Off-season vegetables

Description: The production of off-season vegetables in winter is one of the effective ways to ensure the annual supply of vegetables. Mainly refers to the delayed production of spring and summer vegetables in autumn and early production in spring. Cold protection measures must be taken when planting to achieve the purpose of early market.

Location selection

Areas where vegetables are produced during the off-season season in winter are required to choose a place with warm climate, sufficient sunshine, low altitude or hilly plain area, convenient water source, suitable soil conditions, and as far as possible a wind barrier (such as a high mountain barrier or other buildings on the north) ), to avoid direct attack by cold wind.

Variety selection

For the production of non-seasonal vegetables in winter, we should choose varieties with cold tolerance, strong disease resistance, and early maturity. Varieties that are delayed in autumn also require heat resistance in the seedling stage. For example, the pepper has Xinxin 4, Xinhua 5, Xiangyan 9 pepper, Xiangyan 10 pepper, Xiangyan 11 pepper, Guangjiao 2 and Layou 4, and eggplant has Fengqi 1 and Fengqi 2. Cucumbers such as Jinza No. 3 cucumber, Jinza No. 4 cucumber, Jinchun No. 4 cucumber, and early-green generation zucchini are all good protected cultivated varieties.

High-quality and efficient cultivation technology

In winter, greenhouse vegetables are insulated and cold-proof, and adequate carbon dioxide can be injected into the greenhouse.

Nutrient bowl nursery

The black plastic nutrient bowl has the function of absorbing heat during the day and protecting the roots at night. A plastic nutrient bowl is placed in the sunbed to raise seedlings. When the outside temperature is around -10°C, the temperature in the border is 6～7°C, and the temperature in the nutrient bowl is 10 At around ℃, the seedlings can grow slowly without freezing damage.

Preparation of thermal nutrient soil

Chicken manure is hot manure, and cow manure is air-permeable manure rich in mucus. After the two are decomposed, 20% is taken and 60% of fine soil is mixed. Such nutrient soil has good heat absorption and heat generation performance, good seedling ecological environment, well-developed root system, strong absorption capacity, and strong frost-resistant plants.

Irrigate roots with rooting element when dividing seedlings

Rooting element is reasonably formulated with calcium, phosphorus, zinc and other nutrients related to root growth. Calcium determines the thickness of the root system, phosphorus determines the number of roots, and zinc determines the growth rate and length of the root system. After using rooting hormone, the root system can increase by about 70%, and the deep root can increase by 25%. The root system is well-developed, and the absorption capacity is strong, and the vines will not be frostbitten due to poor cold resistance caused by lack of water and nutrients.

Enough water to keep warm and prevent freezing damage

The specific heat of moisture is higher than that of air, and heat dissipation is slow. In winter, the indoor soil moisture content is moderate, the pores and cracks of the cultivated layer are fine, the root system is not suspended, the soil is insulated, and the root system is not damaged by freezing. Therefore, frost damage of seedlings is mostly caused by lack of water. Therefore, watering enough water before winter or choosing good weather (watering above 20℃) can prevent frost damage.

Cultivation insulation and cold protection

The ground slab is condensed, and the hot air entering the cultivated layer during the day is restricted. The soil storage heat energy is small. In addition, the compacted soil has large and deep cracks and poor aggregate structure. It is easy to lose heat in the first half of the night, and the room temperature is low in the second half of the night, which is easy to cause freezing damage. Shallow cultivating can break the ground and close the cracks, which can not only control the transpiration of groundwater and take away heat energy, but also preserve moisture, heat insulation, cold protection and seedlings.

Foliar spray of nutrients to resist cold

In winter, the temperature is low, the light is weak, and the absorption capacity of the root system is weak. Spraying photosynthetic micro-fertilizer on the leaves can supplement the lack of nutrients caused by the lack of nutrition in the root system. Foliar spraying with rice vinegar can inhibit bacteria and repel insects. When mixed with sugar and superphosphate, it can increase the sugar content and hardness of the mesophyll and improve the cold resistance. After freezing damage, the leaves appear alkaline and shrink, and spraying vinegar can alleviate the damage. It is advisable to use 100-300 times liquid, and use less or no growth hormones to prevent lowering cold resistance.

Repeatedly airing seedlings

The highest temperature in the shed in the morning on a sunny day in winter can reach over 32℃. At this time, the air should be repeatedly released to reduce the temperature difference between indoor and outdoor, so that the plants can slowly adapt to the environment and grow vigorously. Beware of prolonged one day and catching cold for ten days, causing flashing and freezing damage. ?

Supplement carbon dioxide

The ratio of carbon to nitrogen to crop yield is 1:1, and the requirement of crop to carbon to nitrogen ratio is 30:1. At present, the majority of farmers are aware of the effect of nitrogen in increasing yield, but ignore the effect of carbon. In winter, greenhouse vegetables are prone to yellowing. One hour after the sun comes out, it can absorb the carbon dioxide produced by the respiration of crops and the decomposition of soil microorganisms at night. It will be in a carbon starvation state around 12 o'clock. When the temperature is high, the greenhouse film can be opened and closed. Into the outside carbon dioxide, improve resistance and yield. Closing the shed when the temperature is low and artificially replenishing carbon dioxide can enhance the cold resistance of crops and greatly increase the yield.

Cover the thatch in time

Generally, the shed absorbs heat and stores temperature during the day, and the energy released at night accounts for 50% to 60% of the total indoor space; the soil absorbs and emits heat accounts for 20% to 30%; the space heat storage accounts for 20% to 30%. According to the temperature of the day, the room temperature may be kept at about 18°C ​​within 1 hour after covering. If it is higher than 18℃, it can be covered later, if it is lower than 18℃, it should be covered earlier.

Use straw thatch

The thermal conductivity of straw thatch is lower than that of cattail thatch, and it has good protection against cold. In addition, the texture of straw thatch is soft and dense, which can reduce conduction heat loss, and the minimum indoor night temperature can be increased by 2 to 3 ℃.

Cover multilayer film insulation

Seedlings are grown in the greenhouse, the seedbed is covered with a film, and then a small arch shed is supported at a height of 1 meter. At night, it is covered with a layer of film outside the small arch shed or 20 cm from the inside of the large shed. In this way, all kinds of seedlings can be bred without heating. After planting, cover the ground ridges with mulch to protect moisture and increase temperature, but do not seal the ground tightly. Leave 15-20 cm so that the heat stored in the soil during the day can be slowly radiated through the uncovered ground to the space at night to make it 5～5 in the morning. At 7 o'clock the minimum temperature increased by 1 to 2°C. Cover the grass thatch with a layer of membrane, or support a membrane at a distance of 20 cm from the membrane to form a thermal insulation layer, which can increase the room temperature by 1 to 3°C. ?

Use purple light film

Ultraviolet rays in the solar spectrum in winter are only about 5% of that in summer. The white film cannot transmit ultraviolet light, and the purple light film can transmit ultraviolet light. Ultraviolet spectrum can inhibit diseases and kill bacteria, control plant growth and promote nutrient accumulation. The room temperature before and after the winter solstice of the purple light film is 2～3℃ higher than that of the green film.

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