14 F,. A. CARLSON 
less consistent than those in the first foot. This inconsistency 
may be accounted for by lack of soil uniformity. 
The limed plats not only contained more organic carbon, 
but also gave higher yields, than the unlimed plats. The yields 
are expressed in graph form in figure 1 (page 17). 
With one exception there was a greater percentage of nitro- 
gen in the limed plats than in the unlimed plats. The plats in 
rotation all showed a loss of nitrogen in the first foot for the 
ten-years period, while the plats in grass increased in nitrogen. 
Plat 7009, which was kept bare, lost a marked percentage of 
nitrogen in the first foot. Plat 7011, on which the rotation, in- 
cluded legumes, lost a smaller percentage of nitrogen in the first 
foot than did the plats in rotation without legumes. 
These results are consistent with the results obtained on the 
lysimeter tanks (Lyon and Bizzell, 1918). The soil in the lysim- 
eter tanks was obtained from the plats used in these experi- 
ments. It was found that the nitrogen in the drainage water 
from the lysimeter tanks was less where the tank soils had 
been kept in grass, than in a rotation. It was shown also that 
the tank soils kept bare lost more nitrogen than the cropped 
‘tank soils. 
Ratio of carbon to witrogen in plats before and after treatment 
The ratios of carbon to nitrogen in plats before and after 
treatment are given in table 4. The data show the close relation 
between these two elements in the soils studied. The ratio was 
wider in the first foot of soil than in the second foot. The various 
treatments did not cause any constant change in the carbon- 
nitrogen ratio. The effect, if any. was too inconsistent to be con- 
‘sidered significant. 
The results compare favorably with those obtained by Hess 
(1901). He found that the ratio of carbon to nitrogen was not 
materially affected by the treatment appiied. Dyer (1902) also 
reported that the carbon and nitrogen contents of the upper 
stratum of the soil were higher than those of the lower stratum, 
and that the ratio of carbon to nitrogen was wider in the upper 
stratum. Alway and McDole (1916) likewise found that the ratio 
of carbon to nitrogen was lower in the second foot than in the 
surface foot. 
