20 BULLETIN 974, U. S. DEPARTMENT OF AGRICULTURE. 
stocky growth and lay down many more fruipf buds for the succeeding 
year. 
On an area at Whitesbog in which the proportion of peat to sand 
was too small to bring about the most vigorous growth of the bushes, 
an experiment was made in the application, at the rate of 600 pounds 
per acre, or one-eighth of a pound per square yard, of a special fer- 
tilizer which is in successful use in cranberry culture as the result 
of a series of experiments by the New Jersey State Agricultura] Ex- 
periment Station. Important characteristics of this fertilizer are 
its acidity and its comparative freedom from residues of sulphur. 
The blueberry bushes to which this fertilizer was applied made con- 
spicuously better growth than those that were not fertilized, but 
they neither grew better nor fruited better than bushes mulched 
with 1 to 2 inches of rotted peat. . 
In 1919 and 1920 Mr. Charles S. Beckwith, of the New Jersey 
Agricultural Experiment Station, conducted a series of fertilizer 
experiments with blueberries at Whitesbog. The most successful 
results were obtained with a fertilizer applied in the spring of 1919, 
made up as follows: 
Pounds 
Nitrate? 0 feS@da ne 8 is 2) a ee ERS te ae lie Sa pees 170 
mB Sch (at OM 09 616) 6 Dn aan Seema ae Man EIS eRe Mdm emt TNC OS NEO gee seve Mes et 230 
Steamed bone 22/80 “WUTR. eoiaG Oise Bie Vee Sess 340 
Phosphate rock) 8S is a eeOyy Gi k Pee AT ee eee 340 
Betaahl oc ops Pees ey AE ok vas ee as gee ee ee OR ee 170 
The yield in 1920 from bushes thus fertilized was more than three 
times as great as from unfertilized bushes in the same very sandy 
soil. On the basis of this experiment Mr. Beckwith has recommended 
the application of this fertilizer at the rate of 600 pounds per acre, 
or an eighth of a pound per square yard.’ 
As a result of these preliminary fertilizer experiments and in view 
of the fact that the swamp blueberry fruits abundantly and con- 
tinuously in soils containing the proper proportion and quality of 
peat and sand, the use of manure or any chemical fertilizer in such 
plantations is not at present advocated. But if the proportion of 
peat to sand is so low that the bushes appear to be suffering for 
nourishment a mulch of rotted surface peat or half-rotted oak leaves 
should be applied, or a chemical fertilizer similar in character to 
the one described above, or some organic nitrogenous substance, such 
as soy-bean meal or cottonseed meal. 
The swamp blueberry does not require a yearly pruning. When 
one of the stems of a bush becomes unproductive from injury or old 
age it should, of course, be cut out. Ifa large part of a bush needs 
removal it is better to cut all the stems to the ground and let the 
THWor the details of this experiment, see ‘“ The Effect of Fertilizers on Blueberries,” 
published in Soil Science, v. 10, pp. 309 to 312, with plate, October, 1920. 
