Method for precisely applying silicon fertilizer to betula bournei

Abstract

The invention provides a method for precisely applying silicon fertilizer to betula bournei, and belongs to the technical field of forest cultivation. The silicon fertilizer application method comprises the steps of seedling stage fertilization and adult plant stage fertilization. The seedling stage fertilization comprises the steps of applying straw organic fertilizer, silica fume and calcium superphosphate as base fertilizer before sowing, irrigating sodium silicate and zinc sulfate after true leaves are expanded, and spraying seaweed essence and silica sol when seedlings are 10-15 cm high; the step of fertilizing in the adult plant stage comprises the substeps of applying nitrogen-phosphorus-potassium compound fertilizer and calcium silicate to roots before germination in spring, and spraying calcium-magnesium fertilizer and nano silicon dioxide in the fast-growing stage in summer. The fertilizing method provided by the invention can promote the growth of the Birch bournei, improve the stress resistance of outplanting seedlings, and also can improve the wood performance of adult plants.

Description

Technical Field

[0001] The invention belongs to the technical field of forest cultivation, and in particular relates to a method for accurately applying silicon fertilizer to birch. Background Art

[0002] Betula fujianensis is a deciduous broadleaf tree species in the Betulaceae family. It is a rare plant endemic to Fujian Province, China. It is primarily found in the Luobuyan Provincial Nature Reserve in Sanming City, Fujian Province, and grows in subtropical mixed evergreen and deciduous broadleaf forests at altitudes above 500 meters.

[0003] Fujian birch has high economic and ecological value. In terms of economy, Fujian birch wood has medium density and moderate hardness, with an air-dry density of 0.683g / cm 3 About, the dry density is 0.634g / cm 3 The low differential shrinkage value gives it excellent machining properties and makes it widely used in furniture manufacturing, interior decoration, construction materials, and handicraft production. From an ecological perspective, as an important component of the forest ecosystem, Fujian birch is of great significance in maintaining regional ecological balance. It can conserve water resources, maintain water and soil, provide habitats for many organisms, and play a key role in regulating the climate and purifying the air.

[0004] CN110999701A discloses a method for sowing and raising seedlings of birch seeds, but it only involves the sowing of birch and does not involve the subsequent management process. However, birch currently faces many challenges in the process of growth and reproduction, and the problem of fertilization is particularly prominent. Unreasonable fertilization methods result in poor wood properties of birch. At present, most of the fertilization for birch lacks scientific planning, and the type, amount and time of fertilizer are often determined by experience, without fully considering the differences in nutritional requirements of birch at different growth stages.

[0005] Therefore, it is urgent to develop a scientific and reasonable fertilization method to promote the growth of B. minnesota seedlings and improve the stress resistance of B. minnesota seedlings and the wood properties of mature plants. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a method for accurately applying silicon fertilizer to Birch fujianensis, to promote the growth of Birch fujianensis, to improve the stress resistance of Birch fujianensis seedlings, and to improve the mechanical properties of Birch fujianensis wood after it matures.

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

[0008] A method for precisely applying silicon fertilizer to birch, comprising fertilizing at the seedling stage and fertilizing at the mature plant stage; fertilizing at the seedling stage comprises applying straw organic fertilizer, silica ash and superphosphate as base fertilizer before sowing, irrigating with sodium silicate and zinc sulfate after the true leaves unfold, and spraying with seaweed extract and silica sol when the seedlings reach a height of 10-15 cm; fertilizing at the mature plant stage comprises applying nitrogen, phosphorus and potassium compound fertilizer and calcium silicate to the roots before budding in spring, and spraying with calcium magnesium fertilizer and nano-silicon dioxide during the rapid growth period in summer.

[0009] Preferably, the seedling stage is from sowing to transplanting at the second year, and the mature plant stage is from transplanting to maturity.

[0010] Preferably, before sowing, straw organic fertilizer 1.5-2.5kg / m 2 , silica fume 30-50g / m 2 With superphosphate 30-50g / m 2 Mix into the seedbed soil.

[0011] Preferably, after the true leaves are unfolded, a mixed solution of 0.03%-0.05% sodium silicate and 0.04-0.06% zinc sulfate is irrigated.

[0012] More preferably, the application amount of the mixed solution is 100-150 mL / plant, applied once every 1-2 weeks, and applied 2-3 times.

[0013] Preferably, the seedlings are 10-15 cm tall and are sprayed with a mixture of 0.1-0.2% seaweed extract and 0.1-0.3% silica sol until water droplets appear on the leaves but do not drip.

[0014] Preferably, before the spring buds emerge, 50-80 g of N:P2O5:K2O=10-20-10 compound fertilizer × transplanting years / plant and 10-15 g of calcium silicate × transplanting years / plant are applied to the roots.

[0015] More preferably, before the spring buds emerge, 5-7 g of silicon-dissolving bacteria agent is mixed and applied × transplanting years / plant, and the number of effective living bacteria of the bacteria agent is ≥ 2 × 10 8 CFU / g.

[0016] Preferably, during the summer rapid growth period, 5-10 g of calcium magnesium fertilizer × transplanting years / plant and 1-2 g of nano silicon dioxide × transplanting years / plant are sprayed.

[0017] Preferably, the fertilization at the adult stage also includes applying base fertilizer to the roots before dormancy in autumn; the base fertilizer includes 0.2-0.4 kg of decomposed organic fertilizer × transplanting years / plant, and 20-30 g of silicon calcium magnesium fertilizer × transplanting years / plant.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The precise silicon fertilization method for birch trees provided by the present invention forms a systematic nutrition management program by scientifically planning the type, amount, and application time of fertilizers at different growth stages. This method has significant advantages in promoting the growth of birch trees and improving wood properties, as follows:

[0020] Applying straw organic fertilizer, silica ash and superphosphate as base fertilizer before sowing can improve soil structure, promote seed germination and increase the emergence rate; apply sodium silicate and zinc sulfate after the true leaves unfold, and spray seaweed essence and silica sol when the seedlings are 10-15cm tall to promote seedling growth, optimize emergence characteristics, especially increase the phytolith content, and enhance the seedlings' resistance to lodging and resistance to pests.

[0021] By combining the nutritional needs of the budding and rapid-growing stages with the supplementation of trace elements, the nutrient supply is highly aligned with the physiological needs of the birch. Experiments have shown that the fertilization method of the present invention can promote the growth of the birch, increasing its plant height and diameter at breast height. The method also promotes the deposition of silicon in the xylem, thereby improving the mechanical properties of the wood. DETAILED DESCRIPTION

[0022] The present invention provides a method for precise silicon fertilization of birch trees. By optimizing the type and ratio of fertilizers, the method promotes the emergence and growth of birch trees and improves their stress resistance. It can also improve the mechanical properties of the wood of mature birch trees. The method comprises the following steps:

[0023] In the present invention, the seedling stage is from sowing to transplanting at the second year, and the mature plant stage is from transplanting to maturity. In the mature plant stage, the amount of fertilizer is gradually increased with the number of years of transplanting.

[0024] 1. Fertilization during the seedling stage:

[0025] (1) Before sowing:

[0026] Apply straw organic fertilizer, silica fume and superphosphate as base fertilizer; preferably straw organic fertilizer 1.5-2.5kg / m 2 , silica fume 30-50g / m 2 With superphosphate 30-50g / m 2 Mix and apply to seedbed soil; further preferred straw organic fertilizer 2kg / m 2 , silica fume 40g / m 2 With superphosphate 40g / m 2 . Straw organic fertilizer and silica fume can improve soil structure, increase soil organic matter content, and provide a good soil environment for seed germination and seedling growth; superphosphate can provide the phosphorus element required for seedling growth and promote root development. The present invention has no special restrictions on the specific sources of straw organic fertilizer, silica fume and superphosphate. As an implementable embodiment, the straw organic fertilizer is made by fermenting and composting crop straw, silica fume is an industrial by-product, and superphosphate is purchased directly from the market.

[0027] The present invention does not specifically limit the sowing method of Fujian birch. As an implementable embodiment, the sowing and seedling raising method of CN110999701A is adopted. The seedbed soil is slightly acidic loam. A layer of humus soil with a thickness of 0.8 cm is spread, and then a layer of red heart soil with a thickness of 2 cm is spread. It is then scraped flat with a board and base fertilizer is mixed in the red heart soil.

[0028] (2) After the true leaves unfold:

[0029] Irrigate with sodium silicate and zinc sulfate; preferably, irrigate with a mixture of 0.03%-0.05% sodium silicate and 0.04-0.06% zinc sulfate; further preferably, irrigate with a mixture of 0.04% sodium silicate and 0.05% zinc sulfate. The preferred amount of the mixture applied is 100-150 mL / plant, further preferably 125 mL / plant; preferably, apply once every 1-2 weeks, 2-3 times, further preferably, apply once every 10 days, and apply twice in a row. Sodium silicate can provide silicon for seedlings, and silicon can enhance the stress resistance of seedlings; zinc sulfate provides zinc, which participates in the synthesis of various enzymes in plants and plays an important role in the growth and development of seedlings.

[0030] (3) Seedling height 10-15cm:

[0031] Spray seaweed extract and silica sol. Preferably, spray a mixture of 0.1-0.2% seaweed extract and 0.1-0.3% silica sol until water forms on the leaves but does not drip. More preferably, spray a mixture of 0.15% seaweed extract and 0.2% silica sol. Seaweed extract contains various plant hormones, amino acids, and trace elements, which can promote the growth and development of seedlings. Silica sol forms a protective film on the leaves, enhancing their mechanical strength and resistance to stress.

[0032] 2. After 2 years of cultivation, the seedlings of Betula Fujianensis are transplanted out of the garden and fertilized when they enter the mature stage:

[0033] (1) Before bud break in spring:

[0034] Apply nitrogen, phosphorus and potassium compound fertilizer and calcium silicate to the roots; preferably, apply N:P2O5:K2O=10-20-10 compound fertilizer 50-80g×transplanting years / plant and calcium silicate 10-15g×transplanting years / plant to the roots; further preferably, apply N:P2O5:K2O=10-20-10 compound fertilizer 65g×transplanting years / plant and calcium silicate 12.5g×transplanting years / plant to the roots.

[0035] As a feasible implementation method, in the first year after transplanting, apply 65g / plant of N:P2O5:K2O=10-20-10 compound fertilizer and 12.5g / plant of calcium silicate to the roots; in the second year, apply 130g / plant of N:P2O5:K2O=10-20-10 compound fertilizer and 25g / plant of calcium silicate to the roots; ... in the fifth year, apply 325g / plant of N:P2O5:K2O=10-20-10 compound fertilizer and 62.5g / plant of calcium silicate to the roots; ... in the tenth year, apply 650g / plant of N:P2O5:K2O=10-20-10 compound fertilizer and 125g / plant of calcium silicate to the roots.

[0036] Before spring bud break, the roots of birch trees begin to activate, and dormant bud cells accelerate division, leading to the onset of leaf expansion. This period also sees a surge in demand for nitrogen (to promote leaf formation), phosphorus (to activate root enzymes), and potassium (to regulate osmotic pressure). Compound fertilizers high in phosphorus can stimulate the division of the root apical meristem and enhance the young roots' ability to absorb silicon and potassium. Supplemental silicon fertilizers strengthen the cuticle of newly formed leaves and reduce cell membrane damage caused by low temperatures in early spring.

[0037] In the present invention, it is preferred that the above-mentioned fertilization be mixed with a silicon-dissolving bacterial agent 5-7g × transplanting years / plant, with the effective viable bacterial count of the bacterial agent ≥ 2×10 8 CFU / g; further preferably, a silica-degrading agent (6g x transplanting years / plant) is applied. Silica-degrading agents can decompose soil-fixed silicon into a soluble form (H4SiO4), increasing the bioavailability of silicon.

[0038] (2) Summer rapid growth period:

[0039] Spray calcium magnesium fertilizer and nano silicon dioxide; preferably spray calcium magnesium fertilizer 5-10g×transplanting years / plant, nano silicon dioxide 1-2g×transplanting years / plant; further preferably spray calcium magnesium fertilizer 7.5g×transplanting years / plant, nano silicon dioxide 1.5g×transplanting years / plant.

[0040] During the rapid growth period in summer, the xylem of the stem of the Fujian birch grows thicker rapidly, the photosynthetic rate of the leaves reaches its peak, and the high temperature leads to enhanced transpiration, which makes calcium and magnesium easy to be lost. 2+ ) can stabilize the pectin in the cell wall and prevent cell collapse at high temperatures, magnesium (Mg 2+ ) as the core element of chlorophyll, ensuring the efficiency of light reaction; nano-silica directly enters the mesophyll cells through the stomata, enhancing the mechanical strength of the mesophyll cells.

[0041] In the present invention, it is preferred that the mature plant stage also includes root basal fertilizer before autumn dormancy, further preferably including 0.2-0.4kg of decomposed organic fertilizer × transplanting years / plant, 20-30g of silicon calcium magnesium fertilizer × transplanting years / plant, more preferably 0.3kg of decomposed organic fertilizer × transplanting years / plant, and 25g of silicon calcium magnesium fertilizer × transplanting years / plant. Before autumn dormancy, the leaves of the Fujian birch begin to fall off, the root system enters the second growth peak, and nutrients flow back to the roots for storage. The decomposed organic fertilizer slowly releases humic acid, stimulating the root system to produce new absorbing roots; supplementary application of silicon calcium magnesium fertilizer promotes root development and tree growth.

[0042] In the present invention, when applying fertilizer to the roots, a circular trench with a depth of 20-30 cm is opened along the outer edge of the crown projection. The fertilizer is mixed with the topsoil and then covered with soil and watered. When spraying fertilizer, it is preferred to spray on a cloudy day or in the evening until the leaf surface is evenly moistened but not dripping.

[0043] In the present invention, it is preferred to further include applying quicklime or sulfur powder to the transplanting site after transplanting to adjust the soil pH to 5.5-6.5, and more preferably to 6.0. Betula pentandra is a slightly acidic tree species (pH 5.5-6.5), and adjusting the soil pH to this range is beneficial to the growth of Betula pentandra.

[0044] The present invention has no special limitation on the sources of the fertilizers or microbial agents used, and they can all be purchased from commercial sources.

[0045] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0046] Example 1

[0047] A method for accurately applying silicon fertilizer to birch, comprising the following steps:

[0048] Fertilization during the seedling stage:

[0049] (1) Before sowing

[0050] Straw organic fertilizer 2kg / m 2 , silica fume 40g / m 2 With superphosphate 40g / m 2 Mix into the seedbed soil.

[0051] (2) After the true leaves unfold

[0052] Apply a mixture of 0.04% sodium silicate and 0.05% zinc sulfate at a rate of 125 mL per plant, once every 10 days for two consecutive times.

[0053] (3) When the seedling height is 10-15cm

[0054] Spray a mixture of 0.15% seaweed essence and 0.2% silica sol until water droplets appear on the leaves but do not drip.

[0055] Fertilization during the mature stage:

[0056] The initial pH of the soil at the transplanting planting site was 5.4, which was adjusted to 6.0 by applying quicklime.

[0057] (1) Before spring bud break

[0058] Apply N-P2O5-K2O=10-20-10 compound fertilizer 65g×transplanting years / plant and calcium silicate 12.5g×transplanting years / plant at the root, and mix with silicon-dissolving bacteria agent 6g×transplanting years / plant (effective live bacteria count ≥2×10 8 CFU / g); dig a circular trench (25 cm deep) along the outer edge of the crown projection, mix the fertilizer with the topsoil, and then cover with soil and irrigate.

[0059] (2) Summer rapid growth period

[0060] At 4 p.m. on a cloudy day, spray calcium magnesium fertilizer 7.5g × transplanting years / plant (CaO:MgO=2:1) ​​and nano silicon dioxide 1.5g × transplanting years / plant (nano SiO2 content 30%) until the leaves are evenly moist but not dripping.

[0061] (3) Before autumn dormancy

[0062] Apply 0.3 kg of decomposed organic fertilizer × transplanting years / plant (prepared by mixed fermentation of cow dung: straw = 7:3) and 25 g of silicon, calcium and magnesium fertilizer × transplanting years / plant to the roots; dig a circular ditch (25 cm deep) along the outer edge of the crown projection, mix the fertilizer with the topsoil, cover with soil and water.

[0063] Example 2

[0064] A method for accurately applying silicon fertilizer to birch, comprising the following steps:

[0065] Fertilization during the seedling stage:

[0066] (1) Before sowing

[0067] Straw organic fertilizer 1.5kg / m 2 , silica fume 30g / m 2 With superphosphate 30g / m 2 Mix into the seedbed soil.

[0068] (2) After the true leaves unfold

[0069] Apply a mixture of 0.03% sodium silicate and 0.04% zinc sulfate at a rate of 100 mL per plant, once a week for a total of three times.

[0070] (3) When the seedling height is 10-15cm

[0071] Spray a mixture of 0.1% seaweed essence and 0.1% silica sol until water droplets appear on the leaves but do not drip.

[0072] Fertilization during the mature stage:

[0073] The initial pH of the soil at the transplanting planting site was 5.4, which was adjusted to 6.0 by applying quicklime.

[0074] (1) Before spring bud break

[0075] Apply N-P2O5-K2O=10-20-10 compound fertilizer 50g×transplanting years / plant and calcium silicate 10g×transplanting years / plant at the root, and mix with silicon-dissolving bacteria agent 5g×transplanting years / plant (effective live bacteria count ≥2×10 8 CFU / g); dig a circular trench (20 cm deep) along the outer edge of the crown projection, mix the fertilizer with the topsoil, and then cover with soil and irrigate.

[0076] (2) Summer rapid growth period

[0077] At 4 p.m. on a cloudy day, spray calcium magnesium fertilizer 5g × transplanting years / plant (CaO:MgO=2:1) ​​and nano silicon dioxide 1g × transplanting years / plant (nano SiO2 content 30%) until the leaves are evenly moist but not dripping.

[0078] (3) Before autumn dormancy

[0079] Apply 0.2 kg of decomposed organic fertilizer × transplanting years / plant (prepared by mixed fermentation of cow dung: straw = 7:3) and 20 g of silicon, calcium and magnesium fertilizer × transplanting years / plant to the roots; dig a circular ditch (20 cm deep) along the outer edge of the crown projection, mix the fertilizer with the topsoil, cover with soil and water.

[0080] Example 3

[0081] A method for accurately applying silicon fertilizer to birch, comprising the following steps:

[0082] Fertilization during the seedling stage:

[0083] (1) Before sowing

[0084] Straw organic fertilizer 2.5kg / m 2 , silica fume 50g / m 2 With superphosphate 50g / m 2 Mix into the seedbed soil.

[0085] (2) After the true leaves unfold

[0086] Apply a mixture of 0.05% sodium silicate and 0.06% zinc sulfate at a rate of 150 mL per plant, once every two weeks for two consecutive times.

[0087] (3) When the seedling height is 10-15cm

[0088] Spray a mixture of 0.2% seaweed essence and 0.3% silica sol until water droplets appear on the leaves but do not drip.

[0089] Fertilization during the mature stage:

[0090] The initial pH of the soil at the transplanting planting site was 6.7, which was adjusted to 6.3 by applying sulfur powder.

[0091] (1) Before spring bud break

[0092] Apply N-P2O5-K2O=10-20-10 compound fertilizer 80g×transplanting years / plant and calcium silicate 15g×transplanting years / plant, and mix with silicon-dissolving bacteria agent 7g×transplanting years / plant (effective live bacteria count ≥2×10 8 CFU / g); dig a circular trench (30 cm deep) along the outer edge of the crown projection, mix the fertilizer with the topsoil, and then cover with soil and irrigate.

[0093] (2) Summer rapid growth period

[0094] At 4 p.m. on a cloudy day, spray calcium magnesium fertilizer 10g × transplanting years / plant (CaO:MgO=2:1) ​​and nano silicon dioxide 2g × transplanting years / plant (nano SiO2 content 30%) until the leaves are evenly moist but not dripping.

[0095] (3) Before autumn dormancy

[0096] Apply 0.4 kg of decomposed organic fertilizer × transplanting years / plant (prepared by mixed fermentation of cow dung: straw = 7:3) and 30 g of silicon calcium magnesium fertilizer × transplanting years / plant to the roots; dig a circular ditch (30 cm deep) along the outer edge of the crown projection, mix the fertilizer with the topsoil, cover with soil and water.

[0097] Test Example 1

[0098] Effects of fertilization methods at the seedling stage on the growth (plant height, stem diameter, and crown width) of Betula fujianensis seedlings

[0099] 1. Experimental Design

[0100] Materials: Yellow Betula pumila seeds (from Fujian Forestry Academy, 1000-grain weight ≥ 0.15 g, germination rate ≥ 60%).

[0101] Grouping (3 replicates per group, 50 seedlings per replicate):

[0102] CK group (blank control): only basic seedbed (slightly acidic loam, sprinkled with a layer of 0.8 cm thick humus soil, then sprinkled with a layer of 2 cm thick red heart soil, and then leveled with a board), no fertilizer.

[0103] CF group (conventional fertilization): According to the local nursery conventional method (compound fertilizer 50g / m before sowing 2; spray 0.1% urea after true leaves unfold).

[0104] Group T1 (full fertilizer of the present invention): Fertilization was carried out according to Example 1 at the seedling stage (basal fertilizer: straw organic fertilizer, silica ash 4 kg / m 2 + superphosphate 40g / m 2 When the leaves are in the true leaf stage, irrigate with 125 mL / plant of a mixture of 0.04% sodium silicate + 0.05% zinc sulfate; when the seedlings are 12 cm tall, spray with 0.15% seaweed essence + 0.2% silica sol).

[0105] Group T2 (silicon removal according to the present invention): Based on T1, all silicon-related fertilizers were removed (only straw organic fertilizer and superphosphate were applied as base fertilizer; only zinc sulfate was applied during the true leaf stage; and only seaweed extract was applied during the seedling height stage).

[0106] Management: Greenhouse cultivation (25±2℃), uniform irrigation (maintain soil moisture 60%), light 12h / d.

[0107] 2. Measurement indicators and methods

[0108] Seedling emergence rate (%): Statistical data were collected on the 20th day after sowing.

[0109] Growth indicators (measured every 30 days):

[0110] Plant height (cm): vertical height from stem base to terminal bud.

[0111] Stem diameter (mm): diameter 1 cm above the cotyledons (vernier caliper).

[0112] Number of leaves: True leaves with an expanded number ≥1 cm are counted as effective leaves.

[0113] Biomass (at the time of leaving the field):

[0114] Dry weight of aboveground part (g): oven-dried at 105℃ to constant weight.

[0115] Root activity (μg / g·h): Dehydrogenase activity was determined by TTC method.

[0116] Phytolith content at the time of transplanting (mg / g dry weight): 10 seedlings were randomly selected from each group, and the middle part of the stem was taken as a sample. After washing with deionized water, it was dried at 105℃ to constant weight and ground into powder. The powder was then chemically digested to remove organic matter such as cellulose, lignin, protein, and soluble minerals such as calcium and magnesium, leaving only pure phytoliths for determination of their content.

[0117] 3. Test results

[0118] As shown in Table 1, the seedling emergence rate in the T1 group was significantly higher than that in the CF and CK groups, indicating that the straw organic fertilizer and silica fume + superphosphate base fertilizer effectively improved the soil structure of the seedbed and promoted seed germination. At 60 days, plant height in the T1 group was 43.7% higher than in the CF group, demonstrating that the sodium silicate + zinc sulfate combination significantly accelerated early vegetative growth. All indices in the T2 group were significantly lower than those in the T1 group, indicating that silica sol and seaweed extract synergistically enhance leaf mechanical strength and photosynthetic efficiency, directly promoting biomass accumulation. Root activity in the T1 group was 2.1 times that of the CK group, indicating that sodium silicate significantly activated root metabolism, laying the foundation for rapid growth in the adult stage. The phytolith density and content in the T1 group were significantly higher than in the other groups, indicating that applying silicon fertilizer during the seedling stage significantly promotes phytolith synthesis and deposition in the stems of the Fujian birch, thereby enhancing lodging resistance and pest resistance.

[0119] Table 1 Effects of different fertilization methods on growth indicators and outplanting characteristics of Betula fusca seedlings

[0120]

[0121] Test Example 2

[0122] Effects of fertilization methods after seedling emergence on stress resistance (drought resistance, cold resistance and pathogen resistance) of Betula fujianensis seedlings

[0123] 1. Experimental Design

[0124] When the Betula fujianensis seedlings were planted in the nursery (seedlings were 2 years old), three stress tests were conducted (30 seedlings in each group, 3 replicates):

[0125] (1) Drought stress: Stop watering for 7 days, and measure the wilting index (0-5, 0 = no wilting) and the survival rate after rehydration for 24 hours.

[0126] (2) Low temperature stress: The seedlings were placed in an artificial climate chamber at 5°C for 48 h, and the electrolyte permeability (relative conductivity method) and leaf malondialdehyde (MDA) content (thiobarbituric acid method) were measured.

[0127] (3) Pathogen inoculation: Leaves were inoculated with a suspension of spores of Colletotrichum fuscae (10 5 Spores / mL), and the lesion area of ​​the whole plant was measured after 72 hours (mm 2 ).

[0128] 2. Test results

[0129] As shown in Table 2, the wilting index of the T1 group was only 1.3, and the rehydration survival rate reached 92.4%, which was significantly better than the CK group and the CF group. This is because straw organic fertilizer, silica ash and sodium silicate improved the water retention capacity of the soil around the roots, and the protective film formed by silica sol on the leaf surface can reduce transpiration water loss. At the same time, zinc sulfate and seaweed extract synergistically enhanced the cell osmotic pressure regulation ability; the survival rate of the T2 group decreased by 17.4% compared with T1, confirming the core role of silicon in the drought resistance mechanism. The electrolyte permeability and MDA content of the T1 group were significantly lower than those of the CK group, indicating that the cell membrane damage caused by low temperature was significantly reduced. Calcium silicate and silicon-dissolving bacteria promote the deposition of silicon in the cell wall, forming a "silicification barrier", which can reduce the rate of loss of cell membrane fluidity at low temperatures; Ca in calcium magnesium fertilizer 2+ It stabilizes cell membrane protein structure and reduces electrolyte extravasation. Due to a lack of silicon fertilizer, the MDA content in group T2 increased by 37.4% compared to group T1, indicating that the synergistic effect of silicon, calcium, and magnesium is key to cold resistance. The lesion area in group T1 was 54.7% smaller than in group CK. This is directly related to the mechanical barrier formed by silica sol within mesophyll cells—siliceous deposition hinders the penetration of pathogenic hyphae—and the phytohormones in seaweed extract can induce the expression of pathogenesis-related proteins. The lesion area in group T2 increased by 44.1% compared to group T1, further demonstrating the essential role of silicon in enhancing disease resistance in Fujian birch.

[0130] Table 2 Effects of different fertilization methods on stress resistance of Betula fujianensis seedlings at transplanting

[0131]

[0132] Test Example 3

[0133] Effects of fertilization methods at the mature stage on growth indicators (tree height, diameter at breast height) and wood mechanical properties (density, flexural strength) of Betula fujianensis

[0134] 1. Experimental Design

[0135] Thirty Betula fujianensis seedlings of similar growth were selected and transplanted to red soil (pH 6.0±0.2, organic matter content 2.1%). They were randomly divided into three groups of 10 plants each. The three groups received the same irrigation, weeding, and pest control, and fertilization for eight consecutive years.

[0136] CK group (conventional fertilization group): 500 g / plant of N:P2O5:K2O=15-15-15 compound fertilizer was applied to the roots in spring, summer and autumn respectively.

[0137] Group T1 (complete fertilizer of the present invention): fertilization was performed according to the fertilization method in the mature plant stage of Example 1.

[0138] Group T2 (silicon removal according to the present invention): The difference from the fertilization method of T1 is that silicon fertilizer, silicon-degrading bacteria agent and nano-silicon dioxide were not applied.

[0139] 2. Index measurement

[0140] Growth indicators: Plant height and diameter at breast height (DBH) were measured in November of each year, 1, 3, and 8 years after transplanting. Wood properties were also measured 8 years after fertilization: wood cores (5 mm in diameter) were collected from the base of the trunk and tested for basic density (GB / T 1933-2009, Wood Density Determination Method) and flexural strength (three-point bending test, ASTM D143-2014). Average values ​​were calculated.

[0141] 3. Test results

[0142] As shown in Table 3, the plant height growth of the T1 group (full fertilizer) in the first year was significantly higher than that of the CK group and the T2 group, reflecting the promoting effect of silicon fertilizer on early growth. The diameter at breast height reached 8.2 cm in the fourth year, which is in line with the characteristics of the fast-growing period of Fujian birch (annual average thickening ≥ 2 cm). The growth index of the T2 group (silicon-free) was better than that of the CK but significantly lower than that of the T1, proving that silicon is a key factor in synergizing with nitrogen, phosphorus and potassium to improve growth efficiency. The basic density of the T1 group increased by 7.5% compared with the CK group, because silicon promoted the silicification of the xylem cell wall and increased the density of microfibrils. The flexural strength of the T1 group increased by 21.5% compared with the CK group, because nano-silicon dioxide and calcium magnesium fertilizer synergistically enhanced the cellulose-lignin cross-linking strength.

[0143] Table 3 Effects of different fertilization methods on growth indicators and wood mechanical properties of Betula fusca

[0144]

[0145]

[0146] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for precise silicon fertilization of birch, characterized in that: Including fertilization at the seedling stage and fertilization at the mature plant stage; The fertilization at the seedling stage includes applying straw organic fertilizer, silica ash and superphosphate as base fertilizer before sowing, applying sodium silicate and zinc sulfate after the true leaves unfold, and spraying seaweed essence and silica sol when the seedlings are 10-15 cm tall; The fertilization at the adult stage includes applying nitrogen, phosphorus and potassium compound fertilizer and calcium silicate to the roots before budding in spring, and spraying calcium magnesium fertilizer and nano silicon dioxide during the rapid growth period in summer.

2. The method according to claim 1, characterized in that The seedling stage is from sowing to planting of the Fujian birch at the second year, and the mature plant stage is from planting and transplanting of the Fujian birch to maturity.

3. The method according to claim 1, characterized in that Before sowing, straw organic fertilizer 1.5-2.5kg / m 2 , silica fume 30-50g / m 2 With superphosphate 30-50g / m 2 Mix into the seedbed soil.

4. The method according to claim 1, wherein After the true leaves are unfolded, a mixed solution of 0.03%-0.05% sodium silicate and 0.04-0.06% zinc sulfate is irrigated.

5. The method according to claim 4, characterized in that The application amount of the mixed solution is 100-150 mL / plant, applied once every 1-2 weeks, and applied 2-3 times.

6. The method according to claim 1, characterized in that The seedlings are 10-15 cm tall and are sprayed with a mixture of 0.1-0.2% seaweed essence and 0.1-0.3% silica sol until water droplets appear on the leaves but do not drip.

7. The method according to claim 1, characterized in that Before the spring buds sprout, apply N:P2O5:K2O=10-20-10 compound fertilizer 50-80g×transplanting years / plant and calcium silicate 10-15g×transplanting years / plant to the roots.

8. The method according to claim 7, characterized in that Before the spring buds, apply the silicon-dissolving bacteria agent 5-7g × transplanting years / plant, and the effective living bacteria count of the bacteria agent is ≥2×10 8 CFU / g.

9. The method according to claim 1, characterized in that During the summer rapid growth period, spray calcium magnesium fertilizer 5-10g×transplanting years / plant and nano silicon dioxide 1-2g×transplanting years / plant.

10. The method according to claim 1, characterized in that The fertilization at the adult stage also includes applying base fertilizer to the roots before dormancy in autumn; the base fertilizer includes 0.2-0.4 kg of decomposed organic fertilizer × transplanting years / plant, and 20-30 g of silicon calcium magnesium fertilizer × transplanting years / plant.

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