40 STORRS AGRICULTURAL EXPERIMENT STATION. 
Although the factor 6.25 used for estimating the amount of 
protein in the crop from the quantity of nitrogen as determined 
by analysis is known not to be entirely correct, still for prac- 
tical purposes it is perhaps sufficiently accurate; and in order 
to make the results of these experiments readily comparable 
with those of preceding years as published, it seems best to 
make use of the same factor that has been used in the past. 
EHXPERIMENTS WITH CORN. 2 
As shown in the diagram on page 36, corn is grown on the 
two series of sections lettered A and F at the north and south 
ends of the plots. The same kind of corn, a Rhode Island 
White Cap, is grown on both series. The seed planted on each 
section in any year is that grown on the same section during 
the preceding year. ‘he original seed planted on series F was 
obtained at the beginning of the experiments in 1895. For 
series A a new lot of seed was obtained in 1898. 
Previous to 1898 both series of corn sections, A and F, were 
fertilized in the same manner. It was observed, however, that 
the corn did not appear to grow so well on some of the sections 
of plots treated with the largest quantities of sulphate of am- 
monia as.on those treated with the corresponding amounts of 
nitrate of soda. ‘The question arose whether the soil on the 
former plots might not become acid to such a degree as to be 
unfavorable to the growth of corn. ‘The natural tendency is 
for the ammonia of the sulphate to be changed in the soil into 
nitrous and nitric acids, which are either taken up by the 
plants or leached out of the soil in drainage waters. In the 
nitrate of soda, on the other hand, the nitrogen is in the form 
of nitric acid, which is in like manner removed from the soil 
by the plants and in drainage waters. Thus on the sulphate 
plots the sulphuric acid and on the nitrate plots the soda 
would be left as residues in the soil, to be slowly removed by 
the plants or in drainage waters, and would thus tend to 
accumulate. In such a case, the hypothesis that the soil on 
the sulphate plots, especially where large quantities of the 
material were used, might become so acid as to interfere with 
the growth of corn, would seem to be reasonable. 
The acidity of the soil on these sulphate plots might be cor- 
rected by lime, in which case there would be a tendency toward 
