A soil amendment for improving quality and yield of continuous cropping tomatoes and a method of making the same

Abstract

The application discloses a soil conditioner for improving quality and yield of continuous cropping tomatoes, and raw materials of the soil conditioner include earthworm manure powder, sinomenium acutum powder, fallopia multiflora, limestone powder, humic acid, active adsorbent, composite microorganism, carboxymethyl hydroxyethyl cellulose, acrylamide, crosslinking agent, photoinitiator, catalyst and iron salt. The application also discloses a preparation method of the soil conditioner for improving quality and yield of continuous cropping tomatoes. The application adopts the compounding of the loaded microorganism and the earthworm manure powder, can quickly increase soil water stable aggregates, improve soil physical structure, enhance soil fertility, and has extremely remarkable effect of improving soil, and in combination with the sinomenium acutum and the fallopia multiflora, can not only show the inhibiting effect on fusarium oxysporum in the soil continuously cropped for 5-10 years, but also can continuously enhance soil enzyme activity.

Description

Technical Field

[0001] This invention relates to the field of soil improvement technology, and in particular to a soil conditioner for improving the quality and yield of continuously cropped tomatoes and its preparation method. Background Technology

[0002] Tomatoes are an important species of the Solanaceae family worldwide. Due to their high yield and nutritional value, tomatoes are very popular among farmers and consumers in my country. Currently, tomato production is characterized by intensification and a high multiple cropping index. However, while this has boosted rural economic development, it has also brought many problems to sustainable production. One of the more serious and common problems is the obstacle of continuous cropping.

[0003] Continuous cropping obstacles refer to the phenomenon that, even with normal management practices, continuous cropping of crops can lead to poorer vegetative growth, reduced yield and quality, imbalanced soil microbial communities, and increased pests and diseases. Currently, the production problems and economic losses caused by continuous cropping obstacles are becoming increasingly serious.

[0004] Soil microorganisms are crucial participants in nutrient cycling, organic matter decomposition, disease control, and maintaining soil fertility, playing a vital role in the soil ecosystem. However, with prolonged continuous cropping, the abundance of soil bacteria and actinomycetes shows a trend of first increasing and then decreasing, while fungal abundance shows a continuous increasing trend, and microbial diversity decreases, leading to severe soil degradation. Some soil microbial communities (such as actinomycetes) could originally directly inhibit the growth and reproduction of soil pathogens (such as Fusarium oxysporum) through antagonistic effects, but these are all destroyed with prolonged continuous cropping.

[0005] Earthworm castings are fine granular materials excreted by earthworms as they decompose organic waste in their intestines. They are characterized by high porosity, excellent aeration, drainage, and storage capacity, and high microbial activity. In recent years, people have come to understand earthworm castings as a natural, organic fertilizer that can replace chemical fertilizers in sustainable agricultural production.

[0006] Currently, soil microbial and nutrient imbalances are a major cause of continuous cropping obstacles during the tomato growth period. Furthermore, with increasing years of continuous cropping, farmers further overuse inorganic fertilizers in pursuit of high yields, creating a vicious cycle. Continuous cropping ultimately leads to a loss of both tomato yield and quality. Therefore, research on how to use a combination of earthworm castings and microorganisms to improve tomato yield and fruit quality during long-term continuous cropping, while also improving soil structure, holds great promise. Summary of the Invention

[0007] Based on the technical problems existing in the background technology, the present invention proposes a soil conditioner for improving the quality and yield of continuously cropped tomatoes and its preparation method.

[0008] A soil conditioner for improving the quality and yield of continuously cropped tomatoes comprises the following raw materials: earthworm castings powder, *Sinomenium acutum* powder, *Trachelospermum jasminoides* powder, limestone powder, humic acid, active adsorbent, compound microorganisms, carboxymethyl hydroxyethyl cellulose, acrylamide, crosslinking agent, photoinitiator, catalyst, and iron salt; the mass ratio of earthworm castings powder, *Sinomenium acutum* powder, *Trachelospermum jasminoides* powder, limestone powder, humic acid, active adsorbent, compound microorganisms, carboxymethyl hydroxyethyl cellulose, acrylamide, crosslinking agent, photoinitiator, catalyst, and iron salt is 60-100: 5-15: 1-5: 10-15: 20-40: 18-48: 3-6: 1-2: 1-3: 0.1-0.5: 0.01-0.1: 0.01-0.1: 0.1-1.

[0009] *Qingfengteng*, an extract of the vines of *Menispermum erythrorhizon* and *Menispermum villosum*, belonging to the Menispermaceae family, contains sinomenine, disinomenine, magnoflorine, tetrahydroberberine, isosinomenine, terturaline, sinomenine, dl-eugenol, methyl hexadecanoate, N-demethyltetracycline, magnoflorine, and styracil, as well as β-sitosterol and stigmasterol. *Qingfengteng* has a bitter and pungent taste, and is neutral in nature. It has the effects of dispelling wind and dampness, clearing the meridians, and promoting urination. It is mainly used to treat symptoms such as rheumatic pain, joint swelling, numbness, and itching.

[0010] Trachelospermum jasminoides, an evergreen woody vine belonging to the genus Trachelospermum in the family Apocynaceae, contains trachelospermum glycoside, argentin, arctiin, alkaloids, and flavonoids. It has the effects of dispelling wind and unblocking meridians, cooling blood and reducing swelling. It is mainly used to treat rheumatic fever, sore throat, carbuncles, and injuries from falls.

[0011] Preferably, the crosslinking agent is N-hydroxymethylacrylamide.

[0012] Preferably, the photoinitiator is 2-ketoglutaric acid.

[0013] Preferably, the catalyst is tetramethylethylenediamine.

[0014] Preferably, the iron salt is ferric chloride.

[0015] Preferably, the compound microorganisms include: Bacillus licheniformis, yeast, and Streptomyces griseus; the effective viable count of Bacillus licheniformis is ≥4×10⁻⁶. 8 cfu / g, effective viable yeast count ≥4×10 8 cfu / g, effective viable count of Streptomyces griseus ≥1×10 8 cfu / g.

[0016] Preferably, the active adsorbent is prepared by the following specific steps: Activated carbon, kaolin, attapulgite, and bentonite are mixed evenly and fed into an automatic pelletizing machine. During the pelletizing process, a carboxymethyl cellulose aqueous solution is sprayed on the mixture, and the mixture is calcined at 300-500℃ for 1-2 hours. The active adsorbent is then obtained by cooling.

[0017] This application uses activated carbon combined with kaolin, attapulgite, and bentonite, which are then pelletized under the action of carboxymethyl cellulose and calcined. The resulting activated adsorbent has a large adsorption capacity for composite microorganisms and excellent adsorption performance.

[0018] Preferably, the mass fraction of the carboxymethyl cellulose aqueous solution is 5-10%, and the mass ratio of activated carbon, kaolin, attapulgite, bentonite, and carboxymethyl cellulose aqueous solution is 10-20:5-15:2-10:1-3:1-5.

[0019] Preferably, the earthworm castings powder is 300 mesh and the limestone powder is 300 mesh.

[0020] The above-mentioned method for preparing soil conditioner to improve the quality and yield of continuously cropped tomatoes includes the following steps:

[0021] S1. Add the active adsorbent and composite microorganisms to water and stir for 2-5 hours for adsorption. Add carboxymethyl hydroxyethyl cellulose, acrylamide, crosslinking agent and photoinitiator and stir for 10-30 minutes. Add catalyst and initiate with ultraviolet light for 1-2 hours. Add iron salt and continue stirring for 1-2 hours to obtain the loaded microorganisms.

[0022] S2. Add earthworm castings powder, Chinese artemisia powder, trachelospermum jasminoides powder, limestone powder, and humic acid to the loaded microorganisms, stir evenly, granulate, and dry to obtain a soil conditioner that improves the quality and yield of continuously cropped tomatoes.

[0023] This application employs an activated adsorbent to adsorb microorganisms, followed by cross-linking of acrylamide and N-hydroxymethylacrylamide to form a rigid supporting first network structure for the microorganisms within the activated adsorbent. Carboxymethyl hydroxyethyl cellulose has a large number of hydroxyl and carboxyl groups on its surface, which can form hydrogen bonds with the first network structure. Then, under the action of iron ions, it further cross-links on the surface of the activated adsorbent. The resulting product not only has excellent hydrophilic properties but also exhibits excellent microbial stability within the loaded microorganisms, which can sustainably antagonize the number of Fusarium oxysporum in the soil and enhance bacterial diversity. However, the applicant found that after five consecutive years of cropping, although it can sustainably improve soil structure, it shows a decrease in the inhibitory effect on Fusarium oxysporum in the soil.

[0024] Through experiments, the applicant discovered that combining loaded microorganisms with *Sinomenium acutum* and *Trachelospermum jasminoides* not only exhibits an inhibitory effect on *Fusarium oxysporum* in soils that have been continuously cropped for 5-10 years, but also sustainably enhances soil enzyme activity. Compared to simply adding *Sinomenium acutum* or *Trachelospermum jasminoides*, the rhizosphere soil in this application showed higher enzyme activity and a higher actinomycete / fungus ratio than non-root soils, demonstrating excellent inhibitory effects on *Fusarium oxysporum* in the soil.

[0025] This application further utilizes a combination of loaded microorganisms and earthworm castings powder, which can rapidly increase soil water-stable aggregates, improve soil physical structure, enhance soil fertility, and achieve extremely significant soil improvement effects. Humic acid combines with limestone powder in the soil to form an irreversible aggregate state. Its aggregates are loose and porous with strong water stability, which can effectively promote the process of soil particles approaching each other to form complex particles. Combined with the highly developed pore structure inside the loaded microorganisms, it significantly improves fertilizer utilization. Attached Figure Description

[0026] Figure 1 This is a comparative diagram of soil enzyme (urease, acid phosphatase, catalase, polyphenol oxidase) activities in Example 5, Comparative Example 1, Comparative Example 2, conventional fertilization group, and blank control group.

[0027] Figure 2 This is a comparison chart of the enrichment rates of soil enzymes (urease, acid phosphatase, catalase, and polyphenol oxidase) in Example 5, Comparative Example 1, Comparative Example 2, Conventional Fertilization Group, and Blank Control Group.

[0028] Figure 3 This is a comparison diagram of bacteria / fungi and actinomycetes / fungi in the soil of Example 5, Comparative Example 1, Comparative Example 2, Conventional Fertilization Group, and Blank Control Group.

[0029] Figure 4 The graph shows a comparison of the inhibitory effects of Fusarium oxysporum on Example 5, Comparative Example 1, Comparative Example 2, the conventional fertilization group, and the blank control group.

[0030] Figure 5 This is a comparison chart of the tomato quality and yield obtained from Example 5, Comparative Example 1, Comparative Example 2, conventional fertilization group, and blank control group. Detailed Implementation

[0031] The technical solution of the present invention will now be described in detail through specific embodiments.

[0032] Example 1

[0033] A soil conditioner for improving the quality and yield of continuously cropped tomatoes comprises the following raw materials: 60 kg of earthworm castings powder, 5 kg of *Sinomenium acutum* powder, 1 kg of *Trachelospermum jasminoides*, 10 kg of limestone powder, 20 kg of humic acid, 18 kg of activated adsorbent, 3 kg of compound microorganisms, 1 kg of carboxymethyl hydroxyethyl cellulose, 1 kg of acrylamide, 0.1 kg of N-hydroxymethyl acrylamide, 0.01 kg of 2-ketoglutaric acid, 0.01 kg of tetramethylethylenediamine, and 0.1 kg of ferric chloride.

[0034] Complex microorganisms include: effective viable count ≥ 4 × 10⁻⁶ 8 Bacillus licheniformis CFU / g, with an effective viable count ≥4×10⁻⁶.8 yeast with cfu / g and an effective viable count ≥4×10⁻⁶ 8 Streptomyces griseus at cfu / g.

[0035] The activated adsorbent is prepared by the following specific steps: 10 kg of activated carbon, 5 kg of kaolin, 2 kg of attapulgite, and 1 kg of bentonite are mixed evenly and fed into an automatic pelletizing machine. 1 kg of 5% carboxymethyl cellulose aqueous solution is sprayed on to obtain pellets with a particle size of 1-2 mm. The pellets are calcined at 300℃ for 1 hour and then cooled to obtain the activated adsorbent.

[0036] The above-mentioned method for preparing soil conditioner to improve the quality and yield of continuously cropped tomatoes includes the following steps:

[0037] S1. Add the active adsorbent and composite microorganisms to 50kg of water and stir for 2h. Add carboxymethyl hydroxyethyl cellulose, acrylamide, N-hydroxymethyl acrylamide and 2-ketoglutaric acid and stir for 10min. Add tetramethyl ethylenediamine and initiate with ultraviolet light for 1h. Add ferric chloride and continue stirring for 1h to obtain the loaded microorganisms.

[0038] S2. Add 300-mesh earthworm castings powder, 300-mesh sedum powder, trachelospermum jasminoides powder, 300-mesh limestone powder, and humic acid to the loaded microorganisms, stir evenly, granulate, and dry to obtain a soil conditioner that improves the quality and yield of continuously cropped tomatoes.

[0039] Example 2

[0040] A soil conditioner for improving the quality and yield of continuously cropped tomatoes comprises the following raw materials: 100 kg of earthworm castings powder, 15 kg of *Sinomenium acutum* powder, 5 kg of *Trachelospermum jasminoides*, 15 kg of limestone powder, 40 kg of humic acid, 48 kg of activated adsorbent, 6 kg of compound microorganisms, 2 kg of carboxymethyl hydroxyethyl cellulose, 3 kg of acrylamide, 0.5 kg of N-hydroxymethyl acrylamide, 0.1 kg of 2-ketoglutaric acid, 0.1 kg of tetramethylethylenediamine, and 1 kg of ferric chloride.

[0041] Complex microorganisms include: effective viable count ≥ 4 × 10⁻⁶ 8 Bacillus licheniformis CFU / g, with an effective viable count ≥4×10⁻⁶. 8 yeast with cfu / g and an effective viable count ≥4×10⁻⁶ 8 Streptomyces griseus at cfu / g.

[0042] The activated adsorbent is prepared by the following specific steps: 20 kg of activated carbon, 15 kg of kaolin, 10 kg of attapulgite, and 3 kg of bentonite are mixed evenly and fed into an automatic pelletizing machine. 5 kg of a 10% carboxymethyl cellulose aqueous solution is sprayed on to obtain pellets with a particle size of 1-2 mm. The pellets are then calcined at 500℃ for 2 hours and cooled to obtain the activated adsorbent.

[0043] The above-mentioned method for preparing soil conditioner to improve the quality and yield of continuously cropped tomatoes includes the following steps:

[0044] S1. Add the active adsorbent and composite microorganisms to 100kg of water and stir for 5h. Add carboxymethyl hydroxyethyl cellulose, acrylamide, N-hydroxymethyl acrylamide and 2-ketoglutaric acid and stir for 30min. Add tetramethyl ethylenediamine and initiate with ultraviolet light for 2h. Add ferric chloride and continue stirring for 2h to obtain the loaded microorganisms.

[0045] S2. Add 300-mesh earthworm castings powder, 300-mesh sedum powder, trachelospermum jasminoides powder, 300-mesh limestone powder, and humic acid to the loaded microorganisms, stir evenly, granulate, and dry to obtain a soil conditioner that improves the quality and yield of continuously cropped tomatoes.

[0046] Example 3

[0047] A soil conditioner for improving the quality and yield of continuously cropped tomatoes comprises the following raw materials: 70 kg of earthworm castings powder, 12 kg of *Sinomenium acutum* powder, 2 kg of *Trachelospermum jasminoides*, 13 kg of limestone powder, 25 kg of humic acid, 38 kg of activated adsorbent, 4 kg of compound microorganisms, 1.7 kg of carboxymethyl hydroxyethyl cellulose, 1.5 kg of acrylamide, 0.4 kg of N-hydroxymethyl acrylamide, 0.03 kg of 2-ketoglutaric acid, 0.08 kg of tetramethylethylenediamine, and 0.3 kg of ferric chloride.

[0048] Complex microorganisms include: effective viable count ≥ 4 × 10⁻⁶ 8 Bacillus licheniformis CFU / g, with an effective viable count ≥4×10⁻⁶. 8 yeast with cfu / g and an effective viable count ≥4×10⁻⁶ 8 Streptomyces griseus at cfu / g.

[0049] The activated adsorbent is prepared by the following specific steps: 18 kg of activated carbon, 8 kg of kaolin, 8 kg of attapulgite, and 1.5 kg of bentonite are mixed evenly and fed into an automatic pelletizing machine. 4 kg of a 7% carboxymethyl cellulose aqueous solution is sprayed on to obtain pellets with a particle size of 1-2 mm. The pellets are then calcined at 450℃ for 80 min and cooled to obtain the activated adsorbent.

[0050] The above-mentioned method for preparing soil conditioner to improve the quality and yield of continuously cropped tomatoes includes the following steps:

[0051] S1. Add the active adsorbent and composite microorganisms to 90kg of water and stir for 3h. Add carboxymethyl hydroxyethyl cellulose, acrylamide, N-hydroxymethyl acrylamide and 2-ketoglutaric acid and stir for 25min. Add tetramethyl ethylenediamine and initiate with ultraviolet light for 80min. Add ferric chloride and continue stirring for 100min to obtain the loaded microorganisms.

[0052] S2. Add 300-mesh earthworm castings powder, 300-mesh sedum powder, trachelospermum jasminoides powder, 300-mesh limestone powder, and humic acid to the loaded microorganisms, stir evenly, granulate, and dry to obtain a soil conditioner that improves the quality and yield of continuously cropped tomatoes.

[0053] Example 4

[0054] A soil conditioner for improving the quality and yield of continuously cropped tomatoes comprises the following raw materials: 90 kg of earthworm castings powder, 8 kg of *Sinomenium acutum* powder, 4 kg of *Trachelospermum jasminoides*, 11 kg of limestone powder, 35 kg of humic acid, 28 kg of activated adsorbent, 5 kg of compound microorganisms, 1.3 kg of carboxymethyl hydroxyethyl cellulose, 2.5 kg of acrylamide, 0.2 kg of N-hydroxymethyl acrylamide, 0.07 kg of 2-ketoglutaric acid, 0.02 kg of tetramethylethylenediamine, and 0.7 kg of ferric chloride.

[0055] Complex microorganisms include: effective viable count ≥ 4 × 10⁻⁶ 8 Bacillus licheniformis CFU / g, with an effective viable count ≥4×10⁻⁶. 8 yeast with cfu / g and an effective viable count ≥4×10⁻⁶ 8 Streptomyces griseus at cfu / g.

[0056] The activated adsorbent is prepared by the following specific steps: 12 kg of activated carbon, 12 kg of kaolin, 4 kg of attapulgite, and 2.5 kg of bentonite are mixed evenly and fed into an automatic pelletizing machine. 2 kg of a 9% carboxymethyl cellulose aqueous solution is sprayed on to obtain pellets with a particle size of 1-2 mm. The pellets are then calcined at 350℃ for 100 min and cooled to obtain the activated adsorbent.

[0057] The above-mentioned method for preparing soil conditioner to improve the quality and yield of continuously cropped tomatoes includes the following steps:

[0058] S1. Add the active adsorbent and composite microorganisms to 70kg of water and stir for 4h. Add carboxymethyl hydroxyethyl cellulose, acrylamide, N-hydroxymethyl acrylamide and 2-ketoglutaric acid and stir for 15min. Add tetramethyl ethylenediamine and initiate with ultraviolet light for 100min. Add ferric chloride and continue stirring for 80min to obtain the loaded microorganisms.

[0059] S2. Add 300-mesh earthworm castings powder, 300-mesh sedum powder, trachelospermum jasminoides powder, 300-mesh limestone powder, and humic acid to the loaded microorganisms, stir evenly, granulate, and dry to obtain a soil conditioner that improves the quality and yield of continuously cropped tomatoes.

[0060] Example 5

[0061] A soil conditioner for improving the quality and yield of continuously cropped tomatoes comprises the following raw materials: 8000g earthworm castings powder, 1000g *Sinomenium acutum* powder, 300g *Trachelospermum jasminoides*, 1200g limestone powder, 3000g humic acid, 3000g activated adsorbent, 450g compound microorganisms, 150g carboxymethyl hydroxyethyl cellulose, 200g acrylamide, 30g N-hydroxymethyl acrylamide, 5g 2-ketoglutaric acid, 5g tetramethylethylenediamine, and 50g ferric chloride.

[0062] Complex microorganisms include: effective viable count ≥ 4 × 10⁻⁶ 8 Bacillus licheniformis CFU / g, with an effective viable count ≥4×10⁻⁶. 8 yeast with cfu / g and an effective viable count ≥4×10⁻⁶ 8 Streptomyces griseus at cfu / g.

[0063] The activated adsorbent is prepared using the following specific steps: 1500g activated carbon, 1000g kaolin, 600g attapulgite, and 200g bentonite are mixed evenly and fed into an automatic pelletizing machine. 300g of 8% carboxymethyl cellulose aqueous solution is sprayed on to obtain pellets with a particle size of 1-2mm. The pellets are then calcined at 400℃ for 90min and cooled to obtain the activated adsorbent.

[0064] The above-mentioned method for preparing soil conditioner to improve the quality and yield of continuously cropped tomatoes includes the following steps:

[0065] S1. Add the active adsorbent and composite microorganisms to 8000g of water and stir for 3.5h. Add carboxymethyl hydroxyethyl cellulose, acrylamide, N-hydroxymethyl acrylamide and 2-ketoglutaric acid and stir for 20min. Add tetramethyl ethylenediamine and initiate with ultraviolet light for 90min. Add ferric chloride and continue stirring for 90min to obtain the loaded microorganisms.

[0066] S2. Add 300-mesh earthworm castings powder, 300-mesh sedum powder, trachelospermum jasminoides powder, 300-mesh limestone powder, and humic acid to the loaded microorganisms, stir evenly, granulate, and dry to obtain a soil conditioner that improves the quality and yield of continuously cropped tomatoes.

[0067] Comparative Example 1

[0068] A soil conditioner, the raw materials of which include: 8000g earthworm castings powder, 1000g *Sinomenium acutum* powder, 300g *Trachelospermum jasminoides*, 1200g limestone powder, 3000g humic acid, 3000g activated adsorbent, and 450g compound microorganisms.

[0069] Complex microorganisms include: effective viable count ≥ 4 × 10⁻⁶ 8 Bacillus licheniformis CFU / g, with an effective viable count ≥4×10⁻⁶. 8 yeast with cfu / g and an effective viable count ≥4×10⁻⁶ 8 Streptomyces griseus at cfu / g.

[0070] The activated adsorbent is prepared using the following specific steps: 1500g activated carbon, 1000g kaolin, 600g attapulgite, and 200g bentonite are mixed evenly and fed into an automatic pelletizing machine. 300g of 8% carboxymethyl cellulose aqueous solution is sprayed on to obtain pellets with a particle size of 1-2mm. The pellets are then calcined at 400℃ for 90min and cooled to obtain the activated adsorbent.

[0071] The above-mentioned method for preparing soil conditioner includes the following steps:

[0072] S1. Add the activated adsorbent and composite microorganisms to 8000g of water and stir for 3.5h to obtain the loaded microorganisms;

[0073] S2. Add 300-mesh earthworm castings powder, 300-mesh Chinese artemisia annua powder, trachelospermum jasminoides powder, 300-mesh limestone powder, and humic acid to the loaded microorganisms, stir evenly, granulate, and dry to obtain soil conditioner.

[0074] Comparative Example 2

[0075] A soil conditioner, the raw materials of which include: 8000g earthworm castings powder, 1000g *Sinomenium acutum* powder, 300g *Trachelospermum jasminoides*, 1200g limestone powder, 3000g humic acid, and 450g compound microorganisms.

[0076] Complex microorganisms include: effective viable count ≥ 4 × 10⁻⁶ 8 Bacillus licheniformis CFU / g, with an effective viable count ≥4×10⁻⁶. 8 yeast with cfu / g and an effective viable count ≥4×10⁻⁶ 8 Streptomyces griseus at cfu / g.

[0077] The above-mentioned method for preparing soil conditioner includes the following steps: mixing 300-mesh earthworm castings powder, 300-mesh Chinese artemisia annua powder, Trachelospermum jasminoides powder, 300-mesh limestone powder, humic acid and compound microorganisms evenly, granulating and drying to obtain soil conditioner.

[0078] A pot experiment was conducted at a greenhouse planting base in Liaoning Province. The soil used was the 0-20cm topsoil from tomatoes grown continuously for 5 years at the base, and the soil type was brown soil. After air-drying, the soil was sieved through a 1cm sieve to remove stones and plant debris, and then filled into polyethylene pots with a diameter of 30cm and a height of 28cm, with 15kg of air-dried soil per pot. Its basic properties were as follows: pH = 7.85, organic matter 31.46g / kg, total carbon 15.72g / kg, total nitrogen 1.84g / kg, C / N = 10.18, available nitrogen 135.93mg / kg, available phosphorus 158.56mg / kg, and available potassium 231.76mg / kg.

[0079] Students were randomly divided into 5 groups, with 3 replicates per group. The conventional fertilizer group received fertilizer (urea, superphosphate, potassium sulfate) at concentrations of 0.40 g / kg soil, 0.25 g / kg soil, and 0.40 g / kg soil for N, P2O5, and K2O, respectively. The Example 5 group received the soil conditioner obtained in Example 5; the Comparative Example 1 group received the soil conditioner obtained in Comparative Example 1; and the Comparative Example 2 group received the soil conditioner obtained in Comparative Example 2. The earthworm casting concentration was maintained at 13.10 g / kg soil in all three groups, with additional fertilizer (urea, superphosphate, potassium sulfate) added to maintain consistent N, P2O5, and K2O concentrations across all groups. The blank control group received neither soil conditioner nor fertilizer.

[0080] Each group of fertilizers and soil conditioners were mixed evenly with the soil in one go, and no top dressing was applied during the tomato growing season. The earthworm castings used in this experiment were prepared by feeding earthworms with semi-decomposed cow manure. The surface material of the compost was removed, and the upper layer of material without adult earthworms was collected. The material was separated by passing it through a 2mm nylon sieve, and small earthworms and earthworm eggs were removed. The small particles obtained were the earthworm castings.

[0081] Golden Crown No. 9 tomato variety was used as the test tomato. When the seedlings had 3-4 true leaves, vigorous and relatively uniformly growing seedlings were selected and transplanted into pots. The growth period was 108 days, with a total of 3 fruit clusters retained, of which 4 fruits were retained per cluster. The pots in each group were randomly arranged, and rearranged again after 7 days until the plants were harvested. The greenhouse temperature ranged from 15-35℃, and the soil moisture content was controlled at 70-80% of field capacity during the growing season. Natural light was provided, and conventional management was carried out.

[0082] Soil samples were collected at the tomato vine-pulling stage (108 days after transplanting) and promptly returned to the laboratory. One portion of the fresh soil was passed through a 10-mesh nylon sieve and stored at 4℃ (for soil enzyme activity and microbial quantity analysis) and -80℃ (for microbial quantity, community structure, and quantitative PCR determination of Fusarium oxysporum quantity analysis). Another portion of the fresh soil was air-dried in a cool place and then passed through 20-mesh and 100-mesh nylon sieves for physicochemical property determination.

[0083] When the second cluster of fruits reaches 80-85% maturity, select fruits with similar color to determine the quality of the tomatoes.

[0084] 1. Soil enzyme activity analysis

[0085] The enzyme activity of freshly collected soil was measured.

[0086] Urease was determined by the indophenol blue colorimetric method, with units of mgNH3-N / (g dry soil × d).

[0087] Acid phosphatase activity was analyzed using disodium p-nitrophenyl phosphate (pNPP) (pH = 6.5), unit: mg p-nitropheny / (g×h). Note: In this experiment, the acid phosphatase activity was amplified 25 times due to its low value; therefore, the unit should be ×0.04 mg p-nitropheny / (g×h).

[0088] Catalase activity was determined by KMnO4 titration, unit: mL / (g×h).

[0089] Polyphenol oxidase was determined using the pyrogallol method. Unit: mg red gallol / g dry soil.

[0090] Soil enzyme activity such as Figure 1 As shown, the enzyme activities of group 5 were all higher than those of the other groups, confirming that the soil conditioner obtained in this application can promote the enzyme activity of continuously cropped soil. This may be because the soil conditioner obtained in this application can promote the increase of microbial biomass in the soil, enhance microbial respiration and vigorous biological metabolism, accelerate the decomposition of animal and plant residues in the soil, and increase the abundance of phosphorus-solubilizing microorganisms, which can improve the availability of phosphorus in the soil by releasing phosphatases in vitro. At the same time, the soil conditioner obtained in this application increases the activity of polyphenol oxidase, oxidizing aromatic compounds in the soil into quinones. Quinones react with proteins, amino acids, sugars, minerals and other substances in the soil to generate organic matter and pigments of different molecular weights, completing the cycle of aromatic compounds in the soil, degrading phenolic substances in the soil, slowing down allelopathic interactions between plants, and alleviating the continuous cropping obstacles caused by autotoxic substances.

[0091] 2. Changes in the above-mentioned soil enzyme activities in rhizosphere and non-rhizosphere soils

[0092] Rhizosphere and non-rhizosphere soils were collected using the shake-off method (Riley and Barber 1969, 1970). Soil samples containing intact tomato roots (volume determined by the extent of the root system) were collected. Large clumps of rootless soil were gently shaken off and placed in a plastic bag for mixing; this was considered non-rhizosphere soil. Then, all soil adhering to the root surface was shaken off forcefully to obtain the rhizosphere soil. Rhizosphere and non-rhizosphere soils were collected from each group, mixed thoroughly, and a portion was quartered; each group was repeated three times. The collected soil samples were placed in sterile bags, sealed, and stored at low temperature. After being brought back, the soil samples were air-dried, ground, and sieved for analysis. Enrichment rates were used to represent the degree of enrichment of soil nutrients and enzyme activity in the rhizosphere.

[0093] Enrichment rate = (Rhizosphere content - Non-rhizosphere content) ÷ Non-rhizosphere content × 100%

[0094] like Figure 2 As shown, the conventional fertilization group and the blank control group exhibited negative enrichment rates, indicating that neither fertilization nor the application of chemical fertilizers alone can damage the activity of rhizosphere soil enzymes in tomatoes. However, the addition of the soil conditioners obtained in Example 5 and Comparative Examples 1-2 improved rhizosphere soil enzyme activity, showing positive enrichment rates. The enrichment rates in Example 5 group were the best, confirming that the soil conditioner obtained in this application can effectively improve soil structure.

[0095] 3. Soil microbial abundance

[0096] DNA was extracted from soil samples, and the composition of the soil microbial community was then determined, clustered according to bacteria, fungi, and actinomycetes, such as... Figure 3 As shown.

[0097] The use of chemical fertilizers alone (conventional fertilization group) leads to an increase in the proportion of fungi. Since most soil-borne disease pathogens are fungi, an increase in the number of fungi often indicates an outbreak of soil-borne diseases. Example 5, Comparative Example 1, and Comparative Example 2, on the other hand, resulted in a decrease in the proportion of fungi, improving the diversity and richness of the soil microbial community. Example 5 showed the most significant inhibition of the number of fungi in the soil, demonstrating potential application value for the prevention and control of soil-borne diseases. It also stabilized the structure of the soil microbial community, enhancing its resistance to external infections.

[0098] 4. Inhibits Fusarium oxysporum in continuously cropped soils

[0099] Inhibition effect = (Fusarium oxysporum copy number in blank control soil - Fusarium oxysporum copy number in treated soil) ÷ Fusarium oxysporum copy number in original soil × 100%

[0100] like Figure 4As shown, simply using chemical fertilizers (conventional fertilization group) cannot inhibit Fusarium oxysporum, while the soil conditioners obtained in Example 5 and Comparative Examples 1-2 can inhibit Fusarium oxysporum, with the inhibition effect of Example 5 group being the best. The applicant believes that this is because the soil conditioner obtained in Example 5 directly introduces beneficial bacteria into the soil, improves the soil environment, and promotes the reproduction of beneficial bacteria.

[0101] 5. Tomato quality and yield

[0102] like Figure 5 As shown, the group in Example 5 had the highest tomato yield, as well as the highest sugar-acid ratio and vitamin C content. This confirms that the soil conditioner obtained in this application can increase tomato yield and improve tomato quality.

[0103] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a soil conditioner to improve the quality and yield of continuously cropped tomatoes, characterized in that, Includes the following steps: S1. Add the active adsorbent and composite microorganisms to water and stir for 2-5 hours for adsorption. Add carboxymethyl hydroxyethyl cellulose, acrylamide, crosslinking agent and photoinitiator and stir for 10-30 minutes. Add catalyst and initiate with ultraviolet light for 1-2 hours. Add iron salt and continue stirring for 1-2 hours to obtain the loaded microorganisms. S2. Add earthworm castings powder, Chinese artemisia powder, trachelospermum jasminoides powder, limestone powder, and humic acid to the loaded microorganisms, stir evenly, granulate, and dry to obtain a soil conditioner that improves the quality and yield of continuously cropped tomatoes. The mass ratio of earthworm castings powder, *Sinomenium acutum* powder, *Trachelospermum jasminoides* powder, limestone powder, humic acid, activated adsorbent, composite microorganisms, carboxymethyl hydroxyethyl cellulose, acrylamide, crosslinking agent, photoinitiator, catalyst, and iron salt is 60-100: 5-15: 1-5: 10-15: 20-40: 18-48: 3-6: 1-2: 1-3: 0.1-0.5: 0.01-0.1: 0.01-0.1: 0.1-1; The crosslinking agent is N-hydroxymethylacrylamide; The complex microbial composition includes: Bacillus licheniformis, yeast, and Streptomyces griseus; the effective viable count of Bacillus licheniformis is ≥4×10⁻⁶. 8 cfu / g, effective viable yeast count ≥4×10 8 cfu / g, effective viable count of Streptomyces griseus ≥1×10 8 cfu / g; The activated adsorbent is prepared by the following specific steps: Activated carbon, kaolin, attapulgite, and bentonite are mixed evenly and fed into an automatic pelletizing machine. During the pelletizing process, a carboxymethyl cellulose aqueous solution is sprayed on the mixture, and the mixture is calcined at 300-500℃ for 1-2 hours. After cooling, the activated adsorbent is obtained.

2. The method for preparing a soil conditioner to improve the quality and yield of continuously cropped tomatoes according to claim 1, characterized in that, The photoinitiator is 2-ketoglutaric acid.

3. The method for preparing a soil conditioner to improve the quality and yield of continuously cropped tomatoes according to claim 1, characterized in that, The catalyst is tetramethylethylenediamine.

4. The method for preparing a soil conditioner to improve the quality and yield of continuously cropped tomatoes according to claim 1, characterized in that, The iron salt is ferric chloride.

5. The method for preparing a soil conditioner to improve the quality and yield of continuously cropped tomatoes according to claim 1, characterized in that, The mass fraction of the carboxymethyl cellulose aqueous solution is 5-10%, and the mass ratio of activated carbon, kaolin, attapulgite, bentonite, and carboxymethyl cellulose aqueous solution is 10-20:5-15:2-10:1-3:1-5.

6. The method for preparing a soil conditioner to improve the quality and yield of continuously cropped tomatoes according to claim 1, characterized in that, Earthworm castings powder is 300 mesh, and limestone powder is 300 mesh.

Images