Solar radiation for plant growth.

Published online
01 Jan 1975
Content type
Journal article
Journal title
Journal of Applied Ecology

Szeicz, G.

Publication language


Analysis of theoretical calculations and experimental measurements showed that the photosynthetically useful fraction of the solar spectrum for total (direct + diffuse) radiation was almost independent of atmospheric conditions and was nearly constant at 50 plus or minus 3%. For direct-beam radiation in very clean air in winter, it increased from 35 to 45% as solar elevation increased from 10 to 45 deg ; in summer the range was smaller, 41 to 49% for the same range of solar elevations. The figure for blue sky was 75%. It was concluded that climatological measurements of solar radiation could confidently be used for estimating efficiencies of photosynthesis and crop growth in the field.

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