FIELD EXPERIMENTS WITH FERTILIZERS. alii; 
the fact that these plots have received no fertilizers for the past 
twelve years. The yields on the sections of plots 6a and 64, on 
which mineral fertilizers only were applied, were much better 
than on the sections not fertilized, and perhaps better than 
might be expected considering the fact that no nitrogen has 
been used with the mineral fertilizers on these plots since 18go. 
The results on the sections of plot 66 were considerably better 
than those on plot 6a. ‘The lack of nitrogen in the soil of the 
sections supplied with only mineral fertilizers seemed to have 
caused a pale color in the crop during the growing season, and 
much smaller yields of grain, with considerably less stover. 
On the whole, however, the mineral fertilizers alone appear to 
give better results in these experiments with corn than has 
been obtained in similar experiments with common grasses. 
This would seem to indicate that corn is better able than the 
grasses to gather nitrogen from natural sources. 
The yields obtained on the sections of plots 7 and 10, to 
which the smallest rations of nitrogen (25 pounds per acre) 
were applied, were considerably larger, especially on series A, 
than the yields obtained where only mineral fertilizers were 
used. The increase on plot 10 is somewhat greater than that 
on plot 7. This difference is doubtless due in part at least to 
the fact that in heavy rains the soil on plot 7 becomes washed 
so that the conditions for growth are less favorable than on the 
other plots. On the sections of plots 8 and 11, where 50 pounds 
of nitrogen per acre was used, there was quite an increase in the 
yields over those obtained from the use of either mineral fer- 
tilizers only or minerals plus the small ration of nitrogen. 
The yield of crop from the sections of plots 9 and 12, on which 
75 pounds of nitrogen per acre were used, was slightly greater 
on series A than was obtained from sections where 50 pounds 
of nitrogen was used, but in the case of the corresponding sec- 
tions on series F there was no increase. In fact there was a 
falling off in yield on section F of plot 12 as compared with 
section F of plot 8. This condition can probably be accounted 
for by assuming that the soil on section F of plot 12 had become 
so acid as to interfere with the growth of corn. ‘This is ex- 
plained below in the discussion of the yields with and without 
lime. 
The relatively small increase in yield from the large ration 
of nitrogen as compared with that from the medium and small 
