What should I pay attention to when growing vegetables in greenhouse?

Planting techniques of vegetables in greenhouse

Vegetable greenhouse planting technology is a commonly used technology, which has good thermal insulation performance and can eat out-of-season vegetables at any time, and is deeply loved by people. One type of greenhouse commonly used for growing vegetables is a solar greenhouse with columns. There are many rows of columns in this greenhouse, which strengthens the stability of the whole greenhouse and greatly improves the ability of resisting pressure and snow.

First, the greenhouse vegetables watering matters needing attention

Reasonable watering is an important measure to ensure the healthy growth and increase the yield of greenhouse vegetables. In winter, the temperature is low, and the watering of greenhouse vegetables is different from other seasons. It depends on both the weather and the situation of seedlings to avoid side effects. According to experience, the following four measures should be taken to water vegetables in greenhouse:

1. Suitable watering time The watering of greenhouse vegetables in winter should be arranged around noon, preferably after 10 in the morning and before 3 pm. During this period, the greenhouse temperature is high and the side effects are minimal. Avoid watering in the morning and evening to avoid freezing vegetables. Try to use well water for watering, because the temperature of well water is high, which can reduce the physiological stimulation to vegetables.

2. Flexible watering according to the weather conditions: According to the weather conditions, master the principle of "properly watering more on sunny days, less or no watering on cloudy days, and never watering on snowy days". When the weather turns from sunny to cloudy, the amount of water should be gradually reduced and the interval should be appropriately lengthened; When it turns cloudy to sunny, the amount of water changes from small to large, and the interval time changes from long to short accordingly.

3. Watering should be focused: the temperature in different parts of the greenhouse is quite different, and the watering amount should be different. In the south of the greenhouse and near the heat sources such as stoves and flues, the soil moisture and evaporation nearby are large, and the watering amount can be appropriately larger; The temperature in the east, west and north of the greenhouse is low, the sunshine time is short, and the watering amount is less.

4. Shallow water should not be too large. At low temperature, vegetables in the greenhouse evaporate slowly, and the water demand decreases accordingly. Therefore, the amount of watering should be small and the interval should be appropriately long. Flooding should be avoided, and watering or spraying should be adopted to avoid vegetable retting caused by low temperature and high humidity. In the first two days after watering, it is easy to increase the humidity in the shed, so we should pay attention to reasonable ventilation and cooling to prevent diseases. Ventilation is generally appropriate when the temperature is high at noon.

Second, greenhouse vegetable fertilizer and water management technology

Organic fertilizer should be applied to vegetables in greenhouse. Organic fertilizer can improve soil structure, enrich soil microorganisms, increase soil fertility, fertilizer supply and water capacity of livestock. Moreover, priority should be given to the application of base fertilizer, and 5000 kilograms of decomposed organic fertilizer should be applied per mu to facilitate future production management and reduce or avoid the harm of secondary salinization of soil in the shed. When using chemical fertilizer, we should pay attention to deep application and don't overdo it at one time. No chemical fertilizer is allowed on the ground in the shed. After the producers master the above principles of fertilization, they can carry out topdressing according to crop types, different growth stages and individual growth conditions. If topdressing is carried out in low temperature season, it should be carried out at noon on sunny days. After topdressing, it should be ventilated for 1~2 hours until the water on the leaves is dry. Where conditions permit, carbon dioxide fertilization can be carried out to increase yield.

Drip irrigation is better for vegetables in greenhouse, which can save water and reduce the humidity in greenhouse. If there is no drip irrigation facilities, irrigation or ditching can also be done. Try not to furrow irrigation in low temperature season, and water it at noon on sunny days. After watering, open the shed for ventilation, and it is best to combine irrigation with topdressing. If the soil in the shed is very dry, furrow irrigation is really needed, and furrow irrigation can only be carried out after continuous fine weather. During furrow irrigation, water cannot overflow the border.

Third, how to prevent greenhouse vegetables from weak light

In winter and spring, vegetables cultivated in plastic greenhouses often suffer from weak light damage (referred to as "weak light disease") due to insufficient light. The general symptoms are: poor plant growth and soft stems; Leaves are thin, light in color and easy to turn yellow; The flower bud differentiation is poor, the flower organ is abnormal, and the flower and fruit drop are serious; The fruit grows slowly, with light color, astringent taste and color difference. Low light syndrome has a certain effect on the yield and quality of vegetables.

Preventive measures: mainly improve the lighting conditions in the shed as much as possible. When planting, appropriately increase the row spacing between plants and reduce the shading between plants. Keep the greenhouse film clean to prevent water droplets and dust from adhering to the film surface. In the middle and late period of vegetable growth, when the temperature outside the film reaches 65438 05℃ around noon, part of the film should be properly removed to let the sun shine directly in the greenhouse. In addition, according to the experiment, a reflective curtain with a width of 2m and a length of 3m is spliced by aluminum-plated polyester film and hung on the upper end of the column behind the plastic greenhouse (or greenhouse), with the lower edge perpendicular to the ground, which can increase the ground brightness by 40%-43%, the greenhouse temperature by three or four degrees Celsius, the ground temperature by 65,438 0.8℃-2.9℃ and the tomato yield by 465,438 0.8%. Laying silver-gray film or aluminum foil on the ground can also increase the light intensity between plants, make the fruit well colored, and effectively prevent the premature aging of the lower leaves.

4. What should I pay attention to when building a vegetable greenhouse?

1. The durability of vegetable greenhouses must be considered. The durability of greenhouse is affected by the aging resistance of greenhouse materials and the bearing capacity of greenhouse main structure. In addition to its own strength, the durability of light-transmitting materials is also manifested in the continuous attenuation of light transmittance over time, and the attenuation degree of light transmittance is a decisive factor affecting the service life of light-transmitting materials.

2. Pay attention to thermal insulation performance when building greenhouses. Improving the thermal insulation performance of greenhouse and reducing energy consumption are the most direct means to improve the production efficiency of greenhouse. The heat preservation rate of greenhouse is a basic index to measure the heat preservation performance of greenhouse. The heat preservation rate of greenhouse refers to the ratio of the coverage area of transparent material with low thermal resistance to the sum of the coverage area of greenhouse envelope with high thermal resistance.

3. Greenhouse construction needs good light transmission effect. Light transmittance is the most basic index to evaluate the light transmittance of greenhouse. Light transmittance refers to the percentage of the amount of light penetrating into the greenhouse and the amount of outdoor light. The light transmittance of greenhouse is influenced by the light transmittance of light-transmitting covering materials and the shadow ratio of greenhouse skeleton, and changes with the different solar radiation angles in different seasons.

Five, greenhouse vegetables after freezing measures

During the period of planting vegetables, sometimes vegetables will be frozen, which requires some remedial methods to make vegetables grow normally.

1. Artificial water spraying: water spraying can increase the air humidity in the shed, stabilize the temperature in the shed, and inhibit the evaporation of frozen tissue water, thus promoting the tissue to absorb water.

2. Irrigation insulation: Irrigation can increase the soil heat capacity, prevent the low temperature from dropping, stabilize the atmospheric temperature close to the surface, help the temperature to rise steadily, and restore the function of frozen tissue.

3. Outdoor cooling: After the vegetables in the greenhouse are frozen, the greenhouse cannot be closed immediately to raise the temperature, so that the temperature in the greenhouse can rise slowly to avoid the frozen tissue from necrosis due to the rapid temperature rise.