204 STORRS AGRICULTURAL EXPERIMENT STATION. 
from the results of the soil test experiments here reported wt 
appears that, in the case of the soil upon whitch the experiment was 
made, the peculiarities of the crop grown in any particular expert- 
ment ts of more importance than any deficiency of the soil in regu- 
lating the demand for fertilizers. During the ten years in which 
the experiments have been made on the field with a rotation of 
crops, the ingredient or ingredients that have been most essential 
have varied with the crop. When corn and oats were grown phos- 
phoric acid and nitrogen appeared to be most essential, while the 
requirement of potatoes seemed to be potash. 
Ln soil tests made for a number of years by the Station, tn coop- 
eration with farmers on farms in different parts of the State, the 
results in numerous instances have shown that deficiencies in the 
sou rather than the kind of crop have regulated the demands for 
Jertilizers. Some soils are naturally lacking in some one of the 
essential ingredients of plant food, but are well supplied with the - 
others; while other soils, like that in experiments at the Station, 
show no special deficiency tn any one of the essential ingredients 
of plant food, but seem to be lacking in all of them. The particu- 
lar importance of these results to the farmer ts the indication of the 
need of studying and testing his own soil to learn tts deficiencies 
and peculiar needs. 
