MAR. 19, 1923 WHERRY: ACIDITY AND LIME-REQUIREMENT OF SOILS 101 
TABLE 1—Summary or Vauuss or Corrricient C [L. R. = C X (S. A. — 1).] 
VALUES OF COEFFICIENT C 
SOILS STUDIED NO. DESCRIPTION 
Range Average} Class 
SSIS ete ese sel Variously fertilized 0.0015-0.0020 | 0.0018/0.002+ 
1 Manured 0.0022 0.0022 
Siltiloam sot 5 Limed, in part 0.0057-0.0063 | 0.0053/0.005— 
Mediacid peat..... 4 Cranberry bog 0.0040-0.0070 | 0.0055 
Pit Loam we sO Limed, balance 0.0075-0.0091 | 0.0085|0.01 
Gravelly loam..... 1 In part 0.010 0.010 
Gravelly loam..... 2 In part 0.019 -0.026 | 0.023 |0.02+ 
7 Limed, in part 0.018 -0.036 | 0.027 
Gravelly loam..... 3 Balance; limed, in part 0.038 -0.050 | 0.044 |0.05— 
Subacid peat...... 4 Cranberry bog, depths 0.036 -0.064 | 0.047 
Subacid peat...... 2 Cranberry bog, others 0.076 -0.077 | 0.077 |0.1 
Gravelly loam..... 3 Limed, in part 0.076 -0.136 | 0.100 
Subacid peat...... 2 Limed, balance 0.166 -0.200 | 0.183 |0.2+ 
Gravelly loam..... 1 Limed, balance 0.200 — 0.200 
Since this paper was prepared, over a year ago, a new series of 
comparisons of lime-requirement and active acidity has been published 
by Harlan W. Johnson.® On calculating the coefficient C for his 
data, the following classes are found to be represented: 
TABLE 2 
Finesandy loam...| 1 Knox 0.007— 0.007 | 0.005 
Finesandyloam...| 1 Buckner 0.015- 0.015 | 0.01 
Various loams..... 7 Lindley, O’Neill, ete. 0.023-0.035 | 0.028 | 0.02 
Various loams..... 10 Plainfield, Shelby, etc. 0.037-0.070 | 0.050 | 0.05 
Various loams..... 10 Buckner, Tama, etc. 0.077-0.121 0.086 | 0.1 
Various loams..... a Judson, Marshall, etc. 0.166-0.301 | 0.234 | 0.2 
Various loams..... 2 Wabash, Waukesha. 0.378-0.588 | 0.483 | 0.5 
Various loams..... Z Hancock, Bremer 0.9 -2.5 high 
Again the values of C show a wide range. This author furnishes 
data on organic matter present in these soils, and it is interesting to 
find that on plotting the values of C against the organic matter, they 
are found to be on the whole proportional; it is also striking that the 
lime-requirement itself is a function of the organic content, averaging 
one-sixth of the latter. These relations indicate that the organic 
§ Soil Sci., 13; 7. 1922. 
