NH,NO3 equivalent to 200 kg N per hectare), 2 percent agricultural grade

sulfur (reduced pH from 7.6 to 5.4), and 5 percent organic matter (alfalfa

meal).

The mixing and potting of soil was done in closed systems within a

full containment dust hood.
Soil was potted in 22-cm diameter plastic pots
which were sleeved inside of 10-liter plastic buckets, and then covered with

5 em of #16 silica sand to prevent soil particle resuspension.

Seeds were

planted in the sand immediately above the soil surface.
Moisture was supplied
by irrigation with deionized water.
Cooling air for the glasshouse was drawn
through medical filter media and activated charcoal filters.

Results from radiochemical analysis of Area 13 soil subsamples are given in

Table 1.
Reasonable uniformity in 239*240py and 24!am contents was obtained
by the mixing process; however, the activity levels turned out to be much
lower than had been anticipated.
As a result, it was necessary to combine the
plant material grown on similar treatments of the three sets into just one set
of three pooled replicates in order to obtain an adequate sample size for

radioassay.

Barley plants were grown first on the Area 13 soil and harvested

in the dough stage by cutting them at a point about 5 cm above the top of the

sand layer and dividing them into straw and fruit head samples.

Alfalfa was

grown next on these soils.
Three successive cuttings of forage were harvested
in the quarter-bloom stage and combined to form one set of three pooled replicates for radiochemical analysis.
As with barley, the alfalfa plants were cut
about 5 cm above the sand surface as an added precaution to prevent contamination from soil particles.
Results from the first experiment showed need for working with soil containing
higher levels of contamination.
In addition, the response from the soil
amendment treatments indicated a practical influence from only the DTPA chelating agent.
Consequently, a second series of experiments was run using soil
collected from eight of the NAEG study areas.
For these experiments, the soil
was collected from a site within each fallout area at which FIDLER activity
readings ranged from 20,000 to 30,000 cpm.
The design of each soil experiment
consisted of three sets, with and without DTIPA chelate, replicated three times

(3 sets x 2 DTPA x 3 replicates = 18 pots).

the same as described above for Area 13 soil.

Mixing and potting methods were

The 239°249py and 24!am contents

and ratios for these soils are given in Table 2.

Wheat and soybean plants

were grown on these soils, harvested, and pooled into one set of three replicates each, in order to provide an adequate sample of plant tissue for radiochemical analysis.
Results for the wheat crop have not yet been returned from
the contract analytical laboratory.

RESULTS AND DISCUSSION

Data from the first experiment with barley plants are given in Table 3.

The

results for both Pu and Am radionuclide uptake were very erratic and reminiscent

of the kinds of variability often encountered during our earlier investigations

(Nishita et al., 1961) of plant uptake of radionuclides from soils contaminated
with fallout material from aboveground nuclear weapon tests at NTS.
In this

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