Net shed seedling substrate and preparation method and application thereof

Abstract

The invention relates to the field of agricultural seedling raising, and discloses a net shed seedling raising substrate and a preparation method and application thereof, the net shed seedling raising substrate comprises a modified peat-attapulgite composite material, perlite, a water-absorbing gel, a complex microbial inoculant and a fertilizer component; the modified peat-attapulgite composite material is prepared by compounding peat and attapulgite in an acid leaching manner by using a hydrochloric acid solution; the water-absorbing gel is prepared by forming a double-layer network structure by using aminated diatomite, an aminated water-absorbing polymer, sodium alginate, an initiator, a cross-linking agent, an accelerator, calcium bentonite and a calcium chloride solution, the aminated diatomite is prepared by modifying by using dopamine, and the aminated water-absorbing polymer is prepared by using polyvinyl alcohol and agar as polymeric monomers. According to the invention, the water-absorbing gel and the modified peat-attapulgite composite material are added into the seedling culture substrate, so that the conductivity can be reduced, the maximum water-holding capacity is improved, and the cultured plant has thick stems and strong seedlings.

Description

Technical Field

[0001] The present invention belongs to the technical field of agricultural seedling raising, and particularly relates to a net shed seedling raising substrate, a preparation method thereof and an application thereof. Background Art

[0002] Seedling raising refers to creating a suitable environment for seedling growth according to the characteristics and environmental requirements of each period of seed germination and seedling growth, so as to achieve the purpose of improving the survival rate of seedlings, strengthening the seedlings, reducing costs and increasing yields. Successful seedling raising can achieve the effect of half harvest with strong seedlings. Therefore, seedling raising is an important means for vegetables to obtain early maturity, high yield and high quality production, and plays a crucial role in vegetable cultivation. Using living active peat substrate products for industrialized seedling raising of rice and protected vegetables meets the needs of high-yield and high-efficiency agriculture and the local government's demand for sustainable agricultural development.

[0003] Compared with conventional soil seedling raising, substrate seedling raising has the advantages of simple usage, seed saving, labor saving, time saving, land saving and easy management. The seedlings and seedlings grown on high-quality substrate products generally have the characteristics of uniform emergence, developed root systems, good growth and short or no slow seedling period after transplanting. Traditional seedling raising substrates are generally composed of humus soil mixed with relatively loose local straws, without standardization and with strong randomness in preparation, resulting in uneven seedling raising quality and poor operability. Substrates made from waste materials are the focus of current market development and scientific research. Existing substrates made from waste materials generally have problems such as high electrical conductivity and poor water retention. After being planted in the spring drought area with water shortage, the seedling plugs are prone to water loss and need to be replenished with water in time to avoid poor seedling conditions in the later stage. Summary of the Invention

[0004] To solve the deficiencies mentioned in the above background art, the purpose of the present invention is to provide a net shed seedling raising substrate, a preparation method thereof and an application thereof. By adding a water-absorbing gel and a modified peat-attapulgite composite material to the net shed seedling raising substrate, the electrical conductivity can be reduced, the maximum water holding capacity can be increased, and the cultivated plants have thick stems and strong seedlings.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A net shed seedling raising substrate, comprising the following components in parts by weight: 50-70 parts of a modified peat-attapulgite composite material, 20-30 parts of perlite, 5-15 parts of a water-absorbing gel, 5-10 parts of a compound microbial agent, and 10-20 parts of a fertilizer component; The modified peat-palygorskite composite material is prepared by acid-leaching and compounding peat and palygorskite with hydrochloric acid solution; the water-absorbing gel is prepared by forming a double-network structure with aminated diatomite, aminated water-absorbing polymer, sodium alginate, initiator, cross-linking agent, accelerator, calcium-based bentonite and calcium chloride solution, wherein the aminated diatomite is prepared by modifying with dopamine, and the aminated water-absorbing polymer is prepared by using polyvinyl alcohol and agar as polymerization monomers and glutaraldehyde as a cross-linking agent by emulsion polymerization method; The preparation method of the water-absorbing gel comprises the following steps: (1) Take diatomite and place it in a crucible, put it into a muffle furnace and calcine it at a constant temperature of 350-400 °C for 4-5 h. After taking it out, put it into a container containing hydrochloric acid solution and stir for 1-2 h, then place it in a water bath at 70-90 °C and continue to stir for 0.5-1 h. Finally, filter, wash and dry it to prepare pretreated diatomite; (2) Take the pretreated diatomite and add 3-6 g / L of hydrochloric acid dopamine solution, stir it under vacuum conditions for 3-4 h, and then filter, wash and dry it to prepare aminated diatomite; (3) Mix the polyvinyl alcohol aqueous solution and the agar aqueous solution evenly, add polyvinylpyrrolidone and stir to mix. Adjust the pH value of the system to 2-4 with hydrochloric acid solution, and then add glutaraldehyde to mix to obtain a mixed solution. Take span 80 and dissolve it in liquid paraffin, add the obtained mixed solution and stir for 25-40 min, and then place it at 50-70 °C and stir to react for 4-6 h. After the reaction is completed, filter, wash and dry it to prepare a water-absorbing polymer; (4) Take the water-absorbing polymer, toluene and triethylamine in a reactor, add 3-aminopropyltriethoxysilane in a nitrogen atmosphere, place it at 100-115 °C and reflux for 4-6 h. After the reaction is completed, filter, wash and dry it to prepare an aminated water-absorbing polymer; (5) Take the aminated diatomite and the aminated water-absorbing polymer and ultrasonically disperse them in deionized water, add calcium-based bentonite and continue to ultrasonically disperse evenly, then add sodium alginate, sodium persulfate, N,N-methylenebisacrylamide and tetramethylethylenediamine and stir to mix to obtain component one. Drop component one into calcium chloride solution in a nitrogen atmosphere. After the dropping is completed, let it stand for 8-12 h. Finally, wash and dry it to prepare a water-absorbing gel.

[0006] Preferably, the compound microbial agent is composed of Bacillus velezensis, Trichoderma harzianum, Bacillus subtilis agent and Trichoderma viride agent mixed in a mass ratio of 1:1:1-3:1-2; the fertilizer component is composed of urea, potassium sulfate compound fertilizer and potassium magnesium sulfur triple fertilizer mixed in a mass ratio of 1:3:2.

[0007] Preferably, the preparation method of the modified peat-palygorskite composite material comprises the following steps: drying peat and palygorskite to constant weight, grinding and pulverizing them, adding peat to a hydrochloric acid solution with a concentration of 1-5 mol / L, stirring well for 25-40 min, then adding palygorskite and continuing to stir for 20-30 min, and finally centrifuging, washing, and drying to obtain the modified peat-palygorskite composite material.

[0008] Preferably, in the step (3), the mass concentration of the polyvinyl alcohol aqueous solution is 5-10%, and the mass concentration of the agar aqueous solution is 8-12%.

[0009] Preferably, in the step (3), the addition ratio of the polyvinyl alcohol aqueous solution, the agar aqueous solution, polyvinylpyrrolidone, glutaraldehyde, span 80, and liquid paraffin is 4-6 mL: 4-5 mL: 0.4-0.7 g: 0.2-0.3 mL: 0.5-0.7 mL: 25-30 mL.

[0010] Preferably, in the step (5), the mass concentration of the calcium chloride solution is 0.5-2%.

[0011] Preferably, in the step (5), the mass ratio of the aminated diatomite, the aminated water-absorbing polymer, calcium-based bentonite, sodium alginate, sodium persulfate, N,N-methylenebisacrylamide, and tetramethylethylenediamine is 0.1-0.25: 0.05-0.1: 0.15-0.25: 2-3: 0.2-0.5: 0.3-0.5: 0.35-0.5.

[0012] The preparation method of the greenhouse seedling-raising substrate as described above comprises the following steps: mixing the modified peat-palygorskite composite material and perlite by weight, adding them to a mixer to crush into particles, and screening the particles to a size of 0.1-1 mm. Adding the screened particles to a stirring kettle, and then adding the water-absorbing gel, composite microbial agents, and fertilizer components by weight and stirring and mixing evenly to obtain the greenhouse seedling-raising substrate.

[0013] The application of the greenhouse seedling-raising substrate as described above in potato seedling raising.

[0014] The beneficial effects of the present invention: The present invention utilizes The present invention uses hydrochloric acid solution to acid-leach peat and attapulgite for modification treatment, which can activate the active groups of peat to enhance its adsorption characteristics. The surface of attapulgite becomes loose, the pores increase, and the adsorption performance is significantly enhanced. After acid-leaching and compounding peat and attapulgite, the surface structure of peat becomes loose, and fine particles are scattered on the surface, making its surface more uneven, which is conducive to increasing the exposure of active sites for adsorption. In addition, the present invention uses dopamine to perform surface amination modification on pretreated diatomite. At the same time, the present invention uses polyvinyl alcohol and agar as polymerization monomers and glutaraldehyde as a cross-linking agent to prepare a water-absorbing polymer by emulsion polymerization. The polymer microspheres formed by the combination of polyvinyl alcohol and agar have characteristics such as low density, high specific surface area, and porosity. Then, 3-aminopropyltriethoxysilane is grafted to prepare an aminated water-absorbing polymer to further improve the adsorption performance of the water-absorbing polymer. Then, the present invention forms a copolymer of aminated diatomite and aminated water-absorbing polymer with sodium alginate. Sodium persulfate is used as an initiator, N,N-methylenebisacrylamide is used as a cross-linking agent, and tetramethylethylenediamine is used as an accelerator. Calcium-based bentonite has the characteristics of high ion exchange capacity and large surface area. It interacts with the copolymer to form a network structure. Then, calcium ions cross-link sodium alginate to form calcium alginate, forming a second network structure. And sodium alginate can be used as a carrier to fix calcium-based bentonite. The formed calcium alginate intercalated calcium-based bentonite is conducive to the dispersion of calcium-based bentonite. The prepared water-absorbing gel has excellent water absorption and water retention performance. The present invention adds the water-absorbing gel and the modified peat-attapulgite composite material to the net shed seedling-raising substrate, which can reduce the conductivity, increase the maximum water holding capacity, and cultivate strong plant stems and thick seedlings. Detailed implementation manners

[0015] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present invention.

[0016] Example 1 A preparation method of a modified peat-attapulgite composite material includes the following steps: Place peat and attapulgite in an oven at 50 °C and dry to constant weight, then grind and crush. Take 5 g of peat, add 300 mL of 1 mol / L hydrochloric acid solution, stir well for 30 min, then add 1 g of attapulgite and continue to stir for 30 min. Finally, centrifuge, wash, and dry to prepare a modified peat-attapulgite composite material.

[0017] Example 2 A preparation method of a water-absorbing gel includes the following steps: (1) Take 10 g of diatomite and place it in a crucible. Put it into a muffle furnace and calcine it at 400 °C for 4 h. After taking it out, put it into hydrochloric acid with a mass fraction of 4 wt% and stir for 1 h. Then place it in a water bath at 80 °C and continue to stir for 1 h. Finally, carry out suction filtration, washing, and drying to prepare pretreated diatomite; (2) Take 10 g of pretreated diatomite and add it to 200 mL of a 5 g / L hydrochloric acid dopamine solution. Stir for 4 h under vacuum conditions, and then carry out suction filtration, washing, and drying to prepare amino-functionalized diatomite; (3) Take 5 mL of an aqueous solution of polyvinyl alcohol with a mass concentration of 10% and 5 mL of an aqueous solution of agar with a mass concentration of 12%, mix them evenly, add 0.5 g of polyvinylpyrrolidone and stir to mix. Use hydrochloric acid solution to adjust the pH value of the system to 3, then add 0.2 mL of glutaraldehyde and mix to obtain a mixed solution. Take 0.6 mL of Span 80 and dissolve it in 30 mL of liquid paraffin, add the obtained mixed solution and stir for 30 min, then place it at 65 °C and stir and react for 5 h. After the reaction is completed, carry out filtration, washing, and drying to prepare a water-absorbing polymer; (4) Take 5 g of the water-absorbing polymer, 100 mL of toluene, and 2 mL of triethylamine in a reactor. Add 5 mL of 3-aminopropyltriethoxysilane in a nitrogen atmosphere, place it at 105 °C and reflux for 6 h. After the reaction is completed, carry out filtration, washing, and drying to prepare amino-functionalized water-absorbing polymer; (5) Take 0.2 g of amino-functionalized diatomite and 0.1 g of amino-functionalized water-absorbing polymer, ultrasonically disperse them in 50 mL of deionized water, add 0.15 g of calcium-based bentonite and continue to ultrasonically disperse evenly. Then add 2 g of sodium alginate, 0.25 g of sodium persulfate, 0.34 g of N,N'-methylenebisacrylamide, and 0.41 g of tetramethylethylenediamine and stir to mix to obtain Component 1. Under a nitrogen atmosphere, drop Component 1 into 300 mL of a calcium chloride solution with a mass concentration of 1%. After the dropping is completed, let it stand for 10 h. Finally, carry out washing and drying to prepare a water-absorbing gel.

[0018] Example 3 A method for preparing a water-absorbing gel includes the following steps: (1) Take 10 g of diatomite and place it in a crucible. Put it into a muffle furnace and calcine it at 400 °C for 4 h. After taking it out, put it into hydrochloric acid with a mass fraction of 4 wt% and stir for 1 h. Then place it in a water bath at 80 °C and continue to stir for 1 h. Finally, carry out suction filtration, washing, and drying to prepare pretreated diatomite; (2) Take 10 g of pretreated diatomite and add it to 200 mL of a 5 g / L hydrochloric acid dopamine solution. Stir for 4 h under vacuum conditions, and then carry out suction filtration, washing, and drying to prepare amino-functionalized diatomite; (3) Take 6 mL of an aqueous solution of polyvinyl alcohol with a mass concentration of 7% and 4 mL of an aqueous solution of agar with a mass concentration of 10%, mix them evenly, add 0.6 g of polyvinylpyrrolidone and stir to mix. Adjust the pH value of the system to 3 with hydrochloric acid solution, then add 0.3 mL of glutaraldehyde and mix to obtain a mixed solution. Take 0.6 mL of Span 80 and dissolve it in 30 mL of liquid paraffin, add the obtained mixed solution and stir for 30 min, then place it at 65 °C and stir for reaction for 5 h. After the reaction is completed, filter, wash, and dry to prepare a water-absorbing polymer; (4) Take 5 g of the water-absorbing polymer, 100 mL of toluene and 2 mL of triethylamine in a reactor, add 6 mL of 3-aminopropyltriethoxysilane in a nitrogen atmosphere, place it at 110 °C and reflux for 6 h. After the reaction is completed, filter, wash, and dry to prepare an aminated water-absorbing polymer; (5) Take 0.15 g of aminated diatomite and 0.05 g of aminated water-absorbing polymer, ultrasonically disperse them in 30 mL of deionized water, add 0.17 g of calcium-based bentonite and continue to ultrasonically disperse evenly, then add 2 g of sodium alginate, 0.33 g of sodium persulfate, 0.3 g of N,N'-methylenebisacrylamide and 0.35 g of tetramethylethylenediamine and stir to mix to obtain Component 1. Under a nitrogen atmosphere, dropwise add Component 1 to 300 mL of a calcium chloride solution with a mass concentration of 0.5%. After the dropping is completed, let it stand for 10 h. Finally, wash and dry to prepare a water-absorbing gel.

[0019] Example 4 A method for preparing a water-absorbing gel includes the following steps: (1) Take 10 g of diatomite and place it in a crucible, put it in a muffle furnace and calcine it at a constant temperature of 400 °C for 4 h. After taking it out, put it in hydrochloric acid with a mass fraction of 4 wt% and stir for 1 h, then place it in a water bath at 80 °C and continue to stir for 1 h. Finally, filter, wash, and dry to prepare pretreated diatomite; (2) Take 10 g of pretreated diatomite and add it to 200 mL of a 5 g / L hydrochloric acid dopamine solution, stir under vacuum conditions for 4 h, then filter, wash, and dry to prepare aminated diatomite; (3) Take 5 mL of an aqueous solution of polyvinyl alcohol with a mass concentration of 10% and 5 mL of an aqueous solution of agar with a mass concentration of 12%, mix them evenly, add 0.7 g of polyvinylpyrrolidone and stir to mix. Adjust the pH value of the system to 4 with hydrochloric acid solution, then add 0.25 mL of glutaraldehyde and mix to obtain a mixed solution. Take 0.6 mL of Span 80 and dissolve it in 30 mL of liquid paraffin, add the obtained mixed solution and stir for 30 min, then place it at 70 °C and stir for reaction for 4 h. After the reaction is completed, filter, wash, and dry to prepare a water-absorbing polymer; (4) Take 5 g of the water-absorbing polymer, 100 mL of toluene and 2 mL of triethylamine in a reactor. Add 5 mL of 3-aminopropyltriethoxysilane in a nitrogen atmosphere, and reflux at 105 °C for 6 h. After the reaction is completed, filter, wash and dry to prepare the amino-functionalized water-absorbing polymer. (5) Take 0.25 g of the amino-functionalized diatomite and 0.1 g of the amino-functionalized water-absorbing polymer, ultrasonically disperse them in 50 mL of deionized water, add 0.25 g of calcium-based bentonite and continue to ultrasonically disperse evenly. Then add 3 g of sodium alginate, 0.47 g of sodium persulfate, 0.44 g of N,N'-methylenebisacrylamide and 0.5 g of tetramethylethylenediamine, stir and mix to obtain Component 1. Drop Component 1 into 300 mL of a 2% calcium chloride solution in a nitrogen atmosphere. After dropping, let it stand for 12 h. Finally, wash and dry to prepare the water-absorbing gel.

[0020] Example 5 A greenhouse seedling-raising substrate, comprising the following components by weight: 55 parts of the modified peat-attapulgite composite material prepared in Example 1, 21 parts of perlite, 7 parts of the water-absorbing gel prepared in Example 2, 5 parts of the compound microbial agent, and 10 parts of the fertilizer component. The compound microbial agent is composed of Bacillus velezensis, Trichoderma harzianum, Bacillus subtilis agent and Trichoderma viride agent mixed in a mass ratio of 1:1:3:2. The fertilizer component is composed of urea, potassium sulfate compound fertilizer and potassium-magnesium-sulfur triple fertilizer mixed in a mass ratio of 1:3:2.

[0021] The preparation method of the above greenhouse seedling-raising substrate comprises the following steps: Mix the modified peat-attapulgite composite material and perlite by weight, add them to a mixer and crush them into particles. Add the sieved particles to a stirring kettle, and then add the water-absorbing gel, compound microbial agent and fertilizer component by weight, stir and mix evenly to prepare the greenhouse seedling-raising substrate.

[0022] Example 6 A greenhouse seedling-raising substrate, comprising the following components by weight: 60 parts of the modified peat-attapulgite composite material prepared in Example 1, 25 parts of perlite, 10 parts of the water-absorbing gel prepared in Example 2, 7 parts of the compound microbial agent, and 14 parts of the fertilizer component. The compound microbial agent is composed of Bacillus velezensis, Trichoderma harzianum, Bacillus subtilis agent and Trichoderma viride agent mixed in a mass ratio of 1:1:3:2. The fertilizer component is composed of urea, potassium sulfate compound fertilizer and potassium-magnesium-sulfur triple fertilizer mixed in a mass ratio of 1:3:2.

[0023] The preparation method of the above greenhouse seedling-raising substrate is the same as that of Example 5.

[0024] Example 7 A greenhouse seedling-raising substrate, comprising the following components by weight: 66 parts of the modified peat-palygorskite composite material prepared in Example 1, 30 parts of perlite, 15 parts of the water-absorbing gel prepared in Example 2, 10 parts of the compound microbial agent, and 18 parts of the fertilizer component, wherein the compound microbial agent is composed of Bacillus velezensis, Trichoderma harzianum, Bacillus subtilis agent and Trichoderma viride agent mixed in a mass ratio of 1:1:3:2, and the fertilizer component is composed of urea, potassium sulfate compound fertilizer and potassium magnesium sulfur triple fertilizer mixed in a mass ratio of 1:3:2.

[0025] The preparation method of the above-mentioned greenhouse seedling-raising substrate is the same as that in Example 5.

[0026] Comparative Example 1 A method for preparing a water-absorbing gel includes the following steps: (1) Take 10 g of diatomite and place it in a crucible, put it into a muffle furnace and calcine it at 400 °C for 4 h, take it out and put it into a hydrochloric acid solution with a mass fraction of 4 wt% and stir for 1 h, then place it in an 80 °C water bath and continue to stir for 1 h, and finally filter, wash and dry to obtain pretreated diatomite; (2) Take 10 g of pretreated diatomite and add 200 mL of a 5 g / L hydrochloric acid dopamine solution, stir under vacuum conditions for 4 h, and then filter, wash and dry to obtain amino-functionalized diatomite; (3) Take 0.2 g of amino-functionalized diatomite and ultrasonically disperse it in 50 mL of deionized water, add 0.15 g of calcium-based bentonite and continue to ultrasonically disperse it evenly, then add 2 g of sodium alginate, 0.25 g of sodium persulfate, 0.34 g of N,N-methylenebisacrylamide and 0.41 g of tetramethylethylenediamine and stir to mix to obtain Component 1. Drop Component 1 into 300 mL of a 1% calcium chloride solution under a nitrogen atmosphere. After the dropping is completed, let it stand for 10 h, and finally wash and dry to obtain the water-absorbing gel.

[0027] Comparative Example 2 A method for preparing a water-absorbing gel includes the following steps: (1) Take 10 g of diatomite and place it in a crucible, put it into a muffle furnace and calcine it at 400 °C for 4 h, take it out and put it into a hydrochloric acid solution with a mass fraction of 4 wt% and stir for 1 h, then place it in an 80 °C water bath and continue to stir for 1 h, and finally filter, wash and dry to obtain pretreated diatomite; (2) Take 10 g of pretreated diatomite and add 200 mL of a 5 g / L hydrochloric acid dopamine solution, stir under vacuum conditions for 4 h, and then filter, wash and dry to obtain amino-functionalized diatomite; (3) Take 5 mL of a polyvinyl alcohol aqueous solution with a mass concentration of 10% and 5 mL of an agar aqueous solution with a mass concentration of 12%, mix them evenly, add 0.5 g of polyvinylpyrrolidone and stir to mix. Adjust the pH value of the system to 3 with hydrochloric acid solution, then add 0.2 mL of glutaraldehyde and mix to obtain a mixed solution. Take 0.6 mL of Span 80 and dissolve it in 30 mL of liquid paraffin, add the obtained mixed solution and stir for 30 min, then place it under stirring reaction at 65 °C for 5 h. After the reaction is completed, filter, wash, and dry to prepare a water-absorbing polymer; (4) Take 5 g of the water-absorbing polymer, 100 mL of toluene, and 2 mL of triethylamine in a reactor, add 5 mL of 3-aminopropyltriethoxysilane in a nitrogen atmosphere, place it under reflux reaction at 105 °C for 6 h. After the reaction is completed, filter, wash, and dry to prepare an amino-functionalized water-absorbing polymer; (5) Take 0.2 g of amino-functionalized diatomite and 0.1 g of amino-functionalized water-absorbing polymer, ultrasonically disperse them in 50 mL of deionized water, then add 2 g of sodium alginate, 0.25 g of sodium persulfate, 0.34 g of N,N'-methylenebisacrylamide, and 0.41 g of tetramethylethylenediamine and stir to mix to obtain Component 1. Under a nitrogen atmosphere, drop Component 1 into 300 mL of a calcium chloride solution with a mass concentration of 1%. After the dropping is completed, let it stand for 10 h, and finally wash and dry to prepare a water-absorbing gel.

[0028] Comparative Example 3 A greenhouse seedling-raising substrate, comprising the following components in parts by weight: 66 parts of the modified peat-attapulgite composite material prepared in Example 1, 30 parts of perlite, 8.5 parts of diatomite, 6.5 parts of calcium-based bentonite, 10 parts of compound microbial agent, and 18 parts of fertilizer component, wherein the compound microbial agent is composed of Bacillus velezensis, Trichoderma harzianum, Bacillus subtilis agent, and Trichoderma viride agent mixed in a mass ratio of 1:1:3:2, and the fertilizer component is composed of urea, potassium sulfate compound fertilizer, and potassium magnesium sulfur triple fertilizer mixed in a mass ratio of 1:3:2.

[0029] The preparation method of the above greenhouse seedling-raising substrate is the same as that of Example 5.

[0030] Comparative Example 4 A greenhouse seedling-raising substrate, comprising the following components in parts by weight: 55 parts of peat, 11 parts of attapulgite, 30 parts of perlite, 15 parts of the water-absorbing gel prepared in Example 2, 10 parts of compound microbial agent, and 18 parts of fertilizer component, wherein the compound microbial agent is composed of Bacillus velezensis, Trichoderma harzianum, Bacillus subtilis agent, and Trichoderma viride agent mixed in a mass ratio of 1:1:3:2, and the fertilizer component is composed of urea, potassium sulfate compound fertilizer, and potassium magnesium sulfur triple fertilizer mixed in a mass ratio of 1:3:2.

[0031] The preparation method of the above greenhouse seedling-raising substrate is the same as that of Example 5.

[0032] Performance detection Perform performance tests on the water-absorbing gels prepared in Examples 2-4 and Comparative Examples 1-2: (1) Water absorption capacity test: Weigh 1 g of the water-absorbing gel and immerse it in 2000 mL of deionized water. After soaking for 12 h to fully swell, filter it through double-layer gauze until no more water drips. Weigh the water-absorbing gel, which represents the water absorption capacity of the water-absorbing gel. Each sample is tested 5 times and the average value is taken. The data results are shown in Table 1.

[0033] (2) Water retention capacity test: Weigh 100 g of the fully swollen water-absorbing gel and place it in a beaker. Place the beaker in an incubator at 35 °C and weigh it regularly every 24 h. Each sample is tested 5 times and the average value is taken. The data results are shown in Table 1.

[0034] (3) Repeated water absorption capacity test: Weigh 1 g of the water-absorbing gel and add 2000 mL of distilled water to make it fully absorb water. After 12 h, filter it through double-layer gauze and weigh the water-absorbing gel. Then place the swollen water-absorbing gel in an oven at 80 °C to dry, add distilled water to make it fully absorb water again, and then dry it. Repeat the test 10 times, record the weight of the water-absorbing gel after each re-swelling. Each sample is tested 5 times and the average value is taken. The data results are shown in Table 1.

[0035] Table 1 Results of sample performance tests

[0036] From the data results in Table 1, it can be seen that the water-absorbing gels prepared in Examples 2-4 of the present invention have excellent water absorption and water retention properties. Among them, the water-absorbing polymer component was not introduced into the water-absorbing gel in Comparative Example 1, and the calcium-based bentonite component was not introduced into the water-absorbing gel in Comparative Example 2. The measured water absorption capacity, water retention capacity and repeated water absorption capacity of Comparative Examples 1-2 are worse than those of Examples 2-4, indicating that the addition of the amino-functionalized water-absorbing polymer and calcium-based bentonite both improve the water absorption and water retention properties of the water-absorbing gel to a certain extent.

[0037] The performance of the greenhouse seedling-raising substrates prepared in Examples 5-7 and Comparative Examples 3-4 was tested: Substrates with known volume and mass were immersed in deionized water, fully absorbed water, and then drained by gravity. This process was repeated 3 times to ensure that the substrates were saturated with water. After draining by gravity for 30 minutes, their volume and mass were measured again. Then, they were placed in an oven at 105 °C and dried for 7 days, and the mass was measured again. The maximum water-holding capacity, total porosity, and aeration porosity values were calculated; the electrical conductivity was measured with a conductivity meter; Potato seeds were germinated, and then the substrates prepared in Examples 5-7 and Comparative Examples 3-4 were filled into 128-well trays, with 200 g of substrate used per tray. The substrate in the tray was watered thoroughly, sown, with 1 seed sown in each hole, and the sowing depth was 0.5 cm. After sowing, water was sprayed again, and clear water was sprayed once every 7 days. 28 days after sowing, the plant height and stem diameter of the potato seedlings were measured, and the data results are shown in Table 2.

[0038] Table 2 Test Results of Sample Performance

[0039] It can be seen from the data results in Table 2 that the seedling-raising substrates prepared in Examples 5-7 of the present invention are more suitable for the growth of potatoes than Comparative Examples 3-4. Among them, in Comparative Example 3, the water-absorbing gel was replaced with diatomite and calcium-based bentonite, and the measured water-holding capacity, plant height, and stem diameter were lower than those in Examples 5-7. In Comparative Example 4, peat and attapulgite were not modified, and the measured aeration porosity, water-holding capacity, electrical conductivity, plant height, and stem diameter were worse than those in Examples 5-7, indicating that acid-leaching and compounding of peat and attapulgite can improve the seedling-raising performance of the substrate.

[0040] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0041] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A net shed seedling medium, characterized in that: The invention comprises the following components in parts by weight: 50-70 parts of modified peat-attapulgite composite material, 20-30 parts of perlite, 5-15 parts of water-absorbing gel, 5-10 parts of composite bacterial agent, and 10-20 parts of fertilizer component; The modified peat-attapulgite composite material is prepared by acid-leaching peat and attapulgite with a hydrochloric acid solution; the water-absorbing gel is prepared by forming a double-layer network structure using amino diatomite, amino water-absorbing polymer, sodium alginate, an initiator, a cross-linking agent, an accelerator, calcium-based bentonite and a calcium chloride solution, wherein the amino diatomite is prepared by modification with dopamine, and the amino water-absorbing polymer is prepared by an emulsion polymerization method using polyvinyl alcohol and agar as polymerization monomers and glutaraldehyde as a cross-linking agent; The preparation method of the water-absorbing gel comprises the following steps: (1) Put diatomite in a crucible, put it in a muffle furnace and calcine it at a constant temperature of 350-400°C for 4-5 hours, take it out and put it in a container filled with hydrochloric acid solution and stir it for 1-2 hours, then put it in a 70-90°C water bath and continue to stir it for 0.5-1 hour, and finally filter, wash and dry it to prepare pretreated diatomite; (2) adding 3-6 g / L dopamine hydrochloride solution to the pretreated diatomaceous earth, stirring for 3-4 h under vacuum conditions, and then filtering, washing, and drying to prepare amino diatomaceous earth; (3) Mix the polyvinyl alcohol aqueous solution and the agar aqueous solution evenly, add polyvinyl pyrrolidone and stir to mix, adjust the pH value of the system to 2-4 with hydrochloric acid solution, then add glutaraldehyde and mix to obtain a mixed solution, dissolve Span 80 in liquid paraffin, add the obtained mixed solution and stir for 25-40 minutes, then place at 50-70° C. and stir to react for 4-6 hours, and after the reaction is completed, filter, wash and dry to prepare a water-absorbing polymer; (4) placing a water-absorbing polymer, toluene and triethylamine in a reactor, adding 3-aminopropyltriethoxysilane in a nitrogen atmosphere, and subjecting the mixture to reflux reaction at 100-115° C. for 4-6 hours. After the reaction is completed, filtering, washing and drying are performed to obtain an amino-absorbent polymer; (5) Aminated diatomaceous earth and amino water-absorbing polymer are ultrasonically dispersed in deionized water, calcium bentonite is added and ultrasonically dispersed evenly, and then sodium alginate, sodium persulfate, N,N-methylenebisacrylamide and tetramethylethylenediamine are added and stirred to obtain component one, and component one is added dropwise to calcium chloride solution in a nitrogen atmosphere. After the addition is completed, the solution is allowed to stand for 8 to 12 hours, and finally washed and dried to obtain a water-absorbing gel.

2. The net shed seedling raising matrix according to claim 1, characterized in that: The composite bacterial agent is formed by mixing Bacillus velez, Trichoderma harzianum, Bacillus subtilis and Trichoderma viride in a mass ratio of 1:1:1-3:1-2; the fertilizer component is formed by mixing urea, potassium sulfate type compound fertilizer and potassium magnesium sulfur three-in-one fertilizer in a mass ratio of 1:3:

2.

3. The net shed seedling raising matrix according to claim 1, characterized in that: The preparation method of the modified peat-attapulgite composite material comprises the following steps: drying peat and attapulgite to constant weight, grinding and crushing, adding 1-5 mol / L hydrochloric acid solution to the peat and stirring for 25-40 min, then adding attapulgite and stirring for 20-30 min, and finally centrifuging, washing and drying to prepare the modified peat-attapulgite composite material.

4. The net shed seedling raising matrix according to claim 1, characterized in that: In the step (3), the mass concentration of the polyvinyl alcohol aqueous solution is 5-10%, and the mass concentration of the agar aqueous solution is 8-12%.

5. The net shed seedling raising matrix according to claim 1, characterized in that: In the step (3), the addition ratio of the polyvinyl alcohol aqueous solution, the agar aqueous solution, the polyvinyl pyrrolidone, the glutaraldehyde, the Span 80 and the liquid paraffin is 4-6 mL: 4-5 mL: 0.4-0.7 g: 0.2-0.3 mL: 0.5-0.7 mL: 25-30 mL.

6. The net shed seedling raising matrix according to claim 1, characterized in that: The mass concentration of the calcium chloride solution in step (5) is 0.5-2%.

7. The net shed seedling raising matrix according to claim 1, characterized in that: In the step (5), the mass ratio of the amino diatomaceous earth, the amino water-absorbing polymer, the calcium-based bentonite, the sodium alginate, the sodium persulfate, the N,N-methylenebisacrylamide and the tetramethylethylenediamine is 0.1-0.25: 0.05-0.1: 0.15-0.25: 2-3: 0.2-0.5: 0.3-0.5: 0.35-0.

5.

8. A method for preparing a net shed seedling substrate according to any one of claims 1 to 7, characterized in that: The following steps are involved: Parts by weight of modified peat-attapulgite composite material and perlite are mixed and added to a mixer and crushed into particles. The particle size after screening is 0.1-1 mm. The screened particles are added to a stirring tank, and then parts by weight of water-absorbing gel, composite bacterial agent and fertilizer components are added and stirred to mix evenly to prepare the net shed seedling matrix.

9. Use of the net shed seedling substrate according to any one of claims 1 to 7 in potato seedling cultivation.

Images