New York AGRICULTURAL EXPERIMENT STATION. 369 
TAWLE IX.—AMOUNTS OF PLANT Foop USsEp PER ACRE. 
Number of |-~: Phosphoric | Potash Lime Magnesia 
VARIETY, trees an acre. Nitrogen. acid (P.0O;). | (K20.) (CaO.) (MgO). 
: Lbs. Lbs Lbs. Lbs Lbs 
i Ways) (oh Wee, oe Oe 35 DED 14.0 55.0 57.0 23.0 
jE pe ons oe ge ae 120 74.5 18.0 72.0 114.0 35.0 
IBORTHOE ihe cae ls. oss 120 29.5 7.0 33.0 38.0 11.0 
Plum Renita ate Perens eaux 120 29.5 825 38.0 41.0 13.0 
NOTICE 7k a0 kc sg Be 240 45.5 15.5 57.0 65.5 19.0 
It is evident that the amounts of plant-foot constituents given 
in this table were present in the soil in available form during the 
growing season and within reach of the root systems of the trees. 
If one knew that there were no available plant-food in the soil, 
the above. quantities would be the smallest amounts that one 
should apply for a season’s growth. On the other hand, if one 
knew how much available plant-food were present in the soil, 
then it would simply be necessary to supplement this supply, 
if it were less than the season’s requirements. At present we can 
ascertain what we want to know about the amount of available 
plant-food the soil can furnish only by rather crude experiment- 
ing. 
_ It is quite noticeable from the figures given in Table IX that 
an acre of peach trees uses considerably larger quantities of 
plant-food than any of the other varieties of fruit trees given. 
The apple used approximately the same amounts per acre as the 
quince. 
The amounts of nitrogen and potash used by any one kind of 
fruit trees were approximately the same in most cases while 
the amount of phosphoric acid was only about one-fourth the 
nitrogen or potash. In most commercial fertilizers used on fruit 
trees the phosphoric acid is present in proportions about four 
times the nitrogen. This is on the assumption that the soil con- 
tains more nitrogen relatively than phosphoric acid, which may 
or may not be true in individual cases. The question may be 
raised as to whether quantities of phosphoric acid are not fre- 
quently applied much in excess of the actual need of a season’s 
crops. 
AMOUNTS OF PLANT-FOOD CONSTITUENTS USED PER ACRE BY DIFFER- 
ENT PARTS OF TREE. 
It is desirable to notice the amounts of plant-food constituents 
used per acre by different parts of fruit trees, since in some sea- 
sons no fruit is borne and under these conditions only the leaves 
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