In wintering greenhouse vegetables, there are many kinds of severe weather. Unfavorable climatic conditions have a great impact on the production of solar greenhouse vegetables. Therefore, the field management of solar greenhouses must be strengthened during this period. Disclaimer: Some articles in this website have been transferred from the Internet. If you are involved in third party legal rights, please inform this website. phone Food Acidulants,Free Xanthan Gum,Guar Gum,Citric Acid Monohydrate Shanghai J.Shine Co.,Ltd , https://www.jshinechem.com
First, improve lighting conditions
1. Improve the structure of greenhouses. The best conditions to use galvanized steel greenhouses. The film is best to use non-drop film, the general film is better than polyethylene film; white materials can be applied to building materials and walls, which can increase the reflected light and extend the service life; increase the height of the canopy, can also improve lighting in the canopy condition.
2, with a reasonable planting. When planting different varieties of vegetables in the greenhouse, it is necessary to make the north high and south low and cultivate it properly. When sowing seeds, they must be oriented in the same direction. When transplanting, the cotyledons should be arranged in parallel, and the cultivation specifications should be strictly implemented.
3, keep the film clean. It is necessary to regularly clean and clean the water droplets and dust on the shed film, and clear the snow in time after snowing to increase the transparency and the amount of light. In addition, under the premise of not significantly affecting the temperature of the shed, warm covering materials such as grass rakes covered on the outside of the shed should be properly exposed as early as possible to ensure the lighting area.
4, artificial fill light. It is particularly important to implement artificial fill light in dark plastic greenhouses or in insufficient sunlight, but due to the high cost, it is difficult to promote it in large areas at present, but it can be used as an emergency measure to improve lighting conditions in the shed. The requirements and practices are: artificial light supplements require greater light intensity; crops have the strongest absorption of red light and blue-violet light, so the source of the light is fluorescent, arc xenon lamps, high-pressure mercury lamps; winter fill light to the day After going out, it is usually 2 hours to 3 hours a day. If it is rainy, it can be filled all day.
Second, scientific fertilization watering
Due to improper watering and fertilization, the phenomena of rot, roots and wilting of vegetables are widespread in winter vegetable production, which seriously affects the economic benefits of vegetable farmers. In this reminder farmers friends, watering and fertilizing should be careful.
1, watering
Watering vegetables in winter greenhouses should be arranged on sunny days. After watering, it is best to have several consecutive sunny days. The day should be chosen in the morning. This is not only the difference between the water temperature and the ground temperature is small, the ground temperature is easy to recover, but also there is sufficient time to eliminate the air humidity that is increased due to watering. Generally, it should not be selected at noon, so as to avoid affecting the root physiological function at high temperature. Should not be watered in the evening and snow days, to avoid causing the shed to recover from the temperature, humidity is too large, causing vegetable diseases.
When the vegetable water in the greenhouse is seriously deficient, the plants are wilting and the leaves are scorched; when the water is too much, the soil is deficient in oxygen and causes the roots to rot, and the stems and leaves on the ground yellow and even die. In the winter greenhouse, the temperature of watering is low, the amount of air is small, and the water consumption is low. At this time, the humidity changes greatly after watering, and it has a long duration, so it needs to be poured with water. When the temperature in the shed is relatively low, the number of watering should be reduced as much as possible, and the amount should be small. Avoid flooding and flooding to prevent the roots of vegetables from falling when the temperature is low and high humidity. Also be sure to use normal temperature water for irrigation.
2, fertilization
(1) It is a combination of organic fertilizer and inorganic fertilizer. That is, the combination of slow effect and quick effect. Many farmers in the winter fertilization material or applied a lot of chemical fertilizers, in addition to the application of chemical fertilizers in addition to lower ground temperature, such as chemical fertilizer to nitramine, urea and other nitrogen-based, short-term vegetable growth is good, but the lack of long-acting, plants susceptible to premature aging. Some of the red fertilizers are mainly cake-fat or diammonium phosphate. The effect is not good, and sometimes it also causes losses. The main reason is that the cake-fat is not fermented, and its fermentation takes some time.
(2) The top dressing is mainly water-soluble fertilizer. The use of the humic acid package fertilizer Jia Mei to gain profits and the internal potassium content to take measures to solve the problem of raising ground temperature and activating nutrition on the one hand, and increasing fertility on the other hand Root elongation, expanding the area of ​​roots to absorb the fertilizer, so that the plant roots absorb as much nutrients as possible.
(3) It is a combination of Dashui and Xiaoshui Chong Shi. Many vegetable farmers have applied large-scale fertigation regardless of the seedling stage and the result period, making the fertilizer and water excessively large and causing rot and roots to rot. Regardless of bio-fertilizers, organic-inorganic fertilizers, and chemical fertilizers, it is necessary to look at seedlings and use fertilizers, and apply them in a scientific manner.
(4) It is a combination of organic fertilizer and chemical fertilizer. Jiamei is profitable to contain a large amount of organically-activated nutrition and macro- and micro-nutrients. It has the functions of activating soil, raising the temperature of the ground, and expanding roots. It not only increases soil organic matter, increases air permeability, but also promotes root growth and nutrient uptake.
Third, timely dehumidification
The humidity of the air in the solar greenhouse is often greater than the exposed ground and is in a state of excessive humidity. Therefore, the air humidity management in the solar greenhouse is mainly dehumidification. The dehumidification measures in production are summarized as follows:
1, ventilation ventilation dehumidification ventilation is a good way to reduce humidity. Ventilation must be done at high temperatures, otherwise it will cause the room temperature to drop. If the temperature drops too quickly during ventilation, close the vents in a timely manner to prevent a sudden drop in temperature and damage the vegetables.
2. Reasonable watering and watering are the main factors that cause indoor humidity to increase. Winter and spring production can choose sunny gutters or ramets watering, film cover can be used under the film dark irrigation. Watering should strictly control the amount of water, to prevent indoor humidity is too high. After each watering, the air is properly ventilated, and timely slashing of loose soil can reduce soil moisture and reduce air humidity.
3, plastic film cover with plastic film can reduce the evaporation of soil moisture, is an important measure to reduce indoor air humidity. For example, in the solar greenhouse, large and small ridge distances and double ridges are used to cover the mulch. When water is poured, water flows into the small ridges under the mulch. The mulch prevents the evaporation of moisture, which also prevents the humidity of the air in the shed from being greatly increased.
4, warming and dehumidification using this method can meet the vegetable temperature requirements, but also reduce the relative humidity of the air. When the plants grow to have resistance, the watering canopy is heated to about 30°C for 1 h, and then ventilated and vented. After 3-4 hours, the temperature of the shelf can be repeated less than 25°C.
5, the use of good moisture absorption material moisture permeability and moisture absorption good insulation curtain material, such as non-woven fabrics can prevent condensation on the inner surface, and prevent dew from falling on the plant, thereby reducing the air humidity.
6, natural moisture can use straw, wheat straw, quicklime and other materials in the row to adsorb water vapor or fog, to achieve the purpose of dehumidification.
7. Cultivated dehumidification By cutting off the soil capillaries, soil capillary water can be prevented from rising to the surface and large amounts of soil moisture can be avoided.
8, increase the amount of light to increase the amount of light can increase the room temperature, room temperature rise, often ventilation, to achieve the purpose of dehumidification.
Fourth, strengthen greenhouse warming and insulation measures
In the early stages of vegetable growth, early flowering and fruiting, the daytime temperature is controlled at about 23°C, and the thermometer should not be hung under the tuyere. It should be hung in the middle to see the average temperature. The full fruit period requires a temperature of 28-30°C. This temperature refers to the temperature of the fruit, so the thermometer must be hung in the first fruit position, approximately 30 cm above the surface. If less than 10 °C, it is not conducive to vegetable growth, it is necessary to take timely measures for insulation. Specific can take the following measures:
1. Improve the heat insulation of straw curtains The straw curtains on the greenhouse should be compacted. In order to improve the insulation performance, in order to prevent the rain and snow from wetting the straw curtain in the deep winter season, an ordinary agricultural film or old film can be added on the straw screen.
2. Increase the thermal insulation of the back wall When building the back wall, stick a layer of bricks on the soil wall, or build a hollow insulation wall. The wall is filled with straw or polystyrene foam board. In the cold area, fire walls can be built directly to facilitate the increase of temperature.
3. Excavate the cold-proof ditch outside the shed to dig 40-60 cm wide and 40-50 cm cold-proof ditch outside the greenhouse. Fill in sawdust, weeds, horse dung, straw and other insulation materials. Insulation effect. When the cold is approaching, adding grass or corn stalk around the shed at night can increase the temperature of the shed by 2-3 degrees Celsius.
4. Dig back into the furrow along the planting line at 30-35 centimeters, dig a ditch 45 cm deep and 50 cm wide. Spread about 5 cm of rice hull or wheat bran at the bottom of the ditch and at a distance of 5 cm from the ditch side wall. Centimeters hit a wooden stake, fixed between the stakes and side walls filled with corn stover. The top of the gulch is 60-70 cm long and bundles of corn stalks with a diameter of 10 cm are covered. The soil is used in the ditch. In addition to leaving the work track, the rest of the ground is covered with a mulch. The whole shed forms an “S†shaped ditch that communicates with each other. Set aside at a slightly higher level and turn it on or off in time to control the temperature.
5, the establishment of temporary warming measures can be set in the shed temporarily 2-3 heaters with power of 1600-2500W, the direction of the export of the heater does not directly facing the plants.
6. Hang a light curtain in the greenhouse. Hang a plastic film or foil coated with a metal layer on the back wall of the greenhouse. Hang 1 meter every 2-3 meters to reduce the absorption of heat energy by the wall. Raise the temperature inside the booth by 2- 3 degrees Celsius.