Nitrogen, phosphorus, potassium, silica, iron, alumina, and base-exchange capacity were determined on nine Iowa soils and correlations made in an attempt to devise a system of soil mapping to be used when these constituents of the soil and soil extract were known. The results secured indicate a definite relationship between these constituents in each of the soils studied. However, no apparent relationship existed between the variations and soil type. The P2O3 content of all soils was found to vary directly with the base-exchange capacity of the soil.
Proceedings of the Iowa Academy of Science
©1933 Iowa Academy of Science, Inc.
Killinger, G. B. and Smith, F. B.
"Variations in the Chemical Composition of Soils of Various Types,"
Proceedings of the Iowa Academy of Science, 40(1), 96-96.
Available at: https://scholarworks.uni.edu/pias/vol40/iss1/40