A Fertility Program for Celery Production


 A third important property of these soils is their high ni-
 trogen content. Inorganic soils under continuous cropping
 inevitably become nitrogen deficient, unless applications of
 nitrogenous materials are made from time to time. In peat
 and muck soils, natural chemical processes and micro-organisms
 within the soil are always at work disintegrating the organic
 material, and these processes result in a gradual release of the
 nitrogen in forms available to plants.
 Fourthly, almost all of these organic soils overlie marl or
limestone, and the upward movement of soil waters during the
dry season carries with it dissolved calcium and magnesium
salts. For this reason none of these soils is highly acid and the
addition of limestone or hydrated lime is neither desirable nor
necessary.
 There are, of course, certain disadvantages inherent in these
soils. We have already mentioned the absolute necessity of
drainage ditches, and the advantages of mole drainage. There
is also one direct danger inherent in organic soils wherever
they may be located. This is the danger of fire-a dry muck or
peat soil may be badly damaged by burning. On such a burned
soil the problem of fertilization is greatly complicated because
of the alkaline residues resulting from the burning, and since
the fertilizer problem is already a complex one the burning off
of these soils should be avoided when possible.
 Peat and muck soils are almost universally deficient in both
potassium and phosphorus, and the Everglades soils are no ex-
ception. In southern Florida there may also be a deficiency of
available manganese, zinc and copper in the soil. Since the
primary purpose of a good fertility program is to make avail-
able to the growing plants a proper balance of all needed nutrient
materials throughout the growing period of the crop, several
experiments were designed for the purpose of studying this
problem. They necessarily cover such essential points as the
amount per acre of each fertilizer material which must be sup-
plied to give the best possible yield, the most satisfactory method
of applying the fertilizer, the best time for applying the fertilizer
(whether entirely before planting or in part as a side-dressing),
and, finally, the fertilizer program which will return the highest
dividends over and above the cost of fertilization per unit area.
In short, it was desired to find the most economically sound
fertility program for growing celery in the Everglades.