*' USE 4F NITRATE OF SODA IN THE GROVE.


I Nitrogen (ammonia) is the one element of plant food that

is at once the most important in the citrus grove and at the

same time the most difficult to supply in sufficient quantity

without^over-supplying it.

Our Experiment Station has shown that it is the one element

that is leached out of the soil more quickly than any other.

If, therefore, a sufficient amount is supplied under favorable

weather conditions and this is followed by a sudden, heavy fain-

fall this element is washed out of the soil and lost so far as

the citrus tree is concerned. If, on the other hand a large

arubtoo ac to guard a-n5t ammonia hungry. we have favdr-

able climatic conditions following, an over-supply v& be pres-

ent f==-"-tfm- e. It is not material from what source the am-

monia is supplied, leaching rains will cause a large amount to

be washed out of the soil and it will require time for the organ-

isms of the soil to prepare an additional amount of available

ammonia for the use of the tree. It does not matter what time

of year these rains may occur,if these rains are sufficiently

Iaeavy to drench the soil the available ammonia will be carried

off with the water. The amount that is arkied aw.ay will depend

upon the amount and suddenness of the rainfall. iWhen aor Florida

soil is moderately dry, such as we normally think of as jZU

s:jme fo tree growth, it requires about one inch of rainfall to

properly moisten the soil to approximately the depth to which the

roots penetrate. Any excess rainfall above this amount is likely

to pass into the subsoil or below.



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lfitrate of soda is the one element commercial fer-

tilisess that is immediately available as plant food. Sulphate

of anmmonia, tankage, vottonseed meal as well as other organic

ormmonias require a transformation by the soil organisms before

the afrmonia is in proper shape for use by the tree as food.

From this it will be seen that when a grove is suffer-

ing from want of ammonia, the quickest way of supplying the

need is by the use of nitrate of soda. This conditions is

indicated, usually, by lack of the deep green color in the leaves.

Itbs is of course not the only factor which caused tihe leaves to

lose their color.


WHEN TO USE. As nitrate of soda is the form of

ammonia most easily leached from the soil, we naturally want to

apply it when there is the least probability of leaching rains

to occur. This period of the year occurs from about the latter

part of September until sometime in the spring or early summer.-

But this is viewing the question only from the standpoint of loss

of ammonia from leaching. We must remember that nitrate of

soda is the most readily available form that we have consequent-

ly a heavy application of nitrate of soda followed by a period

of unusually good soil conditions, is likely to stimulate growth

quite rapidly. Consequently an application made three or four

weeks before a frost, or freezing weather, is likely to stim-

ulate the trees into growth just in time to be caught by the

frost. Consequently it is inadvisable to apply nitrate of soda

at such a time as would cause such a stimulation. If during

the early fall or in the spring the trees should show need of









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ammonia, an application of nitrate of soda will quickly relieve

the situation. If nitrate of soda should be applied to a grove

just previous to blooming time, at the rate, say, of 5 lbs. of

nitrate of soda to a tree that is likely to bear 10 boxes of

fruit, it will have a very beneficial effect, provided the

moisture conditions of the soil are quite normal. If, however,

a rainfall should occur t at is just heavy enough to moisten

the soil well but not heavy enough to leach the nitrate, there

is some possibility of causing an abnormal shedding of bloom.

Professor Collison's exact experiments have shown

that the ammonia from dried blood and cottonseed meal is leached

out of the soil more readily than sulphate of ammonia. Conse-

quently the time to apply sulphate of ammonia is during that per-

iod of the year when the ammonification bacteria are working

most rapidly and when leaching rains may be expected, that is,

the late spring, summer and early fall.