CN111374026A - Special seedling culture substrate and preparation method thereof - Google Patents

Abstract

The invention provides a special substrate for seedling culture and a preparation method thereof, wherein the substrate comprises peat soil, vermiculite, perlite and perlite micropowder, and the volume ratio of the peat soil, the vermiculite, the perlite and the perlite micropowder is 3-6: 1-4: 0.5-1.5. The main components of the matrix are peat soil, vermiculite and perlite, the matrix enables the physical and chemical properties to be close to soil through the synergistic interaction among various single matrixes, and after the matrix is mixed and processed according to the proportion, the matrix is suitable for planting various crops, has a good seedling raising effect and is suitable for various growth stages of the crops.

Description

A kind of special substrate for raising seedlings and preparation method thereof

technical field

The invention relates to the field of soilless culture substrates, in particular to a special substrate for seedling cultivation and a preparation method thereof.

Background technique

As my country's soilless culture technology has higher and higher requirements for the quality of seedlings, the existing substrate formulations can no longer meet the seedlings standards of efficient plant factories.

In the process of raising seedlings, the basic criteria for "cultivating good seedlings" are: high seedling emergence rate and neat germination potential. Focus on two indicators: the germination potential of the whole plate and the germination potential of a single hole (when there are many seedlings in one hole). The germination time should be Less than 2 days, the longer the time, the greater the impact on the yield and loss, and it is more unfavorable for the standardized production of plant factories. In order to save labor and raw material costs, the existing matrix formula does not pay enough attention to seedling raising work, which is easy to cause excessive water retention capacity, resulting in low germination rate or root rot, or poor water retention capacity, resulting in insufficient water during seedling raising, resulting in low germination rate or poor growth. At the stage of "growing seedlings", the requirement of "growing seedlings" cannot be met.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a special substrate for seedling raising and a preparation method thereof, aiming at the deficiencies of the prior art.

In order to achieve the above purpose, the present invention first provides a special matrix for seedling cultivation, the matrix includes peat soil, vermiculite, perlite and perlite micropowder, and the volume between the peat soil, vermiculite, perlite and perlite micropowder is The ratio is 3 to 6:1 to 4:0.5 to 1.5:0.5 to 1.5.

As a further improvement of the above technical solution, the volume ratio among the peat soil, vermiculite, perlite and perlite micropowder is 3.5-5:2-3:0.7-1.2:0.7-1.2.

As a further improvement of the above technical solution, the volume ratio between the peat soil, vermiculite, perlite and perlite micropowder is 4:2:1:1.

As a further improvement of the above technical solution, it also includes plant ash, and the volume ratio of the peat soil, vermiculite, perlite, perlite micropowder and plant ash is 3～6:1～4:0.5～1.5:0.5～1.5:0.05～ 0.2.

As a further improvement of the above technical scheme, the humidity of the substrate is 28-30%, the bulk density of the substrate is 0.15-0.2 g/cm ³ , the total porosity is 88-93%, and the pH of the leachate per unit volume of the substrate is 5.5-6.0.

As a further improvement of the above technical solution, the particle size of the peat soil is less than 2 mm, the bulk density is 0.1-0.2 g/cm ³ , and the total porosity is 85-90%.

As a further improvement of the above technical solution, the vermiculite has a particle size of 1-2 mm, a bulk density of 0.07-0.2 g/cm ³ , and a total porosity of 90-95%.

As a further improvement of the above technical solution, the particle size of the perlite is 2-4 mm, the bulk density is 0.1-0.3 g/cm ³ , and the total porosity is 90-93%.

As a further improvement of the above technical solution, the particle size of the perlite micropowder is 0.07-0.2 mm, the bulk density is 0.18-0.22 g/cm ³ , and the total porosity is 90-95%.

The present invention also provides a preparation method of a special substrate for seedling cultivation, comprising the following steps:

Step a. Divide the raw peat into brick-sized peat blocks with a masonry knife, put the peat blocks into the hammer mill one by one, the rotating speed is 2000-3000 rpm, and the diameter and width of the screen mesh are 1.5-2cm to obtain uniform and consistent peat. Peat;

Step b. Take 30-60 parts of peat soil, 10-40 parts of vermiculite, 5-15 parts of perlite, and 5-15 parts of perlite micropowder, pour the prepared perlite, vermiculite and perlite into the mixer successively Micro powder and peat soil, ensure the correct ratio of raw materials before feeding;

Step c. Start the mixer at a speed of 1000-2000 r/min, stir for 10-20 minutes and stop, check the discharge, use a hygrometer to detect the humidity of the prepared substrate at 28-30%, and knead it into a ball and release it. The bulk density of the matrix is 0.15-0.2 g/cm ³ , the total porosity is 88-93%, and the pH of the leachate per unit volume of the matrix is 5.5-6.0.

Beneficial effects of the present invention:

The invention provides a special substrate for seedling cultivation and a preparation method thereof. The substrate comprises peat soil, vermiculite, perlite and perlite micropowder, and the volume ratio among the peat soil, vermiculite, perlite and perlite micropowder is 3～6:1～4:0.5～1.5:0.5～1.5, the particle size of the perlite is 0.27～1.4mm, and the particle size of the perlite micropowder is 0.07～0.2mm. The main components of the matrix are peat soil, vermiculite, perlite, and perlite micropowder, and the matrix can make its physical and chemical properties close to the suitable state of plant germination through the synergistic effect between various single matrixes. After and processing, it is suitable for planting many kinds of crops and has good seedling effect.

In some embodiments, the humidity of the matrix is 28-30%, the bulk density of the matrix is 0.15-0.2 g/cm ³ , the total porosity is 88-93%, the pH of the leachate per unit volume of the matrix is 5.5-6.0, and the bulk density of the matrix is light. , the total porosity is large, and when the saturated water holding capacity is reached, the ratio of matrix:moisture:air is 2:1:1, which is conducive to the growth of plant roots; good buffering, it can support the above-ground parts of plants without tilting and does not hinder the underground root system It has high water absorption rate, strong water holding capacity, and can quickly absorb water even in a dry state. It has fertility and excellent seedling effect.

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail as follows.

Detailed ways

Terms as used herein:

"Prepared by" is synonymous with "comprising". As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or device comprising the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such composition, step, method, article or device elements.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or a range bounded by a series of upper preferred values and lower preferred values, this should be understood as specifically disclosing any upper range limit or preferred value and any lower range limit or all ranges formed by any pairing of preferred values, whether or not the ranges are individually disclosed. For example, when a range "1-5" is disclosed, the described range should be construed to include the ranges "1-4", "1-3", "1-2", "1-2 and 4-5" , "1 to 3 and 5", etc. When numerical ranges are described herein, unless stated otherwise, the ranges are intended to include the endpoints and all integers and fractions within the range.

"Mass part" refers to a basic measurement unit that represents the mass ratio relationship of multiple components, and 1 part can represent any unit mass, such as 1 g, 2.689 g, and the like. If we say that the mass part of the A component is a part, and the mass part of the B component is b part, it means the ratio of the mass of the A component to the mass of the B component a:b. Or, the mass of the A component is aK, and the mass of the B component is bK (K is an arbitrary number, representing a multiplier factor). Unmistakably, unlike parts by mass, the sum of parts by mass of all components is not limited to 100 parts by mass.

"and/or" is used to indicate that one or both of the stated circumstances may occur, eg, A and/or B includes (A and B) and (A or B);

A special matrix for seedling cultivation, the matrix comprises peat soil, vermiculite, perlite and perlite micropowder, and the volume ratio between the peat soil, vermiculite, perlite and perlite micropowder is 3-6:1-4 : 0.5 to 1.5: 0.5 to 1.5.

Above, the volume ratio between the peat soil, vermiculite, perlite and perlite micropowder can be 3:3:0.5:0.5, 4:3:0.5:1, 5:3:1:1, 6:3 :1:1, 3:1:0.8:1, 6:3:1.5:1.5, 6:4:1.2:1, 3:2:1:1.2, etc.

In this embodiment, the special substrate for seedling cultivation includes peat soil, vermiculite, perlite and perlite micropowder, and the volume ratio between the peat soil, vermiculite, perlite and perlite micropowder is 3-6:1～ 4:0.5～1.5:0.5～1.5. Through the synergistic effect between various single substrates, the substrate makes its physical and chemical properties close to that of soil. After mixing and processing in the above proportions, it can be suitable for planting many kinds of crops and has a good seedling effect. It can also be applied to crops. It can be widely used in soilless culture nutrient solution film planting at various growth stages.

Peat soil is a natural marshland product (also known as peat or peat) formed after thousands of years. It is the coal with the lowest degree of coalification, and is also the most primitive state of coal. It is sterile, non-toxic and non-toxic. Pollution, good ventilation performance, light weight, water retention, fertilizer retention, beneficial to microbial activity, enhanced biological performance, rich in nutrients, not only a cultivation substrate, but also a good soil conditioner, and contains high organic matter, rot Acids and nutrients.

Preferably, the particle size of the peat soil is less than 2 mm, the bulk density is 0.1-0.2 g/cm ³ , and the total porosity is 85-90%.

Vermiculite is a natural, inorganic, non-toxic, mineral that will expand under high temperature. It belongs to silicate and its crystal structure is monoclinic. Vermiculite can effectively promote the growth of plant roots and the stable development of seedlings, and provide the necessary water and nutrients for plant growth for a long time. grow and increase yield.

Preferably, the vermiculite has a particle size of 1-2 mm, a bulk density of 0.07-0.2 g/cm ³ , and a total porosity of 90-95%.

Perlite is a kind of acidic lava from volcanic eruption. It is a vitreous rock formed by rapid cooling, which is used to increase the permeability and water absorption of the special substrate for seedlings.

Preferably, the perlite has a particle size of 2-4 mm, a bulk density of 0.1-0.3 g/cm ³ , and a total porosity of 90-93%.

Perlite micropowder is an ultra-fine white powder obtained by drying, pulverizing, and sieving natural perlite, and then puffing at high temperature in a cascade electric furnace (rapid heating above 1000 °C), and then vacuum filtration through an exhaust duct. Perlite, the product has the characteristics of non-toxic, odorless, non-flammable, acid and alkali resistance. In this embodiment, compared with adding perlite alone, the matrix added with perlite micropowder has more excellent water retention and water absorption properties, which can improve the uniformity of pores, thereby improving the overall performance of the matrix.

Preferably, the particle size of the perlite micropowder is 0.07-0.2 mm, the bulk density is 0.18-0.22 g/cm ³ , and the total porosity is 90-95%.

As a preferred manner, the volume ratio between the peat soil, vermiculite, perlite and perlite micropowder is 3.5-5:2-3:0.7-1.2:0.7-1.2.

Above, the volume ratio between the peat soil, vermiculite, perlite and perlite micropowder can be 3.5:2:0.7:0.7, 4:2.5:1:1, 5:3:1:1, 4.5:2 :1:1.2, 4:3:1.2:1, 5:3:1.2:1.2, etc.

More preferably, the volume ratio between the peat soil, vermiculite, perlite and perlite micropowder is 4:2:1:1.

As mentioned above, the substrate has light bulk density and large total porosity. When the saturated water holding capacity is reached, the ratio of substrate:moisture:air is 2:1:1, which is conducive to the growth of plant roots; good buffering properties can not only support the aboveground parts of plants The inclination does not hinder the extension and absorption of the underground root system; the water absorption rate is large, the water holding capacity is strong, and it can quickly absorb water in a dry state. When raising seedlings in a plant factory, the rapid alternating drought of the substrate is conducive to cultivating strong seedlings; it has a certain fertility. , it will not react chemically with the components in the nutrient solution and affect the properties of the nutrient solution and itself; when the nutrient solution film system is used to plant the bred seedlings, the substrate and the root system are closely combined and not scattered, so as to avoid damage to the roots, pulling out the seedlings and topping The seedling is convenient, and the efficiency of artificial colonization and post-harvest root cleaning is improved.

Optionally, the special substrate for seedling cultivation further includes plant ash, and the volume ratio of the peat soil, vermiculite, perlite, perlite micropowder and plant ash is 3-6:1-4:0.5-1.5:0.5-1.5:0.05 ~0.2.

Above, the volume ratio of described peat soil, vermiculite, perlite, perlite micropowder and plant ash can be 3:3:0.5:0.5:0.05, 4:3:0.5:1:0.08, 5:3:1: 1:0.1, 6:3:1:1:0.15, 3:1:0.8:1:0.18, 6:3:1.5:1.5:0.1, 6:4:1.2:1:0.1, 3:2:1: 1.2:0.15 etc.

Above, the plant ash can be added when the disease is high to prevent the bred seedlings from producing diseases, and the plant ash is the ash after the plant is burned, so almost all the mineral elements contained in the plant are contained in the plant ash, which can be further used for the crops in the seedling raising. Provide nutrition. Among them, potassium is the most abundant element, generally containing 6-12% potassium, of which more than 90% is water-soluble and exists in the form of carbonate; followed by phosphorus, generally containing 1.5-3%, and also contains calcium, magnesium, silicon , sulfur and trace nutrients such as iron, manganese, copper, zinc, boron, molybdenum.

Optionally, the water content of the substrate is 28-30%, the bulk density of the substrate is 0.15-0.2 g/cm ³ , the total porosity is 88-93%, and the pH of the leachate per unit volume of the substrate is 5.5-6.0.

As mentioned above, the matrix structure is similar to the capillary structure of soil; it has the characteristics of light bulk density, moderate total porosity, strong water retention performance, good air permeability, which is greatly beneficial to the growth of plant roots, and can also quickly absorb water in a dry state, and It has fertility itself, does not require fertilization management, and has excellent seedling effect.

A preparation method of a special substrate for raising seedlings, comprising the following steps:

Step a. Divide the original peat into brick-sized peat blocks with a masonry knife, put the peat blocks into the hammer mill one by one, the rotating speed is 2000-3000 rpm, preferably 2800 rpm, and the screen diameter and width are 1.5 -2cm, get peat soil;

Step b. Get 30-60 parts of peat soil, 10-40 parts of vermiculite, 5-15 parts of perlite, and 5-15 parts of perlite micropowder, pour the prepared perlite, vermiculite and perlite into the mixer successively Micro powder and peat soil, ensure the correct ratio of raw materials before feeding;

Above, in step b, peat soil can be 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 60 parts, etc.;

Vermiculite can be 10, 15, 20, 25, 30, 35, 40, etc.;

Perlite can be 5 parts, 7 parts, 9 parts, 10 parts, 12 parts, 15 parts, etc.;

Perlite micropowder can be 5 parts, 7 parts, 9 parts, 10 parts, 12 parts, 15 parts, etc.;

When feeding into the mixer, the prepared perlite, vermiculite, perlite micropowder and peat soil should be poured in sequence. The reason is that perlite, vermiculite and perlite micropowder are light substances, and they are easy to fly when they are placed on the upper layer of the mixer for mixing. If the mixing fails or the raw material is lost, the material needs to be put into the bottom of the mixer and covered with peat soil for mixing.

Step c. Start the mixer at a speed of 1000-2000 rpm, preferably 1400 rpm, stir for 10-20 minutes and stop, check the discharge, use a hygrometer to detect the humidity of the prepared matrix at 28-30%, knead it into a ball and let go That is, the dispersed state is suitable; the bulk density of the matrix is 0.15-0.2 g/cm ³ , the total porosity is 88-93%, and the pH of the leachate per unit volume of the matrix is 5.5-6.0.

After passing the test, place it in a large black bucket or seal it for later use.

A method of using a special substrate for seedling cultivation, comprising the following steps:

Humidification: Before sowing, pour 25 liters of substrate into the multi-functional dough mixer, start the dough mixer, the speed is 1000-2000 rpm, and at the same time, use the high-pressure mist pump to spray ultra-filtered water to the substrate, and the water spraying speed is 1 liter. /min, the water consumption is 3-8% of the matrix used, humidify and stir for 10-15 minutes, and stop the machine to obtain the seedling matrix;

Sowing: The seedling substrate obtained above can be directly used for filling and covering soil during sowing. After sowing is completed, water from the top or bottom irrigation to complete the seedling work;

Colonization: Stop watering or irrigating the bred seedlings 12 hours before the colonization, which is beneficial to the combination of the root system and the substrate when pulling or topping the seedlings.

Example 1

The present Example 1 provides a special substrate for seedling raising. By volume, 40 parts of peat soil, 20 parts of vermiculite, 10 parts of perlite, and 10 parts of perlite micropowder are mixed to form a special substrate for seedling raising, which is used for raising spinach seeds. Planting, spinach seeds are often difficult to achieve a germination rate of more than 75% due to their hard seed shells and strict requirements on the moisture and air of the seedling substrate. Use this formula substrate to sow spinach seeds in 200 holes, use 2.2 liters of soil per plate, water after covering with soil, and germinate in a nursery room at 20-22 °C.

At the same time, a control group was set up. The control group was planted with a commercial substrate, and the commercial substrate was planted with a volume ratio of peat soil, vermiculite, and perlite in a volume ratio of 4:2:1. Other conditions were consistent with the experimental group. After 3 days of planting, the experimental group and the control group were observed and measured. The observation and measurement items included seedling emergence rate, germination potential, seedling height, length and width of the first true leaf, and fresh weight, and the average value shall prevail. The measurement results are as follows: shown in Table 1.

Example 2

This example 2 provides a special substrate for seedling cultivation. By volume, 40 parts of peat soil, 20 parts of vermiculite, 10 parts of perlite, and 10 parts of perlite micropowder are mixed to form a special substrate for seedling cultivation, and 200 holes of cruciferous leafy vegetables are carried out. The seedlings are raised in trays, sow using the matrix of this formula, use 2.2 liters of soil for each tray, water after covering with soil, and promote germination in the nursery room at 20-25°C.

At the same time, a control group was set up. The control group was planted with a commercial substrate, and the commercial substrate was planted with a volume ratio of peat soil, vermiculite, and perlite in a volume ratio of 4:2:1. Other conditions were consistent with the experimental group. After 3 days of planting, the experimental group and the control group were observed and measured. The observation and measurement items included seedling emergence rate, germination potential, seedling height, length and width of the first true leaf, and fresh weight, and the average value shall prevail. The measurement results are as follows: shown in Table 1.

Example 3

The present Example 3 provides a special substrate for seedling raising. By volume, 40 parts of peat soil, 20 parts of vermiculite, 10 parts of perlite, and 10 parts of perlite micropowder are mixed to form a special substrate for seedling raising. The formula substrate is sown with 2.2 liters of soil per plate, watered after covering with soil, and germination is promoted in the nursery room at 20-25°C.

At the same time, a control group was set up. The control group was planted with a commercially available substrate. The commercial substrate was planted with a volume ratio of peat soil, vermiculite, and perlite in a volume ratio of 4:2:1. Other conditions were the same as the experimental group. After 3 days of planting, the experimental group and the control group were observed and measured. The observation and measurement items included seedling emergence rate, germination potential, seedling height, length and width of the first true leaf, and fresh weight, and the average value shall prevail. The measurement results are as follows: shown in Table 1.

Example 4

The present Example 4 provides a special substrate for seedling raising. By volume, 40 parts of peat soil, 20 parts of vermiculite, 10 parts of perlite, and 10 parts of perlite micropowder are mixed to form a special substrate for seedling raising, and 200 plugs of cucumber are used for seedling raising. The formula substrate is sown with 2.2 liters of soil per plate, watered after covering with soil, and germination is promoted in the nursery room at 20-25°C.

At the same time, a control group was set up. The control group was planted with a commercial substrate, and the commercial substrate was planted with a volume ratio of peat soil, vermiculite, and perlite in a volume ratio of 4:2:1. Other conditions were consistent with the experimental group. After 3 days of planting, the experimental group and the control group were observed and measured. The observation and measurement items included seedling emergence rate, germination potential, seedling height, length and width of the first true leaf, and fresh weight, and the average value shall prevail. The measurement results are as follows: shown in Table 1.

Table 1. The effect of formula matrix applied to different vegetable plug seedlings

Through the test results of Table 1, it can be known that the special substrate for seedling raising of the present invention is better than the commercially available substrate for raising seedlings, and the emergence rate, germination potential and fresh weight are all higher, the first true leaf is sturdy, and the height of emergence is relatively short, It can prevent leggy growth; it has wide applicability and can be used for seedlings of various types of vegetables.

Example 5

The present Example 5 provides a special substrate for seedling cultivation. By volume, 30 parts of peat soil, 10 parts of vermiculite, 5 parts of perlite, and 5 parts of perlite micropowder are mixed to form a special substrate for seedling cultivation. Others are the same as in Example 1. The measurement results are shown in Table 2.

Example 6

This example 6 provides a special substrate for seedling cultivation. By volume, 60 parts of peat soil, 40 parts of vermiculite, 15 parts of perlite, and 15 parts of perlite micropowder are mixed to form a special substrate for seedling cultivation. Others are the same as in Example 1. The measurement results are shown in Table 2.

Example 7

This example 7 provides a special substrate for seedling cultivation. In parts by volume, 50 parts of peat soil, 30 parts of vermiculite, 10 parts of perlite, and 10 parts of perlite micropowder are mixed to form a special substrate for seedling cultivation. Others are the same as in Example 1. The measurement results are shown in Table 2.

Example 8

This Example 8 provides a special substrate for seedling cultivation. By volume, 40 parts of peat soil, 25 parts of vermiculite, 8 parts of perlite, and 8 parts of perlite micropowder are mixed to form a special substrate for seedling cultivation. Others are the same as in Example 1. The measurement results are shown in Table 2.

Comparative Example 1

This comparative example 1 provides a special substrate for seedling raising. By volume, 80 parts of peat soil, 10 parts of vermiculite, and 10 parts of perlite micropowder are mixed to form a special substrate for seedling raising. Others are the same as in Example 1. The measurement results are shown in Table 2.

Comparative Example 2

The comparative example 2 provides a special substrate for seedling cultivation. By volume, 70 parts of peat soil, 5 parts of vermiculite, 10 parts of perlite and 10 parts of perlite micropowder are mixed to form a special substrate for seedling cultivation. Others are the same as in Example 1. The measurement results are shown in Table 2.

Table 2. Effects of different formula substrates on spinach seed plug seedlings

Through the test results in Table 2, it can be known that the special substrate for seedling raising of the present invention has better seedling raising effect than the substrates of Comparative Examples 1-2, and the emergence rate, germination potential and fresh weight are all higher than those of Comparative Examples 1-2. The leaves are stout, and the height of the seedlings is short, which can prevent leggy growth.

Since the numerical range of each process parameter involved in the present invention may not be fully reflected in the above embodiments, those skilled in the art can fully imagine that the present invention can be implemented as long as any numerical value falls within the above numerical range, Of course, any combination of specific values within the numerical ranges of the several items is also included. Here, for the sake of space, the examples giving specific values within one or more numerical ranges are omitted, which should not be regarded as insufficient disclosure of the technical solutions of the present invention.

The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow. Process flow can be implemented. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., fall within the protection scope of the present invention.

Claims (10)

1. The special seedling culture substrate is characterized by comprising peat soil, vermiculite, perlite and perlite micropowder, wherein the volume ratio of the peat soil to the vermiculite to the perlite micropowder is 3-6: 1-4: 0.5-1.5.

2. The special substrate for seedling culture according to claim 1, wherein the volume ratio of the peat soil, the vermiculite, the perlite and the perlite micropowder is 3.5-5: 2-3: 0.7-1.2.

3. The special substrate for seedling culture according to claim 1, wherein the volume ratio of the peat soil, the vermiculite, the perlite and the perlite micropowder is 4:2:1: 1.

4. The special substrate for seedling culture according to claim 1, further comprising plant ash, wherein the volume ratio of the peat soil, the vermiculite, the perlite micropowder and the plant ash is 3-6: 1-4: 0.5-1.5: 0.05-0.2.

5. The substrate special for seedling culture according to claim 1, wherein the substrate has a humidity of 28-30% and a bulk density of 0.15-0.2 g/cm³The total porosity is 88-93%, and the pH of the leaching solution per unit volume of the matrix is 5.5-6.0.

6. The special substrate for seedling culture according to claim 1, wherein the peat soil has a particle size of less than 2mm and a volume weight of 0.1-0.2 g/cm³The total porosity is 85-90%.

7. The special substrate for seedling culture according to claim 1, wherein the particle size of the vermiculite is 1-2 mm, and the volume weight is 0.07-0.2 g/cm³The total porosity is 90-95%.

8. The special substrate for seedling culture according to claim 1, wherein the perlite has a particle size of 2-4 mm and a volume weight of 0.1-0.3 g/cm³The total porosity is 90-93%.

9. The special substrate for seedling culture according to claim 1, wherein the perlite micropowder has a particle size of 0.07-0.2 mm and a volume weight of 0.18-0.22 g/cm³The total porosity is 90-95%.

10. The preparation method of the special substrate for seedling culture is characterized by comprising the following steps:

a, dividing raw peat into peat blocks with the sizes of the bricks by using a bricklayer cutter, putting the peat blocks into a hammer mill one by one, rotating at 2000-3000 r/min, and obtaining uniform peat soil with the diameter and width of a screen mesh of 1.5-2 cm;

b, taking 30-60 parts of peat soil, 10-40 parts of vermiculite, 5-15 parts of perlite and 5-15 parts of perlite micro powder, sequentially pouring prepared perlite, vermiculite, perlite micro powder and peat soil into a stirrer, and ensuring correct raw material proportion before feeding;

starting the stirrer, stirring at the speed of 1000-2000 rpm for 10-20 minutes, stopping the stirrer, discharging, detecting the humidity of the matrix by using a hygrometer at 28-30%, and preferably kneading the matrix into a lump by hands, and loosening the dispersed matrix by hands; the volume weight of the matrix is 0.15-0.2 g/cm³The total porosity is 88-93%, and the pH of the leaching solution per unit volume of the matrix is 5.5-6.0.