The concentration of carbon dioxide in the atmosphere is normally about 0.03 per cent but the soil atmosphere usually contains considerably more than this amount especially in the vicinity of roots of rapidly growing plants. The carbon dioxide produced by the plant roots and by microbiological action diffuses from the soil and increases the concentration of carbon dioxide in the atmosphere immediately surrounding the above-ground portions of the plant. It is this carbon dioxide from the soil which the plant utilizes in its growth and hence the significance of an adequate supply is at once apparent. The influence of carbon dioxide on plant growth and on bacterial action in the soil and its effect on the availability of phosphorus and potassium have been studied to some extent but the problem as a whole is far from solved as yet.
Proceedings of the Iowa Academy of Science
©1937 Iowa Academy of Science, Inc.
Smith, F. B.; Brown, P. E.; and Millar, H. C.
"The Effect of Carbon Dioxide on the Yield, Phosphorus and Calcium Contents of Wheat,"
Proceedings of the Iowa Academy of Science, 44(1), 79-84.
Available at: https://scholarworks.uni.edu/pias/vol44/iss1/12