xt7xd21rhb39 https://exploreuk.uky.edu/dips/xt7xd21rhb39/data/mets.xml   Kentucky Agricultural Experiment Station.  journals kaes_circulars_004_624 English Lexington : The Service, 1913-1958. Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Circular (Kentucky Agricultural Experiment Station) n. 624 text Circular (Kentucky Agricultural Experiment Station) n. 624  2014 true xt7xd21rhb39 section xt7xd21rhb39 I
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 CONTENTS y
Kentucky Fertilizer Law ...................................................... 3
Oxide and Elemental Labeling ............................................ 7
F0rm of Fertilizers ................................................................ 8 _
Dry mixed fertilizers ........................................................ 9
Dry fertilizer materials .................................................... 11
Fluid mixed fertilizers ...................................................... 11
Fluid fertilizer materials ................................................ 12 i
Deciding What Fertilizer to Use ........................................ 13
i
This circular rr*p{accs [.(’(If'l(’f 171 mu] Aliso. 209-.·\. 4

 Fertilizer Facts for Kentucky
By Kenneth L. Wells, Extension Specialist in Soils
Kentucky farmers used nearly three—quarters of a million
tons of commercial fertilizer in 1968. That’s over twice the
tonnage they purchased in 1945. But that’s not the whole story _
—in 1945 each 100—pound bag of fertilizer purchased contained,
on the average, just over 20 pounds plant nutrients. In 1968 _
this had nearly doubled. Each 100 pounds of fertilizer now —
contains, on the average, nearly 36 pounds of plant nutrients.
Total plant nutrient consumption was over one—fourth million
tons in 1968, a drastic increase from the 60,000 tons used in
1945. These trends in fertilizer used on Kentucky farms are
. l shown in Figures 1-3 below; they point out the increase in use
of fertilizer for crop production which has taken place in
Kentucky.
Why has fertilizer use increased at such a pace? Many
factors are responsible, such as the availability of more highly
concentrated fertilizers, a more efficient fertilizer marketing
system, better machinery, and the like. However, the cost-
· price squeeze which Kentucky farmers have operated under
quite likely has been a major reason for increased fertilizer
consumption. In trying ways to increase production efficiency,
. the farm producer has become aware that he can profit from
I adequate use of fertilizers. Money spent for fertilizer and lime
is favorably related to greater cash receipts from crops sold.
This trend for crop receipts to increase as more fertilizer and
lime is used is shown in Figure 4. In today’s agriculture in
Kentucky the use of fertilizer for increasing crop production is
an integral part of profitable farming systems.
KENTUCKY FERTILIZER LAW
All materials offered for sale as fertilizer in Kentucky must
have the guaranteed chemical content clearly labeled on the
bag or on a tag attached to the bag for bagged fertilizers, or on
the invoice for bulk fertilizers, either diy or fluid. The label for
dry mixed fertilizer shown in Figure 5 is an example of an
acceptable label for field or agricultural grades. If plant nutri-
ent content other than nitrogen, phosphorus, and potassium is
{ claimed by the seller, the nutrients claimed must also be
3

 mrs cormskciu. t=&¢. To P1'CV(‘]1t POSSll)lC COI1fllSlOI1 l)Ct\VCC‘l1
n gallons and pounds of fluid fertilizers, always purchase fluids
bv the wound instead of bv the fallon.
I , l , B
5

 Can5ump`{¤•n ol Plant ,
uutnmts (•/¤)
40
/¤~¤,¤-¤
0
3c
/ q/-.
20 ,1;.;-¢ O
\0
O
945 \950 \955‘ \%0 \%5 mo
-YEAR`
Figure 3.-—Aver¤ge Plant Nutrient Composition of all Com- _
mercial Fertilizers Used in Kentucky Since l94S
CASH RECE\Vl'$ FROM
CROPS Cvmllwns cl   _ I
500
0
men
400
° \:6$ \;66
300 HSS
o
\960
¤
R50
200
0  
o no 3o 40 So
Fswtilnur uml Lime €1.pewyz.$(rm\\x¤ns ol? $) R
Figure 4.-—Increase in Expenditures for Fertilizer and Lime as i
Related to Increased Cash Receipts for Crops Sold
6

 The table below shows which other elements can be claimed
in fertilizers sold in Kentucky, and the minimum percent which
can be claimed.
Element Minimum content (%)
Calcium (Ca) ............................................ 1.00
Magnesium (Mg) ...................................... 0.50 U
Sulfur (S) .................................................. 1.00 ·
Boron (B) .................................................. 0.02 -
Chlorine (Cl) ............................................ 0.10
Cobalt (Co) .............................................. 0.0005
Copper (Cu) ............................................ 0.05
_ Iron (Fe) .................................................... 0.10
‘ Manganese (Mn) ...................................... 0.05
Molybdenum (Mo) .................................. 0.0005
Sodium (Na) .............................................. 0.10
Zinc (Zn) .................................................... 0.05
Occasionally a material is offered for sale as a so—called
“soil conditioner” and carries no guarantee of plant food con-
' tent. The profitable use of such materials is highly questionable.
It is always best to buy a material for which plant food content
is guaranteed. Then you know the plant food value of the
I product.
More detailed information on the Kentucky Fertilizer Law
can be obtained from the Division of Regulatory Services, Ken-
tucky Agricultural Experiment Station, Lexington, Kentucky
40506.
OXIDE AND ELEMENTAL LABELING
By law, the content of all plant nutrients sold in Kentucky,
except for phosphorus and potassium, must be expressed on
the elemental basis. This includes nitrogen. It means that the
guaranteed content of all nutrients except phosphorus and
potassium is in terms of pounds of pure element per 100 pounds
of fertilizer. Phosphorus and potassium have traditionally been,
and are presently, guaranteed on an oxide basis instead of the
_ pure element basis. Phosphorus content is guaranteed as P¤O¤
and potassium content is guaranteed as KgO. Since P;O¤ con-
I tains only 44 percent of the pure element phosphorus, this
means that each pound of guaranteed P;O:. contains only 0.44
7

 GUARANTEED ANALY5\S
Nl`l-ROGEN - _.___ - $.00%
AVMLABLE l>l'lO$Pl'l0RlC AUD .... _ .... l0.00%
  QYOYO $Ul‘l:Qt€ O; pO`l`¤5l'l .... —- l5.00%
Figure S.——Ex¤mple ofthe Fertilizer Lcbel for Fertilixers Sold in n
Kentucky
pound of pure phosphorus. By the same token, KgO contains
only 83 percent pure potassium, which means there is 0.83
pound pure potassium for each pound of K;O guaranteed on
the bag. This is sometimes confusing in interpreting soil test A
results in order to make fertilizer recominendations. Always
he sure you know which hasis your recommendations are on- y
the oxide or elemental. ·
The following conversion factors simplify converting oxide
to element or element to oxide:
pounds oxide l’,();, x 0.44 ; pounds elemental phosphorus
pounds elemental P x 2.29 Z pounds oxide ILO;
pounds oxide K,() x 0.83 Z pounds elemental potassium
pounds elemental K x 1.20 Z pounds oxide KJ)
FORM OF FERTll.lZERS
Both dry and fiuid fertilizers are available to Kentucky
farm producers. There is no particular agronomic difference
luetween dry and fluid fertilizers on a pound—for-pound plant
food lvasis. This means that so long as the same amount of
plant nutrients is applied to a particular soil-crop—climatic
8 a

 situation there should be no difference in agronomic effective-
ness between fluid and dry fertilizers except in a few instances
where dry mixed fertilizers have been over-ammoniated. In
over—ammoniated dry fertilizers, the water-solubility of phos-
phorus is reduced. This is not a factor of major concern, how-
ever, unless the water-solubility of phosphorus drops below
40 to 50 percent. Most field experiments under soil-climatic-
cropping conditions prevalent in the southeastern United States
have shown 40 to 60 percent water—soluble phosphorus to be
adequate for most agronomic crops. For short season horti- ‘
cultural crops such as Irish potatoes or snap beans, use of more
highly water-soluble phosphates can be an advantage. Nitrogen _ '
and potassium in dry and fluid fertilizer are generally com-
parable in water—solubility.
There are also no particular agronomie differences between
pulverized and granulated or mixed fertilizers and fertilizer
- materials so long as they have been properly manufactured and
are comparably applied on a pound—for—pound plant nutrient
basis.
Sometimes a question arises concerning the effectiveness of
applying fertilizer in the form of foliar sprays directly on the
crop as contrasted to the prevalent method of applying fertil-
izers to the soil for subsequent crop use. For foliar application,
~ the plant food content of the spray has to be very low or the
plants will “burn.” This means that several applications of a
foliar spray are necessary per season. This also limits the amount
l_ of primary plant nutrients which can be applied as a foliar
spray, and as a result the total pounds of N—I’-K needed for
most profitable production cannot feasibly be applied to most
crops. In some instances of micro-nutrient dehciences, foliar
applications can be effective since only very small amounts of
micro-nutrients are actually needed.
Both dry and fluid fertilizers are commonly sold as either
mixtures or materials. Mixtures are fertilizers containing more
than one primary nutrient (N,l’, or K) while materials are
fertilizers containing only one primary nutrient. Trends in
forms used in Kentucky are shown in Figure 6.
Dry Mixed Fertilizers
Dry mixed fertilizers are manufactured and sold as either
pulverized, granulated, or bulk blended mixtures. They can
be bought either bagged or in bulk.
* 9

 use at ctkss (°/on
YEAR o 20 40 so 80 wo
M4  
 
**6*  
 
we  
CLASS 0r FERTu.iz£R
! Dry Murtures V
E Dry l‘·‘|¤T.•.rn¤\S
W Flunl Mcttenuks
Fluul Mwturu
Figure 6.——FertiIizer Use Trends in Kentucky, by Class of Fertil-
izer ‘
Pulverized mixtures have the advantage of uniformity of
grade and a low cost of production. Usually pulverized mix-
tures contain calcium and sulfur, since ordinary superphos-
phate (2()f»£ l’;()s) is a common ingredient and contains sizable
amounts of gypsum (calcium sulfate). Their main disadvantage .
is commonly a low analysis and a less desirable physical condi-
tion than granular mixtures. Granular mixtures are more free
flowing than pulverized mixtures. They also supply calcium
and sulfur when ordinary superphosphate (20%) is used in V
making them. Granulated mixtures are also more uniform in
plant food content per granule. Their main disadvantage is a
high cost of manufacturing. Over-ammoniation can decrease
the solubility of phosphorus in either pulverized or granular
dry mixtures.
Bulk blended mixtures are made by physically mixing
fertilizer materials (those containing only one primary nutri-
ent) and certain mixed fertilizers. Either pulverized or granu-
lar products can be blended in this manner. Granular bulk
blended mixtures have the advantages of good physical proper-
ties and loxv cost of production. Grades can also be blended to
fit the exact ratio desired. The main disadvantage is the possi-
bility of non-uniform blending unless proper equipment and
properly selected materials are used.
.·\s indicated in Figure 7, bagged dry mixtures are by far '
the most commonly used form of mixed fertilizer in Kentucky. ‘
10 ~

 F DRY BULK
22 %
FLUID
  I   I
DRY BAGGED
V 77 °/a `
t Figure 7.-Use of Mixed Fertilizers, by Class, in Kentucky, 1967
Dry Fertilizer Materials
As indicated above, fertilizer materials are those containing
only one of the primary nutrients (N,P, or   Examples of
dry materials commonly sold in Kentucky and their primary
· nutrient content are shown in the following table:
Primary nutrient Content of primary
- contained nutrient
Amonium Nitrate ...................... Nitrogen 33.5% N
Ammonium Sulfate .................... Nitrogen 20-21% N
Sodium Nitrate .......................... Nitrogen 16.0% N
Muriate of Potash ...................... Potassium 60-62% KZO
Sulfate of Potash ........................ Potassium 48-50% KBO
Ordinary superphosphate ............ Phosphorus 20.0% PJ);
Triple superphosphate ................ Phosphorus 46-48% l’,();
Fluid Mixed Fertilizers
Mixed fertilizers in the fluid form are now availahle in some
sections of Kentucky. They are of two typcs—clear mixtures
and suspensions (either a true suspension or a slurry). Both
Y are commonly manufactured hy so-called hot-mix or cold—mix
processes. Hot mixing refers to the great amount of heat which
I is produced hy mixing phosphoric acid with ammonia to make
the fertilizer. \Vhen a hase hlend from a hot-mix plant is used
11

 in making other grades, the process is called cold—mix since
no heat is produced. The main difference between clear and
suspension mixtures is analysis. Clear mixtures are of lower
analysis because plant nutrients, especially potash, crystallize
and “salt out” at higher concentrations. Suspensions are made
by adding a small amount of a gelling—type clay to a clear base
solution. This thickens the mixture to about the consistency of
motor oil and enables greater amounts of plant nutrients to be
added, especially potash, which do not settle out of the solution
very fast because of the increased thickness. Both clear and
suspension mixtures are uniform in plant food content. Special
equipment, depending on whether the mixture is a clear fluid
or a suspension fluid, is required for their application. This
involves using a tank applicator with properly designed pumps,
hoses, nozzles, and circulation equipment for the type of fluid
mixture used. When properly designed application equipment
is used, fluid mixtures can readily be applied either broadcast
or in the row.
Fluid Fertilizer Materials
The most common fluid materials available in Kentucky are
the nitrogen solutions and anhydrous ammonia. The nitrogen
solutions range from about 20 to 32 percent total nitrogen,
while anhydrous ammonia contains 82 percent total nitrogen.
Nitrogen solutions commonly are made from a mixture of
ammonium nitrate and urea solutions. This means that about i t
half the total N is present as urea, about one—fourth in the
ammonium form, and one—fourth in the nitrate form. All the N
in anhydrous ammonia is in the ammonia form. `,
Keep in mind that while anhydrous ammonia is a liquid in
the tank, it immediately vaporizes to ammonia gas when it is
released from the applicator hose. For this reason special .
precautions have to he taken in its use. This involves observing
safety precautions to avoid the anhydrous ammonia gas from
contacting your body, since it can be poisonous and cause
serious skin burns. More specific safety details can be obtained
from the dealer who sells the anhydrous ammonia or from the
dealer who sells the application equipment. From the agro-
nomic standpoint, anhydrous ammonia must be properly put
into and sealed into the soil. or it will be lost to the atmosphere,
since it emerges from the injector as a gas.
12 .
I

 DECIDING WHAT FERTILIZER TO USE
There is no standard answer which will indicate what fertil-
izer should be used for all circumstances. This will depend on
the individual situation of the customer. The first step in
formulating a fertility program is to determine what and how
much is needed. A soil test is the best method for determining
this information. Since soil acidity greatly affects the efficiency
of fertilizer use by the crop, acidity should be adjusted to
tolerable levels by use of agricultural limestone before applica- .
tion of fertilizers. For detailed information on how much lime
and fertilizer to apply, see Lime and Fertilizer Recommendation .
Guide, Circular 619, University of Kentucky Cooperative
Extension Service.
After deciding how much fertilizer to use, one of the most
important factors to consider is cost applied on the field per
pound of nitrogen, phosphorus, potassium, or any other nutrient
- to be purchased. Other items to consider are availability of the
fertilizer (what you want, when you want it, where you want
it), and thc services provided by the fertilizer dealer (credit,
custom application, custom blending, soil testing, etc.).
VVhatever fertilizer you decide is best, be sure to use the
correct amounts for the crop to be grown, so that you can
expect a profitable rcturn from your fertilizer investment.
‘ 13

 `
Agricultural and Home Economics Extension Service of the University of Kentucky,
the United States Department of Agriculture cooperating. Charles E. Barnhart, Direc-
tor. Issued in l·Lll‘[ll(‘¥`IlI1Cl‘ of the Acts nf May 8 and June 30, 1914, A
IOM — 1 - 70