一、棚室蔬菜生产需要补充二氧化碳 由于棚室与外界几乎隔绝,空气中的二氧化碳补充不进来,而靠微生物分解有机质和作物呼吸获得的二氧化碳远远满足不了棚菜光合作用的需要。一般棚室内二氧化碳浓度的日变化是,早晨揭苫时浓度最高,为700—1000ppm,9点时降到300ppm左右,10—11点降到200ppm以下,14—16点由于光合作用强度减 First, the greenhouse production of vegetables need to add carbon dioxide Greenhouse almost isolated from the outside world, the air does not come in the carbon dioxide supplement, and rely on microbial decomposition of organic matter and crop carbon dioxide can not meet the greenhouse photosynthesis far. In general, the daily variation of carbon dioxide concentration in greenhouse is the highest concentration at 700-1000ppm in morning exposures, 300ppm at 9 o’clock, and below 200ppm at 10-11, and 14-16 due to the decrease of photosynthesis intensity