External shading mainly refers to covering the outside of the greenhouse with a sunshade net to directly block the solar radiation outside the greenhouse, thus effectively reducing the temperature inside the greenhouse.

The purpose of the sunshade system outside the greenhouse is:

1. Sunshade and burn protection: The sunshade system can improve the ecological environment in the greenhouse by adjusting the light. In summer, when the indoor temperature rises to a certain value, according to different shading rates, part of the sunlight can be reflected, part of the sunlight can be blocked outside the shed, and the other part of the sunlight can be diffused indoors, so as to ensure that crops can be prevented from being burned by strong light and achieve the purpose of shading.

2. Shading and cooling: The external shading system is mainly suitable for shading and cooling in summer, closing the shading net and reducing the temperature in the greenhouse by 5~8℃, thus reducing the temperature in the greenhouse. By adjusting the opening and closing of the sunshade net, the light demand of the greenhouse can be met.

3. Shading and dimming: The shading system can meet the needs of different crops for sunlight by selecting shading nets with different shading rates.

4, high needle anti-ultraviolet: anti-ultraviolet, heavy rain, reduce the damage to the top of the greenhouse.

5, anti-rainstorm: it is conducive to moisturizing and drought prevention. There is more rainfall in the southern climate, mostly concentrated in summer, because the mechanical strength of sunshade nets is higher.

6. Moisturize and reduce transpiration: Covering with sunshade net can effectively reduce the transpiration of plants, which is conducive to maintaining indoor humidity, thus reducing irrigation times.

7. Use net to prevent hail: High-strength sunshade net has hail protection function.