Reusable turf-free special substrate for rape seedling culture and preparation method of reusable turf-free special substrate

Abstract

The invention discloses a reusable turf-free special substrate for rape seedling culture and a preparation method thereof. The invention relates to a reusable turf-free special substrate for rape seedling culture. The reusable turf-free special substrate comprises 50-65% of an organic carrier, 30-45% of an inorganic auxiliary material and 5-7% of a nutrition and biological regulation agent, the percentage is mass percentage; the nutrition and biological regulating agent consists of a slow-release nutrition bag and a microbial agent in a mass ratio of (3-5): (1-2); the slow-release nutrition comprises sulfur coated urea, ammonium polyphosphate and potassium humate; the mass ratio of N in the sulfur coated urea to P2O5 in the ammonium polyphosphate to K2O in the potassium humate is (15-20): (10-15): (18-25), and the coating thickness of the sulfur coated urea is 10-15 [mu] m; and the biological regulating agent is at least one of trichoderma harzianum T-22 or bacillus subtilis BS-208. Through precise formula design, a directional fermentation process and functional module integration, the problems of nutrient imbalance, structural defects, biological pollution and the like in the rape seedling raising stage are systematically solved.

Description

Technical Field

[0001] The invention relates to a reusable peat-free special substrate for rapeseed seedling cultivation and a preparation method thereof, and belongs to the technical field of rapeseed planting. Background Art

[0002] At present, the preparation of rapeseed seedling substrate mainly relies on the following technical routes:

[0003] (1) Universal seedling medium:

[0004] Ingredients and proportions: Mainly peat, vermiculite and perlite (typical volume ratio 6:2:2), with a small amount of compound fertilizer (N-P2O5-K2O=15-15-15).

[0005] Process steps: coarse crushing of raw materials → simple mixing → adjusting pH to 6.0-6.5 → packaging.

[0006] Application status: It is widely used in the cultivation of seedlings of eggplants, fruits and leafy vegetables, but the effect is not good when directly applied to rapeseed seedlings.

[0007] (2) Organic waste regeneration matrix:

[0008] Raw materials: Agricultural waste (such as rice husks, mushroom residues, straw) is composted and fermented to replace peat.

[0009] Process: compost fermentation (temperature 50-60℃ for 15 days) → add inorganic auxiliary materials (such as leavening agent).

[0010] Defects: Incomplete fermentation leads to an imbalance in the carbon-nitrogen ratio (C / N>30), inhibiting nitrogen absorption by seedlings.

[0011] (3) Chemical synthesis of light matrix:

[0012] Methods: A porous structure was constructed with chemical materials such as polyacrylamide and urea-formaldehyde resin, and nutrient solution was added artificially.

[0013] Development bottleneck: high cost (average cost per mu is three times that of traditional substrates), and long-term use can easily lead to salt accumulation (EC value > 3.0mS / cm).

[0014] The existing rapeseed seedling substrate has the following problems:

[0015] (1) The nutrient supply does not match the needs of rapeseed seedlings:

[0016] Rapeseed seeds are sensitive to nitrogen from germination to the 2-leaf stage, and high concentrations of ammonium nitrogen (>50 mg / kg) inhibit radicle elongation (experimental data, see Acta Agronomica Sinica 2021). However, the general matrix releases nutrients too quickly, and low concentrations of nutrients (EC <1.5 mS / cm) are required during the seedling stage. However, the initial EC value of existing matrix is ​​generally >2.0 mS / cm, resulting in a seedling burn rate of >10%.

[0017] (2) The physical structure is not suitable for the development of rapeseed roots:

[0018] The pore distribution is unreasonable: the proportion of large pores (>100μm) is less than 15% (the ideal value is 25%-30%), and the root system hypoxia causes the number of lateral roots to decrease by 40%-50%.

[0019] Poor water holding capacity: The water content of the substrate fluctuates greatly (>80% after irrigation → <30% after 24 hours), causing water stress at the cotyledon stage.

[0020] (3) High risk of biological contamination:

[0021] Pathogen residues: Organic matter that has not been thoroughly fermented carries root rot bacteria (such as Pythium ultimum), with an incidence rate of 12%-18% during the seedling stage (comparative test data).

[0022] Allelopathic inhibition: When the concentration of phenolic acids (such as vanillic acid) in straw compost is greater than 20 μg / g, the elongation of rapeseed hypocotyls is inhibited (literature support: DOI 10.1016 / j.plaphy.2020.05.035).

[0023] (4) Insufficient environmental adaptability:

[0024] Poor temperature buffering: The thermal conductivity of traditional substrates is high (>0.8W / m·K). When raising seedlings in early spring, the temperature of the root layer is 3-5℃ lower than the environment, delaying emergence by 2-3 days.

[0025] Low pH stability: The pH of the peat substrate dropped from 6.2 to 4.8 after continuous irrigation, resulting in calcium deficiency heart leaf curl.

[0026] (5) Sustainability Deficiencies

[0027] Dependence on peat resources: Peat mining destroys wetland ecology. The EU has enacted law to restrict its use (imposing an environmental tax from 2024), forcing costs to rise.

[0028] Non-reusable: The traditional matrix is ​​severely hardened after use (bulk density from 0.3g / cm 3 Increased to 0.9g / cm 3 ), the secondary utilization rate is less than 30%. Summary of the invention

[0029] The present invention provides a reusable peat-free rapeseed seedling-specific substrate and a preparation method thereof, which systematically solves the problems of nutrient imbalance, structural defects, biological pollution, etc. in the seedling stage through precise formula design, directional fermentation process and functional module integration.

[0030] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0031] A reusable peat-free rapeseed seedling-specific matrix, comprising 50-65% of an organic carrier, 30-45% of an inorganic auxiliary material, and 5-7% of a nutrient and biological regulator; the percentages are by mass;

[0032] The nutrition and biological regulators are composed of a slow-release nutrition package and a microbial agent in a mass ratio of (3-5):(1-2);

[0033] The slow-release nutrient includes sulfur-coated urea, ammonium polyphosphate and potassium humate; the mass ratio of N in the sulfur-coated urea, P2O5 in the ammonium polyphosphate and K2O in the potassium humate is (15-20): (10-15): (18-25), and the coating thickness of the sulfur-coated urea is 10-15 μm;

[0034] The biological regulator is composed of Trichoderma harzianum T-22, Bacillus subtilis BS-208 and Bacillus mucilaginosus ACCC 10015, and the volume ratio of the three is (1:1:0.5-1). % in this application is not specifically stated, and all the ratios are mass percentages; all the ratios are not specifically stated, and all the ratios are mass ratios.

[0035] The mass sum of the above organic carrier, inorganic auxiliary material and nutrition and biological regulator is 100%.

[0036] The slow-release nutrient package in this application has a release period of 30-40 days, which matches the demand curve of rapeseed seedlings: "low nutrients before the 2-leaf stage, and increased fertilizer requirements after the 4-leaf stage".

[0037] Trichoderma harzianum T-22: spore concentration ≥ 1×10 8 CFU / g, degrade allelopathic substances such as vanillic acid and ferulic acid, directly decompose the ester bonds or carboxyl groups of allelopathic substances, make them lose their toxicity, and promote the healthy growth of plants.

[0038] Bacillus subtilis BS-208: spore concentration ≥ 5×10 7 CFU / g, secreted antimicrobial peptides to inhibit root rot bacteria (inhibition rate ≥85%).

[0039] In order to improve the growth stability of rapeseed seedlings, the inorganic auxiliary material contains functional additives, which are composed of thermosensitive gel microspheres and palygorskite powder in a mass ratio of (2-3): (1-2); wherein the thermosensitive gel microspheres are: acrylic acid-chitosan copolymer microspheres, with a particle size of 0.5-1mm, a phase change temperature of 15-25°C, releasing heat at low temperatures (solidification heat), absorbing heat at high temperatures, maintaining the root zone temperature stable within ±2°C, and a water holding rate of ≥400%; palygorskite powder: 200 mesh, pH buffering capacity ≥50mmol / kg, stabilizing the pH of the matrix; palygorskite powder absorbs organic acids secreted by Bacillus mucilaginosus through ion exchange, delays acid depletion, and prolongs the phosphorus activation cycle to more than 30 days.

[0040] The inorganic auxiliary material is composed of expanded vermiculite, perlite and functional additives in a mass ratio of (15-25): (10-15): (3-5).

[0041] The above expanded vermiculite has a particle size of 3-6 mm and a bulk density of 0.1-0.2 g / cm 3 , porosity ≥ 80%; perlite, particle size 2-4mm, pre-washed to EC value ≤ 0.5mS / cm to reduce salt interference.

[0042] In order to improve the seedling rate, the organic carrier is composed of a mushroom residue-biochar complex and decomposed straw compost in a mass ratio of (40-60): (5-10); the mushroom residue-biochar complex is a mixture of fermented mushroom residue and rice husk charcoal in a mass ratio of 1: (1-2), and the moisture content is ≤10%.

[0043] The C / N ratio of the fermentation residue is 25-30; the specific surface area of ​​the rice husk charcoal is ≥200m 2 / g, porosity ≥80%; phenolic acid content in mature straw compost ≤5μg / g, cellulose degradation rate ≥85%.

[0044] The raw material used for the above-mentioned mature straw composting is a mixture of wheat straw (cut into 3-5 cm sections) and chicken manure with a C / N ratio of 25-28:1.

[0045] The rice husk charcoal replaces peat, provides a stable source of organic matter, adsorbs phenolic acid allelopathic substances (adsorption rate>90%), and optimizes the pore structure.

[0046] The method for preparing the above-mentioned fungus residue-biochar complex comprises the following steps:

[0047] 1) Mushroom residue crushing and adjustment:

[0048] Crush fresh edible fungus cultivation waste (oyster mushroom residue, shiitake mushroom residue) to a particle size of ≤5 mm, adjust the water content to 55-60% (spray deionized water or dry), and obtain fungus residue;

[0049] 2) Directed fermentation:

[0050] Adding bacterial agents: inoculating cellulose-decomposing bacteria into the fungus residue, with an inoculation amount of 0.5-1wt% (based on the mass of the fungus residue); wherein the cellulose-decomposing bacteria are Trichoderma viride and Bacillus licheniformis in a volume ratio of 1:2;

[0051] Fermentation conditions: temperature of 55-60 DEG C, killing insect eggs (lethal temperature of flea beetle eggs ≥53 DEG C), retaining functional microbial activity, maintaining for 5-7 days, turning the pile once every 24 hours, ensuring oxygen penetration, and obtaining fermented fungus residue; premixing 0.2wt% of Bacillus subtilis spore powder (based on the mass of the fermented fungus residue) in the fermented fungus residue, using the residual phosphate in the fermented fungus residue as an inducer, and activating the phosphate-solubilizing function of the strain in advance.

[0052] 3) Biochar composite:

[0053] The fungus residue obtained in step 2) is mixed with rice husk charcoal in a mass ratio of 1:(1-2), and dried at 50-60° C. until the moisture content is ≤10%, to form a fungus residue-biochar complex.

[0054] The method for preparing the above-mentioned mature straw compost comprises the following steps:

[0055] 1) Raw material pretreatment:

[0056] Cut wheat straw into 3-5cm segments, mix with chicken manure at a C / N ratio of 25-28:1, and adjust the initial moisture content to 60-65%;

[0057] 2) High temperature fermentation (divided into three stages):

[0058] Stage 1 (warming period): adding 0.2 wt% of EM bacteria and 0.1 wt% of white rot fungi based on the weight of wheat straw, and maintaining at 40-50°C for 3 days;

[0059] Stage 2 (high temperature period): 55-65℃ for 10-12 days, turning the pile every day to kill pathogens (such as Pythium spore inactivation rate> 99%);

[0060] Stage 3 (maturity): 40-45℃ for 7 days, spray lime water to adjust pH to 6.5-7.0;

[0061] 3) Screening and testing:

[0062] The undegraded crude fiber was removed by 10-mesh sieve, and the phenolic acid content was detected (HPLC method) ≤ 5 μg / g.

[0063] The method for preparing the above-mentioned reusable peat-free rapeseed seedling-specific substrate comprises the following steps:

[0064] 1) The organic carrier (mushroom residue-biochar complex + mature straw compost) and the expanded vermiculite and perlite in the inorganic auxiliary materials are put into a double-shaft mixer in proportion, and mixed at a speed of 20-25 rpm for 15-20 minutes to ensure uniformity (coefficient of variation ≤ 5%);

[0065] 2) Under the condition of temperature ≤40°C, add the slow-release nutrient pack, the mixture of Trichoderma harzianum T-22 and Bacillus subtilis BS-208, the thermosensitive gel microspheres, Bacillus colloids (need to be packaged separately and added before the palygorskite powder is added) and palygorskite powder in stages. Except for Bacillus colloids, stir the previous material at 20-25rpm for 3-5 minutes before adding the next material; stir at 15-20rpm for 1-3 minutes after adding Bacillus colloids, add palygorskite powder, and stir at 20-25rpm for 5-8 minutes to obtain a mixed matrix;

[0066] That is to say, compared with other materials, the stirring speed and time after the addition of Bacillus colloids are shortened to avoid mechanical shear damage to the bacteria. The stirring speed and temperature after the addition of the slow-release nutrient package, the mixture of Trichoderma harzianum T-22 and Bacillus subtilis BS-208, and the thermosensitive gel microspheres are stirred at 20-25rpm for 3 to 5 minutes; the stirring speed and temperature after the addition of Bacillus colloids are stirred at 15-20rpm for 1 to 3 minutes; the stirring speed and temperature after the addition of palygorskite powder are stirred at 20-25rpm for 5 to 8 minutes.

[0067] 3) Spraying citric acid-potassium dihydrogen phosphate buffer (0.1 mol / L) into the mixed matrix to adjust the pH of the matrix to 6.0-6.5; then adding deionized water or humic acid solution to control the initial EC value to 1.2-1.5 mS / cm;

[0068] 4) Using ozone fumigation at a concentration of 50-80ppm for 2-3 hours can inactivate residual pathogens (such as Fusarium inactivation rate ≥ 99.5%) and retain beneficial microorganisms such as Trichoderma and Bacillus (survival rate ≥ 90%);

[0069] 5) The moisture content is controlled at 30-35% to avoid premature germination of microorganisms and ensure storage stability. It is vacuum packed at 5-10L / bag, the storage temperature is ≤25℃, and the shelf life is ≥6 months.

[0070] In the above step 2), the temperature is controlled at ≤40° C. to avoid inactivation of the bacterial agent (the survival rate of Trichoderma spores is ≥95%).

[0071] This application solves the problem of nutrient release mismatch:

[0072] The initial EC value of the existing matrix is ​​too high (>2.0mS / cm), resulting in a seedling burn rate of >10% during the seed germination period; the nitrogen form is unbalanced (ammonium nitrogen accounts for >50%), inhibiting the development of the radicle; the lack of a slow-release mechanism cannot match the growth curve of the seedlings with "low nutrients in the early stage and gradual demand in the later stage";

[0073] The slow-release nutrient package of the present application controls the release rate through the thickness of the sulfur coating (10-15 μm), so that the EC value is stabilized at 1.2-1.5 mS / cm; ammonium polyphosphate (water-soluble ≤5%) provides a neutral phosphorus source, avoids the toxicity of ammonium nitrogen (ammonium nitrogen accounts for less than 30% in the seedling stage), and matches the demand curve of rapeseed seedlings "low nutrients before the 2-leaf stage, and increased fertilizer requirements after the 4-leaf stage".

[0074] This application optimizes the physical structure of the substrate for rapeseed seedlings, breaks through the restrictions of traditional substrate pore distribution and water holding capacity on rapeseed seedlings, and adapts to root development:

[0075] The existing matrix macropores account for less than 15%, root hypoxia leads to a 40%-50% reduction in the number of lateral roots; the water holding rate fluctuates violently (80% after irrigation → <30% after 24 hours), causing water stress at the cotyledon stage; the bulk density is too high (>0.8g / cm 3 ), hindering the main root from taking root and the efficiency of nutrient absorption;

[0076] The biochar (porosity ≥ 80%) and vermiculite (bulk density 0.1-0.2g / cm 3 ) work synergistically to increase the proportion of macropores to 25-30%; the water holding rate of thermosensitive gel microspheres is ≥400%, which controls the fluctuation of matrix water content within 50%-70% (the fluctuation range of traditional matrix is ​​30-80%).

[0077] This application eliminates the risks of biological contamination and allelopathic inhibition:

[0078] The uncomposted organic matter in the existing substrate carries root rot pathogens (such as Pythium ultimum), and the disease rate during the seedling stage is >12%; the phenolic allelopathic substances in straw compost (such as vanillic acid concentration >20μg / g) inhibit hypocotyl elongation; the survival of insect eggs (flea beetles, aphids) increases the cost of pest control during the seedling stage.

[0079] The present application adopts ozone fumigation to replace traditional high-temperature sterilization, while eliminating pathogenic microorganisms, retaining the activity of Trichoderma harzianum T-22 (spore survival rate ≥ 95%); Trichoderma degrades vanillic acid to <5 μg / g (HPLC verification), eliminating allelopathic inhibition.

[0080] This application improves environmental adaptability and stability:

[0081] The existing matrix has a high thermal conductivity (>0.8W / m·K). In a low temperature environment, the temperature of the root layer is 3-5℃ lower than the environment, which delays emergence. After continuous irrigation, the pH drops sharply from 6.2 to 4.8, inducing calcium deficiency physiological diseases (such as heart leaf curl). Salt accumulation (EC value>3.0mS / cm) causes salt stress in seedlings, and the emergence rate decreases by>20%.

[0082] The pH buffering capacity of palygorskite powder in this application is ≥50mmol / kg, ensuring that the pH is stable at 6.0-6.8 after irrigation (the pH of traditional substrates fluctuates to 4.8); biochar-gel microspheres synergistically reduce the thermal conductivity to 0.3-0.5W / m·K (traditional substrates>0.8W / m·K); the EC value is controlled at 1.2-1.5mS / cm to avoid salt stress. It improves the seedling obstacles caused by insufficient substrate temperature, pH and salt buffering capacity.

[0083] This application achieves low carbonization and sustainability of the matrix:

[0084] The existing substrate has a high dependence on peat (accounting for more than 60%), and its mining damages the wetland ecology and the cost is rising year by year; the substrate is severely compacted after use (bulk density from 0.3g / cm 3 Increased to 0.9g / cm 3 ), the reuse rate is less than 30%; the cost of chemical synthetic substrates is high (the average cost per mu is 3 times that of traditional substrates), making it difficult to promote.

[0085] The present invention uses biochar to replace peat, reducing wetland damage; adding phosphate-solubilizing bacteria (Bacillus subtilis) to improve the effectiveness of phosphorus in the continuous cropping matrix, making the reuse rate reach 80% (traditional matrix <30%). This solves the core contradiction between the unsustainable resources and poor economic efficiency of traditional technologies.

[0086] The present invention aims at the core requirements of rapeseed seedling stage for low salt stress, high oxygen environment, temperature stability, biosafety and sustainability, and achieves the following goals by systematically solving the above five major technical problems:

[0087] Reduce the seedling burn rate during the seedling raising period from >10% to <3%;

[0088] Improve the germination rate to >95% (the average of traditional substrate is 78%);

[0089] Reduce the frequency of substrate replacement for successive cropping (extend from annual replacement to 3-year recycling).

[0090] The technologies not mentioned in the present invention are all referred to the prior art.

[0091] The present invention is significantly superior to the prior art in terms of seedling raising efficiency, resource utilization, environmental friendliness, etc. through innovative formula and process design. The specific beneficial effects are as follows:

[0092] 1. Significantly improved seedling raising efficiency and survival rate:

[0093] 1. The emergence rate and strong seedling rate have been significantly improved:

[0094] Seedling emergence rate: increased from 78% of traditional substrate to ≥95% (data from the example);

[0095] Seedling burn rate: reduced from >10% to ≤3%, EC value precisely controlled (1.2-1.5mS / cm) to avoid salt stress;

[0096] Strong seedling rate: the number of lateral roots increased by 50%, and the dry weight of the root system increased by 45% (control test P < 0.01).

[0097] 2. Shortened the seedling raising cycle:

[0098] Seedling emergence time: In the early spring, under low temperature conditions, the root zone temperature is stable (±2°C fluctuation), and the seedling emergence time is shortened by 2-3 days;

[0099] Seedling cycle: The proportion of seedlings that meet the standards at the 4-leaf stage increased from 60% to 90%, saving more than 20% of seedling management costs.

[0100] 2. Optimized resource utilization and cost control:

[0101] 1. Reduced raw material costs:

[0102] 60-70% of the peat in the existing substrate is completely replaced, achieving zero peat. The cost of the mushroom residue-biochar complex is only 40% of that of peat (the average substrate cost per mu is reduced from 800 yuan to 480 yuan).

[0103] 2. Realize waste resource utilization:

[0104] The utilization rate of agricultural waste such as mushroom residue and straw reaches 100%, reducing environmental pollution.

[0105] 3. Extend the service life of the substrate:

[0106] The reuse rate was improved: from <30% of the traditional substrate to ≥80%, and the porosity remained >70% after three consecutive years of cropping; after adding Bacillus subtilis, the effective phosphorus content in the substrate after three consecutive years of cropping was still maintained at ≥25mg / kg (initial value was 35mg / kg), while the control group (without phosphate-solubilizing bacteria) dropped to ≤8mg / kg.

[0107] Reduced nutrient supplement costs: Slow-release nutrient packs reduce the number of topdressing times and save 30% of fertilizer input.

[0108] 3. Environmental friendliness and significant ecological benefits:

[0109] 1. Reduce ecological damage:

[0110] Zero use of peat: avoiding wetland exploitation, reducing carbon emissions by 50kg per ton of substrate (based on LCA life cycle assessment);

[0111] Reduction of chemical pesticides: Microbial agents inhibit diseases, and the use of fungicides in the seedling stage is reduced by 70%;

[0112] Reduction of water eutrophication: Bacillus subtilis activates inherent phosphorus in the soil, reduces the amount of exogenous phosphorus fertilizer added by 30%, and reduces the risk of water eutrophication.

[0113] 2. Significant pollution prevention and control:

[0114] Allelopathic substance degradation: Trichoderma harzianum T-22 degraded phenolic acids to a safe threshold (<5 μg / g);

[0115] Zero salt discharge: No chemical synthetic materials are added to avoid the risk of secondary soil salinization.

[0116] 4. Improved operational convenience and stability:

[0117] 1. Simplified process:

[0118] Sterilization process: Ozone fumigation (2-3 hours) replaces traditional high-temperature sterilization (6-8 hours), reducing energy consumption by 60%;

[0119] Mixing uniformity: The dual-axis stirring process makes the coefficient of variation of matrix components ≤5% (conventional process>15%).

[0120] 2. Ability to adapt to environmental fluctuations:

[0121] Temperature buffer: Thermosensitive gel microspheres maintain stable root zone temperature, and the germination rate is still >90% in low temperature environment (5°C);

[0122] pH self-regulation: The buffering capacity of palygorskite powder is >50mmol / kg, and the pH is stabilized at 6.0-6.8 after continuous irrigation. DETAILED DESCRIPTION

[0123] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0124] In each case: Preparation of acrylic acid-chitosan copolymer microspheres reference: Khan MA, Azad AK, Safdar M, et al. Synthesis and characterization of acrylamide / acrylic acid Co-polymers and glutaraldehyde crosslinked pH-sensitive hydrogels [J]. Gels, 2022, 8 (1): 47.;

[0125] The coating thickness of sulfur-coated urea (Sinochem Fertilizer'Yihua' brand slow-release urea) is 10-15μm, the particle size is 2-4mm, and the 24-hour water solubility rate is ≤5%, which meets the GB / T 23348-2021 slow-release fertilizer standard.

[0126] Ammonium polyphosphate (purchased from Sichuan Longmang) is a long-chain water-insoluble phosphorus source with a degree of polymerization of ≥20, a P2O5 content of ≥70%, a pH of 6.0-7.0, and a particle size of 80-100 mesh.

[0127] Potassium humate (purchased from Shanxi Meibang) has a humic acid content of ≥60%, a K2O content of ≥12%, water-insoluble matter of ≤5%, and a pH of 8.0-9.5, which meets the HG / T 5046-2016 humic acid fertilizer standard.

[0128] Trichoderma harzianum T-22 was purchased from China Agricultural Microbiological Culture Collection Center (ACCC 30152);

[0129] Bacillus subtilis BS-208 was purchased from China Agricultural Microbiological Culture Collection Center (ACCC 11025);

[0130] Bacillus mucilaginosus was purchased from China Agricultural Microbiological Culture Collection ACCC 10015.

[0131] Trichoderma viride was purchased from China Agricultural Microbiological Culture Collection Center (ACCC 30115);

[0132] Bacillus licheniformis, purchased from Jiangsu Greentech Biotechnology Co., Ltd. LK-BL01 preparation, spore concentration 6×10 8 CFU / g;

[0133] The EM (Effective Microorganisms) bacteria are the WQ-EM compound bacterial agent produced by Beijing Woqi Biotechnology Co., Ltd.; the white rot fungus is bio-52267 produced by Beijing Biobowei Biotechnology Co., Ltd.

[0134] Example 1: Basic formula (mushroom residue-biochar complex accounts for 50%)

[0135] (1) Formula composition (mass percentage)

[0136] Organic carrier 58%, including:

[0137] Mushroom residue-biochar complex: 50% (mushroom residue: biochar = 1:1)

[0138] Mature straw compost: 8% (phenolic acid content 4.2μg / g, cellulose degradation rate 87%)

[0139] Inorganic auxiliary materials 35%, including:

[0140] Vermiculite: 20% (particle size 4mm, bulk density 0.15g / cm 3 )

[0141] Perlite: 12% (particle size 3mm, EC 0.4mS / cm)

[0142] Thermosensitive gel microspheres: 2% (acrylic acid-chitosan copolymer microspheres, particle size 0.5-1mm, phase transition temperature 18°C, water holding capacity ≥400%)

[0143] Palygorskite powder: 1% (200 mesh, pH buffering capacity ≥ 50mmol / kg)

[0144] Nutritional and biological regulators 7%, including:

[0145] Slow-release nutrient package: 5%; composed of sulfur-coated urea, ammonium polyphosphate and potassium humate, the mass ratio of N in sulfur-coated urea: P2O5 in ammonium polyphosphate: K2O in potassium humate is = 18:12:20, sulfur-coated urea: particle size 1-2mm, coating thickness 10-15μm; ammonium polyphosphate: water solubility ≤5%; potassium humate: chelated potassium. Glial Bacillus and ammonium polyphosphate form a "chemical slow release-biological activation" dual-pathway phosphorus supply mode, which increases the phosphorus utilization rate from 30% of the traditional matrix to 65%. Slow-release nutrient package, release period 30-40 days, matching the seedling growth curve.

[0146] Microbial agent: 2%, composed of Trichoderma harzianum T-22, Bacillus subtilis BS-208 and Bacillus subtilis in a volume ratio of 1:1:1, Trichoderma harzianum T-22 1×10 8 CFU / g, Bacillus subtilis BS-208 5×10 7 CFU / g, Bacillus spp.≥2.0×10 8 CFU / g.

[0147] (2) Preparation steps:

[0148] Pretreatment of fungus residue:

[0149] Crushed the mushroom residue into 3mm pieces and adjusted the moisture content to 58%;

[0150] Inoculate Trichoderma viride and Bacillus licheniformis (volume ratio 1:2) with an inoculation amount of 0.8%, ferment at 58°C for 6 days, turn the compost every day, and finally add 0.2wt% of Bacillus mucilaginosus spore powder;

[0151] After fermentation, the fungus residue (C / N=28) was mixed with rice husk charcoal in a ratio of 1:1 and dried at 60°C to a moisture content of 9.5%.

[0152] Preparation of mature straw compost:

[0153] Cut wheat straw into 4 cm segments, mix with chicken manure at a C / N ratio of 25, and adjust the moisture content to 62%;

[0154] Add EM (Effective Microorganisms) bacteria 0.2wt% + white rot fungi 0.1wt% according to the weight of wheat straw, ferment in three stages (40℃×3 days→60℃×12 days, daily turning→45℃×7 days), spray lime water to adjust the pH to 6.5-7.0;

[0155] After being decomposed, it was passed through a 10-mesh sieve and the phenolic acid content was 4.2 μg / g (HPLC detection).

[0156] Matrix Mixing:

[0157] The organic carrier and the inorganic auxiliary materials of expanded vermiculite and perlite were put into a double-shaft mixer (rotating speed 22 rpm, time 18 minutes);

[0158] The slow-release nutrient pack, the mixture of Trichoderma harzianum T-22 and Bacillus subtilis BS-208, the thermosensitive gel microspheres, the colloidal Bacillus and the palygorskite powder are added step by step, and the temperature is controlled to be ≤38°C; except for the colloidal Bacillus, the previous material is added and stirred at 22 rpm for 3 minutes, and then the next material is added, and the colloidal Bacillus is added and stirred at 18 rpm for 2 minutes, and the palygorskite powder is added and stirred at 22 rpm for 5 minutes to obtain a mixed matrix;

[0159] Spray 0.1 mol / L citric acid-potassium dihydrogen phosphate buffer into the mixed matrix, adjust the pH to 6.3, and add deionized water to adjust the EC value to 1.2 mS / cm (more suitable for salt-sensitive varieties).

[0160] Sterilization and packaging:

[0161] Ozone fumigation (concentration 65ppm, time 2.5 hours), vacuum packaging (8L / bag, moisture content 32%).

[0162] (3) Application and testing:

[0163] Seedling cultivation method:

[0164] Plug tray specifications: 72-well plug tray, each well filled with 20 mL of matrix;

[0165] Sowing: rapeseed variety "Zhongshuang No. 11", 2 seeds per hole, covering soil thickness 0.5cm;

[0166] Environment: day / night temperature 20℃ / 15℃, humidity 70%, natural light.

[0167] 15 days after sowing, the seedling emergence rate, seedling burn rate, root dry weight (mg), and root length (cm) were tested. The 4-leaf stage was considered mature.

[0168] Example 2: High biochar ratio scheme (mushroom residue-biochar complex accounts for 60%)

[0169] (1) Formula composition (mass percentage)

[0170] Organic carrier 65%, including:

[0171] Mushroom residue-biochar complex: 60% (mushroom residue: biochar = 1:2)

[0172] Mature straw compost: 5% (phenolic acid content 3.8μg / g)

[0173] Inorganic auxiliary materials 30%, including:

[0174] Vermiculite: 15% (particle size 4mm, bulk density 0.15g / cm 3 )

[0175] Perlite: 10% (particle size 3mm, EC 0.3mS / cm)

[0176] Thermosensitive gel microspheres: 3% (acrylic acid-chitosan copolymer microspheres, particle size 0.5-1mm, phase transition temperature 18°C, water holding capacity ≥400%)

[0177] Palygorskite powder: 2% (200 mesh, pH buffering capacity ≥ 50mmol / kg)

[0178] 5% nutrients and bioregulators, including:

[0179] Slow-release nutrient package: 4%; composed of sulfur-coated urea, ammonium polyphosphate and potassium humate, the mass ratio of N in sulfur-coated urea: P2O5 in ammonium polyphosphate: K2O in potassium humate is 20-10-25, sulfur-coated urea: particle size 1-2mm, coating thickness 10-15μm; ammonium polyphosphate: water solubility ≤5%; potassium humate: chelated potassium. Slow-release nutrient package, release period 30-40 days, matching the seedling growth curve.

[0180] Microbial agent: 1%; the composition is Trichoderma harzianum T-22, Bacillus subtilis BS-208 and Bacillus subtilis in a volume ratio of 1:1:1, Trichoderma harzianum T-22 1×10 8 CFU / g, Bacillus subtilis BS-208 5×10 7 CFU / g

[0181] (2) Preparation and application refer to Example 1.

[0182] (3) Test results

[0183] 1. Comparison of seedling raising performance (test period: 30 days)

[0184]

[0185] 2. Nutrient utilization and slow-release effect

[0186]

[0187] 3. Environmental adaptability and reusability

[0188]

[0189] Example 3: Low-cost formula (mushroom residue-biochar complex accounts for 40%)

[0190] (1) Formula composition (mass percentage)

[0191] Organic carrier module 50%, including:

[0192] Mushroom residue-biochar complex: 40% (mushroom residue: biochar = 1:1)

[0193] Mature straw compost: 10% (phenolic acid content 5.0μg / g)

[0194] Inorganic auxiliary materials module 45%, including:

[0195] Vermiculite: 20% (particle size 4mm, bulk density 0.15g / cm 3 )

[0196] Perlite: 15% (EC 0.5mS / cm)

[0197] Thermosensitive gel microspheres: 7% (0.5-1mm)

[0198] Palygorskite powder: 3% (200 mesh, pH buffering capacity ≥ 50mmol / kg)

[0199] Nutrition and Bioregulation module 5%, including:

[0200] Slow-release nutrient package: 3%; composed of sulfur-coated urea, ammonium polyphosphate and potassium humate, the mass ratio of N in sulfur-coated urea: P2O5 in ammonium polyphosphate: K2O in potassium humate is = 15-15-18, sulfur-coated urea: particle size 1-2mm, coating thickness 10-15μm; ammonium polyphosphate: water solubility ≤5%; potassium humate: chelated potassium. Slow-release nutrient package, release period 30-40 days, matching the seedling growth curve.

[0201] Microbial agent: 2%, composed of Trichoderma harzianum T-22, Bacillus subtilis BS-208 and Bacillus subtilis in a volume ratio of 1:1:1.

[0202] (2) Preparation and application: Refer to Example 1. Thermosensitive gel is omitted in this example: it is suitable for warm areas (ambient temperature>15°C).

[0203] Comparative Example 1

[0204] The traditional matrix of peat: vermiculite:perlite=6:2:2 was used as a comparison.

[0205] Comparative Example 2

[0206] Compared with Example 1, the slow-release nutrient package was omitted, and the rest was the same as in Example 1.

[0207] Comparative Example 3

[0208] Compared with Example 1, the biological regulator was omitted, and the rest was the same as in Example 1.

[0209] Performance comparison of each example

[0210]

[0211] Low temperature test example:

[0212] The germination of the seedlings in Example 2 and the traditional substrate under the low temperature environment in early spring was tested, and the rest was referred to Example 1.

[0213] Using the matrix of Example 2, in the early spring low temperature environment (day / night temperature 12°C / 5°C), the emergence rate is still >92%, the root zone temperature is 14±1.5°C, and the seedling period is 18 days. In the low temperature environment (5°C) of the traditional matrix, the emergence rate is 62%, the root zone temperature is 10.3±3.5°C, and the seedling period is 25 days. Compared with the traditional matrix, the number of lateral roots using the matrix of Example 2 increased by 52%, and the dry weight of the root system increased by 45.6%.

[0214] Example 2 The substrate maintained a porosity of >70% after three consecutive years of cropping, and the effective phosphorus content in the substrate maintained at ≥25 mg / kg (initial value was 35 mg / kg). However, the traditional substrate was severely hardened after one use, and the effective phosphorus content dropped to ≤8 mg / kg, and could not be reused.

[0215] The substrate cost of Example 2 is about 420 yuan / ton, and the average annual cost per mu is 320 yuan; while the traditional substrate cost is about 680 yuan / ton, and the average annual cost per mu is 800 yuan.

[0216] The present invention is the world's first rapeseed seedling-specific matrix that integrates slow-release nutrition + biological control + temperature control buffer matching; it realizes the "zero peat, low salt, high circulation" green seedling mode, which meets the EU ecological certification standards (EC 834 / 2007). After using the matrix of the present invention, the delivery cycle of rapeseed seedling orders is shortened by more than 5 days, and the customer complaint rate (weak seedlings, diseased seedlings) has dropped from 15% to less than 1%. 500 acres of seedling fields save 160,000 yuan in costs and increase revenue by 240,000 yuan per year.

Claims

1. A reusable peat-free rapeseed seedling-raising substrate, characterized in that: It includes 50-65% organic carrier, 30-45% inorganic auxiliary material and 5-7% nutrition and biological regulator; the percentages are by mass; The nutrient and biological regulator are composed of a slow-release nutrient package and a microbial agent in a mass ratio of (3-5):(1-2); The slow-release nutrient includes sulfur-coated urea, ammonium polyphosphate and potassium humate; the mass ratio of N in the sulfur-coated urea, P2O5 in the ammonium polyphosphate and K2O in the potassium humate is (15-20): (10-15): (18-25), and the coating thickness of the sulfur-coated urea is 10-15 μm; The biological regulator is composed of Trichoderma harzianum T-22, Bacillus subtilis BS-208 and Bacillus subtilis, and the volume ratio of the three is 1:1:(0.5~1).

2. The reusable peat-free rapeseed seedling-raising substrate according to claim 1 is characterized in that: The inorganic auxiliary material contains functional additives, which are composed of thermosensitive gel microspheres and palygorskite powder in a mass ratio of (2-3): (1-2); wherein the thermosensitive gel microspheres are: acrylic acid-chitosan copolymer microspheres, with a particle size of 0.5-1mm, a phase change temperature of 15-25°C, and a water holding rate of ≥400%; palygorskite powder: with a particle size of 150-200 meshes and a pH buffering capacity of ≥50mmol / kg.

3. The reusable peat-free rapeseed seedling-raising substrate according to claim 1 or 2, characterized in that: The inorganic auxiliary material consists of expanded vermiculite, perlite and functional additives in a mass ratio of (15-25):(10-15):(3-5).

4. The reusable peat-free rapeseed seedling-raising substrate according to claim 3 is characterized in that: Expanded vermiculite, particle size 3-6mm, bulk density 0.1-0.2g / cm 3 , porosity ≥ 80%; perlite, particle size 2-4mm, pre-washed to EC value ≤ 0.5mS / cm.

5. The reusable peat-free rapeseed seedling-raising substrate according to claim 1 or 2, characterized in that: The organic carrier is composed of a fungus residue-biochar complex and decomposed straw compost in a mass ratio of (40-60): (5-10); the fungus residue-biochar complex is mixed with fermented fungus residue and rice husk charcoal in a mass ratio of 1: (1-2), and the moisture content is ≤10%.

6. The reusable peat-free rapeseed seedling-raising substrate according to claim 5, characterized in that: The C / N ratio of fermented fungus residue is 25-30; the specific surface area of ​​rice husk charcoal is ≥200m 2 / g, porosity ≥80%; phenolic acid content in mature straw compost ≤5μg / g, cellulose degradation rate ≥85%.

7. The reusable peat-free rapeseed seedling-raising substrate according to claim 5, characterized in that: The raw material used for decomposed straw composting is a mixture of wheat straw and chicken manure with a C / N ratio of 25 to 28:

1.

8. The reusable peat-free rapeseed seedling-raising substrate according to claim 5, characterized in that: The preparation method of the fungus residue-biochar complex comprises the following steps: 1) Mushroom residue crushing and adjustment: The fresh edible fungus cultivation waste is crushed to a particle size of ≤5 mm, and the water content is adjusted to 55-60% to obtain fungus residue; 2) Directed fermentation: Adding bacterial agents: inoculating cellulose-decomposing bacteria into the bacterial residue, with an inoculation amount of 0.5-1wt%; wherein the cellulose-decomposing bacteria are Trichoderma viride and Bacillus licheniformis in a volume ratio of 1:2; Fermentation conditions: temperature 55-60°C, maintained for 5-7 days, turning the pile every 24 hours to obtain fermented fungus residue; premixing 0.2wt% of Bacillus subtilis spore powder into the fermented fungus residue; 3) Biochar composite: The fungus residue obtained in step 2) is mixed with rice husk charcoal in a mass ratio of 1:(1-2), and dried at 50-60° C. until the moisture content is ≤10%, to form a fungus residue-biochar complex.

9. The reusable peat-free rapeseed seedling-raising substrate according to claim 5, characterized in that: The method for preparing mature straw compost comprises the following steps: 1) Raw material pretreatment: Cut wheat straw into 3-5cm segments, mix with chicken manure at a C / N ratio of 25-28:1, and adjust the initial moisture content to 60-65%; 2) High temperature fermentation: Stage 1: Add 0.2wt% EM bacteria and 0.1wt% white rot fungi based on the weight of wheat straw, and maintain at 40-50℃ for 3 days; Stage 2: 55-65℃ for 10-12 days, turning the compost daily; Stage 3: 40-45℃ for 7 days, spraying lime water to adjust pH to 6.5-7.0; 3) Screening: The undegraded crude fiber was removed through a 10-mesh sieve, and the phenolic acid content was ≤5μg / g.

10. A method for preparing the reusable peat-free rapeseed seedling-specific substrate according to any one of claims 1 to 9, characterized in that: The steps include: 1) Add the expanded vermiculite and perlite in the organic carrier and the inorganic auxiliary materials in proportion into a biaxial mixer and mix them at a rotation speed of 20-25 rpm for 15-20 minutes; 2) under the condition of temperature ≤40°C, adding the slow-release nutrient pack, the mixture of Trichoderma harzianum T-22 and Bacillus subtilis BS-208, the thermosensitive gel microspheres, the colloidal Bacillus and the palygorskite powder in stages, except for the colloidal Bacillus, stirring the previous material at 20-25 rpm for 3-5 minutes, and then adding the next material, stirring the colloidal Bacillus at 15-20 rpm for 1-3 minutes after adding, adding the palygorskite powder, and stirring at 20-25 rpm for 5-8 minutes to obtain a mixed matrix; 3) Spraying citric acid-potassium dihydrogen phosphate buffer (0.1 mol / L) into the mixed matrix to adjust the pH of the matrix to 6.0-6.5; then adding deionized water or humic acid solution to control the initial EC value to 1.2-1.5 mS / cm; 4) Use ozone fumigation at a concentration of 50-80ppm for 2-3 hours to inactivate residual pathogens; 5) The moisture content is controlled at 30-35%, and the product is vacuum packed at 5-10L / bag. The storage temperature is ≤25℃ and the shelf life is ≥6 months.

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