The soil profile increments of 0 to 5,-5 to 10, 10 to 15, 15 to 25, 25 to
40,
and 40
surveys,
to
so
60 cm are
they
can
those developed
easily
be
on previous
compared
with
collected from Enewetak and Bikini Atolls.
the
LLNL Marshall
bulk
of
data
Islands
previously
We have found that a 40-cm depth
encompasses most of the active root zone of the subsistence crops that we have
sampled in the Northern Marshall Islands.
A trench was dug with a backhoe or
shovel radially from the trees to minimize root damage.
After the sidewall of
the trench was scraped to avoid any possible contamination from the digging
process,
collected
samples were collected from the sidewall.
from a
surface
area
about
25
cm
on
a
The O-to-5-cm sample was
side.
The
area
was
expanded by about 10 cm on each side and cleared to a depth of 5 cm.
then
The upper
surface (1 to 2 em) of this enlarged region (35 by 35 cm) was then cleared to
ensure that neither surface soil nor soil from a preceding increment had fallen
onto it.
(i.-e.,
The next sample was then taken from the entire depth of the increment
5 to 10 cm)
for an area of about 25 em= within the enlarged region.
‘This procedure was repeated until the final depth increment of 40 to 60 cm had |
been collected.
A total of approximately 500 to 900 g of
soil was
collected
for each profile increment.
Many soil profiles were collected at
associated plant samples were taken.
manner described above.
sites around
the
islands where no
These profiles were collected in the same
While the sample profile sites are selected more or
less randomly, it is advantageous to choose a relatively undisturbed site with
litter and surface soil intact.
MARINE SAMPLES
Water Sampling
Large-volume
locations
in
cylindrical
particulates.
seawater
each
samples
lagoon.
fiber-cartridge
Groundwater
All
liter)
samples
filter
(well
(56.5
into
water)
were
15-gal
and
were
taken
filtered
plastic
cistern
from
through
barrels
water
to
various
a
Il-p
separate
(rainwater
from
dwelling roofs) samples (56.5 liter) were collected whenever available at the
atolls.
The
groundwater
separate particulates.
was
filtered
through
1-
Cistern water was not filtered.
and
0.4-y
filters
to
All water samples and
corresponding particulates (filters) were sent to LLNL for processing.