New York AGRICULTURAL EXPERIMENT STATION. 321 
the soil will remain stored up for a period of years; the potash 
will remain for a few years at least; and the lime is of more or 
less permanent value in the soil. Meanwhile it is possible that 
all of these compounds will have a beneficial effect on the cover 
crops grown in the orchard. Still, it is not profitable to buy 
fertilizers and store them in the soil in this way. 
Since the ordinary farm and garden crops on the Station 
grounds, on soils quite similar to that upon which this experi- 
ment was carried on, show more or less marked beneficial effects 
from the use of potash and phosphoric acid fertilizers, it may 
be assumed that, during the fifty-seven years this orchard has 
been growing, general farming has been more exhaustive of the 
elements added in this experiment than have the apple trees. 
There are many facts that lead us to assume that the apple 
does not quickly exhaust a soil, but to the contrary wears a soil 
but little. This experiment suggests that such may be the case, 
but of course does not prove it; for the question is a complicated 
one, involving many factors not here considered. 
The practical application of the information obtained by this 
experiment is, that the apple grower should not apply manures 
in quantity until he has obtained some evidence as to what focd 
elements, if any, are needed in his soil. Good evidence in this 
direction is furnished by the trees themselves. So long as trees 
are growing well, adding a fair amount of new wood each year, 
and producing good crops of well-colored fruit, it may be taken 
for granted that they need no additional food from fertilizers. 
Should the growth and behavior of the trees be otherwise, it 
may be suspected that they need more, or other foods, and ex- 
periments should be set on foot to determine what and how 
much. 
PLAN FOR FERTILIZER EXPERIMENT. 
The following is a brief plan whereby a man may determine, 
in some measure at least, what fertilizers his orchard needs. . 
The plan is adapted from a fertilizer experiment which has now 
been running for ten years in a young apple orchard on the 
Station grounds. 
The trees selected for this experiment should be of the same 
variety and age and should stand in a soil as uniform in texture 
and fertility as the orchard affords. Unless one has positive 
proof that the trees do not need any one or more of the three 
II 
