4 BULLETIN 1221, U. S. DEPARTMENT OF AGRICULTURE. 
TABLE 1.—Percentages of moisture in soil columns at different distances above water, as 
obtained from the Riverside experiments. 
cs ae 
Distance Riverside | Whittier | Distance Riverside stele 
above above 
water. soil. acaLar. soil. soil. 
Inches. Per cent. | Per cent. Inches. Per cent. | Per cent. 
22. 85 46.74 19 TS. GO Fh See 
B) adil See eae 45. 33 TAME PM joey co eee & 34.75 
4 DISET | RAIS 22 isto wal ccc te 
6 tories dace 40. 25 242 ores 32. 82 
7 PYLE [he MOE 25 1653502 aeons 
aaa ern a 40. 7! 28 15. 00 24. 59 
10 285) Tse. Ey 31 14. 36 5. 59 
es Gee 40. 84 = RS age 8 eae abe aa 
13 20: 59: Ae 4.2 = | 37 | 13.05 4.60 
eo eee ee BOUL Sa | ye AG.-9 a) AD. WP eg 
16 207054) 1 atone 43 Pee ie oe ee 
AS (s VERA 36. 49 | 
| | 
A glance at the table and Figure 1 shows that the distribution of 
moisture is not regular from one end of the column to the other. 
For the Riverside soil it is observed that the percentage of moisture 
is about the same for the first 7 inches. From there to near the to 
of the column the percentage of moisture decreases regularly ab 
distance above water. 
For the Whittier soil it is observed that the percentage of moisture 
is a trifle greater at 12 inches than at 6 inches above water, while a 
_ little over 5 per cent more moisture was found at 3 inches than at 6 
inches. It is observed that in both columns the moisture content 
decreases rather uniformly with difference in height above the lower 12 
to 16inches. The results obtained from these two columns, while not 
in any way considered conclusive, due to methods of sampling, created 
a doubt as to the uniformity of moisture distribution in vertical soil 
columns having the lower end in water. It was to clear up this doubt 
and eliminate other apparent irregularities arising in the Riverside 
work that the other experiments recorded in this bulletin were under- 
taken. 
SOIL USED. 
The soils used in the experiments were: 
Decomposed granite (sandy) from Riverside, Calif. 
Heavy black clay loam from the coastal plain near Whittier, Calif. _ 
Idaho sandy loam. 
Idaho lava ash loam. 
Medium clay loam from Santa Clara Valley, Calif. 
Medium loam from Cache Valley, Utah. 
Each of these soils was taken from the top 8 inches of the field, 
and none contained any artificial fertilizer. ach sample was mixed 
thoroughly, screened through a 10-mesh screen and remixed into a 
uniform mass. 
WILTING PERCENTAGES. 
For the sake of comparison and reference the wilting point and 
moisture equivalent of the soils used were ascertained, and these 
factors, as determined by the Briggs-Shantz method by C. A. Jensen 
of the Bureau of Plant Industry, are recorded in Table 2. 
