A Fertility Program for Celery Production


fertilizer. Since it was found that a 12% potash fertilizer,
applied at the rate of one ton per acre prior to setting the plants
to the field was, on the average, best for celery, the comparison
on the extreme right in the figure tells the story with respect
to phosphate requirements of this crop. Over a five-year period
the 9% phosphate formula, at a cost of about $9.50 an acre
more than that of the 412% fertilizer, actually gave a slightly
reduced annual yield. However, the first two years of this
period the 9% analysis fertilizer gave higher yields than did
the 41/2%, which indicates that a soil reserve was built up
by the third year which served to make the 41/ % analysis
fertilizer sufficient thereafter. The "fixing" of the phosphate
in the soil in a relatively insoluble form undoubtedly has some
effect upon these results. It is probable that a 6% material
would be satisfactory, and perhaps more economical than a
change from a 9 to a 41/2% fertilizer material at the start of
the third year on celery land.

TABLE 4.-THE ECONOMIC VALUE OF PHOSPHATE FERTILIZERS FOR CELERY
 PRODUCTION IN THE EVERGLADES.
 Fertil- I Yield Cost i Total Re-
 Treatment i izer per Cost per per turn per Net Profit
 Number Formula'I Acre2 Acre" Crate Acre' per Acre

 A-1 0-0-0 174 $159.55 $0.92 $ 87.00 -$72.55 (loss)
 A-2 0-41/-0 222 176.07 .79 111.00 65.07 (loss)
 B-1 0-0-6 i 352 179.29 .51 176.00 3.29 (loss)
 B-2 0-4Y2-6 435 188.81 .43 217.50 + 28.69
 B-3 0-9-6 466 198.33 .43 233.00 + 34.67
 C-1 0-41/-12I 538 201.55 .37 269.00 + 67.45
 C-2 0-9-12 536 211.07 .39 268.00 + 56.93

 'One ton applie I at planting, one ton applied later as side-dressing.
 2Calculated to the number of 70-lb. field-trimmed crates of marketable celery produced
per acre.
 3Including cost of fertilizer materials, cost of mixing fertilizer @ $3.50 a ton, and all
field costs up to and including stripping and field grading.
 "Assuming a return to the grower of 50c per field-trimmed crate, after all packinghouse
charges, brokerage fees, freight costs, etc., have been deducted.

 Inasmuch as cost data for potash and nitrogen materials
required a more comprehensive analysis than has proven neces-
sary with phosphate fertilizers, Table 4 is included principally
for reference and for convenient comparison. The economic
value of a 41/2% phosphate formula should be evident from
this table. The preceding paragraph suggests the use of a 6%
phosphate fertilizer, rather than a 41/3%, but this difference
is of minor importance, and would depend upon the previous