What is the role of carbon dioxide fertilization in greenhouse?

Carbon dioxide is one of the essential main raw materials for pepper photosynthesis to produce nutrients, also known as "gas fertilizer". Carbohydrate in pepper is mainly carbon dioxide accumulated through photosynthesis, and then through a series of complicated processes or combined with other substances to form other substances needed in pepper. Therefore, photosynthesis with carbon dioxide as the main raw material is the material basis for pepper to obtain high yield and high quality. The change of carbon dioxide concentration in greenhouse has certain regularity, especially in early spring and low temperature season in winter. In order to keep warm, greenhouses are often relatively closed. At night, due to the respiration of plants and the activities of microorganisms, the carbon dioxide content increases, reaching 500 x1ct6 ~ 600 x10-6 before sunrise, which is 300X 10_6(0. 03% 6 (compared with air content) After sunrise, with the increase of photosynthesis of pepper plants, carbon dioxide was consumed by plants, and its concentration decreased rapidly, which was obviously lower than that in the open field without outdoor air, and sometimes even fell below 100X 10-6. At this time, the concentration can not meet the needs of pepper photosynthesis, and the concentration of carbon dioxide has become one of the main limiting factors to improve the photosynthetic intensity of pepper. Therefore, supplementing a certain concentration of carbon dioxide at this time will promote plant photosynthesis to accumulate nutrients and increase yield.