Various investigators have shown that carbon dioxide is important in the soil in making the plant food elements available. As a result attempts have been made to use solvents which are similar to carbon dioxide in their solubility effects on soil phosphorus. In many cases, the available phosphorus as measured by these solvents has correlated rather well with crop responses to phosphate fertilizer in the field, but the correlation is not perfect in all soils.
Proceedings of the Iowa Academy of Science
©1935 Iowa Academy of Science, Inc.
Millar, H. C.; Smith, F. B.; and Brown, P. E.
"The Relative Solubility of Soil Phosphorus in Different Solvents,"
Proceedings of the Iowa Academy of Science, 42(1), 99-102.
Available at: https://scholarworks.uni.edu/pias/vol42/iss1/34