A method for double-cropping flue-cured tobacco rotation planting in the tobacco-growing areas of Shandong Province

Abstract

The present invention discloses a method for double-cropping flue-cured tobacco rotation planting in the Shandong tobacco-growing area, belonging to the technical field of flue-cured tobacco rotation planting methods. The planting method consists of the following steps: sowing winter pasture 70, fertilizing, spraying nutrient solution, irrigating and topdressing, rye mowing, and flue-cured tobacco planting; for the fertilization, fertilization is carried out 6-8 days after the sowing is completed, and compound fertilizer is used during fertilization. 9-11 days after the fertilization is completed, chelated fertilizer is applied to the rotation area; for the spraying of nutrient solution, nutrient solution is evenly sprayed on the rotation area at the beginning of November. The present invention can change the current situation of continuous cropping of flue-cured tobacco in the Shandong tobacco-growing area, increase the multiple cropping index of tobacco field soil, improve soil fertility and tobacco leaf quality, promote the growth and development of flue-cured tobacco, and avoid the adverse effects on the growth and development, tobacco leaf quality and yield of flue-cured tobacco caused by the late transplanting period of tobacco plants and insufficient nitrogen supply in the early stage.

Description

Technical Field

[0001] The present invention relates to the technical field of flue-cured tobacco rotation planting methods, and particularly relates to a flue-cured tobacco rotation planting method with two harvests in one year in the Shandong tobacco-growing area. Background Art

[0002] In the Shandong tobacco-growing area, due to the lack of effective rotation crops, continuous cropping is mostly adopted for flue-cured tobacco. Long-term continuous cropping of flue-cured tobacco has led to continuous cropping obstacle factors such as soil nutrient imbalance and soil compaction in tobacco fields, severely restricting the sustainable utilization of tobacco field soil and the improvement of tobacco leaf quality.

[0003] As a protective tillage measure, tobacco field rotation can balance soil nutrients, regulate the structure of microbial flora, reduce the occurrence of crop soil-borne diseases and continuous cropping obstacles, improve crop yield and crop quality. The flue-cured tobacco transplanting work in the Shandong tobacco-growing area is generally completed before May. From October of the previous year to April of the next year, for a period of up to 6 months, due to the lack of suitable rotation crops, the tobacco-growing land is left idle.

[0004] Silage is a kind of roughage obtained by chopping green forage with a moisture content of 65 - 75% and then inhibiting the reproduction of various miscellaneous bacteria through the fermentation of anaerobic lactic acid bacteria under airtight anaerobic environmental conditions. Silage has a sour and fragrant smell and is rich in nutrients. It is known as the "grass can" and is an excellent feed for feeding livestock such as cattle and sheep, and is widely favored by livestock breeding enterprises.

[0005] Taking advantage of the opportunity of the idle tobacco field soil, screening suitable silage crops for rotation with flue-cured tobacco is the most effective means to overcome the continuous cropping obstacle factors in tobacco fields.

[0006] Through investigation, it is found that Dongmu 70 ryegrass is an ideal silage crop for the following reasons: Dongmu 70 ryegrass has a high sugar content and is easy to make into silage; Dongmu 70 ryegrass is rich in nutrients such as crude protein and essential amino acids, and has high contents of trace elements such as iron, manganese, and zinc, with good palatability, and is suitable for raising cattle and sheep; the feeding effect of Dongmu 70 ryegrass is better than that of alfalfa and corn straw. In addition, when using Dongmu 70 ryegrass silage to feed meat sheep, compared with alfalfa hay and corn straw silage, the cost is lower and the benefit is higher.

[0007] Through further investigation and research, it is found that in Xuancheng, Anhui, the effects of turning over three green manure varieties in tobacco fields were studied. Compared with the treatments of Astragalus sinicus and Medicago hispida, the tobacco leaf yield and output value after the treatment of Dongmu 70 ryegrass were higher, and the internal chemical components of the tobacco leaves were more suitable; the research in Xuchang, Henan pointed out that both turning over and incorporating Dongmu 70 ryegrass and mowing it can increase the content of soil organic matter and the activity of soil invertase in the surface soil layer, but the chemical component coordination of the tobacco leaves in the mowing treatment is better than that in the turning over and incorporating treatment, and the economic benefit is higher. Therefore, Dongmu 70 ryegrass is an ideal previous crop for flue-cured tobacco and is suitable for rotation with flue-cured tobacco.

[0008] Most of the flue-cured tobacco planting areas in Shandong are concentrated in hilly and mountainous regions, with medium to low soil fertility. Winter Grazing 70 ryegrass is alkali-tolerant, drought-tolerant, barren-tolerant, has strong disease resistance, fast growth rate, and high yield. Its variety characteristics are very suitable for promotion and planting in the Shandong tobacco-growing areas. In the 1990s and the early 21st century, trial plantings were carried out in the main tobacco-growing areas such as Weifang and Linyi, and through the treatment of turning over and burying the green manure, it had good effects on soil fertility, tobacco leaf quality, etc.

[0009] However, compared with conventional tobacco planting, when rotating flue-cured tobacco with Winter Grazing 70 ryegrass, it will affect the transplanting period of tobacco plants, delaying the transplanting period of tobacco plants from May 1st to May 10th, thus affecting the growth of tobacco plants and resulting in a delay in the harvest period of tobacco plants. In addition, because the stubble after the cutting of Winter Grazing 70 will remain in the tobacco field soil and is difficult to degrade in the short term, it will compete with the roots of flue-cured tobacco for nitrogen in the soil during the microbial decomposition process, and will also affect the development of tobacco plants in the short term, resulting in short and slow-growing tobacco plants, small and light-colored tobacco leaves. Summary of the Invention

[0010] In view of the deficiencies of the existing technology, the present invention provides a method for rotating and planting flue-cured tobacco with two harvests in a year in the Shandong tobacco-growing area, which can change the current situation of continuous cropping of flue-cured tobacco in the Shandong tobacco-growing area, increase the multiple cropping index of tobacco field soil, improve soil fertility and tobacco leaf quality, promote the growth and development of flue-cured tobacco, and avoid the adverse effects on the growth and development of flue-cured tobacco, tobacco leaf quality, yield, and harvest period caused by the late transplanting time of tobacco plants and insufficient nitrogen supply.

[0011] To solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0012] A method for rotating and planting flue-cured tobacco with two harvests in a year in the Shandong tobacco-growing area, which consists of the following steps: sowing Winter Grazing, fertilizing, spraying nutrient solution, irrigating and topdressing, cutting ryegrass, planting flue-cured tobacco;

[0013] For the sowing of Winter Grazing, at the end of September, after all the tobacco stalks are removed, the land is prepared and the seeds of Winter Grazing 70 ryegrass are sown;

[0014] The sowing density is 7 - 10 kg / mu, and the sowing depth is 4 - 5 cm;

[0015] For the fertilization, fertilization is carried out 6 - 8 days after the sowing is completed. Compound fertilizer is used for fertilization. 9 - 11 days after the fertilization is completed, chelated fertilizer is applied to the rotation area;

[0016] The contents of nitrogen, phosphorus, and potassium in the compound fertilizer are 14 - 16%, 14 - 16%, and 14 - 16% respectively;

[0017] The dosage of the compound fertilizer is 15 - 20 kg / mu;

[0018] The dosage of the chelated fertilizer is 9 - 11 kg / mu;

[0019] The preparation method of the chelated fertilizer is as follows: dissolve wheat oligopeptide in water to prepare a mixed aqueous solution; then add calcium chloride, zinc chloride, mannan oligosaccharide, fulvic acid, and L-hydroxyproline to the mixed aqueous solution, and stir evenly at 40-50°C to obtain the chelated fertilizer;

[0020] In the preparation of the chelated fertilizer, the mass ratio of wheat oligopeptide, water, calcium chloride, zinc chloride, mannan oligosaccharide, fulvic acid, and L-hydroxyproline is 9-11:58-62:1.8-2.2:0.8-1.2:0.4-0.6:0.8-1.2:0.5-0.7;

[0021] For the sprayed nutrient solution, evenly spray the nutrient solution on the rotation area at the beginning of November;

[0022] The dosage of the nutrient solution is 14-16 kg / mu;

[0023] The preparation method of the nutrient solution is as follows: dissolve pregelatinized starch, chitosan oligosaccharide, methionine, calcium nitrate, and ferrous sulfate in water and stir evenly;

[0024] In the preparation of the nutrient solution, the mass ratio of pregelatinized starch, chitosan oligosaccharide, methionine, calcium nitrate, ferrous sulfate, and water is 4.5-5.5:0.8-1.2:0.4-0.6:0.8-1.2:1.4-1.6:58-62;

[0025] For the irrigation and topdressing, from after the sowing of winter rye 70 to before the harvest, irrigate once in winter, irrigate once after the beginning of spring, and topdress once in early spring;

[0026] When topdressing, use calcium ammonium nitrate, and the topdressing amount is 8-12 kg / mu;

[0027] The content of nitrate nitrogen in the calcium ammonium nitrate is ≥14%, and the content of ammonium nitrogen is ≥1%;

[0028] For the rye mowing, mow the winter rye 70 at the end of April of the following year, and then plow, ridging, and plant the rotation field;

[0029] The depth during plowing is 25-35 cm, the ridging height is 30 cm, and the row spacing is 1.1-1.3 m;

[0030] For the flue-cured tobacco planting, complete the field flue-cured tobacco transplanting work in early May of the following year. The plant spacing during transplanting is 0.4-0.6 m, and then transfer to the conventional flue-cured tobacco production management.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] (1) The method of double-cropping flue-cured tobacco rotation planting in the Shandong tobacco-growing area of the present invention can increase the multiple cropping index of tobacco fields and improve soil fertility. By rotating winter forage 70 rye with flue-cured tobacco, the physical and chemical properties of the soil before flue-cured tobacco transplanting are improved. Compared with the conventional continuous cropping tobacco fields, the contents of organic matter, alkaline hydrolyzable nitrogen, available phosphorus, and available potassium in the soil increase by 19.8%, 52.4%, 53.2%, and 50.3% respectively, the activities of urease, invertase, and phosphatase in the soil increase by 87.3%, 166.1%, and 262.4% respectively, and the contents of dissolved organic carbon (DOC) and labile organic carbon (LOC) increase by 209.2% and 42.4% respectively;

[0033] (2) The method of double-cropping flue-cured tobacco rotation planting in the Shandong tobacco-growing area of the present invention can promote the growth and development of flue-cured tobacco. 35 days after flue-cured tobacco transplanting, the plant height can reach 18.33 cm, the number of leaves can reach 11, the leaf length can reach 47.67 cm, and the leaf width can reach 27.33 cm; 70 days after flue-cured tobacco transplanting, the plant height can reach 114 cm, the number of leaves can reach 20.2, the leaf length can reach 69.51 cm, the leaf width can reach 32.4 cm, and the stem girth can reach 12.60 cm;

[0034] (3) The method of double-cropping flue-cured tobacco rotation planting in the Shandong tobacco-growing area of the present invention can promote the growth and development of flue-cured tobacco and improve the quality of tobacco leaves. The yield of the flue-cured tobacco planted can reach 146.4 kg / mu, the output value can reach 3,262.0 yuan / mu, the proportion of top-grade tobacco can reach 67.2%, and the average price can reach 22.28 yuan / kg. Compared with the conventional continuous cropping tobacco in Yantai, the yield increases by 8.4%, the output value increases by 3.2%, and the proportion of top-grade tobacco increases by 61.5%;

[0035] (4) The method of double-cropping flue-cured tobacco rotation planting in the Shandong tobacco-growing area of the present invention can improve the appearance of tobacco leaves. The maturity score of the flue-cured tobacco planted can reach 8.1, the color score can reach 8.1, the identity score can reach 8.3, the leaf structure score can reach 8.7, the oil content score can reach 6.7, the chroma score can reach 5.5, and the total score can reach 45.4;

[0036] (5) The method of double-cropping flue-cured tobacco rotation planting in the Shandong tobacco-growing area of the present invention can improve the soil carbon pool management index. Compared with the conventional continuous cropping tobacco fields, the increase rate of the carbon pool management index is 38.79%;

[0037] (6) The method of double-cropping flue-cured tobacco rotation planting in the Shandong tobacco-growing area of the present invention can increase the income of tobacco farmers. The fresh weight of the winter forage 70 rye harvested is 2,519 kg / mu, and the cost of silage feed is calculated at 0.45 yuan / kg on average. The output value per mu can reach 1,133.55 yuan. After deducting the production cost and management cost of 400 yuan per mu, the net income from planting winter forage 70 rye is 733.55 yuan / mu;

[0038] (7) The method for rotating and planting flue-cured tobacco with two harvests in a year in the Shandong tobacco-growing area of the present invention realizes crop rotation and stubble change in tobacco fields, reduces the occurrence and spread of diseases and pests in flue-cured tobacco fields, especially soil-borne diseases. After the stubble of winter rye 70 is cut and turned over, it can provide a large amount of fresh organic matter for soil microorganisms, which is beneficial to increasing microbial diversity, improving the microbial community structure and the micro-ecological environment of tobacco field soil;

[0039] (8) The method for rotating and planting flue-cured tobacco with two harvests in a year in the Shandong tobacco-growing area of the present invention can avoid affecting the transplanting period of tobacco plants. By using chelated fertilizers and nutrient solutions, the chelated fertilizers and nutrient solutions can supply nutrients to winter rye 70 while improving the nutrients in the soil of the rotation area and the growth rate of tobacco plants, avoiding the adverse effects on the growth and development, leaf quality and yield of flue-cured tobacco caused by the late transplanting period of tobacco plants, and shortening the growth period of flue-cured tobacco;

[0040] (9) The method for rotating and planting flue-cured tobacco with two harvests in a year in the Shandong tobacco-growing area of the present invention can avoid affecting the nitrogen in the tobacco field soil. Compared with the conventional continuous cropping tobacco field, the chloride ion content in the soil is reduced by 13.3%;

[0041] (10) The method for rotating and planting flue-cured tobacco with two harvests in a year in the Shandong tobacco-growing area of the present invention constructs a business model integrating the production, sales and marketing of silage suitable for the healthy development of tobacco leaf production areas, meeting the demand of the livestock market for silage;

[0042] (11) The method for rotating and planting flue-cured tobacco with two harvests in a year in the Shandong tobacco-growing area of the present invention solves the problem that the domestic forage planting scale fails to keep up with the development pace of the livestock industry, there is a large market gap, and the supply is seriously unbalanced with the demand of the livestock industry. Planting winter rye 70 as silage not only meets the market demand for silage, but also increases the income of tobacco farmers, which is beneficial to promoting farmers' income increase and realizing rural revitalization. Detailed implementation mode

[0043] In order to have a clearer understanding of the technical features, objectives and effects of the present invention, the specific implementation mode of the present invention will be described now.

[0044] Example 1

[0045] A method for rotating and planting flue-cured tobacco with two harvests in a year in the Shandong tobacco-growing area is specifically as follows:

[0046] 1. Winter rye sowing: On September 30th, after all tobacco stalks are removed, the land is prepared according to the requirements for sowing wheat, and then the seeds of winter rye 70 are sown by drilling. The sowing density is controlled at 7.5 kg / mu, and the sowing depth is 4 cm;

[0047] 2. Fertilization: Fertilization is carried out 7 days after the sowing is completed. Compound fertilizer is used during fertilization, and the dosage of the compound fertilizer is 15 kg / mu. 10 days after the fertilization is completed, chelated fertilizer is applied to the rotation area, and the dosage of the chelated fertilizer is 10 kg / mu. To avoid adverse effects on tobacco plants, herbicides and insecticides are not used during the planting period of winter rye 70;

[0048] The nitrogen, phosphorus, and potassium contents in the compound fertilizer are 15%, 15%, and 15% respectively;

[0049] The preparation method of the chelated fertilizer is as follows: Dissolve wheat oligopeptide in water to prepare a mixed aqueous solution; then add calcium chloride, zinc chloride, mannan oligosaccharide, fulvic acid, and L-hydroxyproline to the mixed aqueous solution, and stir at a stirring speed of 120 rpm at 50 °C for 1 h to obtain chelated fertilizer;

[0050] Among them, the mass ratio of wheat oligopeptide, water, calcium chloride, zinc chloride, mannan oligosaccharide, fulvic acid, and L-hydroxyproline is 10:60:2:1:0.5:1:0.6;

[0051] 3. Spraying nutrient solution: On November 1, the nutrient solution is evenly sprayed on the rotation area, and the dosage of the nutrient solution is 15 kg / mu;

[0052] The preparation method of the nutrient solution is as follows: Dissolve pregelatinized starch, chitosan oligosaccharide, methionine, calcium nitrate, and ferrous sulfate in water and stir evenly;

[0053] Among them, the mass ratio of pregelatinized starch, chitosan oligosaccharide, methionine, calcium nitrate, ferrous sulfate, and water is 5:1:0.5:1:1.5:60;

[0054] 4. Irrigation and topdressing: From the sowing of winter rye 70 to before harvesting, irrigate once in winter and once after the beginning of spring, and topdress once in early spring. Calcium ammonium nitrate is used during topdressing, and the topdressing amount is 10 kg / mu;

[0055] The nitrate nitrogen content in the calcium ammonium nitrate is ≥14%, and the ammonium nitrogen content is ≥1%;

[0056] 5. Rye mowing: Mow winter rye 70 on May 1 of the following year, and sell it as silage feed to relevant livestock breeding enterprises after mowing. Then plow and ridging the rotation field. The depth during plowing is 30 cm, the ridging height is 30 cm, and the row spacing is 1.2 m;

[0057] 6. Flue-cured tobacco planting: Complete the field flue-cured tobacco transplanting work on May 10 of the following year. The plant spacing during transplanting is 0.5 m, and then transfer to the conventional flue-cured tobacco production management.

[0058] Comparative Example 1

[0059] At the end of September, after all tobacco stalks are removed, the tobacco-growing land is left fallow until the end of April of the following year. In late April of the following year, the tobacco-growing land is plowed, ridged, and planted. The plowing depth is 30 cm, the ridging height is 30 cm, and the row spacing is 1.2 m. Then, the field flue-cured tobacco transplanting work is completed in the first ten days of May of the following year. The plant spacing during transplanting is 0.5 m, and then it turns to conventional flue-cured tobacco production management.

[0060] Experimental Example 1

[0061] The physical and chemical property indexes of the soil after plowing in Example 1 in the 5th mowing step on May 1 of the following year when the winter pasture 70 is mowed are tested. At the same time, for comparison, the physical and chemical property indexes of the soil after plowing the tobacco-growing land at the end of April of the following year in Comparative Example 1 are tested. The test results are as follows:

[0062]

[0063] From the above results, it can be seen that the contents of organic matter, alkaline hydrolyzable nitrogen, available phosphorus, and available potassium in the soil of Example 1 are increased by 19.8%, 52.4%, 53.2%, and 50.3% respectively compared with the soil of Comparative Example 1. The chloride ion content is reduced by 13.3%. The activities of urease, sucrase, and phosphatase in the soil are increased by 87.3%, 166.1%, and 262.4% respectively. The contents of dissolved organic carbon (DOC) and labile organic carbon (LOC) are increased by 209.2% and 42.4% respectively.

[0064] Experimental Example 2

[0065] The agronomic traits of flue-cured tobacco 35 days and 70 days after transplanting in the 6th flue-cured tobacco planting step of Example 1 are tested. At the same time, for comparison, the agronomic traits of flue-cured tobacco 35 days and 70 days after transplanting in Comparative Example 1 are tested. The test results are as follows:

[0066]

[0067]

[0068] As can be seen from the above results, when comparing the leaf length and leaf width of the flue-cured tobacco in Example 1 35 days after transplanting with those of the flue-cured tobacco in Comparative Example 1 35 days after transplanting, the leaf length and leaf width of the flue-cured tobacco in Comparative Example 1 are higher than those in Example 1, indicating that a late transplanting period will affect the growth rate of flue-cured tobacco. However, when comparing the leaf length, leaf width, and stem diameter of the flue-cured tobacco in Example 1 70 days after transplanting with those of the flue-cured tobacco in Comparative Example 1 70 days after transplanting, the leaf length, leaf width, and stem girth of Comparative Example 1 are all lower than those of the flue-cured tobacco in Example 1, indicating that Example 1 can avoid the adverse effects of a late tobacco transplanting period on the growth and development of flue-cured tobacco, the quality and yield of tobacco leaves, thereby improving the growth rate of flue-cured tobacco, shortening the growth period of flue-cured tobacco, avoiding the impact of a late transplanting period on the harvesting period, and ensuring that harvesting can be carried out during the normal flue-cured tobacco harvesting period.

[0069] Test Example 3

[0070] The yields and economic benefits of the flue-cured tobacco planted in Example 1 and Comparative Example 1 were investigated, and the investigation results are as follows:

[0071]

[0072] As can be seen from the above results, from the perspective of tobacco-growing benefits, the per-acre yield and per-acre output value of Example 1 are higher than those of Comparative Example 1. The yield increased by 8.4%, the output value increased by 3.2%, and the proportion of top-grade tobacco increased by 61.5%.

[0073] Test Example 4

[0074] The appearance quality of the flue-cured tobacco planted in Example 1 and Comparative Example 1 was scored, and the scoring results are as follows:

[0075]

[0076] As can be seen from the above results, the total score of Example 1 is higher than that of Comparative Example 1.

[0077] Test Example 5

[0078] The carbon pool quality of the soil after cutting and plowing the winter forage 70 in late April of the following year in the 5th cutting step of Example 1 was tested. At the same time, for comparison, the carbon pool quality of the soil after plowing the tobacco-growing land in late April of the following year in Comparative Example 1 was tested, and the test results are as follows:

[0079]

[0080] As can be seen from the above results, compared with Comparative Example 1, the carbon pool quality of the soil in Example 1 was significantly improved, and the increase rate of the carbon pool management index was 38.79%.

[0081] Test Example 6

[0082] The mu yield of winter rye 70 obtained in the 5th mowing step of Example 1 was statistically analyzed, and the statistical results are as follows:

[0083]

[0084] As can be seen from the above results, the fresh weight of winter rye 70 harvested in Example 1 was 2519 kg / mu. The cost of silage feed was calculated at 0.45 yuan / kg, and the mu output value could reach 1133.55 yuan. After deducting the production cost and management cost of 400 yuan per mu, the net income from planting winter rye 70 was 733.55 yuan / mu.

[0085] Unless otherwise specified, the percentages used in the present invention are all mass percentages.

[0086] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for double-cropping flue-cured tobacco rotation planting in the tobacco-growing area of Shandong, characterized in that, It consists of the following steps: sowing of winter rye 70, fertilization, spraying of nutrient solution, irrigation and topdressing, rye mowing, and flue-cured tobacco planting; For the sowing of winter rye 70, at the end of September, after all the tobacco stalks are removed, the land is prepared and the seeds of winter rye 70 are sown; For the fertilization, it is carried out 6 - 8 days after the sowing is completed. Compound fertilizer is used during fertilization. 9 - 11 days after the fertilization is completed, chelated fertilizer is applied to the rotation area; The preparation method of the chelated fertilizer is as follows: wheat oligopeptide is dissolved in water to prepare a mixed aqueous solution; then calcium chloride, zinc chloride, mannan oligosaccharide, fulvic acid, and L-hydroxyproline are added to the mixed aqueous solution and stirred evenly at 40 - 50 °C to obtain the chelated fertilizer; For the spraying of the nutrient solution, the nutrient solution is evenly sprayed on the rotation area at the beginning of November; The preparation method of the nutrient solution is as follows: pregelatinized starch, chitosan oligosaccharide, methionine, calcium nitrate, and ferrous sulfate are dissolved in water and stirred evenly; During the sowing of winter rye 70, the sowing density of the seeds of winter rye 70 is 7 - 10 kg / mu, and the sowing depth is 4 - 5 cm; In the compound fertilizer, the contents of nitrogen, phosphorus, and potassium are 14 - 16%, 14 - 16%, and 14 - 16% respectively; The dosage of the compound fertilizer is 15 - 20 kg / mu; The dosage of the chelated fertilizer is 9 - 11 kg / mu; In the preparation of the chelated fertilizer, the mass ratio of wheat oligopeptide, water, calcium chloride, zinc chloride, mannan oligosaccharide, fulvic acid, and L-hydroxyproline is 9 - 11:58 - 62:1.8 - 2.2:0.8 - 1.2:0.4 - 0.6:0.8 - 1.2:0.5 - 0.7; The dosage of the nutrient solution is 14 - 16 kg / mu; In the preparation of the nutrient solution, the mass ratio of pregelatinized starch, chitosan oligosaccharide, methionine, calcium nitrate, ferrous sulfate, and water is 4.5 - 5.5:0.8 - 1.2:0.4 - 0.6:0.8 - 1.2:1.4 - 1.6:58 - 62; For the irrigation and topdressing, from the sowing of winter rye 70 until before the harvest, it is irrigated once in winter and once after the spring begins, and topdressed once in early spring; Calcium ammonium nitrate is used during the topdressing, and the topdressing amount is 8 - 12 kg / mu; In the calcium ammonium nitrate, the content of nitrate nitrogen is ≥14%, and the content of ammonium nitrogen is ≥1%; 2. The method for double-crop flue-cured tobacco rotation planting in Shandong tobacco-growing area according to claim 1, characterized in that, For the rye mowing, the winter rye 70 is mowed at the end of April of the next year, and then the rotation field is plowed, ridged, and planted; The depth during plowing is 25 - 35 cm, the ridging height is 30 cm, and the row spacing is 1.1 - 1.3 m; 3. The method for double-crop flue-cured tobacco rotation planting in the Shandong tobacco-growing area according to claim 1, wherein For the flue-cured tobacco planting, the field flue-cured tobacco transplanting work is completed in the first ten days of May of the next year. The plant spacing during transplanting is 0.4 - 0.6 m, and then it is transferred to the conventional flue-cured tobacco production management.

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