1，Choose the right shed film
In the actual construction of the greenhouse, the following requirements need to be followed. First, the film must have a higher light transmittance. This is because light is very important for photosynthesis of crops. Good light can effectively improve the nutrients of greenhouse vegetables. Secondly, it is necessary to choose a non-toxic and harmless greenhouse film to effectively prevent the greenhouse film from adversely affecting the growth of crops.
Finally, when relevant conditions permit, choose a non-drip membrane, because there are related active agents on the surface of the membrane, and its surface tension is very strong, so that the condensed water under the membrane forms a water-retaining film on the membrane and runs along the surface of the membrane. Flow into the soil.
2，Choose the right vegetable variety
In the actual selection of vegetable planting varieties, a reasonable choice should be made according to their different seasonal attributes. It is required to sow and raise seedlings in advance before the arrival of winter and spring. At this time, vegetable varieties with good selectivity, strong heat resistance, strong disease resistance, and high comprehensive yield are required to effectively ensure that they are under low temperature conditions.
The greenhouse can be developed for normal use and sold in the morning. For example, cucumbers and tomatoes are very sensitive to pests and diseases under conditions of high temperature and humidity or low temperature and humidity. Choosing a variety with strong disease resistance can effectively prevent damage from related diseases and insect pests.
3，control the temperature
① Insulation in winter
Grasp the heat preservation time of the cover, and deduct the peeling film when the outside temperature drops to 18°C. When the temperature is 12 ~ 14 ℃, cover with straw mat or insulation quilt. When the temperature is 3 ~ 5℃, cover with insulation quilt and two layers of straw mats.
In winter, the reflective film hanging on the back wall is tied up in the afternoon to allow the wall to collect heat. Before covering the grass, put down the reflective film again. Using a straw bioreactor, dig a trench with a width of 60 ~ 70 cm and a depth of 25 ~ 30 cm to fill with straw.
Place 8 kilograms of microbial inoculants per 667 square meters, cover more than 20 cm with straw, and soak the straw with water. The straw can gradually decompose under the action of microorganisms to release heat and carbon dioxide. The winter solar greenhouse is the best measure to increase the temperature of the greenhouse and improve the quality and efficiency of vegetable production.
②Cooling in summer
After May, with the increase of light and the rapid rise of temperature, the temperature in the equipment can easily exceed 30°C. In order to reduce the temperature in the facility, measures such as shading nets and timely ventilation have been adopted. On sunny days 10:00-15:00, pull up the shading net to promote crop growth.
4，control humidity
The principle of low-cost dehumidification technology facilities in winter is based on rapid condensation heat to cool the humid air, which effectively reduces the humidity of the air, reduces the energy consumption of the compressor, and greatly reduces the cost.
Water air-conditioning is used in the summer shed to cool the groundwater at low temperature. In winter, 3 to 5 water conditioners are installed for every 667m2 of the greenhouse, pools are dug outside the greenhouse, and outdoor low-temperature water is circulated in the water conditioners. Due to the low outdoor water temperature, a good condensation and dehumidification effect can be achieved.
5，control the light
Due to the low overall temperature in winter, the greenhouse requires multiple layers of coverage to effectively ensure the normal growth of crops in the greenhouse. However, this also affects the acceptance of crops under light intensity, thereby reducing the yield of vegetables to varying degrees.
In response to this phenomenon, relevant staff can appropriately reduce the covering on the scaffold during the day, and increase it reasonably at night according to the actual situation. It is best to use a non-drip film. This is because it has good light transmittance, and the actual light transmittance is higher than that of ordinary films.
In addition, the dust and snow on the surface of the film should be cleaned up in time. This is because dust and snow on the surface of the film will also affect the light absorption of the crops in the shed. Therefore, controlling the light intensity in the greenhouse is one of the main tasks to effectively increase the actual yield of crops.
6，increase the amount of organic fertilizer
Fertilizer is a key factor affecting the growth of vegetables. If compound fertilizers are used blindly during the growth of vegetables, the soil will gradually develop in the direction of eutrophication, causing the problem of soil salinization, which will adversely affect the subsequent growth of vegetables.
Therefore, in the process of fertilizer management, it is necessary to increase the amount of organic fertilizer, reduce the use of compound fertilizer, and use organic matter in organic fertilizer to improve the soil environment. In addition, organic fertilizer will not pollute the soil and the surrounding environment, effectively reducing the cost of vegetable cultivation.
For rural areas, organic fertilizer sources are more extensive, and animal husbandry and vegetable planting can be closely integrated to form a modern agricultural composite industrial structure, which has a positive impact on the future development of the agricultural system.
7，soil freezing and thawing
The soil in northern China undergoes freezing and thawing once a year, forming a unique ecosystem. However, the soil of the vegetable facility does not undergo freezing and thawing in winter, which destroys the original ecological balance of the soil. Therefore, in order to protect the ecological environment, greenhouse soil freezing and thawing measures should be taken.
The specific method is from mid-December to mid-February of the following year, when the conditions of light, temperature and humidity are not good, and it is difficult for vegetables to grow. During this period, the greenhouse should be idle for two months, and the soil should be frozen and thawed, which can effectively kill harmful diseases and insect pests in the soil.
