Table 1—SAMPLING STATIONS
Rainfall
Soil
Altitude
1954-1956
in./yr
pHs
Ref.
Locality
Al
A2
A3
Cwmystwyth, Cardigan
Cwmystwyth, Cardigan
Cwmystwyth, Cardigan
1200
1100
800
60
60
60
4.3
4.5
4.9
0.14
0.17
1.0
Peat on shale
Soil, grass,
(free draining)
sheep bone
Peat on shale
Soil, grass
B
Vyrmwy, Montgomery
1100
62
5.4
1.8
Peat on shale
Soil, grass,
2.7
(free draining)
Free draining
soil on sand-
sheep bone
Soil, sheep
bone
Cc
Talgarth, Brecon
ft
Total Ca,
1050
36
6.2
g/kg
Type
(free draining)
Samples
stone
D
Princetown, Devon
1300
81
5.6
5.8
Sandy peat
Soil, grass,
E
Rookhope, Durham
1600
42
3.6
0.4
Peaty sandy
Soil, grass,
F
Norwich, Norfolk
G
Boxworth, Cambs,
85
26
7.5
4.7
157
22
6.8
14.6
on granite
loam with
podsol layer
Sandy loam
with gravel
Dark brown
loam with
H
Aldermaston, Berks.
250
25
6.0
1.6
I
Culham, Oxon
180
22
6.6
3.0
chalk
Sandy soil
with humus
Sandy soil
sheep bone
sheep bone
Soil, grass,
sheep bone
Soil, grass,
sheep bone
Soil, grass
Soil, grass
on lower
J
K
Grove, Berks.
Chilton, Berks.
250
400
25
7.1
24
39
8.0 156
greensand
Heavy gault
clay
Calcareous
clay with
Spee ecoe lay
Soil, grass
Soil, grass
flint
test the penetration with depth. At A3 one single square yard soil sample only was taken in May,
but when the sampling was repeated in November, twelve cores were taken.
At the five auxiliary stations, repeated samples of grass were taken at intervals from May
to September 1956. Samples were of two types: (1) Accumulated growth taken from previously
untouched plots; (2) Fresh grass which had grown since the last cutting.
4 RESULTS ON SOIL, GRASS AND SHEEP BONE
4.1 Sr®° in Soil
A list of the results of Sr°® analysis of soils taken in 1956 is given in Appendix 1, anda
summary of the results by HCl extraction is given in columns 3 to 5 of Table 2. In Fig. 4 the
sr*? activity by HCl extraction per unit area of soil to depth 4 in.* is compared with the annual
rainfall at the samestations in the years 1954-1956. The line on the graph showsthe fallout of
Sr*° which would have occurredif it is proportional to rainfall, using as reference point the
cumulative total in rain of 5.6 mc/km? to July 1956, measured at Milford Haven, where the
annual rainfall is 38 in. (Stewart et al., 1956, extended by further measurements). There isa
rather large scatter in the results from the stations Al, A2 and A3, but otherwise there is good
agreement between the fallout of Sr*® believed to have occurred in rain, and that found in the
top 4 in. of soil.
*The unit puc/m* is used in Table 2 and Appendix 1. The unit mc/km’, equivalent to 1000 puc/m? is
used in Fig. 4, because this unit is a commonly used measure of fallout generally.
213