How To Correct It 
In an emergency, a foliage spray 
containing zinc is the best means of 
correcting zinc deficiency in plants 
other than onions or Russet Burbank 
potatoes. To make an effective spray, 
dissolve 1 pound of zinc sulfate and 
a cupful of household detergent in 50 
gallons of water. Apply the solution 
when the plants are small, using low- 
pressure ground spraying equipment. 
Wet the foliage thoroughly. One or 
more repeat applications may be neces- 
sary. 
Applying zinc to the soil generally 
gives better results than spraying it 
on the foliage, and zinc thus applied 
is available to plants for 4 or 5 years— 
perhaps longer. Any zinc compound 
that will dissolve in dilute hydrochloric 
acid is satisfactory as a fertilizer 
material to be applied to the soil. Such 
compounds include zinc sulfate, zinc 
oxide, zinc carbonate, and zinc am- 
monium sulfite. 
(The merits of chelated zinc — 
organic compounds of zinc—as foliage 
sprays or soil treatments for field or 
vegetable crops have not offset the 
higher cost.) 
Zinc is held firmly in the soil. It 
cannot be leached out by rain or by 
irrigation water. Likewise, it cannot 
be carried by soil water to the roots 
of plants. Roots must grow to the zinc. 
So zinc fertilizer. to serve its purpose, 
must be mixed into the soil where 
developing roots can come into contact 
with it. 
For nonsandy soil on which an 
annual crop is to be seeded, the 
recommended method of correcting 
zinc deficiency is to incorporate 10 
pounds of zinc per acre into the soil 
by plowing it under, or drill it in a 
band 2 inches below the seeding depth, 
2 inches to the side of each seed row. 
On sands, apply 3 to 5 pounds of zinc 
Washington, D. C. 
per acre in the same way. In fields 
of perennial crops, such as hops, broad- 
cast 20 to 30 pounds of zinc per acre 
and mix it into the soil, or drill it in 
a band at a depth of 10 inches, 1 foot 
to each side of each row of plants. 
Any of the zinc compounds recom- 
mended for use as soil treatments can 
be applied alone or used in a mixed 
or liquid fertilizer. Zinc is more effec- 
tive if banded with nitrogen fertilizer 
than if banded alone. The zinc content 
of a commercial mixed fertilizer is 
printed on the bag. The availability 
of zine used in a fertilizer mixture is 
not reduced by phosphate. If you mix 
zinc sulfate with dry nitrogen fertilizer, 
spread the mixture immediately to 
avoid caking. 
Zinc applied to soil or as a foliage 
spray at the rates recommended. here 
will not injure crop plants. 
How To Prevent It 
Since the surface layer of a soil 
usually contains most of the available 
zinc, anything that guards the soil 
against abnormal erosion helps to pre- 
vent zinc deficiency. In addition, the 
following practices help maintain an 
adequate supply of available zinc in 
the soil: 
e In using phosphates as fertilizers, 
take care not to apply them at rates 
higher than those recommended. For 
reasons not yet well established, too 
heavy use of phosphates can cause zinc 
deficiency in some soils. 
e Encourage development of extensive 
root systems by crop plants. Since 
zinc cannot move in the soil, its avail- 
ability to plants depends largely on 
movement of plant roots to it. Exten- 
sive root development is favored by 
tillage practices that prevent compact- 
ing of soil; by methods of water man- 
agement that prevent waterlogging of 
soil; and by crop rotations such as 
those including clover or alfalfa. 
Issued November, 1961 
asec ag es 
For sale by the Superintendent of Documents, U.S. Government Printing Office, 
Washington 25, D.C. 
Price 15 cents 
