A functional vegetable seedling substrate based on vegetable stalk modification

Abstract

The present application belongs to the field of planting nutrient soil, and particularly relates to a functional vegetable seedling substrate based on modified vegetable straw. The substrate components include, by weight fraction, 6-7 parts of peat, 3-4 parts of tomato straw humification base material, 1.5-2 parts of perlite, 0.1-0.3 parts of nutrient element loaded biochar, 0.1-0.2 parts of mineral humic acid potassium, and 0.01-0.03 parts of diatomite. The present application uses a rapid humification process to produce high-quality tomato straw humification base material, uses an anaerobic pyrolysis process to produce modified tomato straw biochar base material, and through efficient compounding of nutrient elements, mineral elements and the like, produces a new process and new product of functional vegetable seedling substrate based on modified tomato straw.

Description

Technical Field

[0001] This invention belongs to the field of planting nutrient soil, specifically relating to a functional vegetable seedling substrate based on modified vegetable straw. Background Technology

[0002] Peat moss is environmentally friendly, healthy, and safe, characterized by its stable structure, excellent permeability, strong water retention capacity, high organic matter content, and absence of pathogens. It is currently a mainstream raw material for vegetable seedling substrates on the market. However, peat moss is also a non-renewable resource, unevenly distributed, and expensive. Therefore, finding alternatives to peat moss, utilizing local resources, and developing green, low-cost recycled waste resources as seedling substrates is urgently needed.

[0003] In 2021, my country's tomato production reached 69.7 million tons. Calculated with an economic coefficient of 0.7, the amount of residual plants was considerable. Vegetable straw has a high water content of 50% to 70%, low calorific value, and is easily decomposed, resulting in a low effective utilization rate. There is a significant regional, seasonal, and structural surplus of straw waste. This easily leads to: (1) After each vegetable crop rotation, a large amount of straw waste clogs waterways, rots, and smells foul, easily causing air, soil, and water pollution. (2) Vegetable straw contains high levels of nutrients, which are wasted if not utilized. Currently, the utilization rate of tomato straw is low, which easily causes pollution. Therefore, the reuse of tomato straw has become a research focus.

[0004] Studies have shown that adding microbial agents can accelerate the composting process, improve compost maturity, and reduce biotoxicity. The high temperatures generated during composting inhibit the growth of most microorganisms, reducing the types and quantities of microorganisms involved, which is detrimental to efficient composting conversion. Thermophilic microorganisms can withstand high-temperature environments and play an important role in the composting process. Furthermore, ultra-high temperature composting can promote organic matter degradation, accelerate the compost maturity process, and efficiently kill harmful substances such as insect eggs in a short time, increasing organic matter retention, reducing greenhouse gas emissions, and achieving carbon reduction and efficiency improvement while maintaining product quality. Current research mainly focuses on the application of ultra-high temperature composting for manure. For example, Chen Qianqian (2023) studied the effects of thermophilic compound bacteria on the physicochemical properties and maturity of livestock and poultry manure (75% sheep manure and 25% chicken manure) compost; Xing Weijie (2019) studied the effects of thermophilic deodorizing fermentation agents on pig manure compost fermentation. There are few reports on high-temperature fermentation composting processes for manure and straw composite materials. Meanwhile, functional seedling substrates mostly focus on exploring the effects of adding single microbial agents. For example, Zhang Yuanguo (2022) studied the effects of Trichoderma harzianum and Bacillus subtilis in tomato seedling substrates; Sun Yueyue (2016) explored the growth-promoting effects of actinomycete agents and fungal agents on melon plug seedlings after being applied to seedling substrates. The application of nutrient-loaded biochar in functional seedling substrates is still lacking. Summary of the Invention

[0005] In view of the current situation where tomato straw has low utilization rate and is prone to pollution, the purpose of this invention is to provide a functional vegetable seedling substrate based on modified vegetable straw.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A functional vegetable seedling substrate based on modified vegetable straw, wherein the substrate components include, by weight: 6-7 parts peat, 3-4 parts decomposed tomato straw substrate, 1.5-2 parts perlite, 0.1-0.3 parts nutrient-loaded biochar, 0.1-0.2 parts mineral-derived potassium humate, and 0.01-0.03 parts diatomaceous earth.

[0008] The tomato straw composting substrate comprises: tomato straw, fresh cow manure, and a thermophilic compound microbial agent; wherein the ratio of tomato straw, fresh cow manure, and thermophilic compound microbial agent is 1-1.5:3-5:0.001-0.0015; preferably 1:3:0.001.

[0009] The extremely thermophilic compound microbial agent includes thermophilic marine bacteria, thermophilic mycelium, thermophilic streptomyces, urea-bacterium, and thermophilic neobacterium; wherein the ratio of the amounts of thermophilic marine bacteria, thermophilic mycelium, thermophilic streptomyces, urea-bacterium, and thermophilic neobacterium is 4-5:2-3:1-2:2-4:1-2, and the preferred ratio is 4:2:1:2:1.5.

[0010] The thermophilic marine bacterium was sourced from the China General Microbiological Culture Collection Center, with strain number CGMCC1.12207; the viable count was not less than 7.5 × 10⁻⁶. 9 CFU / g;

[0011] The thermophilic filamentous yeast was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC2.4939; the viable count was not less than 2 × 10⁻⁶. 9 CFU / g;

[0012] The thermophilic and coprophilic Streptomyces was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC4.6959; the viable count was not less than 3.5 × 10⁻⁶. 9 CFU / g;

[0013] The *Bacillus urealyticum* strain was obtained from the China General Microbiological Culture Collection Center, with strain number CGMCC1.7272; the viable count was not less than 5.5 × 10⁻⁶. 9 CFU / g;

[0014] The thermophilic neobacterium was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC1.12771; the viable count was not less than 2.5 × 10⁻⁶.9 CFU / g.

[0015] The thermophilic marine bacteria, the thermophilic filamentous yeast, the thermophilic streptomyces, the urea-bacterium, and the thermophilic neobacterium were all purchased from the China General Microbiological Culture Collection Center.

[0016] The preparation method of the tomato straw compost is as follows: crush tomato straw with a moisture content of 50-70% into 1-3cm pieces, mix it with fresh cow manure, add an extremely thermophilic compound microbial agent for composting treatment, turn the compost once every two days for the first 6 days of composting, and turn it once every 5 days in the later stage, keeping the compost moisture content at 50%-60%. When the temperature of the compost pile drops below 32℃, stop turning the pile and let the temperature of the pile drop to the ambient temperature to obtain the tomato straw compost.

[0017] The nutrient-loaded biochar is obtained by mixing tomato straw biochar raw material with calcium sulfate, magnesium sulfate, ferrous sulfate, copper sulfate, zinc sulfate, manganese sulfate, sodium molybdate, and borax, and then grinding it through a 200-mesh sieve.

[0018] Based on the weight of the tomato straw biochar raw material, the following amounts were added: calcium sulfate 3-5%, magnesium sulfate 3-5%, ferrous sulfate 0.5-0.8%, copper sulfate 0.3-0.5%, zinc sulfate 0.5-0.6%, manganese sulfate 0.2-0.3%, sodium molybdate 0.1-0.2%, and borax 0.5-0.8%.

[0019] Tomato straw biochar precursor is prepared by pyrolysis of tomato straw using an oxygen-limited pyrolysis method.

[0020] Specifically, the preparation method of tomato straw biochar is as follows: fresh tomato straw is crushed into 3-5 cm pieces, dried to constant weight, and then pyrolyzed using an oxygen-limited pyrolysis method at a temperature of 400-450℃, preferably 400℃. After anaerobic drying for 2-2.5 h, preferably 2 h, the tomato straw biochar is naturally cooled to room temperature to obtain the tomato straw biochar.

[0021] The preparation method of the nutrient-loaded biochar is as follows: 3-5% calcium sulfate, 3-5% magnesium sulfate, 0.5-0.8% ferrous sulfate, 0.3-0.5% copper sulfate, 0.5-0.6% zinc sulfate, 0.2-0.3% manganese sulfate, 0.1-0.2% sodium molybdate, and 0.5-0.8% borax are mixed with tomato straw biochar stock. The mixture and agate balls are added to an agate jar at a ratio of 1-1.5:10 (w / w), preferably 1:10 (w / w). The mixture is then placed in a planetary ball mill at a speed of 300-320 rpm, preferably 300 rpm, and ground for 4-5 hours, preferably 4 hours. After grinding, the mixture is passed through a 200-mesh sieve to obtain the nutrient-loaded biochar.

[0022] A method for preparing a functional vegetable seedling substrate based on modified vegetable straw is as follows: peat, decomposed tomato straw substrate, perlite, nutrient-loaded biochar, mineral-derived potassium humate, and diatomaceous earth are mixed evenly according to the stated weight parts to obtain a functional vegetable seedling substrate based on modified tomato straw.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention aims to utilize tomato straw through a composite process of "substrate-based + functionalization" to develop a new type of green, low-carbon, and low-cost vegetable seedling substrate.

[0025] This invention employs a rapid composting process to produce high-quality tomato straw compost substrate and an anaerobic pyrolysis process to produce tomato straw modified biochar substrate. Through efficient formulation of nutrients and minerals, a new process and product for producing functional vegetable seedling substrates based on modified tomato straw are developed.

[0026] The tomato straw compost material in the vegetable seedling substrate of this invention is a product of processing tomato straw into substrate and fertilizer. It has a loose structure, excellent water retention and porosity, and can partially replace the traditional non-renewable seedling substrate resource - peat. It can serve as a basic carrier for crop seedling production and realize the resource utilization of agricultural waste.

[0027] The fresh cow manure in the vegetable seedling substrate of this invention enriches the nutrient ratio of the tomato straw composting substrate and adjusts the C / N ratio of the tomato straw humification material, achieving the harmless treatment and fertilization of livestock manure. The compounded extremely thermophilic microbial agent can rapidly raise the temperature of the compost pile in a short time, significantly improving the composting efficiency of tomato straw and shortening the composting time by 7-10 days compared to conventional decomposition microbial agents on the market. The nutrient-loaded biochar is obtained by pyrolyzing agricultural waste—tomato straw—under high-temperature and semi-anaerobic conditions. It has a rich porous structure, a large specific surface area, and good porosity, exhibiting strong adsorption capacity and excellent retention of water and nutrients. Through further physical modification, such as ball milling to graft nutrients onto the biochar, the internal pore network of the biochar is exposed, oxygen-containing functional groups are introduced into the surface of the biochar, the specific surface area is expanded, and nutrients are encapsulated and adsorbed by the biochar, preventing nutrient loss and enabling slow release and continuous supply of nutrients, effectively improving utilization. Peat is a common material needed for crop seedling substrates. Rich in organic matter and trace elements, it is loose and porous, with excellent water and fertilizer retention, making it an excellent carrier for crop seedling growth. Perlite has a strong water absorption and retention capacity, providing a continuous supply of moisture to seedlings. Its porous structure increases the oxygen content in the substrate and can adsorb nutrients. Potassium humate, a short-chain molecular structure extracted from natural humic acid, loosens the substrate, improves its water and fertilizer retention capacity, regulates pH, and strengthens the adhesion and rapid absorption capacity of plant roots. Diatomaceous earth has a unique porous structure, increasing the substrate's aeration, water retention, and fertilizer retention, while also containing various trace elements. Through the optimized combination of these inorganic minerals and organic materials, complementary advantages can be achieved, providing excellent aeration, water retention, and fertilizer retention conditions for the seedling substrate, enabling a slow-release supply of trace elements, stimulating crop seedling root development, and laying the foundation for strong seedling production.

[0028] This invention, through the compounding of the above components, can significantly improve the decomposition efficiency of tomato straw, shortening the decomposition time by 7-10 days compared to conventional decomposing microbial agents. It also enhances the stability of micronutrients, preventing their loss during irrigation. Furthermore, this invention reuses the large amount of tomato straw generated during vegetable farming, turning waste into treasure and greatly reducing environmental pollution risks. The production of tomato straw biochar using the limited-oxygen pyrolysis method can significantly reduce carbon emissions and achieve carbon sequestration. The decomposed tomato straw substrate has strong water and fertilizer retention capacity, excellent permeability, and high humus content, and can partially replace peat, effectively replacing non-renewable resources and providing a technical approach for the green development of seedling substrates. Attached Figure Description

[0029] Figure 1 The diagram shows the dynamic temperature changes in composting treatments in the embodiments and comparative examples of this invention.

[0030] Figure 2The desorption rate of Zn, Fe, Mn and Cu by nutrient-loaded biochar in Example 3 of this invention is shown. Detailed Implementation

[0031] Example 1

[0032] The functional vegetable seedling substrate (T1) based on tomato straw modification comprises, by weight, 6 parts peat, 3 parts decomposed tomato straw substrate, 1.5 parts perlite, 0.3 parts nutrient-loaded biochar, 0.1 parts mineral-derived potassium humate, and 0.01 parts diatomaceous earth.

[0033] The components of the tomato straw composting substrate include: tomato straw, fresh cow manure, and extremely thermophilic compound microbial agent; the ratio of tomato straw, fresh cow manure, and extremely thermophilic compound microbial agent is 1:3:0.0015.

[0034] The extremely thermophilic compound microbial agent includes thermophilic marine bacteria, thermophilic mycelium, thermophilic streptomyces, urea-bacterium, and thermophilic neobacterium; the ratio of the amounts of thermophilic marine bacteria, thermophilic mycelium, thermophilic streptomyces, urea-bacterium, and thermophilic neobacterium is 4:3:1:2:1.

[0035] The thermophilic marine bacterium was sourced from the China General Microbiological Culture Collection Center, with strain number CGMCC1.12207; the viable count was not less than 7.5 × 10⁻⁶. 9 CFU / g;

[0036] The thermophilic filamentous yeast was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC2.4939; the viable count was not less than 2 × 10⁻⁶. 9 CFU / g;

[0037] The thermophilic and coprophilic Streptomyces was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC4.6959; the viable count was not less than 3.5 × 10⁻⁶. 9 CFU / g;

[0038] The *Bacillus urealyticum* strain was obtained from the China General Microbiological Culture Collection Center, with strain number CGMCC1.7272; the viable count was not less than 5.5 × 10⁻⁶. 9 CFU / g;

[0039] The thermophilic neobacterium was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC1.12771; the viable count was not less than 2.5 × 10⁻⁶. 9 CFU / g.

[0040] The thermophilic marine bacteria, the thermophilic filamentous yeast, the thermophilic streptomyces, the urea-bacterium, and the thermophilic neobacterium were all purchased from the China General Microbiological Culture Collection Center.

[0041] Preparation of composted tomato straw substrate: Tomato straw with a moisture content of 50-70% is crushed into 1-3cm pieces, then thoroughly mixed with fresh cow manure (dry weight). The initial C / N ratio of the mixed raw materials is adjusted to 25 using urea. A thermophilic compound microbial agent is added for composting. The effective viable count of the thermophilic compound microbial agent is 5 × 10⁻⁶. 9 CFU / mL, for the first 6 days of composting, turn the compost every two days, and then turn it every 5 days in the later period, keeping the moisture content of the compost at 60%. When the temperature of the compost pile drops below 32℃, stop turning the pile and let the temperature of the pile pile drop naturally to the ambient temperature. When the products in the pile turn brown, have no irritating odor, and have a naturally loose granular structure, it is fully decomposed and you will get tomato straw compost base material.

[0042] Nutrient-loaded biochar was prepared by mixing tomato straw biochar with the following additive amounts: calcium sulfate 3%, magnesium sulfate 3%, ferrous sulfate 0.5%, copper sulfate 0.3%, zinc sulfate 0.6%, manganese sulfate 0.3%, sodium molybdate 0.1%, and borax 0.8%. The mixture and agate balls were added to an agate jar at a ratio of 1:10 (w / w), and then placed in a planetary ball mill at 300 rpm for 4 hours. After grinding, the mixture was passed through a 200-mesh sieve to obtain nutrient-loaded biochar.

[0043] The preparation method of tomato straw biochar precursor is as follows: crush tomato straw into pieces of about 5cm, dry to constant weight, and then pyrolyze using a limited oxygen pyrolysis method at a pyrolysis temperature of 400℃. After anaerobic drying for 2 hours, it is naturally cooled to room temperature to obtain tomato straw biochar precursor.

[0044] Preparation method of functional vegetable seedling substrate (T1) modified with tomato straw: 6 parts peat, 3 parts decomposed tomato straw substrate, 1.5 parts perlite, 0.3 parts nutrient-loaded biochar, 0.1 parts potassium humate, and 0.01 parts diatomaceous earth were mixed evenly to obtain the functional vegetable seedling substrate modified with tomato straw. The physicochemical properties of the seedling substrate are shown in Table 1.

[0045] Example 2

[0046] The functional vegetable seedling substrate (T2) based on tomato straw modification comprises, by weight, 6 parts peat, 4 parts decomposed tomato straw substrate, 1.6 parts perlite, 0.2 parts nutrient-loaded biochar, 0.15 parts mineral-derived potassium humate, and 0.02 parts diatomaceous earth.

[0047] The components of the tomato straw composting substrate include: tomato straw, fresh cow manure, and extremely thermophilic compound microbial agent; the ratio of tomato straw, fresh cow manure, and extremely thermophilic compound microbial agent is 1:3:0.001.

[0048] The extremely thermophilic compound microbial agent includes thermophilic marine bacteria, thermophilic mycelium, thermophilic streptomyces, urea-bacterium, and thermophilic neobacterium; the ratio of the amounts of thermophilic marine bacteria, thermophilic mycelium, thermophilic streptomyces, urea-bacterium, and thermophilic neobacterium is 4:3:2:2:1.

[0049] The thermophilic marine bacterium was sourced from the China General Microbiological Culture Collection Center, with strain number CGMCC1.12207; the viable count was not less than 7.5 × 10⁻⁶. 9 CFU / g;

[0050] The thermophilic filamentous yeast was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC2.4939; the viable count was not less than 2 × 10⁻⁶. 9 CFU / g;

[0051] The thermophilic and coprophilic Streptomyces was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC4.6959; the viable count was not less than 3.5 × 10⁻⁶. 9 CFU / g;

[0052] The *Bacillus urealyticum* strain was obtained from the China General Microbiological Culture Collection Center, with strain number CGMCC1.7272; the viable count was not less than 5.5 × 10⁻⁶. 9 CFU / g;

[0053] The thermophilic neobacterium was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC1.12771; the viable count was not less than 2.5 × 10⁻⁶. 9 CFU / g.

[0054] Preparation of composted tomato straw substrate: Tomato straw with a moisture content of 50-70% is crushed into 1-3cm pieces, then thoroughly mixed with fresh cow manure (dry weight). The initial C / N ratio of the mixed raw materials is adjusted to 26 using urea. A thermophilic compound microbial agent is added for composting. The effective viable count of the thermophilic compound microbial agent is 5 × 10⁻⁶. 9 CFU / mL, for the first 6 days of composting, turn the compost every two days, and then turn it every 5 days in the later period, keeping the moisture content of the compost at 50% to 60%. When the temperature of the compost pile drops below 32°C, stop turning the pile and let the temperature of the pile pile drop naturally to the ambient temperature. When the products in the pile turn brown, have no irritating odor, and have a naturally loose granular structure, it is fully decomposed and you will get tomato straw compost base material.

[0055] Nutrient-loaded biochar was prepared by mixing tomato straw biochar with the following additive amounts: calcium sulfate 5%, magnesium sulfate 3%, ferrous sulfate 0.6%, copper sulfate 0.4%, zinc sulfate 0.6%, manganese sulfate 0.3%, sodium molybdate 0.2%, and borax 0.5%. The mixture was then added to an agate jar with agate balls at a ratio of 1:10 (w / w), and then placed in a planetary ball mill at 300 rpm for 4 hours. After grinding, the mixture was passed through a 200-mesh sieve to obtain nutrient-loaded biochar.

[0056] The preparation method of tomato straw biochar precursor is as follows: crush tomato straw into pieces of about 5cm, dry to constant weight, and then pyrolyze using a limited oxygen pyrolysis method at a pyrolysis temperature of 400℃. After anaerobic drying for 2 hours, it is naturally cooled to room temperature to obtain tomato straw biochar precursor.

[0057] Preparation method of functional vegetable seedling substrate (T2) modified with tomato straw: 6 parts peat, 4 parts decomposed tomato straw substrate, 1.6 parts perlite, 0.2 parts nutrient-loaded biochar, 0.15 parts potassium humate, and 0.02 parts diatomaceous earth were mixed evenly to obtain the functional vegetable seedling substrate modified with tomato straw. The physicochemical properties of the seedling substrate are shown in Table 1.

[0058] Example 3

[0059] The functional vegetable seedling substrate (T3) based on tomato straw modification comprises, by weight, 7 parts peat, 3 parts decomposed tomato straw substrate, 2 parts perlite, 0.2 parts nutrient-loaded biochar, 0.2 parts mineral-derived potassium humate, and 0.02 parts diatomaceous earth.

[0060] The components of the tomato straw composting substrate include: tomato straw, fresh cow manure, and extremely thermophilic compound microbial agent; the ratio of tomato straw, fresh cow manure, and extremely thermophilic compound microbial agent is 1:3:0.001.

[0061] The extremely thermophilic compound microbial agent includes thermophilic marine bacteria, thermophilic mycelium, thermophilic streptomyces, urea-bacterium, and thermophilic neobacterium; the ratio of the amounts of thermophilic marine bacteria, thermophilic mycelium, thermophilic streptomyces, urea-bacterium, and thermophilic neobacterium is 4:2:1:2:1.5.

[0062] The thermophilic marine bacterium was sourced from the China General Microbiological Culture Collection Center, with strain number CGMCC1.12207; the viable count was not less than 7.5 × 10⁻⁶. 9 CFU / g;

[0063] The thermophilic filamentous yeast was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC2.4939; the viable count was not less than 2 × 10⁻⁶. 9 CFU / g;

[0064] The thermophilic and coprophilic Streptomyces was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC4.6959; the viable count was not less than 3.5 × 10⁻⁶. 9 CFU / g;

[0065] The *Bacillus urealyticum* strain was obtained from the China General Microbiological Culture Collection Center, with strain number CGMCC1.7272; the viable count was not less than 5.5 × 10⁻⁶. 9 CFU / g;

[0066] The thermophilic neobacterium was derived from the China General Microbiological Culture Collection Center, with the strain number CGMCC1.12771; the viable count was not less than 2.5 × 10⁻⁶. 9 CFU / g.

[0067] Preparation of composted tomato straw substrate: Tomato straw with a moisture content of 50-70% is crushed into 1-3cm pieces, then thoroughly mixed with fresh cow manure (dry weight). The initial C / N ratio of the mixed raw materials is adjusted to 27 using urea. A thermophilic compound microbial agent is added for composting. The effective viable count of the thermophilic compound microbial agent is 5 × 10⁻⁶. 9 CFU / mL, for the first 6 days of composting, turn the compost every two days, and then turn it every 5 days in the later period, keeping the moisture content of the compost at 55%. When the temperature of the compost pile drops below 32℃, stop turning the pile and let the temperature of the pile pile drop naturally to the ambient temperature. When the products in the pile turn brown, have no irritating odor, and have a naturally loose granular structure, it is fully decomposed and you will get tomato straw compost base material.

[0068] Nutrient-loaded biochar was prepared by mixing tomato straw biochar at the following ratios: calcium sulfate 4%, magnesium sulfate 4%, ferrous sulfate 0.6%, copper sulfate 0.4%, zinc sulfate 0.5%, manganese sulfate 0.3%, sodium molybdate 0.2%, and borax 0.6%. The mixture was then added to an agate jar along with agate balls at a ratio of 1:10 (w / w), and ground in a planetary ball mill at 300 rpm for 4 hours. The resulting biochar was then passed through a 200-mesh sieve. The desorption rates of Zn, Fe, Mn, and Cu after nutrient-loaded biochar loading are shown in the figure. Figure 2 .

[0069] The preparation method of tomato straw biochar precursor is as follows: crush tomato straw into pieces of about 5cm, dry to constant weight, and then pyrolyze using a limited oxygen pyrolysis method at a pyrolysis temperature of 400℃. After anaerobic drying for 2 hours, it is naturally cooled to room temperature to obtain tomato straw biochar precursor.

[0070] Preparation method of functional vegetable seedling substrate (T3) modified with tomato straw: 7 parts peat, 3 parts decomposed tomato straw, 2 parts perlite, 0.2 parts nutrient-loaded biochar, 0.2 parts potassium humate, and 0.02 parts diatomaceous earth were mixed evenly to obtain the functional vegetable seedling substrate modified with tomato straw. The physicochemical properties of the seedling substrate are shown in Table 1, and the dynamic change of composting temperature is shown in the graph. Figure 1 .

[0071] Comparative Example 1

[0072] The difference from Example 3 is that the extremely thermophilic compound microbial agent was replaced with a conventional composting microbial agent (EM fermentation bacteria, purchased from Zhengzhou Baiyibao Biotechnology Co., Ltd.). Other conditions were the same as in Example 3, and the resulting seedling substrate (B1) was prepared. Its physicochemical properties are shown in Table 1, and the dynamic change graph of the composting temperature is shown in [Figure 1]. Figure 1 .

[0073] Comparative Example 2

[0074] The difference from Example 3 is that no nutrients were added to support biochar, while other conditions were the same as in Example 3, and seedling substrate (B2) was prepared. The physicochemical properties are shown in Table 1.

[0075] Table 1. Physicochemical properties of the matrix

[0076] deal with <![CDATA[Bulk density (g / cm 3 )]]> Total porosity (%) pH EC (mS / cm) T1 0.706c 66.36a 6.12a 0.706b T2 0.705c 65.42a 6.18a 0.716b T3 0.708c 67.22a 6.21a 0.727b B1 0.725b 61.41b 6.12a 0.804ab B2 0.736a 62.35b 6.14a 0.812a

[0077] Note: CK is a conventional seedling substrate on the market, while T1, T2, and T3 are three functional tomato straw seedling substrate products produced using this technology, and the same applies below.

[0078] Depend on Figure 1 As can be seen from Table 1, the embodiments of the present invention use an extremely thermophilic compound microbial agent, which can rapidly raise the temperature of the pile in a short time, significantly improve the decomposition efficiency of tomato straw, significantly reduce the bulk density of the substrate, and increase the total porosity of the substrate, thereby giving the substrate better permeability and promoting the healthy growth of seedlings.

[0079] Application examples

[0080] Seedling substrates T1-T3 (example) and B1-B2 (comparative) were used for chili seedlings. Different substrates were filled into seedling trays, chili seeds were sown, and seedlings were raised normally. After 64 days of growth, the growth status of the chili seedlings was investigated. The germination rate and number of leaves were calculated. Plant height and the length and width of three leaves were measured with a ruler, and the average leaf area was calculated and recorded using a formula. Stem diameter was measured with calipers. After harvest, the above-ground parts were cut off at the stem, and the plants were rinsed with distilled water to remove surface dust and root substrate. Surface moisture was absorbed, and the fresh weight of the above-ground and underground parts was weighed separately and recorded to an accuracy of 0.0001g. After processing, the plants and roots are placed on kraft paper and put into an oven at 105℃ for 10 minutes to deactivate enzymes and other active substances in the plant, reducing errors caused by the plant's own consumption during the drying process. Then, the oven is set to 65℃ to constant weight. The dry weight of the above-ground and underground parts is weighed and recorded. The dried above-ground and underground parts of the plants are then placed in the same self-sealing bag for later use.

[0081] Table 2. Effects of functional vegetable seedling substrates on the growth of pepper seedlings.

[0082]

[0083] As shown in Table 2, the plant height, stem diameter, leaf area, aboveground dry weight, underground dry weight, total weight, and seedling vigor index of the chili seedlings in the embodiments of the present invention are all higher than those of the control group. This indicates that the vegetable seedling substrate of the embodiments of the present invention has a loose structure, excellent water retention and porosity, and can be used as a basic carrier for crop seedling production, realizing the slow-release supply of trace elements, stimulating the root development of crop seedlings, and providing a foundation for the production of strong seedlings.

Claims

1. A functional vegetable seedling substrate based on vegetable straw modification, characterized by: The matrix component comprises, by weight parts: peat 6-7 parts, tomato stalk humic base 3-4 parts, perlite 1.5-2 parts, nutrient element loaded biochar 0.1-0.3 parts, mineral humic acid potassium 0.1-0.2 parts, diatomite 0.01-0.03 parts; The tomato stalk humic base component comprises: tomato stalk, fresh cow dung and extremely thermophilic complex microbial agent; wherein the use amount ratio of the tomato stalk, fresh cow dung and extremely thermophilic complex microbial agent is 1-1.5:3-5:0.001~0.0015; The extremely thermophilic complex microbial agent comprises: thermococcus, trichosporon thermophilum, streptomyces thermophilus, bacillus geovaras, and bacillus caldovelox; The use amount ratio of the thermococcus, trichosporon thermophilum, streptomyces thermophilus, bacillus geovaras and bacillus caldovelox is 4~5: 2~3: 1~2: 2~4: 1~2; The nutrient element loaded biochar is obtained by mixing tomato stalk biochar raw body with calcium sulfate, magnesium sulfate, ferrous sulfate, copper sulfate, zinc sulfate, manganese sulfate, sodium molybdate and borax, and then grinding through a 200-mesh sieve; The calcium sulfate, magnesium sulfate, ferrous sulfate, copper sulfate, zinc sulfate, manganese sulfate, sodium molybdate and borax are added in an amount of 3~5%, 3~5%, 0.5~0.8%, 0.3~0.5%, 0.5~0.6%, 0.2~0.3%, 0.1~0.2% and 0.5~0.8% respectively, based on the weight of the tomato stalk biochar raw body.

2. The modified functional vegetable seedling substrate based on vegetable stalks according to claim 1, characterized by: The preparation method of the tomato stalk humic base is as follows: tomato stalk with a water content of 50-70% is crushed, then mixed with fresh cow dung, and then composted by adding the extremely thermophilic complex microbial agent; the compost is turned over once every two days for the first 6 days, and then turned over once every 5 days; the water content of the compost is maintained at 50%~60%; when the temperature of the compost falls to 32℃, the turning is stopped; and when the temperature of the compost falls to the ambient temperature, the tomato stalk humic base is obtained. 3.The modified functional vegetable seedling substrate based on vegetable stalks according to claim 1, characterized in that: The tomato stalk biochar raw body is prepared by using limited oxygen pyrolysis method with tomato stalk as raw material.

4. The modified functional vegetable seedling substrate based on vegetable stalks according to claim 3, characterized by: The preparation method of the tomato stalk biochar raw body is as follows: fresh tomato stalk is crushed to 3~5 cm, dried to constant weight, and then pyrolyzed by using limited oxygen pyrolysis method; the pyrolysis temperature is 400~450℃; after anaerobic drying for 2~2.5h, the pyrolyzed product is naturally cooled to room temperature to obtain the tomato stalk biochar raw body.

5. The modified functional vegetable seedling substrate based on vegetable stalks according to claim 1, characterized by: The preparation method of the nutrient element loaded biochar is as follows: the tomato stalk biochar raw body is mixed with calcium sulfate 3~5%, magnesium sulfate 3~5%, ferrous sulfate 0.5~0.8%, copper sulfate 0.3~0.5%, zinc sulfate 0.5~0.6%, manganese sulfate 0.2~0.3%, sodium molybdate 0.1~0.2% and borax 0.5~0.8%; the mixture and agate balls are added into a maragda jar in a ratio of 1~1.5:10w / w; then the maragda jar is put into a planetary ball mill; the rotation speed is 300~320rpm; the mixture is ground for 4~5h and then sieved through a 200-mesh sieve to obtain the nutrient element loaded biochar.

Images