Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Plants, Soils, and Climate

Committee Chair(s)

Raymond Miller


Raymond Miller


J. P. Thorne


In soil survey work the method now generally used to evaluate the carbonate content of the soil in the field is to observe the amount of effervescence that takes place when the soil reacts with dilute acid. The four degrees of effervescence usually recognized are designated by the symbols eo, e, es, ev and correspond roughly to a lime content of 0-0.5, 0.5-3, 3-15, and above 15 per cent, respectively. This, or course, is a very rough estimate and therefore a method is needed for the quantitative determination of carbonates in the field with a fair degree of accuracy. If such a method were available it would be possible for the soil surveyor to follow accurately in the field the distribution of lime down the profile. It would also make possible the detection of lime "bulges," a consideration of primary importance in soil classification. The method would also be useful to agricultural advisers, especially in connection with the problem of lime induced chlorosis.

There is a large variety of methods for the determination of soil carbonate in the laboratory with varying degrees of accuracy but none of them is very suitable for field use as they either employ complicated apparatus, or in other ways require laboratory facilities. The present study is concerned with the development and evaluation of a rapid method for the determination of soil carbonate in the field. The apparatus used is very simple and easy to carry and to handle under field conditions. The results obtained are sufficiently accurate for the purpose intended; Their accuracy being above that of the semiquantitative effervescence test.

The proposed method is now rendered particularly useful by the availability on the market of small portable kits for the determination of soil moisture in the field which permit the expression of results on a dry basis.