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Studies were conducted to determine why certain soil test methods fail to indicate the actual lime requirement in many Ohio soils. Samples of 14 soils from various areas of the State were collected for study. The soils were incubated with various rates of applied CaCO3 to determine actual lime requirement of each soil. Attempts were made to find laboratory methods that would accurately indicate the lime requirement of each. For these soils the Woodruff method had indicated only about half the amount of the actual lime requirement. The Mehlich triethanolamine method indicated accurately the amount of lime required for the unlimed acid soils. However, this method indicated too high a lime requirement on soils partially limed. Subtraction of the acidity measured above pH 6.8 by the triethanolamine method and then addition of the extractable Al, gave a very good indication of lime needs on all soils not limed above neutrality regardless of lime additions. Addition of extractable Al to total bases and triethanolamine‐measured acidity to pH 6.8 gave nearly constant cation‐exchange capacities of soils regardless of lime additions. These studies have led to development of an improved soil test buffer method for rapid routine laboratory analyses. It appears to be adequate for indicating lime needs of soils regardless of extractable (soluble) Al present.

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The double‐buffer (DB) feature of the recently‐published Yuan method was applied to the Shoemaker‐McLean‐Pratt (SMP) method at several buffer pH levels, shaking times, and soil/solution ratios. The results, based on regression analysis of buffer‐indicated vs. Ca(OH)2‐titrated acidities, indicate that the widely used SMP single‐buffer (SB) method can be improved considerably by incorporation of DB, quick‐test, and mathematical‐adjustment features. However, the SMP‐SB method is still probably the most satisfactory compromise between simplicity of measurement and reasonable accuracy of results for soils of a wide range in lime requirement (LR). The SMP‐DB method with narrow soil/solution ratio and shorter shaking time gave excellent indication of soil LR when adjusted for incomplete reaction with the soil during the shorter “quick‐test” reaction time. This adaptation which looks very promising as an improved method (especially for use on soils of low LR where the SMP‐SB method is known to lack desired accuracy) is included as a recommended improvement of the SMP‐SB method.

perimental errors are large enough to permit this behavior. As a third alternative, however, we recognize that there are appreciable e-dependent contributions to u 2 which do not affect the asymptotic behavior, and it is not clear whether these are considered correctly by dynamic scaling. If the prediction Eq. (2) pertains only to the asymptotically dominant terms, one might use u 2 oce 0 * 33 and £ oce*" 0 -67 for all X and predict a concentration-independent z ^0.34. This value falls within the permitted range of the experimental result. Nonetheless, we remark that the measured z for X=0.1 tends to be higher than any of the predicted values. There has been a tendency also for measurements 15 ' 16 of other transport properties to yield exponents which are larger than the predictions.One might expect also to obtain the approximate amplitude of D from dynamic scaling by setting numerical constants equal to unity and treating the asymptotic proportionality D A~u2 £, as an equality. However, the large latitude in the choice for £ and u 29 and the unknown size of Z 2 in Eq. (1), permit at best an estimate for the order of magnitude of D. For X = 0 and at e = 10" 4 one obtains D^u 2 £, ^ 1.2X10" 3 cm 2 /sec if one uses ! = ! 0 £~a 67 , £ 0 = 2X10~8 cm, and the measured u 2 . 12 With a characteristic length for our geometry of 0.7 cm, this yields r^400 sec at € =10~4 and X = 0. This is consistent with the experimental values of r(X) quoted above and shown in Fig. 3. *Permanent address. 1 G. M. Drabkin, V. A. Noskin, V. A. Trunov, A. F.The role of dimensionality in determining the properties of ordered phenomena such as magnetism, superconductivity, and superfluidity is a subject of continued and current interest. Of particular concern is the question of whether coherent phenomena observed in three-dimensional Shchebetov, and A