The greenhouse is a relatively closed place. The carbon dioxide concentration in the greenhouse is significantly different from the external environment: the carbon dioxide concentration in the atmosphere is relatively stable, generally around 350 ppm. At night, due to the respiration of crops, soil microbial activity and the decomposition of organic matter, carbon dioxide will be released. The concentration of carbon dioxide can be about twice as high as outside the shed; before sunrise, the concentration of carbon dioxide in the shed reaches its highest value, which is higher than outside the shed. -3 times; one hour after sunrise, crops begin to photosynthesize, and carbon dioxide drops to about 300 ppm; at noon, under strong sunlight, the intensity of crop photosynthesis increases, and the carbon dioxide concentration in the shed drops sharply to only 80-150 ppm. Carbon dioxide is one of the essential raw materials for photosynthesis of plants. The content of carbon dioxide in greenhouses directly affects the growth of crops. Excessive or insufficient carbon dioxide will have certain effects on crops:
Excessive carbon dioxide concentration: often cause vegetable crop leaves to curl, affect the normal progress of photosynthesis, will affect the crop's absorption of oxygen, and cannot perform normal respiratory metabolism;
Insufficient carbon dioxide content: dark and dull leaves, late flowering, fewer female flowers, and more flowers and fruits fall off; the leaves are low and flat, perpendicular to the main branch or drooping, and the leaf surface is uneven; more heterogeneous fruits, late on the market, low yield, and few quality fruits .
Sufficient carbon dioxide can ensure the healthy growth of vegetables, increase the chlorophyll content, dark green and shiny leaves; make it bloom early, with fewer flowers and fruits, healthy leaf growth, correct fruit, and high yield.
Therefore, many growers now add a certain amount of gas fertilizer to increase the carbon dioxide content in order to make vegetables grow better and increase yield. So when should the carbon dioxide content in the greenhouse be applied?
As mentioned at the beginning of the article, although there is plenty of sunlight at noon and the roots of plants absorb enough water, because there is not enough carbon dioxide, plants cannot perform photosynthesis, and there will be a shortage of carbon dioxide, which affects the normal growth of crops and affects yield and quality. Therefore, if the vegetables or other crops cultivated in greenhouses and greenhouses are supplemented with carbon dioxide in time after sunrise to meet the requirements of crop photosynthesis, the yield and quality of crops can be greatly increased, and higher profits can be obtained. The flowering and fruiting period of crops is the most vigorous period of photosynthesis, and it is also the key stage for the accumulation of large amounts of dry matter. At this time, the effect of artificial carbon dioxide supplementation is the most obvious.
The installation of carbon dioxide sensors in the greenhouse can ensure timely alarm in the case of insufficient carbon dioxide concentration, so as to use gas fertilizer or increase organic fertilizer to ensure that vegetables, edible fungi, flowers, Chinese medicine, etc. are marketed early, with high quality and high yield. It can be said that the carbon dioxide sensor determines the growth and development, maturity, stress resistance, quality, and yield of crops.
