474 
WOLVERINE 
CORDOVAN HORSE-HIDE 
Comfort Shoe 
Ventura, Cal. 
Wolverine Shoe & Tanning Corp. 
Rockford, Mich. 
Sirs:—I have in my possession a good 
pair of shoes which ,may be of inter¬ 
est to you. I wore them 12 months 
and they are in a good wearing con¬ 
dition still; they are good for 5 Or 6 
more months. They have worn out 
three naif soles and have been reheeled 
twice, and now ready for soles and 
heels again. I bought them of O. H. 
Hedges September 10th, 1922, and 
wore them every working day for 12 
months. Yours truly, 
J. D. King. 
18 Months wear 
is “nothing at all’* for these shoes 
—the secret is in the leather 
The above letter is really re¬ 
markable. Shoes that wear 18 
months in the oil fields! But it is 
only one of hundreds we receive. 
The shoe shown above is the 
Comfort shoe. Tender feet wel¬ 
come this style. For while it’s 
soft and flexible, it wears like 
iron. So light and easy you won’t 
know you have a shoe on. It’s 
ideal for dry weather. 
We also make shoes for 
muddy weather, for the mine, the 
lumber camp, and the hunter. 
Each designed especially for 
its purpose. 
Wolverines are made en¬ 
tirely different from any other 
work shoe. There is a definite 
reason why you can expect them 
to wear longer. 
First, they are the only work 
shoes made of Cordovan horse- 
hide—the toughest fine-fibred 
leather known. Baseballs are 
made of it, because it alone will 
stand the the pounding. 
Wolverine Shoe & Tanning Corp. 
Formerly Michigan Shoemakers 
Rockford, Michigan 
Heretofore, it couldn’t be 
used in shoes. It always “tanned- 
up” too stiff. 
Finally we learned the secret 
in our tanneries—how to make 
it soft. Now you get this tough, 
long wearing leather in Wolver- 
ineshoes—with theupperleather 
soft as a moccasin—and thick, 
too, for protection. We learned, 
too, how to make it stay soft. 
Even after many wettings these 
shoes always dry out soft . 
We want you to try Wolver¬ 
ines. Just to see the difference. 
You’ll notice it at once. If your 
shoe store doesn’t handle them, 
write us. We will send you the 
name of our nearest dealer. 
Allow us to send you a cata¬ 
logue, showing our different 
styles. You will find one exactly 
suited to your needs. 
{ WOLVERINE SHOE & TANNING CORP. 
| Dept 51. Rockford, Mick. 
• Please send me name of nearest Wolverine 
j dealer and catalog. 
I Name. 
| Address.... 
I P. O. and State. 
| My Dealer is.... 
American Agriculturist, May 17 ,1924 
Fertilizers for Potatoes 
What, When, Where and How Much to Apply 
By E. V. HARDENBURG 
We have received so 
many inquiries during the 
past two weeks for information, relative to potato 
fertilizers, we have asked Professor E. V. Har- 
denburg of the College of Agriculture for a com¬ 
prehensive article on the entire subject. Profes¬ 
sor Hardenburg isjone of the foremost authorities 
on potato culture m the country and the following 
article should prove of decided interest to growers. 
T HIS is the time of year when potato 
growers throughout New York State are 
beginning to ponder seriously the questions 
concerned in the fertilization of the potato crop. 
Time spent in this way may bring profitable 
results later in view of the importance of using 
every economy in the farming business in 
these times. Furthermore, it is true that 
relatively more money is spent in commercial 
fertilizer for potatoes than for any other ex¬ 
tensively grown cultivated crop in this State. 
Cost of production figures show that from 20 
to 30 per cent, of the total cost of production 
per acre is spent for fertilizers for this crop. 
What Potatoes Require 
A few years ago the Central Experimental 
Farms at Ottawa, Canada, compared wheat, 
corn and potatoes in respect to the number of 
pounds of nitrogen, phosphoric acid and potash 
removed by average yields of these crops. 
These figures show that there is removed from 
the soil in an acre yield of potatoes about half 
as much nitrogen as in corn, and about an 
equal amount with wheat. Approximately 
twice as much phosphoric acid is removed by 
potatoes as by corn, and about the same 
amount as in wheat. Similarly, the potato 
removes about twice as much potash as either 
corn or wheat. In other words the nitrogen, 
phosphorus and potassium are removed in a 
normal yield of potatoes in the ratio of 2-1-4. 
Some recent work at the Wisconsin Experiment 
Station indicates that the potato plant uses 
almost as much calcium oxide or lime as it 
does of phosphoric acid. Compared to our 
other common field crops the potato may be 
said to feed relatively heavy of potash. This 
is doubtless one reason for the general practice 
on the part of growers in using fertilizers high 
in potash. Whether this practice is justified is 
a question discussed later in this article. 
The Functions of Plant Foods 
A better appreciation on the part of growers 
as to how each of these plant food elements 
affects the crop might be of service as a guide 
in determining such questions as how much 
and what kind of fertilizer to apply. Nitrogen 
tends to stimulate foliage production, induces 
late maturity, increases susceptibility to disease 
and increases the nitrogen content of the tuber. 
Phosphorus tends to hasten maturity and is 
necessary to the actual formation of starch as 
manufactured in the potato leaves. Potash 
increases the production of starch, thereby 
improving quality and yield and at the same 
time enhances the vigor of the plant. Phos¬ 
phorus has been found to be particularly impor¬ 
tant in the early life of the potato plant and 
seems to function especially in the tuber 
setting process. For example, young tubers 
have been found to be richer in phosphorus 
than mature tubers. Potash, on the other 
hand, seems to be much more useful during the 
later growth period when volume of tubers is 
being increased most rapidly. 
Up to the present time at least 2,000 potato 
fertilizer experiments have been conducted 
and the results published in this country. 
Probably at least half of these were conducted 
between the years 1890 and 1900 and a very 
high proportion of these are on record for the 
States of New York, Ohio, New Jersey and 
Pennsylvania. In more recent years the New 
England States (particularly Maine) have con¬ 
ducted some very interesting fertilizer work on 
potatoes, notably work with potash. The 
results from these vast numbers of experiments 
may be briefly summarized under such phases 
as sources of materials used, analyses used, 
amounts applied, time of application, method 
of application and depth of application. 
Sources of Fertilizing Materials 
The principal sources of nitrogen for this 
crop have consisted of nitrate of soda (18 per 
cent, ammonia), sulfate of ammonia (25 per 
cent, ammonia), tankage (6 to 9 per cent 
ammonia), fish scrap (10 per cent, ammonia), 
dried blood (16 per cent, ammonia) and stable 
manure. It is now recommended that in 
rotations where potatoes follow sod, as is 
common in New York, stable manure be 
applied as a top-dressing to the hay crop at 
least one year before plowing for potatoes. 
This has the advantage of benefiting the hay 
crop in better yields of hay, resulting in a 
better quality of sod to be turned under for 
potatoes, putting the residual manure in a 
more readily available 
form for potatoes, re¬ 
moving the danger of scab infection by the 
manure and finally removing the residual 
effects of the manure sufficiently far from the 
oat crop as to avoid lodging in the latter 
Wherever stable manure is available in suffi¬ 
cient quantity, this may furnish sufficient 
fertilizer for potatoes. Results to date indicate 
that it is often profitable to apply 600 pounds 
to 800 pounds of acid phosphate (16 per cent.) 
at time of planting even where stable manure 
has been used. Experiments to date have 
shown very little preference for either nitrate 
of soda or sulfate of ammonia as sources of 
nitrogen. Neither have organic forms of 
nitrogen, such as dried blood and tankage, 
given any better results than the inorganic 
forms. Choice of material for the nitrogen, 
therefore, becomes mainly a question of rela¬ 
tive cost per unit of ammonia, except where the 
soil is moderately affected with the scab 
organism. Since the scab organism thrives 
best in an alkaline soil and since nitrate of 
soda tends to increase soil alkalinity, growers 
troubled with scab in the soil are urged to use 
sulfate of ammonia in preference to nitrate of 
soda, since this former source of nitrogen tends 
to increase soil acidity because of the sulfur 
in it. 
16% Acid Phosphate Most Desirable 
Acid phosphate (16 per cent.) is at the 
present time the cheapest and most widely 
used form of phosphorus. Relatively little 
bone meal and basic slag are available in this 
country. The principal sources of potash are 
muriate of potash, sulfate of potash, manure, 
salts and kainit. Wood ashes* formerly used, 
are neither available nor desirable. They 
tend to encourage scab production because of 
the large amount of lime they contain. Kainit 
(12 per cent, potash) is a relatively expensive 
form of potash because of the low actual 
potash content. Muriate (50 per cent, 
potash), or the chloride form, is to-day our 
cheapest source of potash. Experiments have 
not shown any preference between the muriate 
and sulfate form so far as yield is concerned 
and sulfate of potash is now considerably the 
more expensive. 
Prior to the World War a 2-8-10 complete 
fertilizer was the one most commonly used 
throughout New York. War-time fertilizer 
experiments showed clearly that our 'potato 
soils had perhaps been temporarily over¬ 
stocked with potash and that profitable yield 
could be obtained with from 3 to 5 per 
cent, of potash. Long Island growers are now 
very generally using a 4-8-5 and up-state 
growers might profitably follow their example. 
In spite of the war-time lessons, too many 
potato growers on our heavier soils in rotation 
are once more using a 10 per cent, potash 
complete fertilizer. In case the potato crop 
is to follow a cultivated crop in the rotation 
600 to 800 pounds of a 4-12-4 will, on the 
average, satisfy the food requirements of the 
potato crop. This might equally well apply 
to cabbage grown in the same place in the 
rotation. The 4-12-4, one of New York's 
“High Five,” will furnish a considerable 
amount of necessary phosphoric acid at 
wholesale cost when compared to present 
prices of lower grade fertilizers such as 4-8-4 
and 2-8-2. As a matter of present day effi¬ 
ciency or cost cutting, high grade goods mean 
equal plant food value at less overhead cost, 
freight rates and labor. Where potatoes are 
grown after sod which has been top-dressed 
500 to 800 pounds acid phosphate should be 
sufficient. 
Amount of Fertilizer to Apply 
The Aroostook County, Maine, and the 
Long Island growers have found it profitable 
for them to use as much as one ton per acre of 
a complete fertilizer for this crop. Potatoes in 
these regions are, however, grown much more 
intensively and more frequently on the same 
land than in up-state New York. There is very 
little evidence that the up-state growers, 
particularly on the heavier soils, can profitably 
use over 800 to 1,000 pounds per acre of 
commercial fertilizer. As already indicated, 
500 pounds of acid phosphate is probably a 
sufficient supplement to stable manure where 
the latter is used. The sandier soils, being 
more deficient in these plant food elements, 
usually demand not only somewhat larger 
applications per acre but are more deficient in 
potash and nitrogen than the heavier soils 
common to Southern and Western New York. 
Time, Method and Depth of Application 
As a result of many experiments in the past 
to determine results from applying fertilizer 
before, at, and after planting, practically no 
advantage has ever been shown for applications 
(Continued on page J/. 81 ) 
