Development of glass greenhouse in Venlo, Netherlands

In the 1950s, a kind of glass house with multiple spires appeared in a small town (Venlo) in the southeast of the Netherlands. Here, we have to mention the climatic conditions of the location of the Netherlands.

The Netherlands is located in a high latitude area. Affected by the ocean, it is warm in winter and cool in summer, but the annual illumination time is very small (about 1500h). In order to maximize the light transmittance of the greenhouse, this all glass greenhouse appears. After later, it is slowly developed into top diffuse scattering glass, which can let light pass through the glass evenly and reduce plant burns. The framework adopts white plastic spraying greenhouse framework to reduce the shadow in the greenhouse. The earliest Venlo glass greenhouse has a span of 6.4m-12m, a bay of 4m and a height of 4-6m. Each span is composed of two spires. After optimization, it gradually becomes the main structure column truss support. The roof is composed of special aluminum alloy profiles, which greatly improves the light transmittance and mechanization. Therefore, in foreign countries, this all glass greenhouse has been named Venlo glass greenhouse in this town. With the wide application of corrugated glass greenhouse, Some greenhouse supporting technologies have also been developed and applied, and the crop yield is getting higher and higher. Slowly, some new varieties with disease resistance, high yield and suitable for seasonal cultivation have been developed, and the Netherlands has gradually become a large agricultural country.

Since the 1970s, soilless cultivation has gradually become popular. The application of rock wool cultivation has greatly improved the cultivation control level and made mechanization and automation a reality. In the early 1980s, the top ventilation system of the thermal insulation system and the Internet of things system developed rapidly, forming a factory mode integrating sowing, seedling raising, harvesting and packaging. Tomato production increased five times.

However, with the rapid development of greenhouse, the problem of nonstandard structure also occurred one after another. Greenhouse collapse accidents occurred in rainy, snowy and windy weather, resulting in heavy losses for farmers and insurance companies. The first greenhouse structure standard came out in 1978, with clear requirements from civil engineering to structure construction and installation. By the 1990s, the development scale of greenhouse in the Netherlands was basically not expanding, but paid more attention to the cultivation of greenhouse research and development seedlings, made greenhouse technology more mature, and made greenhouse develop in the direction of intensive and large-scale. In order to improve the land use efficiency, the Dutch government has avoided crops that require a lot of light and low price, vigorously developed horticulture, animal husbandry and processing industries, and used agricultural subsidy policies to increase farmers' income. The experience of the Dutch model is worthy of reference for all countries to develop modern agriculture.