A fertilization method for increasing potassium content in the middle and upper parts of Yuxi flue-cured tobacco leaves

Abstract

The present invention relates to a fertilization method for increasing the potassium content of the middle and upper tobacco leaves of Yuxi flue-cured tobacco. Large particles are used as base fertilizer, and the amount of potassium applied is determined according to the chloride ion content of the soil, and the last topdressing is applied 10 days later than the conventional topdressing time. Wherein (1) for fields with a soil chloride ion content of <40 mg / kg, the potassium application amount is applied according to the local recommended amount of potassium; (2) for fields with a soil chloride ion content of 40 to 80 mg / kg, the potassium application amount is increased by 15% on the basis of the local recommended amount of potassium; (3) for fields with a soil chloride ion content of 80.1 to 90 mg / kg, the potassium application amount is increased by 20% on the basis of the local recommended amount of potassium. The method of the present invention can increase the potassium content and potassium-chloride ratio of tobacco leaves, make the chemical composition of tobacco leaves more coordinated, and thus improve the quality of tobacco leaves.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural production and planting, and specifically relates to a fertilization method for improving the potassium content of the middle and upper tobacco leaves of Yuxi flue-cured tobacco. Background Art

[0002] Potassium plays an important role and influences on the growth, yield and quality of tobacco and the safety of cigarette products. Therefore, the potassium content of tobacco leaves is often used as one of the indicators for evaluating tobacco quality. Leymonie and Etourneaud pointed out that the minimum potassium content of high-quality tobacco leaves should reach 2%. It is reported that the potassium content of tobacco leaves in the United States, Zimbabwe and other countries is mostly 4-6%, Brazil is 3-4%, and the average potassium content of tobacco leaves in my country rarely exceeds 2%. Compared with foreign countries, the potassium content of tobacco leaves in my country is relatively low, which has become one of the obstacles to further improve the quality of tobacco leaves in my country. From a national perspective, the appropriate potassium content rate of flue-cured tobacco is 40.56%. Among the southern tobacco-growing areas, the appropriate potassium content rate of flue-cured tobacco in Yunnan tobacco-growing area is one of the lowest in several provinces and regions (lower than the national average).

[0003] Tobacco is a potassium-loving crop, absorbing more potassium than any other element. Potassium is an activator of many enzymes and participates in the photosynthesis, respiration, nitrogen metabolism and other life processes of the plant. Adequate potassium supply can ensure the normal metabolism of the tobacco plant and help the plant grow healthily. Potassium is the main osmotic regulating substance in cells, participating in regulating the opening and closing of guard cells. Potassium can enhance the disease resistance and drought resistance of tobacco plants. Tobacco leaves with high potassium content are dark orange in color, have sufficient aroma, good taste, are elastic and tough, have strong filling capacity, and have good smoldering fire holding power and combustion. When tobacco leaves lack potassium, first a yellow-green halo forms at the tip and edge of the leaf, which turns into copper-red or brown necrotic spots in severe cases, and finally the central tissue falls off; the hook tip curls, the leaf surface is uneven; it grows slowly, the mechanical tissue is underdeveloped, and the color is dark brown; the tobacco leaf tissue is rough after baking. Lack of oil, poor elasticity and combustion.

[0004] Increasing potassium fertilizer and improving the effectiveness of potassium in the soil are effective ways to increase the potassium content of tobacco leaves. At present, most of the potassium fertilizers for tobacco in my country are applied as basal fertilizers, and potassium is easily fixed by the soil, and the fixation rate increases linearly with the increase of potassium application; in addition, existing studies have shown that the potassium absorption rate is low in the early stage of flue-cured tobacco growth, and the maximum absorption peak is formed 50 days after transplanting; therefore, there is a time mismatch between the application of potassium fertilizers and the potassium needs of tobacco leaves. Although more potassium fertilizers are applied as basal fertilizers, potassium deficiency may occur in the late stage of tobacco plant growth, especially rhizosphere potassium deficiency. Therefore, it is necessary to adjust the basal topdressing ratio of potassium fertilizers and apply potassium fertilizers in time. Guo Chunyan's research found that the potassium content of the upper, middle and lower tobacco leaves can be increased by 0.1, 0.17 and 0.13 percentage points respectively compared with the conventional fertilization control when potassium fertilizers were applied at a ratio of 1:1:1 at 30d, 45d and 60d after transplanting.

[0005] Yuxi is located in the central part of Yunnan Province. Its three-dimensional climate characteristics are very obvious. It has both mountain plains with four seasons like spring and valleys known as "natural greenhouses". It is one of the most suitable areas for flue-cured tobacco production in my country. Yuxi has a long history of flue-cured tobacco cultivation. Its tobacco leaf quality enjoys a high reputation at home and abroad. It is a well-known "hometown of Yunyan tobacco". In 1953, Yuxi tobacco won the championship with 108 points in the national tobacco leaf evaluation, setting a new milestone for the development of Yuxi flue-cured tobacco production. Yuxi tobacco area is an important production area of ​​high-quality flue-cured tobacco in Yunnan and even the whole country. Therefore, improving the quality and safety of tobacco leaves is of great significance to promoting the sustainable and healthy development of Yunnan tobacco leaf production. At present, Yuxi tobacco area, like other production areas, has also suffered from excessive fertilization in the off-tobacco season, outdated and single formula of special fertilizers for flue-cured tobacco, soil quality degradation due to long-term excessive fertilizers and unscientific use, and nutrient imbalance, which seriously affects the yield and quality of flue-cured tobacco in this area. Therefore, it is necessary to improve the method of potassium fertilizer application and increase the utilization rate of potassium fertilizer based on the soil conditions in the Yuxi tobacco-growing areas and the nutrient requirements of the main local tobacco varieties. Summary of the invention

[0006] In order to overcome the problems existing in the background technology, the present invention provides a fertilization method for increasing the potassium content of the upper tobacco leaves of Yuxi flue-cured tobacco.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A fertilization method for increasing the potassium content of the middle and upper tobacco leaves of Yuxi flue-cured tobacco, using large-particle base fertilizer and determining the potassium application amount according to the chloride ion content of the soil.

[0009] Furthermore, the base fertilizer formula uses a tobacco-specific compound fertilizer containing nitrate nitrogen according to local practice, but the fertilizer particles are enlarged to a diameter of 8 to 10 mm.

[0010] Furthermore, conventional low-nitrogen and high-potassium fertilizers or potassium nitrate or potassium sulfate are used for tobacco, and topdressing is applied three times, with the last topdressing being applied 10 days later than conventional topdressing.

[0011] Furthermore, for fields with soil chloride content <40 mg / kg, the amount of potassium applied during the entire growing period should be based on the local recommended amount.

[0012] Furthermore, for fields with soil chloride content of 40-80 mg / kg, the amount of potassium applied during the entire growing period should be increased by 15% based on the local recommended amount.

[0013] Furthermore, for fields with soil chloride ion content of 80.1-90 mg / kg, the amount of potassium applied during the entire growing period should be increased by 20% based on the local recommended amount.

[0014] Beneficial effects of the present invention:

[0015] The invention directly reduces the contact between potassium fertilizer and soil particles by increasing the size of base fertilizer particles and adopts a secondary granulation process for fertilizer packaging, thereby greatly slowing down the fixation of potassium by the soil; at the same time, the time for topdressing is delayed, and the proportion of the last potassium fertilizer application is increased, so as to meet the characteristics that the potassium absorption rate is low in the early growth stage of flue-cured tobacco and the maximum absorption peak is formed 50 days after transplanting, thereby greatly improving the biological effectiveness of potassium supply and extending the time of potassium supply.

[0016] During the application of the present invention in the two main tobacco producing areas of Jiangchuan District and Eshan in Yuxi City, not only can the growth of msK326 tobacco plants be enhanced, the yield, output value and proportion of high-quality tobacco be increased, but also the content of the main chemical components of tobacco leaves can be more appropriate, the proportions between the components can be more coordinated, and the present invention has excellent performance in tobacco planting, and has the prospect of further large-scale demonstration and promotion. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and beneficial effects of the present invention clearer, the preferred embodiments of the present invention will be described in detail below to facilitate understanding by technicians.

[0018] Example

[0019] 1 Materials and methods

[0020] 1.1 Test materials

[0021] The tobacco variety used for the test was msK326, and standardized floating seedlings were used to transplant healthy seedlings with 5 leaves and 1 heart. The test sites were arranged in separate test plots and managed separately.

[0022] Fertilizers for testing: compound fertilizer for tobacco (N≥12%, P2O5≥6%, K2O≥24%), nitrogen-potassium fertilizer for tobacco (N≥28%, K2O≥5%), potassium sulfate for agriculture (K2O≥50.0%), potassium nitrate (N≥13.5%, K2O≥43.5%), these four fertilizers are provided by local tobacco companies. Large-particle compound fertilizer for tobacco (N≥12%, P2O5≥6%, K2O≥24%) is a trial product commissioned by the research team to relevant enterprises, using the secondary granulation process of fertilizer packaging, and the diameter of fertilizer particles is 8-10mm.

[0023] 1.2 Measurement items and methods

[0024] (1) Physical and chemical properties of tobacco leaves

[0025] Taking the plot as a unit, the tobacco plants are marked according to the leaf position, and the leaves are collected according to the leaf position after maturity. After baking, the main chemical components are determined according to the national tobacco standards. Conventional chemical composition analysis is based on tobacco industry standards such as YC / T 159-2002 "Continuous flow method for determination of water-soluble sugars in tobacco and tobacco products", YC / T173-2003 "Flame photometry for determination of potassium in tobacco and tobacco products", YC / T 160-2002 "Continuous flow method for determination of total alkaloids in tobacco and tobacco products", YC / T161-2002 "Continuous flow method for determination of total nitrogen in tobacco and tobacco products" and YC / T 162-2002 "Continuous flow method for determination of chlorine in tobacco and tobacco products".

[0026] (2) Economic characteristics

[0027] All tobacco plants in the plot are harvested in stages according to maturity requirements. On the day of harvesting, the tobacco leaves are sorted and put into the curing room for curing according to the three-stage process. The cured tobacco leaves are graded according to GB 2635-1992 "Current-cured Tobacco". The weight of tobacco leaves of different grades in each plot is counted and the purchase price of tobacco leaves of this variety in Yuxi City that year is referred to to calculate the yield, output value and proportion of different grades of tobacco leaves.

[0028] (3) Data processing

[0029] The experimental data were statistically analyzed using Excel 2013 and SPSS 21.0 statistical software.

[0030] 2. Implementation location

[0031] The test was conducted in Qianwei Town, Jiangchuan District, Yuxi City, Yunnan Province and Chahe Township, Eshan County in 2017, representing two types of tobacco growing areas: dam-land tobacco growing areas and mountain tobacco growing areas. The chloride ion determination results of the test sites are shown in Table 1.

[0032] Table 1 Soil chloride ion concentrations in different examples

[0033]

[0034] 3. Experimental treatment

[0035] Examples 1-5 all have three treatments: normal potassium treatment, potassium increase by 15% (in terms of K2O), and potassium increase by 30% (in terms of K2O); Example 6 has three treatments: normal potassium treatment, potassium increase by 20% (in terms of K2O), and potassium increase by 40% (in terms of K2O). The increased potassium fertilizer was applied in the form of potassium sulfate. The nitrogen, phosphorus, and potassium nutrient input ratios are shown in Table 2.

[0036] Table 2 Nutrient input for each treatment in different embodiments

[0037]

[0038] In the constant potassium treatment, the base fertilizer used was tobacco-specific compound fertilizer (N≥12%, P2O5≥6%, K2O≥24%), and the topdressing used was tobacco-specific nitrogen-potassium fertilizer (N≥28%, K2O≥5%), agricultural potassium sulfate (K2O≥50.0%), and potassium nitrate (N≥13.5, K2O≥43.5). The topdressing was applied three times, and the last potassium application was 35 days after transplanting.

[0039] For potassium-enhancing treatment, large-particle tobacco-specific compound fertilizer (N≥12%, P2O5≥6%, K2O≥24%, using a secondary granulation process of fertilizer bag fertilizer, and a fertilizer particle diameter of 8-10mm) is used as base fertilizer, and tobacco-specific nitrogen and potassium fertilizer (N≥28%, K2O≥5%), agricultural potassium sulfate (K2O≥50.0%), and potassium nitrate (N≥13.5, K2O≥43.5) are used as topdressing. The topdressing is applied three times, and the last potassium application is 45 days after transplanting.

[0040] 4. Experimental Results

[0041] 4.1 Example 1

[0042] (1) Physical and chemical properties of tobacco leaves

[0043] Taking the plot as the unit, the mature tobacco leaves of the fixed plants were hung according to the leaf position, and samples were taken after baking to determine their main chemical components. The chemical quality of tobacco leaves after baking in each treatment is shown in Table 3. It can be seen from the table that increasing potassium by 15% can reduce the chlorine content of the upper tobacco leaves and the nicotine content of the middle and upper tobacco leaves, with a reduction rate of 22.22% and 2.19% to 9.65%; increasing potassium by 30% can promote the potassium content of the middle tobacco leaves, reduce the nicotine content of the middle and upper tobacco leaves, and the chlorine content of the upper tobacco leaves.

[0044] Table 3 Chemical quality of tobacco leaves in each treatment

[0045]

[0046] (2) Economic characteristics

[0047] The yield and output value data of each treatment in this experiment are shown in Table 4. The treatment with 15% potassium increase can increase the yield of flue-cured tobacco and the proportion of medium and high-quality tobacco. Compared with the control, the yield increased by 5.66% and the proportion of medium and high-quality tobacco increased by 12.08%. However, the total output value did not increase. Therefore, in the fields with chloride ion concentration <30mg / kg, the local recommended potassium application amount can be used, and increasing potassium is not very meaningful.

[0048] Table 4 Economic characteristics of each treatment

[0049]

[0050] 4.2 Example 2

[0051] Taking the plot as a unit, the mature tobacco leaves of the fixed plants were hung according to the leaf position, and samples were taken after baking to determine their main chemical components. The chemical quality of tobacco leaves after baking in each treatment is shown in Table 5. There is no significant difference in the quality index of tobacco leaves between the potassium-enhanced treatment and the normal potassium treatment. Therefore, in the fields with a chloride ion concentration of 30-40 mg / kg, the local recommended potassium application rate can be used, and increasing potassium is not very meaningful.

[0052] Table 5. Physical and chemical properties of tobacco leaves treated with different methods

[0053]

[0054] 4.3 Example 3

[0055] (1) Physical and chemical properties of tobacco leaves

[0056] Taking the plot as the unit, the mature tobacco leaves of the fixed plants were hung according to the leaf position, and samples were taken after baking to determine their main chemical components. In this experiment, tobacco leaves of 4 leaf positions were selected for analysis of tobacco leaf physical and chemical properties, and the selected leaf positions were the 10th leaf, the 11th leaf, the 15th leaf, and the 16th leaf. The physical and chemical properties of tobacco leaves treated with different treatments are shown in Table 6.

[0057] Potassium-enhanced treatments can improve the physical and chemical properties of tobacco leaves and make the proportions of various components more coordinated. Compared with the normal treatment, the 15% potassium-enhanced treatment can increase the total sugar and reducing sugar content of the middle tobacco leaves, reduce the chloride ion content of the middle and upper tobacco leaves, and increase the potassium-chloride ratio of the middle tobacco leaves to the range of 8-12; while the 30% potassium-enhanced treatment can increase the total sugar content of the middle and upper tobacco leaves and the potassium content of the upper tobacco leaves, reduce the chloride ion content of the middle and upper tobacco leaves, and increase the potassium-chloride ratio; the chloride ion content of the middle tobacco leaves decreased by 15.38%, the chloride ion content of the upper tobacco leaves decreased by 4.55% to 13.64%, and the potassium-chloride ratio of most tobacco leaves was between 8 and 9.

[0058] Table 6 Effects of different treatments on the physical and chemical properties of tobacco leaves

[0059]

[0060] (2) Economic characteristics

[0061] The effects of different treatments on the economic traits of flue-cured tobacco are shown in Table 7.

[0062] Table 7 Effects of different treatments on economic traits of flue-cured tobacco

[0063]

[0064] Compared with the normal potassium treatment, the yield, output value, proportion of top-quality tobacco and proportion of medium-high-quality tobacco in the 15% potassium treatment increased, with the yield and output value increasing by 16.89% and 14.89% respectively; the average price, proportion of top-quality tobacco and proportion of medium-high-quality tobacco in the 30% potassium treatment increased, with the proportion of top-quality tobacco increasing by 1.47 percentage points. Therefore, in the fields with chloride ion concentration of 40-60 mg / kg, the best economic benefit is to increase potassium by 15% based on the local recommended potassium application amount.

[0065] 4.4 Example 4

[0066] (1) Physical and chemical properties of tobacco leaves

[0067] Taking the plot as the unit, the mature tobacco leaves of the fixed plants were hung according to the leaf position, and samples were taken after baking to determine their main chemical components. In this experiment, tobacco leaves of 4 leaf positions were selected for analysis of tobacco leaf physical and chemical properties, and the selected leaf positions were the 10th leaf, the 11th leaf, the 15th leaf, and the 16th leaf. The physical and chemical properties of tobacco leaves treated differently are shown in Table 8.

[0068] Table 8. Physical and chemical properties of tobacco leaves treated with different methods

[0069]

[0070] The results showed that increasing potassium fertilizer by 15-30% was beneficial to reducing chloride concentration in tobacco leaves and improving potassium-chloride ratio. Taking all factors into consideration, in fields with chloride concentration of 60-70 mg / kg, increasing potassium by 15% on the basis of the local recommended potassium application rate was the most economically beneficial.

[0071] 4.5 Example 5

[0072] (1) Physical and chemical properties of tobacco leaves

[0073] Taking plots as units, the tobacco plants that were fixed at maturity were marked according to leaf positions, and samples were taken after baking to determine their main chemical components. The physical and chemical properties of tobacco leaves with different treatments are shown in Table 9. As can be seen from Table 9, potassium addition treatment in high-chloride fields can increase the difference between the two sugars, reduce the nicotine content of tobacco leaves, and thus increase the sugar-alkali ratio and nitrogen-alkali ratio.

[0074] Table 9 Chemical quality of tobacco leaves treated

[0075]

[0076] (2) Economic characteristics

[0077] The yield and output value data of each treatment in this experiment are shown in Table 10.

[0078] Table 10 Economic characteristics of each treatment

[0079]

[0080] Potassium-enhanced treatment can increase the yield of flue-cured tobacco and the proportion of medium and high-quality tobacco, which has the effect of improving economic benefits. Among them, the best treatment is to increase potassium by 15%, which can increase the yield by 22.79% and increase the output value by 12206.32 yuan / hm 2 Therefore, in fields with chloride ion concentrations of 70 to 80 mg / kg, the best economic benefit is to increase potassium by 15% based on the local recommended potassium application rate.

[0081] 4.6 Example 6

[0082] (1) Physical and chemical properties of tobacco leaves

[0083] Taking the plot as the unit, the tobacco plants were marked according to the leaf position at maturity, and samples were taken after baking to determine their main chemical components. The physical and chemical properties of tobacco leaves treated with different treatments are shown in Table 11.

[0084] In the ultra-high chlorine fields, potassium-enhanced treatments can increase the potassium content of the middle and upper tobacco leaves, reduce the chlorine content of the upper tobacco leaves, and increase the potassium-chlorine ratio. The potassium-enhanced effect of tobacco leaves treated with 20% potassium increase is better than that of 40%. Compared with the control, the potassium content of the middle and upper tobacco leaves treated with 20% potassium increase increased by 13.19% and 8.39%, respectively, while the potassium content of the middle and upper tobacco leaves treated with 40% potassium increase increased by 9.03% and 2.80%.

[0085] Table 11 Chemical quality of tobacco leaves in each treatment

[0086]

[0087] (2) Economic characteristics

[0088] The yield and output value data of each treatment are shown in Table 12. Potassium-enhanced treatment can increase the yield of flue-cured tobacco and the proportion of medium and high-quality tobacco, which has the effect of improving economic benefits. The 20% potassium-enhanced treatment has a better effect on increasing yield and value. Compared with the normal treatment, the yield increased by 28.07%, the proportion of high-quality tobacco increased by 3.52%, and the output value increased by 20,061.29 yuan / hm2. 2 Therefore, in fields with chloride ion concentrations of 80.1 to 90 mg / kg, the best economic benefit is to increase potassium by 20% based on the local recommended potassium application rate.

[0089] Table 12 Economic characteristics of each treatment

[0090]

[0091] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A fertilization method for increasing the potassium content of the upper and middle parts of Yuxi flue-cured tobacco leaves, characterized in that: Use large-particle base fertilizer and determine the amount of potassium to be applied based on the chloride ion content in the soil; For fields with soil chloride content <40 mg / kg, the amount of potassium applied during the entire growing period should follow the local recommended amount; For fields with soil chloride content of 40-80 mg / kg, the potassium application rate during the entire growth period should be increased by 15% based on the local recommended potassium application rate; For fields with soil chloride ion content of 80.1-90 mg / kg, the amount of potassium applied during the entire growing period should be increased by 20% based on the local recommended amount.

2. A fertilization method for increasing potassium content in the middle and upper parts of Yuxi flue-cured tobacco leaves according to claim 1, characterized in that: The formula of the base fertilizer uses a tobacco-specific compound fertilizer containing nitrate nitrogen according to local practice, but the fertilizer particles are enlarged to a diameter of 8 to 10 mm.

3. A fertilization method for increasing potassium content in the middle and upper parts of Yuxi flue-cured tobacco leaves according to claim 1, characterized in that: Use conventional low-nitrogen and high-potassium fertilizers or potassium nitrate or potassium sulfate for tobacco, and apply topdressing in three times, with the last topdressing applied 10 days later than the conventional topdressing time.

Images