Seedling raising substrate special for leaf vegetables

Abstract

The invention relates to the technical field of planting substrates, and particularly discloses a seedling substrate special for leafy vegetables. The substrate is prepared from a bottom substrate and a covering substrate material, wherein the bottom substrate is prepared from the following substances: turf, perlite, vermiculite, a water-retaining agent loaded with growth promoting elements, potassium nitrate, calcium superphosphate, Previcle and chlorothalonil; the covering substrate is composed of vermiculite and carbendazim. Compared with the prior art, the prepared seedling raising substrate has the advantages of being good in water-retaining property, high in seedling survival rate and the like.

Description

Technical Field

[0001] The invention relates to the technical field of planting substrates, and in particular to a special seedling raising substrate for leafy vegetables. Background Art

[0002] Compared with traditional soil cultivation, soilless cultivation can provide more nutrients needed for crop growth, avoid soil-related pests and diseases, save energy and labor, save water and fertilizer, and overcome geographical restrictions. Using soilless cultivation technology, an environment suitable for crop production requirements can be constructed in environments that restrict agricultural production, such as coke and desert, to achieve the purpose of resource conversion. Compared with hydroponic technology, the equipment required for matrix cultivation is low in cost and easy to operate. The solid matrix plays a buffering role and maintains a stable rhizosphere environment, which is similar to traditional soil cultivation, and the physical and chemical properties of the composite matrix are easy to control. The matrix is ​​a lightweight material that replaces soil to provide nutrition and growth environment for crops. It is rich in nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S) and other elements required for plant growth and development. It can replace soil and reduce the use of fertilizers. Widely used substrates include: peat, vermiculite, slag, etc.

[0003] Chinese patent 201811080699.1 discloses a functional seedling matrix, which is prepared by adding a water retaining agent and a binder to the seedling matrix; the water retaining agent is a starch-based super absorbent resin or potassium polyacrylate, and the binder is attapulgite. The functional matrix of this invention solves the problems of poor water retention and easy lumps of traditional seedling matrices. It not only has the strongest water retention capacity, but also can reduce water loss from daily watering when applied to actual production. At the same time, it can significantly shorten the emergence time and increase the emergence rate. The emergence rate reaches more than 80% on the third day; the functional seedling matrix of this invention can significantly improve water use efficiency, shorten the watering cycle, reduce the impact of drought stress and waterlogging stress on seedlings and promote seedling growth, improve seedling quality, and avoid the appearance of "high-legged seedlings"; when transplanting seedlings, it improves the quality of plug seedlings, shortens the seedling acclimatization time, and improves the survival rate of seedling transplanting; reduces capital costs and labor costs.

[0004] Chinese patent 202111157199.5 discloses a leafy vegetable cultivation matrix. The raw materials for preparing the matrix include 25 to 35 parts of decomposed straw, 20 to 30 parts of earthworm castings, 25 to 30 parts of coconut bran and 3 to 8 parts of oxidizing Bacillus agents by weight. The invention also discloses a preparation method and application of the above-mentioned leafy vegetable cultivation matrix. The leafy vegetable cultivation matrix of the invention does not contain peat components, which can effectively alleviate the contradiction between supply and demand of peat resources. As a beneficial microorganism, oxidizing Bacillus can promote the synthesis of free amino acids in leafy vegetables. The cultivation matrix of the invention is used to grow leafy vegetables, with high yield and high content of free amino acids in the leaves. The preparation method is simple and can be produced in a factory.

[0005] The seedling substrates of the prior art have achieved good results for the cultivation of leafy vegetables, but there are still problems such as poor water retention in the traditional substrate formula, insufficient water after sowing to last until the germination period, and drought during the germination period. At the same time, most substrates have very poor water retention due to their loose texture and strong water permeability, and most of the water leaks out, resulting in a waste of water resources and an increase in labor; the too loose texture of the substrate will also cause the substrate to clump easily, resulting in poor buffering capacity of the seedlings, slow acclimatization in the soil after transplanting, and even reducing the survival rate of transplanting. Summary of the invention

[0006] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a special seedling-raising matrix for leafy vegetables with good water-retaining properties.

[0007] Water retainer, also known as super absorbent polymer, is a water-swelling polymer containing strong hydrophilic groups such as carboxyl and hydroxyl groups and a certain degree of crosslinking. It has the characteristics of strong water absorption, wide source of materials, and easy preparation. It is widely used in agricultural development. After adding water retainer to the soil, it can reduce the bulk density of the soil, increase the total porosity, improve the overall air permeability of the soil, and improve the utilization efficiency of water and fertilizer. Adding water retainer to the seedling medium can not only reduce water loss, but also improve the survival rate of seedlings.

[0008] At present, the types of water retainers are mainly sodium polyacrylate and amide, starch, cellulose and other types. Polyacrylate water retainers and divalent metals such as calcium, magnesium, and manganese in the soil are prone to antagonistic reactions, reducing their water absorption multiples and application effects. Therefore, a new type of water retainer is developed in the present invention, which is modified with cellulose as a skeleton and then grafted with acrylic acid, and then polymerized with polyvinyl pyrrolidone to form an interpenetrating network cross-linked with each other, thereby retaining nitrogen fertilizer and phosphate fertilizer in the network structure, and the amino group in urea can also form hydrogen bonds with the groups on the structure, thereby forming chemical adsorption, further improving the load degree. The prepared water retainer has good water retention capacity, and the network structure formed by it can load the growth-promoting fertilizer therein, which can not only improve the water retention capacity of the matrix and reduce the water permeability, but also play a role in the slow release of nutrients, thereby improving the survival rate of seedlings.

[0009] To achieve the above-mentioned purpose, the present invention provides a seedling raising matrix specially used for leafy vegetables, which is prepared by a bottom matrix and a covering matrix material. The bottom matrix is ​​composed of the following substances: peat, perlite, vermiculite, a water-retaining agent loaded with growth-promoting elements, potassium nitrate, superphosphate, chlorpyrifos, and thiophanate-methyl; the covering matrix is ​​composed of vermiculite and carbendazim.

[0010] The seedling culture matrix comprises, by weight percentage, 45-60% of peat, 20-35% of perlite, 15-20% of vermiculite, 0.15-0.5% of a water retaining agent loaded with growth-promoting elements, 0.0005-0.0015% of potassium nitrate, 0.005-0.015% of superphosphate, 0.0005-0.0015% of polichloramine, 0.0005-0.0015% of thiophanate-methyl, and 0.0005-0.0015% of carbendazim.

[0011] The preparation method of the water-retaining agent loaded with growth-promoting elements comprises the following steps:

[0012] S1: adding 5-15 parts by weight of microcrystalline cellulose to 500-1500 parts by weight of water, then adding 15-35 parts by weight of potassium persulfate and 6-18 parts by weight of cerium ammonium nitrate, stirring for 0.5-2 hours and centrifuging, and drying the residue to obtain a solid; adding the solid to a mixed solution of 300-550 parts by weight of ethanol and sodium hydroxide aqueous solution (volume ratio = 5:1), then adding 150-450 parts by weight of acetone, stirring for 1-2 hours and centrifuging, and washing the residue with acid, water and alcohol, and then drying to obtain modified cellulose;

[0013] S2: adding the modified cellulose in step S1 to 500-1500 parts by weight of water, and then adding 65-100 parts by weight of acrylic acid, 10-25 parts by weight of ethylene glycol dimethacrylate, 15-25 parts by weight of ammonium persulfate and 1-5 parts by weight of urea, heating to 60-80°C and stirring for 1-2h, then adding 10-20 parts by weight of potassium dihydrogen phosphate and 15-40 parts by weight of polyvinyl pyrrolidone, continuing to stir for 2-8h, centrifuging, and drying the residue to obtain a water-retaining agent loaded with growth-promoting elements.

[0014] Furthermore, the mass ratio of the vermiculite used in the bottom matrix and the covering matrix is ​​(150-180):1.

[0015] Beneficial effects of the present invention:

[0016] 1. Compared with the prior art, the matrix in the present invention has strong water retention, can significantly improve water utilization efficiency, and greatly reduce water loss.

[0017] 2. The present invention improves the heat preservation and moisture retention properties of the matrix by adding perlite and vermiculite, and increases the degree of voids in the matrix, which is more conducive to rooting; the use of fungicides reduces the risk of pathogens and improves the disease resistance of seedlings; and the water-retaining agent loaded with growth-promoting elements solves the problems of poor water retention and loss of nutrients at the same time. DETAILED DESCRIPTION

[0018] Polyvinylpyrrolidone, M w =10000.

[0019] Sodium polyacrylate, M w <10000, Shandong Yaotu Biological.

[0020] Comparative Example 1

[0021] The invention discloses a seedling raising matrix specially used for leafy vegetables, which is prepared from a bottom matrix and a covering matrix material, and is prepared from the following raw materials in percentage by weight: the bottom matrix comprises 58.4875% of peat, 25% of perlite, 16% of vermiculite, 0.4% of sodium polyacrylate, 0.001% of potassium nitrate, 0.01% of superphosphate, 0.0005% of chlorpyrifos and 0.0005% of chlorothalonil; the covering matrix comprises 0.1% of vermiculite and 0.0005% of carbendazim.

[0022] Comparative Example 2

[0023] The invention discloses a seedling raising matrix specially used for leafy vegetables, which is prepared from a bottom matrix and a covering matrix material, and is prepared from the following raw materials in percentage by weight: the bottom matrix comprises 58.8875% of peat, 25% of perlite, 16% of vermiculite, 0.001% of potassium nitrate, 0.01% of superphosphate, 0.0005% of chlorpyrifos and 0.0005% of chlorothalonil; the covering matrix comprises 0.1% of vermiculite and 0.0005% of carbendazim.

[0024] Example 1

[0025] A seedling raising matrix specially used for leafy vegetables is prepared from a bottom matrix and a covering matrix material, and is prepared from the following raw materials in percentage by weight: the bottom matrix comprises 58.4875% of peat, 25% of perlite, 16% of vermiculite, 0.4% of a water retaining agent loaded with growth-promoting elements, 0.001% of potassium nitrate, 0.01% of superphosphate, 0.0005% of chlorpyrifos and 0.0005% of thiophanate-methyl; the covering matrix comprises 0.1% of vermiculite and 0.0005% of carbendazim.

[0026] The preparation method of the water-retaining agent loaded with growth-promoting elements comprises the following steps:

[0027] S1: 10 g of microcrystalline cellulose was added to 1 L of water, and then 20 g of potassium persulfate and 11 g of cerium ammonium nitrate were added, and the mixture was stirred for 1 h and then centrifuged at 8500 rpm for 10 min. The residue was dried to obtain a solid; the solid was added to a mixed solution of 450 mL of ethanol and 10 wt% sodium hydroxide aqueous solution (volume ratio = 5:1), and then 300 mL of acetone was added. The mixture was stirred for 2 h and then centrifuged at 10000 rpm for 5 min. The residue was acid washed, water washed, and alcohol washed, and then dried to obtain modified cellulose;

[0028] S2: Add the modified cellulose in step S1 to 1L of water, then add 85g of acrylic acid, 15g of ethylene glycol dimethacrylate, 20g of ammonium persulfate and 4.5g of urea, heat to 70°C and stir for 2h, then add 15g of potassium dihydrogen phosphate and 30g of polyvinyl pyrrolidone, continue stirring for 6h, centrifuge at 10000rpm for 5min, and dry the residue to obtain a water-retaining agent loaded with growth-promoting elements.

[0029] Example 2

[0030] A seedling raising matrix specially used for leafy vegetables is prepared from a bottom matrix and a covering matrix material, and is prepared from the following raw materials in percentage by weight: the bottom matrix comprises 58.4875% of peat, 25% of perlite, 16% of vermiculite, 0.4% of a water retaining agent loaded with growth-promoting elements, 0.001% of potassium nitrate, 0.01% of superphosphate, 0.0005% of chlorpyrifos and 0.0005% of thiophanate-methyl; the covering matrix comprises 0.1% of vermiculite and 0.0005% of carbendazim.

[0031] The preparation method of the water-retaining agent loaded with growth-promoting elements comprises the following steps:

[0032] S1: 10 g of microcrystalline cellulose was added to 1 L of water, and then 20 g of potassium persulfate and 11 g of cerium ammonium nitrate were added, and the mixture was stirred for 1 h and then centrifuged at 8500 rpm for 10 min. The residue was dried to obtain a solid; the solid was added to a mixed solution of 450 mL of ethanol and 10 wt% sodium hydroxide aqueous solution (volume ratio = 5:1), and then 300 mL of acetone was added. The mixture was stirred for 2 h and then centrifuged at 10000 rpm for 5 min. The residue was acid washed, water washed, and alcohol washed, and then dried to obtain modified cellulose;

[0033] S2: Add the modified cellulose in step S1 to 1L of water, then add 55g of acrylic acid, 15g of ethylene glycol dimethacrylate, 20g of ammonium persulfate and 4.5g of urea, heat to 70°C and stir for 2h, then add 15g of potassium dihydrogen phosphate and 30g of polyvinyl pyrrolidone, continue stirring for 6h, centrifuge at 10000rpm for 5min, and dry the residue to obtain a water-retaining agent loaded with growth-promoting elements.

[0034] Example 3

[0035] A seedling raising matrix specially used for leafy vegetables is prepared from a bottom matrix and a covering matrix material, and is prepared from the following raw materials in percentage by weight: the bottom matrix comprises 58.4875% of peat, 25% of perlite, 16% of vermiculite, 0.4% of a water retaining agent loaded with growth-promoting elements, 0.001% of potassium nitrate, 0.01% of superphosphate, 0.0005% of chlorpyrifos and 0.0005% of thiophanate-methyl; the covering matrix comprises 0.1% of vermiculite and 0.0005% of carbendazim.

[0036] The preparation method of the water-retaining agent loaded with growth-promoting elements comprises the following steps:

[0037] S1: 10 g of microcrystalline cellulose was added to 1 L of water, and then 20 g of potassium persulfate and 11 g of cerium ammonium nitrate were added, and the mixture was stirred for 1 h and then centrifuged at 8500 rpm for 10 min. The residue was dried to obtain a solid; the solid was added to a mixed solution of 450 mL of ethanol and 10 wt% sodium hydroxide aqueous solution (volume ratio = 5:1), and then 300 mL of acetone was added. The mixture was stirred for 2 h and then centrifuged at 10000 rpm for 5 min. The residue was acid washed, water washed, and alcohol washed, and then dried to obtain modified cellulose;

[0038] S2: Add the modified cellulose in step S1 to 1L of water, then add 95g of acrylic acid, 15g of ethylene glycol dimethacrylate, 20g of ammonium persulfate and 4.5g of urea, heat to 70°C and stir for 2h, then add 15g of potassium dihydrogen phosphate and 30g of polyvinyl pyrrolidone, continue stirring for 6h, centrifuge at 10000rpm for 5min, and dry the residue to obtain a water-retaining agent loaded with growth-promoting elements.

[0039] Example 4

[0040] A seedling raising matrix specially used for leafy vegetables is prepared from a bottom matrix and a covering matrix material, and is prepared from the following raw materials in percentage by weight: the bottom matrix comprises 58.4875% of peat, 25% of perlite, 16% of vermiculite, 0.4% of a water retaining agent loaded with growth-promoting elements, 0.001% of potassium nitrate, 0.01% of superphosphate, 0.0005% of chlorpyrifos and 0.0005% of thiophanate-methyl; the covering matrix comprises 0.1% of vermiculite and 0.0005% of carbendazim.

[0041] The preparation method of the water-retaining agent loaded with growth-promoting elements comprises the following steps:

[0042] S1: 10 g of microcrystalline cellulose was added to 1 L of water, and then 20 g of potassium persulfate and 11 g of cerium ammonium nitrate were added, and the mixture was stirred for 1 h and then centrifuged at 8500 rpm for 10 min. The residue was dried to obtain a solid; the solid was added to a mixed solution of 450 mL of ethanol and 10 wt% sodium hydroxide aqueous solution (volume ratio = 5:1), and then 300 mL of acetone was added. The mixture was stirred for 2 h and then centrifuged at 10000 rpm for 5 min. The residue was acid washed, water washed, and alcohol washed, and then dried to obtain modified cellulose;

[0043] S2: Add the modified cellulose in step S1 to 1L of water, then add 85g of acrylic acid, 15g of ethylene glycol dimethacrylate, 20g of ammonium persulfate and 4.5g of urea, heat to 70°C and stir for 2h, then add 15g of potassium dihydrogen phosphate and 10g of polyvinyl pyrrolidone, continue stirring for 6h, centrifuge at 10000rpm for 5min, and dry the residue to obtain a water-retaining agent loaded with growth-promoting elements.

[0044] Example 5

[0045] A seedling raising matrix specially used for leafy vegetables is prepared from a bottom matrix and a covering matrix material, and is prepared from the following raw materials in percentage by weight: the bottom matrix comprises 58.4875% of peat, 25% of perlite, 16% of vermiculite, 0.4% of a water retaining agent loaded with growth-promoting elements, 0.001% of potassium nitrate, 0.01% of superphosphate, 0.0005% of chlorpyrifos and 0.0005% of thiophanate-methyl; the covering matrix comprises 0.1% of vermiculite and 0.0005% of carbendazim.

[0046] The preparation method of the water-retaining agent loaded with growth-promoting elements comprises the following steps:

[0047] S1: 10 g of microcrystalline cellulose was added to 1 L of water, and then 20 g of potassium persulfate and 11 g of cerium ammonium nitrate were added, and the mixture was stirred for 1 h and then centrifuged at 8500 rpm for 10 min. The residue was dried to obtain a solid; the solid was added to a mixed solution of 450 mL of ethanol and 10 wt% sodium hydroxide aqueous solution (volume ratio = 5:1), and then 300 mL of acetone was added. The mixture was stirred for 2 h and then centrifuged at 10000 rpm for 5 min. The residue was acid washed, water washed, and alcohol washed, and then dried to obtain modified cellulose;

[0048] S2: Add the modified cellulose in step S1 to 1L of water, then add 85g of acrylic acid, 15g of ethylene glycol dimethacrylate, 20g of ammonium persulfate and 4.5g of urea, heat to 70°C and stir for 2h, then add 15g of potassium dihydrogen phosphate and 40g of polyvinyl pyrrolidone, continue stirring for 6h, centrifuge at 10000rpm for 5min, and dry the residue to obtain a water-retaining agent loaded with growth-promoting elements.

[0049] Test Example 1

[0050] 100g of the water-retaining agent used in the control example and the example was immersed in sufficient water at room temperature to reach a saturated state. Then, the saturated sample (W1) was weighed, and after 12 hours, the sample was taken out, the surface water was wiped off, and the sample was weighed (W2). Water retention = (W2 / W1)*100%.

[0051] Table 1 Water retention rate test of water retaining agent

[0052] Experimental protocol Water retention / % Comparative Example 1 50.3 Example 1 75.1 Example 2 65.4 Example 3 70.4 Example 4 66.2 Example 5 71.6

[0053] From the water retention test, it can be seen that the water-retaining agent prepared in the embodiment has stronger water retention than the conventional water-retaining agent. This may be because cellulose is used as a skeleton to graft and polymerize with acrylic acid, and then forms a network structure entangled with each other with polyvinyl pyrrolidone, which greatly improves the swelling ability. The large number of hydrophilic groups in the molecular structure itself can absorb a large amount of water, and the network structure formed can firmly lock the absorbed water. The amount of acrylic acid added in Examples 2 to 3 is different from that in Example 1, resulting in different water retention rates. This may be because when the amount of acrylic acid is small, the number of hydrophilic groups in the obtained water-retaining agent will also be small, and when the amount of acrylic acid is large, it will increase the cross-linking degree and the structure of the polymer network is too tight, thereby affecting the water absorption. The amount of polyvinyl pyrrolidone added in Examples 4 to 5 is different from that in Example 1. As a linear molecular chain that connects the overall structure in series, the amount added will affect the size of the gaps in the network structure finally formed, thereby affecting the water retention rate.

[0054] Test Example 2

[0055] The total porosity of the matrix reflects the sum of its air and water spaces. Select a container with a volume of V and a weight of m1, put the matrix into the container after drying and weigh m2; soak it in water for 24 hours, weigh the air weight m3; drain the water from the container and weigh m4; calculate the bulk density and porosity according to the following formula. Bulk density (g / cm 3 )=(m2-m1) / V;Total porosity (%)=100%×(m3-m2) / V;Ventilation porosity (%)=100%×(m4-m3) / V. pH determination of matrix: Mix soil and water in a mass ratio of 2:1, stir clockwise with a glass rod for 1min, let stand for 30min, and measure with a pH meter; EC determination of matrix: Mix soil and water in a mass ratio of 2:1, shake for 5min, filter with filter paper, and measure with an EC meter.

[0056] Table 2 Physicochemical properties of the matrix

[0057]

[0058] Seedling medium should have functions similar to soil, need to have good air permeability, water retention, fertilizer retention, etc., structure and composition meet the requirements of plant growth; to have chemical stability, acidity and alkalinity determine nutrient absorption capacity, soluble salt determines the salt concentration around the root system. The formula in the present invention reduces the matrix bulk density by adding raw materials such as perlite and vermiculite as a whole, ensures higher total porosity and ventilation porosity, and the obtained matrix can better coordinate the relationship between root moisture and gas supply. It can be seen from the test results that the matrix formula of the present invention reaches a lower bulk density and better porosity by adding raw materials such as perlite and vermiculite, which can improve the matrix heat preservation and moisture retention performance more suitable for rooting on the one hand, and can also coordinate the relationship between root moisture and gas supply on the one hand. The water retaining agent expands in volume after absorbing water, and the formation of a gel state will have an impact on the physicochemical properties of the matrix, but generally speaking, there is no significant effect.

[0059] Test Example 3

[0060] After mixing and stirring the matrix in the control example embodiment, it was divided into 50-hole seedling trays, and 1 pepper seed was sown in each hole. The seed variety was three ribs, and the sowing depth was 0.5-1.5 cm. After sowing, the composite matrix was covered and then watered. 50 days after sowing, 10 pepper seedlings were randomly sampled from each treatment, and the morphological indicators of the pepper seedlings were measured, including plant height (the distance from the base of the stem to the top crown of the plant), stem diameter, fresh mass and dry mass of the aboveground part, and fresh mass and dry mass of the underground part. The average value was calculated and recorded in the table. The seedling index was calculated based on the measured data. Seedling index = (stem diameter / plant height + underground dry mass / aboveground dry mass) × whole plant dry mass.

[0061] Table 3 Effect of seedling medium on seedling growth

[0062]

[0063] Seedling cultivation is one of the important links in vegetable cultivation, and the quality of seedlings will directly affect the growth and yield of vegetables. Therefore, in order to ensure the quality of seedlings, it is particularly important to select a suitable matrix. The role of the seedling matrix is ​​the same as that of soil, which can support crops and provide nutrients for crops. However, it is different from soil and even better than soil in some aspects. The nutrients contained in different seedling matrices are different, which have an important impact on the plant height, stem diameter, plant fresh quality and dry mass of seedlings, and will have a direct impact on the growth and development of seedlings after transplanting, thereby affecting the yield of crops and then affecting economic benefits. From the comparison of the reference example and the embodiment, it can be found that when the water retaining agent is not added to the matrix, the growth and development of the seedlings will be affected due to its poor water retention, and the growth-promoting elements in the embodiment are not added in the reference example, so the overall growth is not good, and the water retaining agent loaded with growth elements is added in the embodiment, which can not only play a good water retention role, but also can promote the development of seedlings by slowly releasing growth elements, so the seedlings are of good quality, the root system is strong and the growth is good. However, due to the differences in water retention capacity among the different water retaining agents in the examples, the growth potential of the seedlings eventually differed.

[0064] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A seedling-raising substrate for leafy vegetables, characterized in that: The invention is prepared from a bottom matrix and a covering matrix material. The bottom matrix is ​​composed of the following substances: peat, perlite, vermiculite, a water retaining agent loaded with growth-promoting elements, potassium nitrate, superphosphate, pulic acid, and thiophanate-methyl; the covering matrix is ​​composed of vermiculite and carbendazim.

2. The seedling culture medium according to claim 1, wherein: Calculated by weight percentage, it includes 45-60% of peat, 20-35% of perlite, 15-20% of vermiculite, 0.15-0.5% of a water-retaining agent loaded with growth-promoting elements, 0.0005-0.0015% of potassium nitrate, 0.005-0.015% of superphosphate, 0.0005-0.0015% of Prochloraz, 0.0005-0.0015% of Thiophanate-methyl, and 0.0005-0.0015% of Carbendazim.

3. The seedling culture medium according to claim 1, wherein: The water retaining agent loaded with growth-promoting elements is obtained by modifying cellulose, grafting and polymerizing it with acrylic acid, polyvinyl pyrrolidone, etc., and adding nitrogen and phosphorus fertilizers to load it during the polymerization.

4. The seedling culture matrix according to claim 3, wherein The preparation method of the water-retaining agent loaded with growth-promoting elements comprises the following steps: S1: Disperse microcrystalline cellulose in water, add potassium persulfate and cerium ammonium nitrate, stir for 0.5 to 2 hours, centrifuge, and dry the residue to obtain a solid; add the solid to a mixed solution of ethanol and sodium hydroxide aqueous solution, add acetone, stir for 1 to 2 hours, centrifuge, and wash the residue with acid, water, and alcohol, and then dry to obtain modified cellulose; S2: Dispersing the modified cellulose in step S1 in water, adding acrylic acid, ethylene glycol dimethacrylate, ammonium persulfate and urea, adding potassium dihydrogen phosphate and polyvinyl pyrrolidone after heating and stirring, continuing stirring for 2 to 8 hours, centrifuging, and drying the residue to obtain a water-retaining agent loaded with growth-promoting elements.

5. The seedling culture medium according to claim 4, wherein: The volume ratio of ethanol to sodium hydroxide aqueous solution in step S1 is 5:

1.

6. The seedling culture medium according to claim 4, wherein: The heating temperature in step S2 is 60-80°C.

7. The seedling culture medium according to claim 4, wherein: The stirring time in step S2 is 1 to 2 hours.

8. The seedling raising matrix according to claim 1, wherein: The mass ratio of the vermiculite used in the bottom matrix and the covering matrix is ​​(150-180):1.

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