716
HAWTHORNE
0
PrTTI Ta SPT PP iy itt
°
2--
oOo
o
4
oom
00
0
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06
o
Oo
@MOo
——
—
0
cm
om oO
é
0
°
Oo
8
Oo
—
—
oO 0 OO
—
oo
—
Zab
xr
_—
-
Hoo o
=
a
ao 10 b-
=
[So oa o
Fig. 5— Variation in the Sr
.
computed from random speci-
mens of samples removed ina
vertical sequence from the soil
profile of field 4, November
1962.
°
7
12
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pop ao 0
14 fu
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/—
~
4
aan
°
16 }o® @ oOo
—
°
waLertitrrr rt tipvirtliry
0
3
10
15
20
or, NC/M*? PER INCH OF INCREMENT
30 soil samples analyzed, the composite variance for nanocuries per
Square meter exceeded the variance for picocuries per kilogram of soil
19 times. The converse occurred 10 times, and the variances were
equal once. Predictions of compensatory combinations of deviations in
the data, i.e., low kilograms of soil per square meter associated with
high picocuries per kilogram of soil, were unreliable.
Taken together, Figs. 2 to 6showed the variation that existed among
the factors from which the "Sr and the "Cs per unit area of soil were
derived. They were concerned with variability in specimen mass per
unit volume and the variation in fission-product concentration per unit
mass. They demonstrated variation in three-dimensional space.
Another kind of variability encountered in the study is illustrated in
Fig. 7, which shows differences in the rate of production of mass of
alfalfa per unit area. The graph represents the mean production of alfalfa in three fields on the indicated harvest dates. Variances in the
weights of alfalfa for all harvests, in grams per square meter, were
tested for homogeneity by a modified Bartlett’s test.? The variances
among fields were equal for each month; but the variances of individual