CO2匮缺与低风速是温室存在的普遍现象，即使在温室通风状态下也不例外。在温室通风时，为减少CO2逸散、提高CO2利用效率，采用零浓度差CO2施肥法同时进行室内送风，并对试验温室与对照温室内番茄冠层净光合速率、CO2利用效率、番茄冠层蒸腾速率进行调查。结果表明，当太阳辐射强度从383.5 W·m-2增加到940.1 W·m-2时，试验温室番茄冠层净光合速率从1.9 g·m-2·h-1升高到5.3 g·m-2·h-1，比对照温室番茄冠层净光合速率高出1.3~1.6 倍；而试验温室番茄冠层蒸腾速率从0.17kg·m-2·h-1升高到0.56 kg·m-2·h-1，比对照温室番茄冠层蒸腾速率高出1.2~1.4 倍；CO2利用效率近似于1。研究表明，在温室通风状态下采用零浓度差CO2施肥法同时进行室内送风是设施栽培增产的有效途径。
Depletion of CO2 concentration during daytime together with a low air current speed was observed in a naturally ventilated greenhouse. In a ventilated greenhouse, a zero CO2 concentration difference method together with an enhanced air current speed was introduced to decrease the CO2 leakage to outside and improve the CO2 use efficiency. Rates of canopy net photosynthesis and transpiration and CO2 use efficiencies were investigated in tomato experiment greenhouse and control greenhouse, respectively. The results show that when solar radiation increases from 383.5 W·m-2 to 940.1 W·m-2, the canopy net photosynthesis rate increases from 1.9 g·m-2·h-1 to 5.3 g·m-2·h-1, which is 1.3-1.6 times higher than that in the control greenhouse, and the canopy transpiration rate increases from 0.17 kg·m-2·h-1 to 0.56 kg·m-2·h-1, which is 1.2-1.4 times higher than that in the control greenhouse. The CO2 use efficiency is around 1. The above result indicates that the null CO2 balance concentration method together with enhanced air current speed should be considered as an efficient method for improving plant production in protected cultivation.
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