warm water at 30-35°C for 4-8 h; the second-level seeds are first soaked in warm water at 50-55°C for 1.5-2 h, and then soaked in warm water at 25-30°C for 16-20 h. During this period, the water is changed every 2-4 h, and the water temperature during the water change is consistent with the current soaking water temperature.

4. A method for raising seedlings of Xanthoceras sorbifolia according to claim 1, characterized in that: In step S2, the composite enzymatic hydrolysis is to place the seeds soaked in the gradient temperature into a composite enzyme solution, wherein the primary seeds are soaked at 30-35°C for 2-3 hours, and the secondary seeds are soaked at 35-38°C for 5-6 hours; the composite enzyme solution is composed of a mixture of cellulase, hemicellulase, and pectinase in a mass ratio of 3:2:1, with an enzyme concentration of 0.8-1.2%, and the pH value of the solution is adjusted to 4.5-5.5; the magnetic field activation is to place the seeds after enzymatic hydrolysis in a pulsed magnetic field with a magnetic field strength of 40-60 mT, the primary seeds are treated for 10-15 minutes, the secondary seeds are treated for 20-25 minutes, and the pulse frequency is 50-60 Hz.

5. A method for raising seedlings of Xanthoceras sorbifolia trees according to claim 1, characterized in that: In step S2, the variable temperature stratification treatment is to mix the seeds activated by the magnetic field with the stratification matrix in a volume ratio of 1:3~5. The stratification procedure of the first-level seeds is: 5°C low temperature treatment for 7 days, 25°C high temperature treatment for 3 days, 5°C low temperature treatment for 7 days, and 25°C high temperature treatment for 3 days; the stratification procedure of the second-level seeds is: 5°C low temperature treatment for 10 days, 25°C high temperature treatment for 5 days, 5°C low temperature treatment for 10 days, and 25°C high temperature treatment for 5 days; the stratification matrix is a mixture of peat soil, wet sand, and activated carbon in a mass ratio of 5:4:1, and the matrix humidity is maintained at 60~65%.

6. A method for raising seedlings of Xanthoceras sorbifolia trees according to claim 1, characterized in that: The volume ratio of each component of the seedling culture medium in step S3 is: 30-35 parts of leaf mold, 20-25 parts of garden soil, 15-20 parts of river sand, 10-15 parts of decomposed organic fertilizer, and 5-10 parts of ceramsite; the fungicide is carbendazim or thiophanate-methyl, and the addition amount is 0.2-0.3% of the total mass of the matrix; the rooting agent is a mixture of naphthaleneacetic acid and indolebutyric acid in a mass ratio of 1.5-2:1, and the addition amount is 0.02-0.03% of the total mass of the matrix; the slow-release fertilizer is a nitrogen-phosphorus-potassium composite slow-release fertilizer, the mass ratio of nitrogen, phosphorus, and potassium is 3:1:2, and the addition amount is 1-2% of the total mass of the matrix.

7. A method for raising seedlings of Xanthoceras sorbifolia trees according to claim 1, characterized in that: In step S4, a 32-hole seedling tray is used for the first-level seeds, and one seed is sown in each hole at a sowing depth of 1 cm; a 50-hole seedling tray is used for the second-level seeds, and one seed is sown in each hole at a sowing depth of 1.5 cm; after sowing, a layer of vermiculite with a thickness of 0.5-1 cm is covered.

8. A method for raising seedlings of Xanthoceras sorbifolia trees according to claim 1, characterized in that: The parameters regulated by the intelligent environmental control system in step S5 are as follows: the temperature during the germination period is maintained at 25-28°C, the relative humidity is 80-85%, the light intensity is 2000-3000 lux, the light duration is 8-12 h / day, and the carbon dioxide concentration is 800-1000 ppm; the temperature during the seedling period is maintained at 20-25°C, the relative humidity is 70-75%, the light intensity is 4000-6000 lux, the light duration is 10-14 h / day, and the carbon dioxide concentration is 600-800 ppm; the temperature during the seedling period is maintained at 18-22°C, the relative humidity is 60-65%, the light intensity is 6000-8000 lux, the light duration is 12-16 h / day, and the carbon dioxide concentration is 500-600 ppm.

9. A method for raising seedlings of Xanthoceras sorbifolia trees according to claim 1, characterized in that: The precise water and fertilizer management in step S5 is as follows: mist spraying is used during the germination period to keep the substrate moist; watering is done every 3 to 5 days during the seedling stage, and watering is done each time until the substrate moisture content reaches 60 to 65%. At the same time, 0.2 to 0.3% amino acid foliar fertilizer is sprayed every 7 to 10 days; watering is done every 5 to 7 days during the seedling stage, and watering is done each time until the substrate moisture content reaches 55 to 60%. Nitrogen-phosphorus-potassium compound fertilizer is applied every 10 to 15 days, with a nitrogen, phosphorus, and potassium mass ratio of 2:1:2 and a fertilizer amount of 10 to 15 g per square meter of substrate. Watering is done in a timely manner after fertilization.

10. A method for raising Xanthoceras sorbifolia seedlings according to claim 1, characterized in that: The staged hardening treatment in step S5 is as follows: starting 20 days before transplanting the seedlings, in the first stage of 10 days, the temperature is reduced by 2-3°C, the humidity is reduced by 5-10%, and the light intensity is increased by 1000-2000 lux; in the second stage of 10 days, the temperature is further reduced by 2-3°C, the humidity is further reduced by 5-10%, the light intensity is further increased by 1000-2000 lux, and the natural ventilation time is gradually increased.

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