The rise of modern greenhouses in China in the early 20th century

　　China’s modern greenhouse started late. In the late 1950s, a ridge-type large glass greenhouse was built in North China. By the early 1960s, a 1,000 square meter large glass greenhouse was built in the northeast. The greenhouse skeleton was a reinforced concrete structure with large and heavy components and large shading surfaces. The glass inlay on the greenhouse is not standardized, and there is basically no supporting equipment in the greenhouse, which has not formed effective use.

　　my country's first large-scale multi-span greenhouse was built in Yuyuantan Commune, Beijing in 1977, covering an area of ​​1900m2, designed and built by my country itself. The greenhouse frame is an all-steel structure, coated with anti-rust paint, covered with tempered glass, electric windows, fuel oil (later changed to coal) boiler hot water heating, the greenhouse is equipped with sprinkler irrigation devices, mainly used for cultivating cucumber, Tomatoes and other fruits and vegetables. Due to the poor structural performance and the large area of ​​the contiguous area, the lack of effective ventilation and cooling devices, the indoor temperature in summer is too high and production cannot be carried out; in winter, the greenhouse operation due to poor performance such as sealing and heat preservation results in high energy consumption. Since then, large glass greenhouse covering an area of ​​1,000 square meters have also been built in Lanzhou, Mudanjiang and other places. The quality and performance of the greenhouse were not as good as the greenhouse in Yuyuantan, and they were stopped after a few years.

　　In 1982, the Shanghai Municipal Agriculture Bureau organized the construction of the first batch of prefabricated modern greenhouse in my country at the Changzheng Brigade of Jiading County, Shanghai, with a total area of ​​4644 square meters. This batch of greenhouse refers to the structural form of Japanese modern greenhouse. The framework adopts a portal steel frame structure, hot-dip galvanized steel structural parts, on-site assembly of glass and FRP covers, aluminum alloy door and window frames, and rubber strip sealing. Among them, the greenhouse built in the Long March Brigade has an area of ​​2880 square meters, a span of 6m, and a bay of 3m; 10 consecutive spans, 16 bays, a total length of 60m, and a total width of 48m; column height2.2m, roof ridge height 3.8 m, roof angle 26.5°; ridge windows account for 30% of the greenhouse roof area, side windows are sliding windows, accounting for 60% of the greenhouse side wall area; greenhouse design wind load 0.29kN/㎡, snow load 0. 30kN/㎡, constant load 0.30kN/㎡; The internal facilities of the greenhouse are equipped with temperature-controlled automatic plant window mechanism, soil heating electric wire, sprinklerdevice and electric insulation screen system. The greenhouse passed the municipal technical appraisal organized by Shanghai in 1983, and won the second prize of scientific and technological achievements by the Shanghai Municipal Agriculture Bureau.

　　In addition to the insufficient internal facilities and equipment of the Shanghai greenhouse, its main structure, covering materials, inlays, and manufacturing techniques are basically the same as those of modern foreign greenhouse. The quality and overall performance can be guaranteed. It is the first batch of modern greenhouse designed and built by our country in a practical sense.

　　In 1988, China Aerospace Architectural Design and Research Institute, referring to the American greenhouse introduced by Beijing Langshan Nursery, trial-produced a 1,200 square meters arched greenhouse, including the main structure of the greenhouse and additional Temperature, cooling, automatic control systems and cultivation beds are used for forest tree seedlings. They were built in Beijing Langshan Nursery, and they were tested in comparison with the imported American greenhouse. Technical appraisal was conducted in 1989.

　　During 1979 and 1987, my country was in the early stage of reform and opening up. It successively introduced 24 modern greenhouse from Bulgaria, the Netherlands, Rome & nbsp;Nia, the United States, Japan, and Italy. 19.2h square meters, respectively built in Beijing, Heilongjiang, Guangdong, Jiangsu, Shanghai, Xinjiang six provinces and urban areas, of which 60% is used for vegetable production, 40% for flower production. The imported greenhouse are all large-scale multi-span greenhouse, with structures including 6.0m and 8.0mspan single-ridge and double-slope roof types, 6.4m-span double-ridge and double-slope roofs, and 12.8m-span triple Houseridged double-slope roof type, 6m-span zigzag single-slope roof type and 812m-span vault type; skeleton members are hot-dip galvanized steel, aluminum alloy door and window frames; covering materials are glass and glass steel (polypropylene resin fiber Corrugated board>, rubber strip sealing; internal supporting equipment is relatively complete. This time the large-scale introduction of greenhouse, all localities pay attention to the greenhouse itself, but ignore the adaptability to China’s climate and the existence of supporting cultivation techniques in operation Problems such as high energy consumption in winter and difficulty in cooling in summer are generally poor in economic benefits. However, from another perspective, the introduced greenhouse basically represents the type and advanced level of modern greenhouse, which is important for the rise of modern greenhouse in China and the development of modern greenhouse industry , Played a positive role in promoting.

　　Since the early 1980s, with the implementation of China’s reform and opening up policy, on the basis of absorbing foreign technology, Development and research have also been carried out on hot-dip galvanized steel pipe fabricated plastic greenhouse, modern greenhouse, etc.At that time, the newly established China Agricultural Engineering Research and Design Institute (renamed as the Ministry of Agriculture Planning and Design Institute in 1992)has“ Agricultural Environmental Engineering Research Office” (in 1995 changed to “Facility Agriculture Research Institute” organizational system), together with related agricultural scientific research units and universities, the organization undertook “Sixth Five-Year Plan”, &ldquo ; Seventh Five-Year Plan & rdquo; the key scientific research projects of the Ministry of Agriculture and the national science and technology research project & ldquo; hot-dip galvanized steel pipe assembly plastic greenhouse & rdquo;, & ldquo; geothermal greenhouse research and design & rdquo;, & ldquo; natural light artificial climate chamber Research ”, “Comprehensive cultivation technology of plastic greenhouse”, “Soilless cultivation equipment and supporting cultivation technology research” and other related topics, formed a batch of related technical achievements, and supported a batch of them in the middle and late 1980s Professional designated manufacturers, forming a series of products, successively designed and built a batch of large multi-span glass greenhouse for Anhui, Hubei and other provinces and cities' Academy of Agricultural Sciences, Jinan Huangtai Power Plant, Central Guard Corps, etc. Experimental research and production. By the end of the 1980s, the country’s self-designed and built modern greenhouse reached more than 10 hectares. With the introduction of greenhouse, the total number of modern greenhouse in the country reached more than 30 hectares.