Application of corn stalk and earthworm manure in improving tobacco field soil and planting method

Abstract

The application relates to application of corn stalks and earthworm manure in improving tobacco field soil and a planting method, and belongs to the technical field of tobacco planting. In the application, corn stalks and earthworm manure are used to treat tobacco field soil, and planting of Jiaxin Haiyan 101 can increase fresh tobacco leaf yield by about 50%. The improvement method can obviously increase the contents of ammonium nitrogen, nitrate nitrogen, available potassium and phosphorus in the tobacco field soil, significantly increase the structure of the soil rhizosphere microbial community, the abundance and diversity of the bacterial and fungal communities, promote the growth of tobacco leaves in the field, and significantly increase the yield of tobacco leaves, so that the application has important economic value and industrial application scenarios.

Description

Technical Field

[0001] This application relates to the application and planting method of corn stalks and earthworm castings in improving tobacco field soil, belonging to the field of tobacco planting technology. Background Technology

[0002] Agricultural practices are crucial in shaping crop quality and soil health (Ihenetu et al., 2024). Tobacco (Nicotiana acuminata L.) is a globally widespread crop, with cigar production being a major sector of the tobacco industry (Mavroeidis et al., 2024). In the context of global agriculture, tobacco cultivation, particularly cigar production, is essential due to its cultural and economic importance. Sustainable cultivation methods must not only meet economic needs but also address social and environmental issues to satisfy the demand for high-quality cigar tobacco. Cigar tobacco production is a complex agricultural practice requiring specific plant quality and soil characteristics (Wells, 2024). Traditional techniques are associated with soil degradation, declining fertility, and potential adverse effects on tobacco quality. They are typically characterized by heavy reliance on synthetic fertilizers and limited incorporation of organic materials (Masheva, 2024). To address these issues and improve tobacco crop quality and soil health, there is growing interest in using sustainable agricultural techniques (Astapati and Nath, 2023).

[0003] Due to its economic significance, tobacco is widely cultivated in warm temperate and subtropical climate zones (Teng et al., 2024). China is the world's largest tobacco producer, with an output of 3.7 million hectares, followed by Brazil, India, the United States, Zimbabwe, Turkey, and Indonesia (Musona, 2016). Tobacco is one of the few leaf-based crops that has entered the global market, generating foreign exchange and improving the living standards of farmers. Initially, tobacco held religious importance, but claims of its therapeutic benefits have been refuted due to allegations that many tobacco products, including cigarettes, cigars, chewing tobacco, pipes, and snuff, pose positive health risks (Galiatsatos, 2023; Nie, 2024).

[0004] Tobacco is the world's second-largest commodity after gasoline. The annual value of the global tobacco trade is estimated at $400 billion (Hrytsai, 2023). Tobacco leaf production has steadily increased, from 4.2 million tons in 1976 to 5.9 million tons in 1997 (Jacobs et al., 2000). However, the economic significance of tobacco cultivation and processing varies from country to country. Cigarette (sales and import) taxes can be an important source of funding for various states. In Russia, approximately 8% of the national budget is funded by tobacco tax revenue. In China, revenue from tobacco products brings in the equivalent of USD for state-owned enterprises (Yang et al., 2015). Japan Tobacco Corporation generated approximately USD in revenue for the Japanese government in fiscal year 2022 (Statista, 2023). Various developing countries rely on the sale of cash crops such as tobacco to pay off their foreign debt. In 2012, tobacco accounted for 10% of Cuba's total export revenue (WHO, 2012). Tanzania accounts for 15%, Zimbabwe for nearly 25%, Malawi derives two-thirds of its commodity exports from tobacco, and Kenya allocates 13% of its national budget to tobacco (WHO, 2012). In former centrally planned countries in Central and Eastern Europe and Central Asia, tobacco companies are a major source of investment. The cultivation, processing, and export of tobacco make a significant contribution to a country's employment and income. In Italy, many state-owned tobacco factories are located in areas with high unemployment (Strangio and Donatella, 2022). By 2024, Ethiopia's tobacco products market is projected to generate sales exceeding USD (Statista, 2024).

[0005] Tobacco is primarily grown in fertile sandy loam soils. The uptake of heavy metals by tobacco is influenced by soil type, texture, electrical conductivity, organic matter content, and soil pH. The main reason for increased uptake in tobacco is low soil pH, which increases the availability of cadmium (Zhang et al., 2021). Intensive farming practices reduce soil fertility, water retention capacity, and structural stability by consuming organic matter (Gorooei et al., 2023). Furthermore, overuse of conventional fertilizers can lead to nutrient imbalances, soil acidification, and even heavy metal poisoning (Du et al., 2024; He et al., 2024). These challenges negatively impact root development, nutrient uptake, and ultimately, tobacco quality.

[0006] Soil quality is fundamental to ideal plant growth and development (Jahan et al., 2024). Nitrogen, phosphorus, potassium, and magnesium are essential elements for the healthy growth and flavor quality of cigar tobacco leaves (Ren et al., 2024). When soil fertility is balanced, plants can easily access these nutrients. Optimal soil structure promotes healthy root development and nutrient uptake, as well as root permeability, aeration, and drainage (beniich et al., 2023). A rich and diverse soil microbiome is crucial for nutrient cycling, disease prevention, and stimulating plant development (Hartmann and Six, 2022). Poor soil quality negatively impacts the production, quality, and aroma of cigar tobacco. It is typically characterized by nutrient depletion, compaction, and reduced microbial activity (Tang et al., 2023). Sustainable and effective methods are needed to improve soil fertility and tobacco quality in cigar tobacco farms, a vital component of tobacco production in the tobacco industry. Using straw, a common agricultural technique, provides soil microorganisms with additional carbon and nutrient sources—one such strategy. One important factor that has a significant impact on crop yield and soil health is straw application, which affects root exudates and soil microbial activity (Ren et al., 2023).

[0007] Returning straw to the field, the process of replenishing the soil with agricultural residues, offers several ways to address these issues. The decomposition of straw increases the amount of soil organic matter (SOM), which in turn increases microbial activity, water retention, and nutrient storage (Yang et al., 2024). This can promote soil aggregation and improve aeration, drainage, and root growth (Wang et al., 2024). Studies have shown that in cigar tobacco fields, reintroducing straw can significantly increase the organic carbon content in the soil and enhance its physical properties (Tang et al., 2023).

[0008] Organic fertilizers, made from compost or residual plant and animal matter, provide essential nutrients for crops and enhance soil health. Compared to conventional fertilizers, they release nutrients more slowly, reducing leaching and environmental pollution (Wan et al., 2024). In addition to increasing nutrient cycling and soil microbial activity, organic additives also contribute to long-term soil fertility improvement (Yang et al., 2024). Studies have shown that applying organic fertilizers can significantly improve the availability of nutrients in the soil and improve specific quality indicators of cigar tobacco leaves (Iacomino et al., 2022; Su et al., 2022).

[0009] While returning straw and applying organic fertilizer each have their own advantages, applying them together can produce synergistic effects, thereby enhancing the benefits of soil and tobacco quality. Straw provides an easily accessible carbon supply for soil bacteria, accelerates the decomposition of organic fertilizer, and promotes nutrient release (Jiang et al., 2022). In addition to maintaining soil health, straw mulch can also prevent soil erosion caused by wind and water (Lal, 2020). The decomposition of straw increases soil organic matter, enhancing soil structure, water retention capacity, and nutrient availability (Liu et al., 2023). Although improving nutrient uptake and root growth, returning straw to the field maximizes the benefits of organic fertilizer. The results of the effective collaboration of these two methods are as follows: returning straw to the field increases microbial activity, improves soil aggregation, aeration, and drainage, while organic fertilizer further optimizes soil physical properties for optimal plant growth (Jiang et al., 2022). The combined effect of straw and organic fertilizer promotes the accumulation of soil organic matter, thereby enriching soil nutrients and enhancing its long-term health (Chen et al., 2020). Size, yield, organic fertilizer, and straw return to the field all have positive effects on the flavor, aroma, and combustion quality of cigar tobacco leaves (Su et al., 2022). They improve nutrient cycling and release through synergistic interactions, making nutrients more readily absorbed by plants and promoting crop growth and development (Jiang et al., 2022). In addition to promoting nutrient cycling, plant development, and disease resistance, organic fertilizers also maintain soil microbial diversity (Niu et al., 2021). The decomposition of organic matter in fertilizers leads to increased soil organic matter content, enhancing soil structure and fertility (Singh et al., 2020). To mimic the natural nutrient cycle, organic fertilizers release nutrients gradually over time, reducing the risk of leaching and contamination (Li et al., 2021).

[0010] Therefore, developing a method to improve the soil of cigar tobacco fields by combining straw return to the field with organic fertilizer is of great significance for the planting and production of cigar tobacco leaves. Summary of the Invention

[0011] To address the aforementioned issues, this paper presents an application and planting method for improving tobacco field soil using corn stalks and earthworm castings. This method utilizes the combined application of corn stalks and earthworm castings, resulting in a significant increase in the fresh leaf weight of Qiexin Haiyan 101 tobacco, which increased by 53.06% compared to the control and by approximately 50% compared to other groups. This significantly improved the fresh tobacco leaf yield of Qiexin Haiyan 101, greatly increasing production benefits.

[0012] According to one aspect of this application, a method for cultivating Haiyan 101 is provided, the method comprising the following steps:

[0013] 1) Two to three months before transplanting cigar tobacco leaves, prepare the land 2 to 3 times. During the tillage period, mix corn stalks with earthworm castings and bio-organic fertilizer into the topsoil as base fertilizer.

[0014] 2) After land preparation, ridging should be completed 7-10 days before transplanting cigar tobacco leaves. Ridging should be combined with the application of base fertilizer. The base fertilizer includes tobacco-specific fertilizer and magnesium sulfate fertilizer. The tobacco-specific fertilizer includes superphosphate, calcium ammonium nitrate, ammonium sulfate, and potassium sulfate, or the tobacco-specific fertilizer includes triple superphosphate, calcium ammonium nitrate, ammonium sulfate, and potassium sulfate.

[0015] 3) After ridging, cover with plastic film, then use a transplanter to make holes and transplant the seedlings. After transplanting, apply topdressing fertilizer twice, with the same composition as the base fertilizer.

[0016] It should be noted that the base fertilizer includes ammonium calcium nitrate, ammonium sulfate, potassium sulfate, magnesium sulfate, and calcium phosphate or superphosphate. You can choose either calcium phosphate or superphosphate.

[0017] Optionally, the amount of corn stalks added is 100-500 kg / mu; the amount of earthworm castings applied is 50-300 kg / mu.

[0018] Optionally, the amount of corn stalks added is 100-300 kg / mu; the amount of earthworm castings applied is 50-150 kg / mu.

[0019] Optionally, the planting density of Haiyan 101 is 1000-2000 plants / mu.

[0020] Optionally, in step 3), the first topdressing is applied 17 to 23 days after transplanting, and the second topdressing is applied 32 to 38 days after transplanting.

[0021] Optionally, in step 2), the base fertilizer is applied by strip application, and in step 3), the topdressing is applied by drip irrigation.

[0022] Optionally, in step 3), drip irrigation or hole irrigation should be used to irrigate the seedlings thoroughly during transplanting; from the seedling stage to the stage of seedling clustering, the soil moisture should be maintained at 60±10% of the maximum soil water holding capacity, and irrigation should be carried out in time when it is lower than 50%; during the vigorous growth stage, the soil moisture should be maintained at 80±10% of the maximum soil water holding capacity; during the maturity stage, the soil moisture should be maintained at 65±5% of the maximum soil water holding capacity.

[0023] Optional steps include topping and pruning.

[0024] Optionally, after topping, leave 16 to 22 effective leaves.

[0025] According to another aspect of this application, a method for improving tobacco field soil is provided, the method comprising the steps of treating the tobacco field soil by returning corn stalks to the field and applying earthworm castings.

[0026] Optionally, the soil from the tobacco field is used to grow Haiyan 101 tobacco.

[0027] According to another aspect of this application, a method for increasing the yield of fresh tobacco leaves of Haiyan 101 is provided, the method comprising a step of treating the soil in which Haiyan 101 is planted by combining corn stalk return to the field and earthworm castings application.

[0028] According to another aspect of this application, a method for planting Haiyan 101 is provided, the method comprising a step of treating the soil for planting Haiyan 101 by returning corn stalks to the field and applying earthworm castings.

[0029] Optionally, the amount of corn stalks added is 100–500 kg / mu. It should be noted that those skilled in the art can adjust the amount of corn stalks added according to the circumstances. It is understood that the above range is merely an example of a feasible range and does not constitute a limitation on the scheme of this application.

[0030] Optionally, the amount of earthworm castings applied is 50–300 kg / mu. It should be noted that those skilled in the art can adjust the amount of earthworm castings added according to the circumstances. It is understood that the above range is merely an example of a feasible range and does not constitute a limitation on the present application.

[0031] According to another aspect of this application, the application of corn stalks and earthworm castings in the cultivation of Haiyan 101 is provided.

[0032] The beneficial effects of this application include, but are not limited to:

[0033] Applying the proposed fertilization scheme significantly increases the content of ammonium nitrogen, nitrate nitrogen, available potassium, and phosphorus in tobacco field soil, improves the structure of the soil rhizosphere microbial community, and significantly increases the abundance and diversity of bacterial and fungal communities, thereby promoting tobacco leaf growth in the field and increasing tobacco yield.

[0034] Using the proposed method, the combination of corn stalk return to the field and earthworm castings significantly increased the fresh leaf weight of Qiexin Haiyan 101, by 53.06% compared to the control and about 50% compared to other groups. This significantly improved the fresh tobacco leaf yield of Qiexin Haiyan 101, greatly increasing production benefits and demonstrating significant economic value and industrial application scenarios. Attached Figure Description

[0035] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0036] Figure 1 The results show the influence of the relative abundance of soil bacterial communities in tobacco fields on the test example 2 of this application;

[0037] Figure 2 The results show the impact of this application's test example 2 on the Beta diversity of tobacco field soil bacterial communities;

[0038] Figure 3 The results show the impact of test example 2 of this application on the alpha diversity of fungal communities in tobacco field soil.

[0039] Figure 4 The results show the influence of test example 2 of this application on the relative abundance of fungal communities in tobacco field soil;

[0040] Figure 5 The results show the impact of this study on the Beta diversity of the tobacco field soil fungal community in Test Example 2 of this application. Detailed Implementation

[0041] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments. Unless otherwise specified, the raw materials and catalysts in the embodiments of the present application are all purchased through commercial channels.

[0042] In this application, based on the selection of tobacco-specific fertilizers (including superphosphate, calcium ammonium nitrate, ammonium sulfate, and potassium sulfate) and the supplementation of magnesium sulfate fertilizer to prepare the required inorganic fertilizers as base fertilizers, rapeseed straw, corn straw, tobacco straw, earthworm castings bio-organic fertilizer, and decomposed oilseed cake bio-fertilizer are rationally combined and applied as base fertilizers to solve problems such as insufficient soil carbon supply, low organic matter content, low soil water holding capacity and nutrient availability, weak soil microbial activity, threats to tobacco leaf growth and development, and impact on tobacco leaf yield.

[0043] In this application, straw return to the field is combined with organic fertilizer to improve the soil of tobacco fields. The straw used is rapeseed straw, corn straw, and tobacco straw, which are mixed into the topsoil through initial mechanical crushing and subsequent tillage. The straw addition amount for each treatment is 168 kg / mu. The organic fertilizer used is earthworm castings bio-organic fertilizer (100 kg / mu) or well-rotted oilseed cake bio-fertilizer (100 kg / mu). The application methods are as follows: rapeseed straw return to the field + earthworm castings bio-organic fertilizer, corn straw return to the field + earthworm castings bio-organic fertilizer, tobacco straw return to the field + earthworm castings bio-organic fertilizer, rapeseed straw return to the field + well-rotted oilseed cake organic fertilizer, corn straw return to the field + well-rotted oilseed cake organic fertilizer, and tobacco straw return to the field + well-rotted oilseed cake organic fertilizer. The straw return to the field is combined with the organic fertilizer as a base fertilizer. The improvement method described in this application significantly increases the content of ammonium nitrogen, nitrate nitrogen, available potassium and phosphorus in tobacco field soil, improves the structure of soil rhizosphere microbial community, significantly increases the abundance and diversity of bacterial and fungal communities, promotes tobacco field growth, and improves tobacco yield.

[0044] In this application, the tobacco-specific fertilizer (containing calcium ammonium nitrate (N-15%, CaO-25%), superphosphate (P-16%), ammonium sulfate (N-20%), and potassium sulfate (K-50%)) and magnesium sulfate fertilizer were purchased from Mian County, Hanzhong. After purchasing the straw, it was first mechanically crushed by a straw crusher, and then piled up in a drying room for fermentation and decomposition. The specific operation is in accordance with DB61 / T 1561-2022. The earthworm castings organic fertilizer (moisture content 24%, N 1.5%, P2O5 1.2%, K2O 1.5%) was purchased from Luonan, Shaanxi. The hydrolyzed oil residue bio-organic fertilizer (oil residue bio-fertilizer) was purchased from Yangling, Shaanxi. Other materials not mentioned can be purchased or prepared by those skilled in the art, using the selections commonly used by those skilled in the art.

[0045] The present application solution will be described below through specific embodiments.

[0046] Example 1

[0047] This application uses tobacco-specific fertilizers (including superphosphate, calcium ammonium nitrate, ammonium sulfate, and potassium sulfate) and supplements them with magnesium sulfate fertilizer to prepare the required inorganic fertilizers. The ratio of inorganic fertilizer as base fertilizer to topdressing is 1:1. The first topdressing is applied 20 days after transplanting, and the second topdressing is applied 35 days after transplanting, with the application rates being 30% and 20% of the total topdressing amount, respectively. Rapeseed straw, corn straw, and tobacco straw were used in the experimental field. These were mixed into the topsoil through mechanical crushing in the early stage and plowing in the later stage, with each treatment adding 168 kg / mu of straw. Earthworm castings bio-organic fertilizer (100 kg / mu) or oilseed cake bio-fertilizer (100 kg / mu) were used as organic fertilizer. Straw was returned to the field in conjunction with organic fertilizer as base fertilizer. Specific fertilization methods mainly include: control (CK), rapeseed straw return to the field (T1), corn straw return to the field (T2), tobacco straw return to the field (T3), rapeseed straw return to the field + earthworm castings organic fertilizer (T4), corn straw return to the field + earthworm castings organic fertilizer (T5), tobacco straw return to the field + earthworm castings organic fertilizer (T6), rapeseed straw return to the field + decomposed oilseed cake organic fertilizer (T7), corn straw return to the field + decomposed oilseed cake organic fertilizer (T8), and tobacco straw return to the field + decomposed oilseed cake organic fertilizer (T9).

[0048] This experiment was conducted in Zhaobishan Village, Tonggousi Town, Mian County, Hanzhong City, Shaanxi Province. A two-factor randomized controlled trial design was used, with a total of 10 treatments and 3 replicates for each treatment. Two varieties were tested: Guyin 4 (Haiyan 101) for the eggplant core and Qingxue 103 (QX103) for the eggplant sheath. Each variety had 30 plots, for a total of 60 plots, arranged in a randomized block design. The plot area was 0.058 mu (38.5 m²). 2 The planting density of the eggplant cores is 1443 plants / mu (110cm×42cm), with a nitrogen application rate of 11kg / mu and an N:P2O5:K2O ratio of 1:1.2:3.0. The eggplant skin varieties are planted in a concentrated manner under an automatic shade structure, with a planting density of 1638 plants / mu (110cm×37cm), a nitrogen application rate of 9kg / mu, and an N:P2O5:K2O ratio of 1:1:2.8. When applying base fertilizer, 10kg / mu of magnesium sulfate fertilizer is added.

[0049] In one embodiment, the planting density for the eggplant core variety is 1443 plants / mu (110cm×42cm), with 168kg / mu of corn stalks and 100kg / mu of earthworm castings organic fertilizer. The planting density for the eggplant skin variety is 1638 plants / mu (110cm×37cm), with 168kg / mu of corn stalks and 100kg / mu of earthworm castings organic fertilizer. Base fertilizer: Corn stalks and earthworm castings organic fertilizer are mixed into the topsoil during tillage and applied as base fertilizer. Inorganic base fertilizer is then applied during ridging, along with magnesium sulfate fertilizer. Topdressing: The first topdressing is applied 20 days after transplanting, and the second topdressing is applied 35 days after transplanting. Tobacco-specific fertilizers (including superphosphate, calcium ammonium nitrate, ammonium sulfate, and potassium sulfate) are used, supplemented with magnesium sulfate fertilizer to prepare the required inorganic fertilizer.

[0050] In one embodiment, the detailed steps of treating the Haiyan 101 tobacco field include:

[0051] S1. Land preparation should be carried out 2-3 months before transplanting cigar tobacco leaves, ideally in 3 stages. First, promptly remove weeds from the previous crop or fallow land, and shallowly till to a depth of 15-20 cm to remove stubble. Second, deep tillage and sun-dry the soil, increasing the depth appropriately. Third, rotary tillage to break up the soil, ensuring it meets the requirements for ridging in tobacco fields. Depending on the soil pH, quicklime should be applied for disinfection before rotary tillage at a rate of 100 kg / mu, or 150 kg / mu for severely acidified plots (pH < 4.5). Corn stalks, along with earthworm castings, should be mixed into the topsoil as base fertilizer during tillage.

[0052] S2. After land preparation, ridging should be completed promptly, 7-10 days before transplanting cigar tobacco leaves. Ridging should be combined with the application of base fertilizer. When ridging, first mark the row spacing and apply base fertilizer in strips, then mechanically rid the soil along the marked lines. The base fertilizer applied in strips includes inorganic base fertilizer and magnesium sulfate fertilizer.

[0053] S3. Before fertilizing and transplanting tobacco plants, a five-point sampling method was used with a manual soil drill to collect mixed soil samples from the 0-20cm and 20-40cm topsoil layers for analysis of soil physicochemical indicators. The fertilization amount was determined comprehensively based on the soil nutrient analysis results, variety characteristics, production targets, climatic conditions, and cultivation methods. In this example, the ratio of inorganic base fertilizer to topdressing was 1:1. The first topdressing was applied 20 days after transplanting, and the second topdressing was applied 35 days after transplanting, with application rates of 30% and 20% of the total topdressing amount, respectively. For the eggplant core variety, the nitrogen application rate was 11 kg / mu, with an N:P2O5:K2O ratio of 1:1.2:3.0; for the eggplant skin variety, the nitrogen application rate was 9 kg / mu, with an N:P2O5:K2O ratio of 1:1:2.8. Magnesium sulfate fertilizer was supplemented at 10 kg / mu when applying base fertilizer. The amount of straw added for both the eggplant peel and the eggplant core varieties is 168 kg / mu, and the amount of earthworm castings bio-organic fertilizer added is 100 kg / mu. Base fertilizer is applied by strip application; topdressing is applied by drip irrigation.

[0054] S4. Transplanting should be done from late April to early May, with adjustments made as needed based on the year's weather conditions. After ridging, cover with mulch film, then use a transplanter to make holes and transplant the seedlings. The planting density for the eggplant core variety is 1443 plants / mu (110cm×42cm); the planting density for the eggplant skin variety is 1638 plants / mu (110cm×37cm). The specific transplanting method is as follows: After placing the seedlings in the planting holes, cover them with soil, ensuring the growing point of the seedling is 1-2cm above the ground. Then, use drip irrigation or hole irrigation to thoroughly water the seedlings, ensuring each plant receives at least 1kg of water. Use two-color mulch film, white in the middle and black on both sides, with a thickness of 0.008mm or more.

[0055] S5. Before removing the plastic film from the tobacco field, weeds in the furrows should be removed promptly, and the film should be removed in one go. About 35 days after transplanting, or depending on the actual growth of the tobacco field, use mechanical or manual tools to mound the soil between the tobacco rows or in the furrows to the base of the tobacco plants and the top of the ridges, forming an arched ridge of the specified height. After mounding, the ridge height should be more than 30cm, and there should be no weeds in the field.

[0056] S6. When transplanting, water thoroughly according to soil moisture to ensure the seedlings recover as soon as possible. After the seedlings recover until they form a cluster, maintain soil moisture at 60% of the maximum water holding capacity. If it is below 50%, irrigate in time. During the vigorous growth period, maintain soil moisture at 80% of the maximum water holding capacity. If it is insufficient, irrigate in time. During the maturity period, excessive water is not needed. Maintain soil moisture at 60-70% of the maximum water holding capacity.

[0057] S7. For tobacco plants with strong growth and sufficient fertilizer, topping can be omitted or delayed; conversely, topping should be done earlier if the plants are weak or lack fertility. Generally, 16-22 effective leaves should be left after topping. Topping should be done on a sunny morning, first topping disease-free plants, then diseased plants. Remove the toppinged flower buds, flowers, and stems from the field promptly. When topping, ensure the remaining stem is slightly higher than the top leaf. Remove side shoots early and frequently, ensuring the axillary buds are no longer than 5cm, generally every 5 days. Remove the base of the axillary bud along with the side shoot.

[0058] In this application, the amount of corn stalks added is 168 kg / mu, and the amount of earthworm castings bio-organic fertilizer added is 100 kg / mu. Insufficient addition has a weak effect on soil improvement in tobacco fields, with little improvement on the physicochemical properties of the soil, the structure of the rhizosphere microbial community, and the abundance and diversity of bacterial and fungal communities. Tobacco leaf growth and yield are similar to those after conventional inorganic fertilizer application. Excessive addition leads to the accumulation of nitrate nitrogen and phosphorus in the soil, and this accumulation intensifies with increasing years of fertilization, increasing leaching into water bodies. Excessive earthworm castings may cause excessive accumulation of copper, zinc, chromium, lead, and cadmium in the soil, thereby affecting crop growth and deteriorating the soil environment.

[0059] In this application, corn stalks and earthworm castings bio-organic fertilizer are mixed into the topsoil as base fertilizer during tillage, followed by inorganic base fertilizer during ridging, along with magnesium sulfate fertilizer. Organic fertilizer releases nutrients slowly and has a long-lasting effect. If inorganic fertilizer is applied first, followed by corn stalks and earthworm castings, it will slow down the rate at which the soil absorbs nutrients, thus affecting the growth and development of tobacco leaves and the structure of the soil microbial community.

[0060] Inorganic fertilizers, as fast-acting fertilizers, have simpler compositions, higher nutrient content, and are easily absorbed by the root system. Organic fertilizers, on the other hand, have slower effects, weaker nitrogen supply capacity, and unbalanced nutrient content, making them unsuitable for short-term crops. For example, the nitrogen supply from cow manure to winter wheat is only about one-third that of inorganic fertilizers. Therefore, under the same nitrogen input conditions, the yield-increasing effect of organic fertilizers is lower than that of inorganic fertilizers in the initial stage. It takes about 12 to 15 years for organic fertilizers to reach the yield-increasing effect of equivalent chemical fertilizers on winter wheat, and it takes about 5 years for the yield-increasing effect of organic fertilizers on summer corn to be comparable to that of inorganic fertilizers. Without the application of inorganic fertilizers, high-yield and high-quality tobacco leaves cannot be obtained in the short term.

[0061] Land preparation and ridging create a favorable soil structure and surface condition, coordinating factors such as water, nutrients, air, and heat, improving soil fertility, and providing excellent conditions for sowing, crop growth, and field management. Failure to prepare and ridge can lead to poor soil structure and uneven soil surfaces, affecting the quality of tobacco seedling transplantation and consequently impacting tobacco leaf growth and development. Pre-transplanting soil physicochemical properties testing can determine the appropriate fertilization amount for the land, avoiding excessive or insufficient fertilization that could negatively affect soil fertility and tobacco leaf growth. Transplanting under plastic film helps increase soil temperature and retain soil moisture, thereby improving plant growth efficiency and yield. Mulching transplanting is suitable for tobacco seedling transplantation, with under-film transplanting being more suitable for tobacco-growing areas with lower temperatures or in cooler years. Topping and pruning are important measures to improve tobacco leaf yield and quality. This measure optimizes tobacco leaf quality and yield by removing apical dominance and regulating nutrient distribution and growth direction. Not pruning or removing shoots will breed aphids. Aphids usually like tender leaves and flower buds. Not pruning the tops increases the aphids' living space, thus inducing the occurrence of pests and diseases.

[0062] Compared to conventional planting, the application of corn stalks and earthworm castings in this application can improve soil physical and chemical properties, enhance soil fertility, improve soil microbial community structure, promote tobacco growth, and increase tobacco yield.

[0063] Test Example 1

[0064] Using a manual soil auger, a five-point sampling method was employed to collect mixed soil samples from the 0–20 cm and 20–40 cm topsoil layers. After air-drying, the soil samples were ground and sieved before determining ammonium nitrogen, nitrate nitrogen, available phosphorus, and available potassium. Specific testing methods are as follows: Ammonium nitrogen and nitrate nitrogen determinations were performed according to GB / T 42485-2023; available phosphorus determinations were performed according to NY / T1121.7-2014; and available potassium determinations were performed according to NY / T 889-2004.

[0065] Table 1. Influence of Soil Physicochemical Properties in Tobacco Fields

[0066]

[0067] Table 1 shows that, compared with the control (CK) treatment, except for the T3 treatment which had a lower available potassium content in the 0-20cm soil layer, the available potassium content in all treatments remained at a high level. In the 0-20cm soil layer, the CK treatment had the highest available phosphorus content, followed by the T9 treatment. In the 20-40cm soil layer, the available phosphorus content in the treatment combining corn straw and oilseed cake organic fertilizer (T8) was significantly higher than other treatments. The ammonium nitrogen content in the 0-20cm soil layer of the corn straw and oilseed cake organic fertilizer (T8) treatment reached 4.02 mg / kg. The nitrate nitrogen content in the 20-40cm soil layer of the corn straw and earthworm castings (T5) treatment was the highest, reaching 79.01 mg / kg.

[0068] Test Example 2

[0069] DNA Extraction and Sequencing: Total genomic DNA was extracted from the samples using the CTAB method. DNA concentration and purity were monitored on a 1% agarose gel. Based on the concentration, the DNA was diluted to 1 ng / μL with sterile water. Genes at different locations were amplified using primers. 15 μL of primer was used in each PCR reaction. High-fidelity PCR premix (New England Biolabs), 2 μM forward and reverse primers, and approximately 10 ng of template DNA. The PCR products were combined with an equal volume of 1X 206 loading buffer containing SYB Green, and then electrophoresed on a 2% agarose gel to detect the results. The PCR products were pooled at equal densities. The mixture of PCR products was filtered using a Qiagen Gel Extraction Kit (Qiagen, Germany). An index code was added, and... A sequencing library was created using the DNAPCR-Free Sample Preparation Kit (Illumina, USA) according to the manufacturer's instructions. Library quality was evaluated using a Qubit 2.0 fluorometer (ThermoScientific) and an Agilent Bioanalyzer 2100 system. Finally, the library was sequenced on an Illumina NovaSeq instrument, yielding 250 bp paired-end reads.

[0070] Biological information analysis: Raw gene sequencing reads were examined and merged using FLASH and QIIME (V1.9). Uparse software (Uparse V7.0.1001) was used to determine that these sequences were identical operational taxonomic units (OTUs) with a 97% similarity criterion. Sequences were recorded and classified using the SILVA ribosomal RNA gene bank (bacteria), RDP Classifier, and Unified Database (fungi).

[0071] Alpha diversity indices (PD_whole_tree, Observed-species, Chao1, Shannon, Simpson, ace, goods-coverage) were analyzed using Qime 1.9.1, and dilution curves were plotted using R (V4.0.3). The Chao index reflects the abundance of the bacterial community; a higher value indicates a higher abundance. The Shannon and Simpson indices reflect the diversity of the bacterial community; a higher Shannon index and a lower Simpson index indicate greater bacterial community diversity.

[0072] βeta diversity of weighted and unweighted unifracs was calculated using QIIME (V1.9.1). UPGMA cluster analysis showed that higher similarity correlated with smaller inter-sample differences. PCoA analysis was performed using the ade4 and gplot2 packages in R (V2.15.3). UPGMA plots were generated using the upgma.tre function in Qiime (V1.9.1). β diversity distances of weighted and unweighted unifracs were calculated using QIIME software, and then heatmaps were generated in Perl to display the unifrac distances between samples. Venn plots were generated in R using the VennDiagram function; smaller difference coefficients in the Venn plots indicated smaller differences in species diversity. Phylogenetic trees were plotted in Perl in SVG format.

[0073] Table 2. Influence of Alpha diversity in soil bacterial communities in tobacco fields

[0074]

[0075] Table 2 shows that, compared with the control (CK) and straw return treatment alone, the Chao index was significantly increased in the treatments of corn straw combined with earthworm castings (T5) and corn straw combined with oilseed cake organic fertilizer (T8) in the eggplant core. The treatment of corn straw combined with oilseed cake organic fertilizer (T8) increased the Shannon index, while the treatments of corn straw combined with earthworm castings (T5), tobacco straw combined with earthworm castings (T6), rapeseed straw combined with oilseed cake organic fertilizer (T7), and tobacco straw combined with oilseed cake organic fertilizer (T9) decreased the Simpson index and increased the diversity of soil bacterial communities. In the eggplant wrapper, compared with the control (CK) and straw return treatment alone, the Chao index of the treatment with tobacco straw and earthworm castings (T6) was significantly increased; the treatment with corn straw and oilseed cake organic fertilizer (T8) increased the Shannon index, while the treatments with corn straw and earthworm castings (T5), tobacco straw and earthworm castings (T6), rapeseed straw and oilseed cake organic fertilizer (T7), and tobacco straw and oilseed cake organic fertilizer (T9) decreased the Simpson index and increased soil bacterial community diversity. Dilution curve analysis revealed that the α diversity of the T4 treatment in the eggplant core was significantly greater than that of the other groups, while in the eggplant wrapper, the α diversity of the T4 and T1 treatments was significantly greater than that of the other groups.

[0076] Depend on Figure 1 It was found that, compared with the control (CK) treatment, straw return to the field significantly increased the relative abundance of Proteus and other bacteria at both the genus and phylum levels. Compared with straw return to the field, the addition of all organic fertilizers, except for the control (CK), significantly increased the relative abundance.

[0077] Depend on Figure 2 It can be seen that, compared with the CK treatment, the corn stalk and earthworm castings (T5) and tobacco stalk and earthworm castings (T6) treatments in Qiexin Haiyan 101 showed a greater degree of dispersion from other samples in both analyses, indicating that their bacterial communities were constantly changing and varied considerably. The samples generally exhibited a discrete pattern in both analyses, indicating significant differences in bacterial community composition among different samples.

[0078] Depend on Figure 3 It can be seen that, compared with the CK treatment, the diversity of the treatment of applying tobacco straw and oilseed cake organic fertilizer (T9) to the eggplant peel QX103 was significantly increased, followed by the T3 treatment of eggplant core Haiyan 101 and the treatment of applying rapeseed straw and oilseed cake organic fertilizer (T7) to the eggplant peel QX103, and the diversity of both treatments was significantly higher than that of other treatments.

[0079] From the table Figure 4It can be seen that, compared with the CK treatment, at the phylum level, the relative abundance of Basidiomycetes in the T1 treatment of Qie Xin Hai Yan 101 was significantly increased, accounting for nearly 75%, the relative abundance of Chytridactycetes was significantly increased in the tobacco straw and earthworm castings (T6) treatment, and the relative abundance of Mucormycetes was significantly decreased in the tobacco straw and oil cake organic fertilizer (T9) treatment; compared with the CK treatment, the relative abundance of Mucormycetes in the tobacco straw and earthworm castings (T6) treatment of Qie Yi QX103 was significantly decreased, and the relative abundance of Rozia was significantly increased in the T1 treatment.

[0080] Depend on Figure 5 Analysis revealed that the T8 and T6 treatments of QX103 and Haiyan 101 had the lowest Weighted Unifrac and Unweighted Unifrac values ​​(0.459 and 0.607 respectively), indicating the highest similarity. The T2 and T7 treatments of QX103 had lower Weighted Unifrac and Unweighted Unifrac values ​​(0.357 and 0.629 respectively), indicating high similarity and small differences in fungal communities among the samples.

[0081] Test Example 3

[0082] During the vigorous growth and maturity stages of tobacco leaves, plant height, maximum leaf length, maximum leaf width, internode distance between two leaves, and stem circumference of each treatment were measured in the field using a soft measuring tape. The number of leaves was defined as the number of effective leaves per treatment. Field agronomic data indicated the impact of each treatment on the growth and development of the tobacco plants. Fresh leaf weight was the sum of the weights of the upper, middle, and lower leaves harvested from each treatment; a higher weight indicated the highest yield for that treatment. Stem weight was the sum of the stem weights of the tobacco leaves after harvesting. Root weight was the sum of the root weights of the tobacco leaves after harvesting. The measurements of fresh leaf weight, stem weight, and root weight all used a method of partial weight weighing followed by summation. The difference between the wrapper and filler fresh leaf weight lies in the fact that the wrapper and filler are two parts of a cigar; the wrapper is the outer covering of the cigar, while the filler is the innermost structure.

[0083] Table 2. Effects of Tobacco Leaf Vigorous Growth Period and Maturity Period on Agronomic Traits - Eggplant Wrapping Vigorous Growth Period

[0084] deal with Plant height Number of leaves Leaf length Ye Kuan Pitch Stem girth CK 111±5.29a 15.67±1.15ab 53.33±2.08a 35±1a 8.13±0.42ab 7.67±0.58a T1 41.67±7.64d 9.67±0.58d 30.33±1.53d 17.67±2.08e 2.87±0.75e 4.73±0.46c T2 62±15.72c 11.67±1.15c 37.33±3.79c 23±2d 4.63±0.91d 5.83±0.29b T3 92±854b 14±1b 47±0b 28.33±058c 68±0.62c 6.9±0.53a T4 108.33±5.77a 16±1ab 50.67±3.51ab 32.67±1.53ab 7.2±0.26bc 7.33±0.29a T5 108.67±7.57a 15±1ab 49.67±1.15ab 32.33±0.58ab 8.4±0.17a 7.17±0.29a T6 111.67±10.41a 16±1ab 52.67±3.21a 34.33±1.53a 7.87±0.51ab 7.33±0.29a T7 100±9.17ab 14.67±1.15ab 49.33±1.53ab 33±1ab 7.87±0.51ab 6.87±0.23a T8 11433±603a 1667±153a 53±0a 33±2ab 82±0 61ab 74±0.53a T9 99±6.93ab 14.67±1.53ab 49.67±3.79ab 31±2.65bc 8.03±0.25ab 7.27±0.64a

[0085] Table 3. Effects of the vigorous growth period and maturity period of tobacco leaves on agronomic traits - eggplant peel maturity period

[0086] deal with Plant height Number of leaves Pitch Stem girth Leaf length Ye Kuan CK 148.00±3.61bc 17.00±1.53 8.00±0.50a 9.00±0.58a 53.00±1.53a 31.00±1.00a T1 146.00±208f 18.67±0.58 767±0.29e 900±0.50de 52.67±361de 31.33±351d T2 133.00±1.53e 19.00±16.77 5.67±0.00f 7.17±0.00e 44.00±3.21e 24.33±1.53d T3 137.67±4.00d 28.00±17.32 5.17±0.29e 7.33±0.00cd 41.67±058cd 25.00±0.58bc T4 150.33±1.00a 28.00±0.58 6.33±0.50bcd 8.00±0.58bc 47.00±1.73bc 28.00±0.58cd T5 153.00±0.58c 17.67±0.58 7.67±0.29bcd 8.67±0.00ab 50.67±0.58ab 28.67±0.58a T6 146.33±1.00e 17.67±0.58 7.83±0.29ab 9.00±0.00ab 53.33±1.00a 33.33±0.58a T7 143.67±1.15ab 16.67±0.58 8.17±0.76d 8.67±0.58bc 53.33±2.52ab 31.67±1.15ab T8 154.67±2.00a 18.00±0.58 7.17±0.00abc 8.67±0.50bc 50.67±3.21ab 31.33±1.15ab T9 155.67±0.58abc 17.67±0.58 8.00±0.58cd 8.50±0.29ab 51.67±0.58a 30.67±1.53a

[0087] Table 4. Effects of the vigorous growth period and maturity period of tobacco leaves on agronomic traits - vigorous growth period of eggplant core

[0088] deal with Plant height Number of leaves Leaf length Ye Kuan Pitch Stem girth CK 117.67±6.43bc 14.33±1.53d 55.33±2.52abc 35.33±1.15 9.1±0.85ab 7.43±04b T1 107±10.82c 16±1cd 50±2.65d 32.67±2.52 7.97±0.65bc 7.5±0b T2 116±6.93bc 16.33±1.53bcd 55±1abc 35.67±0.58 9.13±1.96ab 7.57±0.55b T3 119.33±13.65bc 17.67±1.15abc 51±1d 32.67±5.03 7.97±0.06bc 7.67±0.29b T4 127.33±9.45b 16.67±0.58bc 55±3abc 34.67±0.58 8.17±0.38bc 7.7±0.35b T5 145±8a 19±1a 57.67±1.53ab 35.33±1.53 6.9±0c 8.4±036a T6 145±5a 18.33±0.58ab 59±2.65a 37±1 10.07±1.22a 8.03±0.06ab T7 121.67±10.6bc 15.67±1.15cd 53.33±4.04bcd 33.33±0.58 8.97±0.06ab 7.5±0.5b T8 125.67±0.58b 16.67±1.53bc 55±1.73abc 35.67±2.89 8.3±0bc 7.83±0.29ab T9 117.67±9.71bc 19±1a 53±3bcd 35±2.65 8.53±0.5ab 7.93±0.12ab

[0089] Table 5. Effects of the vigorous growth period and maturity period of tobacco leaves on agronomic traits - eggplant core maturity period.

[0090] deal with Plant height Number of leaves Pitch Stem girth Leaf length Ye Kuan CK 153.3±0.58 18.33±0.00abc 8.00±0.58a 8.83±0.58ab 52.00±4.36bcd 33.00±3.61ab T1 152.67±1.53 17.67±0.00c 8.83±0.29de 9.67±0.58ab 57.00±1.53abc 35.33±1.00ab T2 153.00±1.00 17.67±0.58a 7.50±0.58de 9.00±0.58ab 56.33±2.08a 32.33±2.52abc T3 154.33±3.00 1867±1.15ab 6.83±0.50e 9.00±0.58b 5667±1.15d 32.33±0.58c T4 152.33±2.00 18.00±0.58bc 7.00±1.04cde 8.33±0.58b 52.00±3.00cd 30.33±2.65bc T5 151.67±0.58 17.00±0.58bc 8.00±0.29de 8.33±0.58b 52.67±2.00cd 31.33±0.58abc T6 153.67±0.58 17.67±0.00abc 7.00±0.00e 8.67±0.29ab 52.33±1.15bcd 33.33±3.06abc T7 153.33±1.00 18.00±0.58abc 7.67±0.29abc 8.83±0.00ab 54.00±1.53abc 31.33±2.08ab T8 152.33±1.53 17.33±0.00c 8.67±029ab 933±0 58a 56.33±1.53abc 35.33±1.15a T9 152.00±1.73 17.33±0.58abc 8.83±1.04bcd 10.00±1.04a 57.33±1.53ab 35.00±0.58abc

[0091] As shown in Tables 2-5, compared with the control (CK) treatment, the combined application of corn stalks and oilseed cake organic fertilizer (T8) and the combined application of tobacco stalks and earthworm castings (T6) in this invention have a relatively positive impact on the field growth of tobacco varieties.

[0092] Table 6. Effect of the weight of the eggplant wrapper and core on the weight of fresh tobacco leaves.

[0093]

[0094] As shown in Table 6, compared with the control (CK) treatment, the fresh tobacco yield of the treatment with rapeseed straw and oilseed cake organic fertilizer (T7) in the eggplant skin QX103 was increased to 1083.16 kg / mu, which is 12.7% higher than the control. The second highest yield was achieved by T9 and T8. In contrast, the fresh tobacco yield of the treatment with corn straw return to the field and earthworm castings (T5) in the eggplant core Haiyan 101 was significantly increased to 1482.75 kg / mu, which is 53.06% higher than the control. It also showed a significant yield increase of about 50% compared with other groups.

[0095] In summary, the application of corn stalks and earthworm castings in Group T5 significantly increased the fresh leaf weight of Qiexin Haiyan 101, with a 53.06% increase compared to the control and about 50% increase compared to other groups. This significantly improved the fresh tobacco leaf yield of Qiexin Haiyan 101 and has important economic value and industrial production application scenarios.

[0096] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for cultivating Haiyan 101, characterized in that, The planting method includes the following steps: 1) Two to three months before transplanting cigar tobacco leaves, prepare the land 2 to 3 times. During the tillage period, mix corn stalks with earthworm castings and bio-organic fertilizer into the topsoil as base fertilizer. The amount of corn stalks added is 100-500 kg / mu; the amount of earthworm castings applied is 50-300 kg / mu; and the planting density of Haiyan 101 is 1000-2000 plants / mu. 2) After land preparation, ridging should be completed 7-10 days before transplanting cigar tobacco leaves. Ridging should be combined with the application of base fertilizer. Base fertilizer should be applied in strips. The base fertilizer includes tobacco-specific fertilizer and magnesium sulfate fertilizer. The tobacco-specific fertilizer includes superphosphate, calcium ammonium nitrate, ammonium sulfate, and potassium sulfate, or the tobacco-specific fertilizer includes triple superphosphate, calcium ammonium nitrate, ammonium sulfate, and potassium sulfate. 3) After ridging, cover with mulch, then use a transplanter to make holes and transplant the seedlings. Water thoroughly with drip irrigation or hole irrigation during transplanting. From seedling emergence to the point of seedling clustering, maintain soil moisture at 60±10% of maximum soil water holding capacity. Irrigate promptly if moisture falls below 50%. During the vigorous growth period, maintain soil moisture at 80±10% of maximum soil water holding capacity. During the maturity period, maintain soil moisture at 65±5% of maximum soil water holding capacity. Apply two top dressings after transplanting: the first 17-23 days after transplanting, and the second 32-38 days after transplanting. The composition of the top dressings is the same as that of the base fertilizer, and they are applied using drip irrigation. It also includes the operation of pruning and removing side shoots, leaving 16 to 22 effective leaves after pruning.

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