The winter has passed and the early spring vegetables in the greenhouse have entered the colonization period one after another. According to years of market conditions, the sooner the early spring vegetables are listed, the higher the price. Two greenhouses that also grow tomatoes, A sheds are one week ahead of B sheds, and the former can sell more than 1,000 yuan more than the latter. This difference is even more pronounced in cucumbers. Early spring vegetables must be planted early if they want to be listed in advance. However, early planting is conditional. If blindly rushing ahead of time violates the local climate change laws, the final result is “unpleased†or even damage to seedlings. . According to the law of climate change in the central province of our province, the planting period of a thermophilic vegetable in a single-layer membrane greenhouse is generally around March 10, when the temperature below 0°C does not appear in the shed, and the average temperature of the 10 cm soil layer is stable. Above 10°C, when planted at that time, vegetable seedlings are basically not exposed to low temperature hazards. If we want to plant early in the period from the end of February to the beginning of March, so that the vegetables will be listed in advance, to obtain high efficiency, the first is to strengthen protection, to overcome the low temperature hazards, the sooner the protection of the planting work, the more strengthened. Greenhouse covers grasshoppers The use of artificial grass cover, the width of the shed 6 ~ 8 meters, height 2.2 ~ 2.5 meters is appropriate, too wide and too high operation inconvenience. Grasshoppers should not be too thick, suitable for 1.5 cm thick, otherwise the haystacks are too heavy to withstand, and manual rolling is not convenient. Last winter, the author of the field survey in Yongcheng, saw a large area of ​​the local bamboo-wood single-layer membrane greenhouse planted in winter is all over the winter lettuce, covering the grasshopper outside the greenhouse at night, the timely planting of tomato lettuce harvest, the use of grasshopper protection Early pre-market low temperature. At present, some sheds in Shouguang, Shandong Province, have begun to configure coiling machines, which reduces the trouble of rolling grasshoppers and enables single-layer membrane greenhouses to be used as a simple type of solar greenhouse. The utility value of greenhouses has been upgraded to a higher level and the benefits have been greatly improved. . Covering the grasshoppers outside the single-layer membrane greenhouse allows the planting period of the thermophilic fruit and vegetables to advance to the middle or late of February. If a layer of membrane is set in the greenhouse, the insulation effect of the second layer covering is better, and the harvesting period will be more advanced. Multilayer covering in the shed Inside the shed body, 20 to 30 centimeters from the top membrane, a bamboo or iron wire is used to form an arch and the membrane is covered. This kind of insulation method is simple, can cover 1 to 2 layers of film, pay attention to the pressure around the film to be strict and can not "run off the air leakage", otherwise it will reduce the effect of insulation and cold. In addition, it should be noted that during the day, the film must be pulled to allow the seedlings to see more light, and in the afternoon the sun must be closed before the sun goes down to save more heat. According to measurements, the temperature can be increased by 1°C to 1.5°C for each additional film in the shed. Through multiple layers of coverage, the heat loss in the shed can be effectively reduced, and the intrusion of external cold air can be blocked. The use of mulch film “covering the land for the first time†has now been widely recognized, especially in the cultivation of vegetables. However, if a transparent membrane is only covered on the ground, it can only increase the ground temperature, and it can not protect the aerial stems and leaves from the hazard of low temperature frost. In addition, the time for raising the ground temperature from the plastic film alone is less than one month. As the area of ​​the membrane surface blocked by the leaves gradually increases, its temperature increasing effect will be reduced until completely lost, but the moisturizing effect still exists. If short bamboo, branches, iron wire, etc. are used to form a small arch with a height of 30 to 40 cm on the colonization ridge, the mulch is covered on the arch, so that the seedlings after planting are in a small space, and the temperature and temperature in the space are All of them can be protected to protect the aerial stems and leaves from the danger of low temperature frost, so that the mulch can be covered and planted on the ground one week earlier. When the seedlings are long enough to withstand the arching membrane, the holes are pierced against the seedlings, the seedlings are pulled out of the holes, and the membranes are finally dropped onto the ground surface membrane. The use of a film of “covering the sky and covering the land†has greatly increased the value of the plastic film and is worth advocating. Whole field covered with black plastic film moisturizing It is the consensus of vegetable growers that the vegetable-covered plastic film for sheds to be planted in winter and spring. Covering the film has the effect of warming, moisturizing and preventing weeds from growing, especially for the post-planting vegetables. How to properly lay the plastic film to the best use of the purpose, in addition to the above-mentioned "first covered days back cover," a film of two usage, there is a whole field is covered with black film. At present, the application of black film is becoming more and more common. Due to the black endothermic effect, an increase in the temperature of the black film itself will transfer part of the heat to the soil layer, thereby increasing the ground temperature. The warming effect of the black membrane is not as good as that of the transparent membrane, but its herbicidal effect is very significant, much better than spraying the herbicide. At present, the transparent film commonly used by growers can increase the temperature because the light can penetrate into the soil to make the light energy become heat energy. However, the biggest drawback is that it is easy to grow weeds under the film to arch the film, and it is not easy to pull the hand. The consumption of water by weeds has brought great harm to the growth of vegetables. The method to solve the problem of the growth of weeds under the transparent film is to spray the closed pre-emergence herbicide on the surface of the ridge before the film is covered, close to the ridge cover film, and then punch the seedlings according to the plant spacing. Although this method can control the growth of some weeds, the effect of weeding is much lower than that of black membranes. Covering the black film is the best choice to prevent the growth of weeds in the greenhouse vegetable production. In addition, the use of black film for better moisture coverage throughout the field. Early water control seedlings At present, the majority of fruit and vegetables grown by vegetable growers belong to medium and late-maturing varieties, and the vegetative growth is slightly stronger. If the temperature is high, water is sufficient, nitrogen fertilizer will be prosperous, and the growth of stems and leaves will be delayed. Therefore, when the seedlings return to growth, they must control the appropriate seedlings to reduce the night temperature without fertilizer, especially nitrogen fertilizer. The length of water control depends on soil quality and seedling growth, and cannot be generalized. If the color of the seedling leaves changes from shallow to dark, it means water can be poured, but the amount of water cannot be large, and it cannot be flooded. Change the habit of pouring water The traditional practice is to pour a large amount of water after planting. This pouring of water will cause the ground temperature to rise for a long time. Moreover, the seedlings also “drink†not so much water. The extra water will carry the soluble nutrients to penetrate into the ground and pollute the groundwater. The author proposes a new approach: planting land first to make water, and then basal fertilizer plowing, and then ridge cover film, film warming, these work is generally carried out 10 days before planting, so that the cold land gradually warmed up For the seedlings to be planted, creating a soil environment with suitable moisture and temperature can be said to be a warm and harmonious “homeâ€. When transplanting, each seedling only needs to pour a bowl of stable seedling water. When the temperature rises, it is watered according to soil and seedling growth. Bosgoo(China)Tecgnology Co., Ltd , http://www.laohuang.com
How to make the greenhouse early spring vegetables listed in advance