1, very popular.

2. Keep the cigarettes.

3, less root water, furrow irrigation, the water depth should be 1/2 of the tobacco ridge, drainage in time after soil moisture saturation. It is forbidden to water or water tobacco seedlings for a long time.

Supplement:

Fertilizer and water management technology in tobacco field;

A fertilization technique:

Fertilization in tobacco field is mainly to supplement the insufficient supply of base fertilizer during transplanting and meet the demand for fertilizer in the middle and late growth period of tobacco leaves. At present, the main methods of topdressing are: applying chemical fertilizer solution to roots, and the other is topdressing outside roots, usually spraying on leaves. Generally speaking, the leaf germination rate of tobacco is the highest within 30 ~ 40 days after transplanting. Therefore, it is necessary to choose the right time for topdressing. If it is too late, it will affect the normal growth of tobacco leaves, and it is not easy to turn yellow in the later stage, which will reduce the quality. Generally speaking, the roots are irrigated with fertilizer solution within 25 days after transplanting, and topdressing is divided into 2 ~ 3 times according to rainfall and tobacco seedling growth. In the middle and late growth period, tobacco leaves sometimes lack potassium. At this time, 0.5% potassium dihydrogen phosphate solution should be sprayed on the back of leaves in time according to the growth of tobacco leaves and soil fertility. In the process of topdressing, we should pay attention to the following points: First, for sandy loam with poor water and fertilizer conservation ability, we should pay more attention to topdressing, appropriately increase the amount and frequency of topdressing and reduce the amount of base fertilizer. Second, topdressing outside the roots should be sprayed on cloudy days or clear and windless evenings. Spraying the back of leaves is more effective and should be avoided at noon on sunny or rainy days. If it rains within 24 hours after fertilization, it needs to be fertilized again. However, due to the fast nutrient supply after water-soluble fertilizer is applied to soil, it is easy to lose with rainfall or irrigation, resulting in low fertilizer utilization rate.

B. water management technology:

Soil moisture is the basis of tobacco growth, so we should pay attention to reasonable irrigation according to the water demand characteristics of tobacco leaves in different growth periods and strengthen water management in tobacco fields. Water management in tobacco fields can be divided into four stages: transplanting water, root extension water, flourishing water and mature water.

1) enough water for transplanting. Irrigation with transplanting water can not only provide sufficient moisture for tobacco leaves, but also increase soil moisture, promote tobacco seedlings to take root quickly, turn green early and improve survival rate. When transplanting, it is necessary to dig big pits and water each hole about 1 kg, which is not only conducive to the survival of tobacco seedlings, but also conducive to eliminating the possible damage to roots caused by excessive or uneven fertilization.

2) less water is poured. As the saying goes, "dry roots grow wet leaves", the clustering stage of tobacco is the most important stage of root growth and development (according to research data, the root growth in the clustering stage will be several times that of the above-ground part). Proper control of water supply is beneficial to the vertical growth of tobacco roots.

3) pour more water. Tobacco leaves need a lot of water in the prosperous period. At this time, irrigation should be done in time to provide enough water to keep the relative water content of soil at 70% ~ 80%. Because the peak season of tobacco leaves is usually rainy season, natural rainfall can meet the water demand of tobacco leaf growth to some extent. If the moisture in the tobacco field is poor and there is no heavy precipitation when the film is uncovered, it must be watered in time. The correct irrigation method is furrow irrigation, and the water depth should be 1/2 of tobacco ridge. When the soil is saturated with water, it should be drained in time, and it is forbidden to flood with water or flood tobacco seedlings for a long time. Avoid watering during the high temperature period at noon. Water should be watered before 9 am or after 5 pm in hot weather, and it can be irrigated all day on cloudy days with low temperature. 4) Pay attention to mature water. Tobacco leaves don't need much water when they are ripe, and generally don't need watering. If the weather is dry at this time, a small amount of water should be lightly irrigated to promote the full elongation of upper tobacco leaves and the timely maturity of middle and lower tobacco leaves. If there is water in the field due to weather, it should be drained in time to prevent waterlogging.