温室蔬菜冬季应增添紫外线照射在不同的季节，乃至一天中的不同时间，植物吸收太阳的能量不仅在数量上，而且在太阳辐射光谱的分布上均有不同。冬季，太阳光谱中的紫外线部分几乎只有夏天的二十分之一，而短波部分甚至减少至夏天的一百分之一。这与冬季太阳离地平线较近有... Greenhouse vegetables should be added in winter ultraviolet radiation in different seasons, and even at different times of the day, plants absorb the sun’s energy not only in quantity, but also in the distribution of solar radiation spectrum are different. In winter, the ultraviolet part of the sun’s spectrum is barely one-twentieth of summer, while the shortwave part is even reduced to one hundredth of summer. This is close to the winter sun from the horizon ...