ofa
two types of experiments under conditions which let us imow
the quantity of 1451 ingested daily,
The results are given by graphs 7 and 6.
dlecussion of the Results
ion
Table 1 shows the large variations ia the percentage of 1173
directly retained by the harvested gress, Two reasonsfor these
obeerved differences are, probably, the height of the grese st
the time of spraying and the tecinique for harvesting the ssuples.
Concerning the influence of the grase height at the tine of
contamination, a prelininary experiment seens to indicate thet #0
linear correletion exists betwen the quentity of fresh material per
anit of surface and the specific activity of the dried saterial.
The exact nature of the correlation curve will be detersined by
later experinents.
In anc. ter wy, calculstion of the correlation between the
quantity of fresh aaterial per mit of surface and the bervested
activiry per wit of serface, shows that the better correlation
coefficient is obtained for en exponential type function (grepa 9),
Concersing the harvesting technique, results show that head-
mowing (cut to soil level) peraite fer better recovery of the redio-
fo we verify that the senpling procedure may have a direct
¥ oo
effect on the results when they are expressed as activity per wit
of harvested surface (microcuris 1251/s?),
Evolution of the apecafia activity of grass from the differeat
pens does not appear either to be influenced by the fact of the
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oe aun criceseelea talily llnnctbt
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