Effect of Drying Some Ohio Soils Upon the Soil Test for Potassium

Abstract

Most Ohio soils release K (from a nonexchangeable form to exchangeable) upon air drying from the field-moist state. The amount released varies from 25 to 100 pounds per acre depending upon soil type. The effect of this release upon the interpretation of soil test recommendations was found to be not significant. Correlations between soil test level and corn yield response to K fertilization were the same or better using air-dried samples as compared with the field-moist samples. Further drying at 110°C. for 24 hours slightly increased or decreased the amount of exchangeable K depending upon the soil type. These values were, in some instances, poorly related to the yield response. Of the three procedures, air drying at room temperature prior to extraction gave the best estimate of the available K level.

Release of non-exchangeable potassium from soils and micaceous minerals during short periods of cropping in the greenhouse

“…(1956), Scott et a_l. (1957), Hanway and Scott (1957), Burns and Barber (1961), Grava et al (1961), Jones et al (1961 ) and Bates (1961) Total K in the soils and minerals was determined by the method described by Jackson (1960, pp. 283-284) except for the fact that the temperature of the sand bath was approxi mately 190° Ce Also, 1.0 to 1.5 g. of soil (oven dry basis) was used and no wetting was required because the soil was already moist.…”