There are four methods to improve the quality of flue-cured tobacco: Soil conditions are the basis of high-quality tobacco system engineering and the primary environmental factor affecting the quality of tobacco leaves. Therefore, we should highlight tobacco field soil improvement technology from the perspective of increasing the income of tobacco farmers, improving the quality of tobacco leaves, making full use of natural advantages, and conducive to the long-term development of tobacco areas, and reduce the impact of adverse ecological conditions on tobacco leaf yield and quality. and efficiency impact. Adhere to the development direction of modern organic tobacco agriculture, rationally apply high-quality and efficient organic fertilizers in tobacco fields, promote green manure cover, implement straw return to fields, cultivate a soil environment for the production of high-quality tobacco leaves, provide a favorable soil environment for the growth of flue-cured tobacco, and lay a solid foundation for the development of modern tobacco agriculture. The foundation provides a guarantee for improving the quality of tobacco leaves.
1. Establish a tobacco-based farming system. Crop rotation is an important part of the crop planting system. It is an effective measure to combine land use and nutrition, increase tobacco leaf and crop yield, and improve tobacco leaf quality. Establish a tobacco-based farming system, and scientifically and rationally arrange crop types and planting sequences in the crop rotation cycle; so that tobacco production can gradually enter a virtuous cycle of stable, sustainable, and healthy development. It reflects "mainly tobacco, balanced development; combination of use and cultivation to fertilize the soil; purification of soil, reduction of diseases; tobacco cultivation, sustainable development."
2. Apply more bio-organic fertilizer and decomposed farmyard manure. Bio-organic fertilizer is made from organic solid waste (including organic waste, straw, human, livestock, poultry manure, cakes, agricultural and sideline products and solid waste generated from food processing) through microbial fermentation, deodorization and complete decomposition. Organic fertilizer. Rich in a variety of functional microorganisms and rich trace elements, it can improve the soil structure, indirectly kill roundworm eggs and root nematodes, play a nutritional, conditioning and health care role in crop growth, allowing the land to absorb organic matter and play a more important role. Great utility.
Bio-organic fertilizer has complete nutrients. It is a nutrient reserve compatible with quick-acting nutrients and slow-acting nutrients, organic nutrients and inorganic nutrients. It can improve soil and improve soil compaction caused by the use of chemical fertilizers. Improve soil physical and chemical properties, increase soil porosity, permeability and exchangeability, and enhance soil water retention, fertilizer retention, and fertilizer supply capabilities. After the beneficial microorganisms in the bio-organic fertilizer enter the soil, they form a mutual growth and proliferation relationship with the microorganisms in the soil, inhibit the growth of harmful bacteria and transform into beneficial bacteria, interact and promote each other, and play a synergistic effect in the group. A large number of metabolites are produced during the growth and reproduction process, which promotes the decomposition and transformation of organic matter. It can directly or indirectly provide crops with a variety of nutrients and stimulating substances, and promote and regulate crop growth. At the same time, the dominant beneficial bacteria formed in the crop root system can inhibit the reproduction of harmful pathogenic bacteria, enhance the crop's resistance to stress and disease, and reduce the disease index of repeated crops. Application in successive years can greatly alleviate obstacles to continuous cropping.
Rotten farmyard manure refers to various organic materials such as human excrement, livestock and poultry excrement that can be used as fertilizer after being piled and decomposed. Decomposed farmyard manure contains various nutrients and rich organic matter needed by crops. It helps to promote the formation of soil aggregate structure, coordinate the ratio of air and water in the soil, and at the same time provides energy and nutrients for microbial life activities and promotes soil microorganisms. The activities loosen the soil and increase its ability to retain water, heat, breath, and fertilizer. It has comprehensive nutrients and long-lasting fertilizer effect. Tobacco leaf production practice has proven that the reasonable and correct application of farmyard manure can effectively improve the physical and chemical properties of tobacco field soil, promote soil microbial activity, activate potential nutrients in the soil, fertilize soil, improve soil, increase tobacco leaf yield, improve tobacco leaf quality, and increase The aroma quality and aroma amount of tobacco leaves play an important role.
3. Vigorously promote the technology of returning straw to fields. Straw return to the field is a method of applying straw (corn straw, sorghum straw, etc.) that is not suitable for direct use to the soil directly or after being piled up and decomposed. Crop straw is an important resource in organic fertilizers. Returning straw to the field can ensure continued agricultural growth, improve soil fertility, maintain the balance of soil organic matter, supplement soil potassium, increase soil nutrient content, improve soil physical properties, increase the number and number of soil microorganisms. It is of great significance to optimize the farmland ecological environment, reduce ground evaporation of soil water, maintain water storage in the cultivated layer, and alleviate the erosion of soil by surface runoff during rainfall, which is conducive to improving the utilization rate of precipitation and combating drought and disasters.
Returning straw to the field not only increases soil organic matter and nutrient content, but also improves the physical properties of the soil and enhances soil permeability.
The humus formed after the straw is returned to the field after decay and decomposition is a colloid agent for the soil structure, which is conducive to the formation of soil aggregate structure, makes the soil permeable, increases the soil's fertilizer and water retention capacity, and reduces the bulk density of the soil. Increased porosity and soil moisture content are beneficial to crop drought resistance. Returning straw to the fields year after year can reduce the amount of chemical fertilizers used and reduce production costs. Production practice shows that the application of straw has a significant effect on improving soil structure. The application of grass straw can improve soil permeability, regulate the nitrogen nutrition of flue-cured tobacco, and make the nitrate nitrogen of flue-cured tobacco increase in the front and then decrease, thereby improving the quality of tobacco leaves.
4. Develop wild rice green manure to press green. Practice has proved that green manure is a good organic fertilizer. Reasonable application has obvious effects in increasing fertilizer sources, reducing input costs for tobacco farmers, improving soil, fertilizing soil, and increasing tobacco leaf yield and quality.
Green manure has complete nutrients, including nitrogen, phosphorus, potassium and other nutrients and organic matter required by crops. It is a bio-organic fertilizer that improves soil and fertilizes soil. It is a method to increase crop yield, improve quality and maintain soil fertility. The key is to develop high-quality feed for animal husbandry.
Green manure is planted regardless of the soil and has long stems and luxuriant leaves. Large-scale green manure can cover the ground, reduce exposed cultivated land, alleviate soil erosion, reduce water and soil loss, increase atmospheric humidity, alleviate atmospheric drought, and improve field ecology. At the same time Prevent crusting after rainfall and reduce surface runoff. Planting green manure can also inhibit the growth of weeds in cultivated land, avoid water and nutrient consumption, create good conditions for agricultural production, make crops grow robustly, and effectively improve the agricultural ecological environment. Planting green manure can reduce the amount of chemical fertilizers and greatly reduce production costs.
After green manure is turned into the soil, it is continuously decomposed under the action of microorganisms. In addition to releasing a large amount of effective nutrients, it also forms humus. The combination of humus and calcium can cement the soil and aggregate the soil particles to form an aggregate structure. The soil with an aggregate structure is loose, has increased porosity, decreased bulk density, is breathable, has strong water and fertility retention, and has good properties of regulating water, fertilizer, air, and heat, which is beneficial to the growth and development of tobacco plants. At the same time, after green manure is applied to the soil, fresh organic energy substances are added, allowing microorganisms to multiply rapidly, enhance their activity, promote the formation of humus and the effectiveness of nutrients, and accelerate soil maturation. Balanced fertilization
Excessive nitrogen fertilizer is the main reason for high nicotine content and poor availability in the upper leaves of flue-cured tobacco, especially after topping, the soil continues to maintain a high nitrogen supply. Therefore, controlling the amount of nitrogen supplied to the soil in the later period is crucial to improving the quality of upper leaves of flue-cured tobacco. Secondly, the form of nitrogen fertilizer has a direct impact on the availability of upper leaves. Nitrate nitrogen can control the nitrogen supply during the maturity stage and inhibit the excessive synthesis of nicotine caused by excessive nitrogen in the later stage. The balanced application of phosphorus, potassium fertilizers and medium and trace elements cannot be ignored to improve the quality and availability of upper leaves of flue-cured tobacco. Phosphate fertilizer can not only promote early growth and rapid growth of tobacco plants, but also increase the reducing sugar content of the upper tobacco leaves after roasting, reduce the tobacco starch content, and improve the aroma and taste of the tobacco leaves. The increase in potassium level can effectively promote the full maturity, material transformation and dry matter accumulation of the upper leaves of flue-cured tobacco, reduce harmful components, make the sugar-alkali ratio moderate, and improve the quality of cigarettes. Therefore, we need to formulate a formula fertilization plan based on soil fertility, flue-cured tobacco varieties and ecological environment. Balanced fertilization and precise fertilization are the guarantee for improving the availability of upper leaves of flue-cured tobacco.
Rational cultivation and scientific topping and leaf retention
Rational planting density can improve the lighting conditions of tobacco plants and promote the coordinated development of carbon and nitrogen metabolism in each part of the tobacco leaves, which is the basis for producing high-quality upper leaves. . The planting density is too small, the total effective leaves are too few, and too much nutrients are allocated to a single tobacco plant, resulting in thicker upper leaves and higher nicotine. The spacing between rows is 110-120cm, the spacing between plants is 50-55cm, and the transplanting size is 1100-1200 plants/667m2. The nicotine content in the upper leaves is suitable. The number of remaining leaves is related to the distribution and utilization of substances, and is significantly negatively correlated with the nicotine content of tobacco leaves. Appropriately increasing the number of remaining leaves and delaying topping can reduce the nicotine content in the upper leaves and increase the sugar-alkali ratio. In terms of production, the number of leaves left and the topping period are determined based on soil fertility, fertilization levels and the growth and appearance of the tobacco plants. It is necessary to prevent too few leaves from being topping too early and the upper tobacco leaves being too large to form an "umbrella-shaped" tobacco plant. To prevent too late topping leaving too many leaves and insufficient nutrition of the upper leaves to form a "tower-shaped" tobacco plant, it is better to use a "waist drum-shaped" tobacco plant. Under normal water and fertilizer conditions, it is appropriate to leave 16-18 leaves per plant, and top them when they are budding or when the first central flower blooms; under low-fertilizer conditions, it is appropriate to reduce the number of leaves left and top them in advance, and apply foliar fertilizer. ; Under high fertilizer conditions, appropriately increase the number of remaining leaves and delay topping.
Scientific experiments show that topping too early or too late will increase the total alkaloids and total nitrogen content of tobacco leaves, which will increase the tar content and total alkaloids in cigarette smoke; and the number of remaining leaves affects The distribution and utilization of substances are significantly negatively correlated with nicotine content. Therefore, in production, we need to determine a reasonable topping time and number of leaves according to the characteristics of different varieties and soil fertility to ensure that the top leaves can fully open. In production, a secondary topping method can be adopted to leave more leaves appropriately to dilute The higher dry matter content in the upper part reduces the nicotine and tar content, solves the problem of excessive thickness of the upper leaves, and improves the usability of tobacco leaves. Under the condition of reasonably retaining leaves, we are determined to solve the current problem of insufficient maturity, and harvest at appropriate maturity according to different maturity standards for different qualities and different parts.
Improve maturity
The field maturity of tobacco leaves is closely related to the quality of the upper leaves of flue-cured tobacco. As the maturity of the upper leaves increases, the structure of the upper leaves becomes looser, and the total sugar and reducing sugar The content increases significantly, the aroma quality and amount increase, and nicotine gradually decomposes. The harvesting period of the upper leaves is when the main color of the tobacco leaves is yellow, there are obvious mature spots on the leaves, and the main veins turn white and shiny. The leaves of underripe upper leaves will be thicker and stiffer after baking, and they are prone to become green or black during the baking process, resulting in a serious reduction in the quality and availability of the upper leaves. Optimize cultivation techniques and fully implement agricultural technical measures to improve tobacco leaf availability.
1. Breed and promote low-tar potassium and high-efficiency flue-cured tobacco varieties. At present, some flue-cured tobacco varieties with lower tar release have been developed internationally through various breeding methods and have been promoted in production. On the basis of maintaining the original quality and style of tobacco leaves, we should focus on reducing the tar content and nicotine content of tobacco leaves, and improving the potassium content and safety. We should screen, cultivate and plant tobacco with high potassium content and low tar and nicotine content. New varieties of tobacco.
2. Vigorously promote balanced fertilization technology and strive to improve the intrinsic quality of tobacco leaves. Fertilization is the core technology of tobacco leaf production, and the level of fertilization directly affects the quality of tobacco leaves. When fertilizing, attention should be paid to increasing the application of cake fertilizer, bio-organic fertilizer, balancing N, P, and K nutrients, and also increasing the application of trace elements such as zinc, boron, and copper to coordinate soil nutrition. At the same time, in tobacco areas, we must start from large-scale agriculture and strictly control the application of chlorine-containing fertilizers. In particular, the use of chlorine-containing compound fertilizers for tobacco leaf pre-crops must be prohibited. In addition, in order to improve the potassium content of tobacco leaves and the utilization rate of potash fertilizer. In production, potassium can be applied in reasonable stages to improve soil physical and chemical properties and maintain appropriate soil moisture content to reduce potassium fixation. By increasing the potassium content of tobacco leaves, the amount of tar and nicotine in the smoke is reduced, thereby improving the usability of the tobacco leaves. Proper baking can not only improve the appearance quality of tobacco leaves, but also effectively improve the internal chemical composition. Therefore, a suitable baking environment is also an important factor in improving the usability of the upper leaves. The upper leaves of flue-cured tobacco are thicker, have a tight structure, low moisture content, and high content of macromolecular organic matter such as starch and protein. Therefore, the yellowing period should be appropriately extended during preparation to fully turn the tobacco leaves into yellow, and promote the coordination and benefit of the materials in the tobacco leaves. direction transformation, thus improving the availability of tobacco leaves. For the upper leaves that are easy to roast, the baking strategy of "low temperature and low humidity to turn yellow, warm and fire twice" should be adopted; for the upper leaves that are easy to get gray, the baking strategy of "low temperature and low humidity to turn yellow, low temperature and dehydration to fix the color" is recommended. should. In addition, the half-drying and half-baking method can also improve the quality of the upper leaves of flue-cured tobacco to a certain extent, reduce the starch content, improve the coordination of chemical components, shorten the baking time, reduce fuel consumption, and reduce costs.
Adopt a three-stage baking process, pay attention to ventilation and moisture removal, and promote heat exchange intensive baking rooms where conditions permit, which can effectively control the release of toxic nitrosamine compounds (TSNA) during the brewing process. Formation and accumulation to improve tobacco leaf safety.
First of all, cigarettes must be strictly classified. First, the harvested tobacco leaves are sorted and stacked according to their parts, sizes and maturity, and then the most representative categories of tobacco leaves (size or maturity) are first compiled. However, in the process of compiling tobacco, the mature (small leaves) and For tobacco leaves that are slightly inferior (large leaves), discard overripe leaves, seriously diseased leaves, raw leaves and black burst leaves that have no baking value. After that, the tobaccos are sorted according to whether they are more mature or less mature. At the same time, different types of usable tobacco leaves must be eliminated and tobacco leaves with no baking value must be discarded. Tobacco weaving should be of the same quality and maturity as the same rod, with uniform density within the rod and similar weight between rods. Secondly, we must pack cigarettes scientifically.
Before loading tobacco, it is necessary to count the number of rods. According to the principle of the same number of rods in each layer, uniformity in the same layer, and yellow leaves drying first, allocate the order and number of each type of tobacco leaves in the kang, so as to realize the baking characteristics of tobacco leaves and the temperature and temperature of the baking room. The wet distribution is regularly connected to improve the baking quality of each layer of tobacco leaves. Generally speaking, in the airflow descending intensive curing room, the top temperature is high and the relative temperature is low. The tobacco leaves are dried first. The tobacco should be yellow and not raw. The bottom temperature is the lowest and the relative humidity is the highest. The tobacco leaves are dried last. The tobacco leaves should be filled with green leaves as much as possible. Put yellow leaves; in the airflow rising intensive curing room, the bottom temperature is high and the relative humidity is low, the tobacco leaves are dried first, and the yellow leaves should be the main ones when loading. The top layer has the lowest temperature and the highest relative humidity, and the tobacco leaves are dried last. The tobacco leaves should be packed first. Be sure to pretend to be raw rather than pretending to be obscene. The temperature and humidity before and after depends on the age when the intensive baking room was built. During the process of weaving and packing cigarettes, handle and place them gently to prevent the tobacco leaves from being damaged or blocked and reducing the quality of the tobacco leaves. When transporting and stacking tobacco leaves, prevent exposure to the sun and excessive squeezing, and minimize abrasions, abrasions, damage, burns and other behaviors that damage the quality of the tobacco leaves. Once again, we need to master the moisture removal skills to solve the problems of green baking, ash hanging and baking dregs. Control the appropriate drying degree of tobacco leaves. Accurately grasp the degree of dryness of tobacco leaves during the baking process to steadily advance the baking stage. Tobacco leaf drying goals: The leaf tips begin to turn yellow, and the leaf body becomes hot and soft; when the tobacco leaves turn 70-80% yellow, the tobacco leaves are basically in strips (the hook tip cannot be reached, otherwise the tobacco will be easily baked); when the tobacco leaves are completely yellow, the tobacco leaves Full drag strip. Before the dry bulb temperature exceeds 43°C, the dryness of the tobacco leaves must reach the edge of the furrow. The dry bulb temperature must exceed 46°C, and the dryness of the tobacco leaves must reach more than half. When the dry bulb temperature exceeds 50°C, the leaf color must be basically fixed. When the dry bulb temperature exceeds 55°C, the tobacco leaves should be completely fixed in color. Otherwise, the tobacco leaves will be easily damaged (at worst, they will be stained with ash, and in severe cases, they will be toasted badly).