The development history of soil free cultivation
Human exploration of plant mineral nutrition can be traced back to the era of Aristotle in 600 BC, but at present, the most popular scientific report on plant mineral nutrition research is the famous willow experiment published by Belgion Jan Van Helmant in 1600. In the middle of nineteenth Century (1842), Wiegmen and Polsloff successfully cultivated plants for the first time with heavy distilled water and salts, and proved that dissolved salts in water were essential for plant growth. But the most outstanding representative figure in this era should be considered as Van Liebig (1803-1873). He proved that the carbon in plant body came from CO2 in air, H and O came from NH3 and NO3, and some other mineral elements came from soil environment. His work is to completely negate the humus nutrition theory was popular at the time, established a prototype of mineral nutrition theory, his theory is also leading modern "nutrition farming" theory. In 1838, J Ruland Geer, a German scientist, identified 15 kinds of nutrient elements for the growth and development of plants. In 1859, Sachs and Knop, a famous German scientist, established a method of using solution culture to plant mineral nutrients. On this basis, it has gradually evolved and developed to become the practical science and technology of today's soil free cultivation. 1920 the preparation of the nutrient solution is standardized, but these are experiments in the laboratory and have not been used in production. In 1929, Professor W.F.Gericke of University of California, using a nutrient solution, successfully produced a tomato with a height of 7.5 meters, and harvested 14 kilograms, which caused great concern. It is thought to be the beginning of the technology of soil free cultivation from experiment to practical. In 1935, some vegetable and flower growers, under the guidance of Gericke, carried out large-scale production practice. For the first time, soil free cultivation has been developed to commercial scale, with the largest area.
0.8 hectares. At the same time, some technology of sand culture and gravel culture has been developed in the Midwest of the United States, and the hydroponic technology is also rapidly spread to Europe, India and Japan. Professor Gericke defines soil free cultivation as "Hydroponics" (hydor is "water"), and ponics is meant to be "placed"). During the Second World War, water culture played a significant role in production. Under the guidance of Professor Gericke, Pan American Airlines planted vegetables on the waste island in the central Pacific Ocean, and solved the problem of fresh vegetables for flight passengers and army service personnel with soilless culture technology. After the British Ministry of agriculture also on water culture interest, London in 1945 the British air force began to soilless culture in Iraq hapania and Bahrain in the Persian Gulf Islands, solve the vegetables on the aircraft by the Palestinian air issues. In Guyana, the West Indies, Central Asia barren sand, Kuwait Oil Company and other units, the use of soilless culture for their employees to produce fresh vegetables. Due to the continuous development of soil free cultivation in the world, the international society of soil free cultivation was established in Holland in September 1955. There were only one working group and 12 members. At the time of the Fifth International soilless culture conference held in 1980, the number of members had developed to 300 in 45 countries. According to incomplete statistics, the world's current research institutions on soil free cultivation are about 130. The cultivated area is also growing, and in New Zealand, 50% of the tomatoes are produced by soil free cultivation. In Italy's horticultural production, soil free cultivation occupies 20% of the proportion. The total production of strawberry in Japan is 66% of the total production, 52% of green pepper, 37% for cucumber and 27% in tomato, with a total area of 500 hectares. Holland is the country with the largest land free cultivation area, with a statistics of 2500 hectares in 1986. At present, the technology of soil free cultivation has been applied and developed in more than 100 countries all over the world.
The research and application of soil free cultivation technology in China started late, but the original soil free cultivation technology has a long history. The bean sprouts, kind of Narcissus is recorded (to have it in the Song Dynasty), but the scientific research and production test is normal, is thing of nearly ten years. In 1975, the Shandong Agricultural University began to use vermiculite to cultivate watermelons, cucumbers, tomatoes and so on. They were all successful. In 1987, the area was 6000 square meters in Shengli Oilfield. The technology of soil free seedling cultivation has been widely used in China. In 1987, Chaoyang District, Beijing, the number of soil free seedling raising was 33.5% of the total number of seedling raising. In 1985, a national conference was held at the Vegetable Research Institute of Hebei Academy of Agricultural Sciences, and a Chinese soilless culture group was founded. A nationwide academic seminar was held in 1986 and 1987. In May 1988, China first attended the seventh annual conference of the international Soilless Culture Society held in Holland, and published papers at the conference, which has attracted the attention of many countries. Since 1990s, soil free cultivation has developed rapidly in China.