Refinement of a Quantitative Method for Determining the Lime Requirements of Soils

Abstract

In determining the lime requirement of kaolinitic soils by direct titration with a calcium hydroxide solution it was found that boiling for 5 minutes reduced the time required for the attainment of equilibrium between the soil and the solution from over 100 hours to 1 hour. The variation in the pH values of the sons at equilibrium with the two methods were in all cases less than 0.1 unit. A precise, rapid laboratory method based on 5-minute boiling is described for determining the lime requirement of these soils. Results of a field experiment are shown to demonstrate the accuracy of the method.