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DEPARTMENT OF AGRICULTURE
NATHAN MAYO, COMMISSIONER
NEW SERIES No. 71
Department of Agriculture
Nathan Mayo, Commissioner
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The underground silo is easily filled. This illustration shows the method of filling without the use of a blower; the silage falls
direct from the cutter into the silo; water is supplied by means of hose which is shown on board in front of the cutter.
TABLE OF CONTENTS
1 .- I n tr o d u c tio n ............................... ................................................................... 7
2 .- T h e T o w e r S ilo .............................. ............................................................... 9
3.-The Under-Ground Silo ................................................ .............. 11
4 .- T h e T ren ch S ilo ....... ........................................................... ....................... 12
5.-Forage Crops Used for Silage ................................................ 13
6. Methods and Costs ........................ ........................ .................. 14
(a) Scope of Study ............................................ .. ............... 15
(b) Type and Cost of Equipment .................................... 16
(c) Ownership of Equipment .......................................... 17
(d) Crew Required for Filling ........................................ 22
7.- C apacities of Silos ................................................................ .................. 25
A silo is a pit or a water-tight and air-tight tower which
is used for the preservation of green crops. Every owner of
livestock is confronted with the problem of feeding his stock
during the winter. It has been found that if certain crops are
gathered just before they reach maturity, and are stored in a
tower or pit of the kind just defined, they will remain green
almost indefinitely. Thus we see that it behooves the livestock
owner to make one of these simple constructions in order that
he may be able to feed his stock better and more cheaply dur-
ing the winter.
Sometimes silage is needed in dry summer months the same
as in the winter-in the extreme south is this particularly
The history of the silo dates back to antiquity, but in general
practice it is a modern invention. It is now considered a neces-
sary part of the equipment on any dairy or beef cattle farm
in climates of severe winters. The silo is not quite so indespen-
sible where grazing can be had the year round. Even so it
often happens, even in Florida, that a dry spell in mid summer
will dry up all pastures and silage must be resorted to or very
expensive feeding of imported dry feeds.
At present a large percent of human food is canned. The
problem of canning stock feed is solved by the silo. Forage
placed in silos goes through a process of fermentation and
respiration of plant cells which produces what is now called
silage, but which was formerly called ensilage. One might
think that green stuff cut and packed in a bulk would rot and
not be long about it, and so it would if stacked in the open.
But when packed in an airtight structure and properly
dampened it merely ferments and keeps its food properties in-
definitely. The air must be excluded. The greater the pres-
sure the better for excluding the air; for this reason it is best
to have a deep silo.
However, under-ground silos are much cheaper and have
proved satisfactory in many of the southern states.
There are three types of silos as to position: (1) the upright
above the found, (2) the upright in the ground, (3) the trench
in the ground. (There are two types of trench silos.) There
are five kinds as to material of which they are composed: (1)
the wooden structure, (2) the concrete, (3) the metal, (4) the
tile, (5) the brick. The shape can be anything desired, though
it is usually cylindrical except in the case of the trench silo
which is usually rectangular.
THE TOWER SILO
The tower silo, or upright silo above the ground, has possibly
been built more than any other kind since its invention 41
years ago. This may be due to the fact that this particular
type of silo is more easily unloaded than the other types. How-
ever, in recent years the trend has been distinctly in favor of
the trench silo.
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ere e vey a good secen of e t tpe of silo t o t .
,...The opening for taking out the silage extends from top to bottom; the doors
--fit into the groove from the inside.
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The tower silo may be built of iany of the materials previously
named: tile, brick, concrete, wood, or steel. However, tile and
steel are possibly more desirable than the others. The silo must
be built strong enough to withstand the great pressure exerted
in the settling of the silage. After this settling has taken
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place there is no more pressure against the walls, but during
the process of settling it may be as high as 330 pounds per sq.
foot at the bottom of a 30 foot silo.
In previous years silos were not built to any great depth.
Consequently, the silage had to be weighted in order to keep
it from spoiling. This weighting is not necessary in the pres-
ent-day tall silos since the silage will pack itself of its own
A silo must necessarily be filled from the top. This is ac-
complished by the use of a blower. The blower may be at-
tached to the cutter, and a long pipe extending from the blower
to the top of the silo is used to carry the material to the top
of the silo. A hole should be left at the top of the silo large
enough for entrance. This hole should be tightly closed except
when it is in use. A series of doors should be left in the side
of the silo in order that the silage may be easily unloaded. Or,
as in the case of the silo in Fig. 1, an opening may be left from
the top of the silo to the bottom. This opening however, must
have air-tight sections in it in order that no air will reach the
silage and spoil it.
The cutter and the blower may be run by a tractor if one is
available, if not any gasoline or kerosene engine may be used
provided it has sufficient horsepower.
It is important to remember that the pipe used to carry the
forage from the blower to the top of the silo should under no
condition be less than 5 or 6 inches in diameter, if it is smaller
than this it will not permit the free flow of air and forage
through it and it will become stopped up. Also-if the pipe is
too large the blower will not furnish sufficient air to fill it.
About 7 or 8 inches is a good size.
Another very important thing to remember in filling any
silo is that the forage must be damp-otherwise it will rot.
If it is possible, a water pipe or hose should be extended to the
top of the silo, and the forage may be watered as it falls from
the blower-pipe. If it is impossible to pump water as high as
the top of the silo, it may be introduced at the bottom of the
A table will be found in the back of this bulletin giving the
capacities of tower silos of various dimensions.
THE UNDERGROUND SILO
The underground silo, or upright silo in the ground, is pos-
sibly not as common as either the tower silo or the trench silo.
They are built largely on the same plan as the tower silo. The
main difference is in the material used. Practically all of the
underground silos are built of concrete. This concrete should
be about 6 or 8 inches thick. Some silos are made of brick and
are sealed with concrete.
The great advantage of this type of silo over the tower silo
is its ease of filling. One can easily see that it needs no blower
to carry the forage to the top. The cutter may be placed on
the edge of the silo and the forage will fall into it. A good
plan of arrangement is the one shown in Fig. 2. Over this
particular silo, a small two story shed was built. The top part
of the shed is used for storing various produce such as potatoes.
Two ends of the ground floor, which is immediately above the
silo, are removable. This provides easy access to the silo in
both loading and unloading it. Also, if the cutter is placed
on one of the open sides a belt may be extended across the top
of the silo to the tractor or other power plant on the other
side. Another advantage in this type of silo is that the forage
is easily watered. A hose may be used very satisfactorilly for
this purpose. Some kind of trough may be placed over the
edge of the silo and directly in front of the cutter. When the
forage flies out of the cutter it will strike the trough, and if
a stream of water is also squirted on the trough it will wet the
forage as it falls into the silo. Perhaps a study of Fig. 2 will
give a better understanding of this process.
After the silo is filled it should be allowed to set for several
days during this time the forage will sink several inches. When
it has finished settling enough more silage should be added
to bring the surface nearly to the edge of the silo. Over this
a layer of straw 6 to 8 inches should be thrown, and 12-14
inches of dirt should be thrown over the straw.
THE TRENCH SILO
The trench silo has many advantages, if some disadvantages,
over the other types of silos. It is cheaper to build and
cheaper to operate than either of the upright silos. Here is
one very efficient kind of silo that every farmer can own. As
one farmer has expressed it: "The only obstacle in the way of
building a trench silo is making up your mind to have one."
The trench silo is exactly what the name implies. It is a
trench dug in the ground for the purpose of preserving silage.
If possible it should be located in clay soil that is not water-
soaked. Of course it should be in as convenient a place as
possible. The sandy soil of southern Florida may present a
problem. In this case it will be necessary to line the walls
and bottom of the silo with boards which should be treated
with creosote if possible. Or better still, if the silo can be lined
with concrete all danger of spoiling from loss of water will be
eliminated. This also eliminates danger of the walls caving in.
In cases where the silo cannot be dug sufficiently deep with-
out becoming filled with water it may be built partially above
the ground. This may be done by extending the boards or
concrete of the sides to a sufficient height above the ground.
It may be banked up on the outside to prevent the sides from
being pushed out by the pressure.
Another advantage of the trench silo is that it can be more
easily enlarged than either of the upright silos. Thus it can
he made to accommodate a growing herd.
The actual cost of a trench silo is negligible. In the right
kind of soil it could be built without any cost whatever, except
the labor. Including the cost of this labor and any materials
that have to be bought, it is estimated that a trench silo can
be built at a cost of applroxiinately 79 cents per ton capacity.
Thus a silo with a capacity of 30 tons would cost $23.70. These
figures also allow a liberal cost for mule labor and the cost
of the roof.
Another advantage of the trench silo over the others is that
it is both easily filled and emptied. It does not need a blower
to elevate the silage when filling, and it may be easily emptied
by shovelling the silage over the side. When feeding from the
silo do not feed a layer from the top length of the silo because
too much of the silage will be exposed to the air and is likely
to spoil. Simply remove the dirt and straw in advance of
daily feeding and cut the necessary slice from the end.
A table of sizes and capacities of trench silos will be found
in the back of this bulletin.
FORAGE CROPS USED FOR SILAGE
There are various kinds of crops that can be converted into
silage. Different ones of these crops may prove better or worse
in different parts of the country according to conditions which
prevail. However, the one universal forage crop which is used
for silage is Indian Corn. It is easy to raise, it preserves nicely,
and it is one of the best foods known for beef and dairy cattle.
It should be cut just before it reaches maturity. If it is cut
too late it is likely to rot. The stalk is cut in the field, and
every bit of it including the ears of corn is ground up in the
cutter. Other good forage crops are sorghum, sunflower,
alfalfa, clover, cowpeas and soybeans, pea or corn cannery
refuse, green oats, beet tops and leaves, and beet pulp.
METHODS AND COSTS OF FILLING SILOS IN
THE NORTH CENTRAL STATES
BY KENNETH H. MYERS,
Associate Agricultural Economist, Division of Farm Management and
Costs, Bureau of Agricultural Economics1
Quotation from U. S. Department of Agriculture Bulletin 1725,
The corn crop from approximately 4,000,000 acres is con-
verted into silage in the United States each year. This method
of harvesting and storing the corn crop is used in all parts of
the country but is most common in the dairy regions, and, to
a lesser extent, in beef-cattle-feeding areas. Corn is cut for
silage on approximately 375,000 farms or on an average of
about 1 farm in 17. Wisconsin leads in total number of farms
on which silage is fed-more than 90,000, or about one third
the total number of farms. Twenty-five percent of the farms
in New York and 20 percent of those in Minnesota reported
this method of harvesting corn in 1929. Corn is cut for silage
on more than one half the farms in the dairy area in northern
The presence of the European corn borer in the United States
has caused more attention to center on equipment and methods
for harvesting corn. The continued spread and increased
numbers of borers will necessitate the adoption of farm prac-
tices by which the entire corn plant is fed to livestock or other-
wise disposed of. Cutting for silage or fodder is an effective
method of controlling the borer if the corn is cut at the ground
surface, and may be the most economical method of control
where the silage or fodder can be fed to dairy or beef cattle.
Improvements in silo-filling machinery and the development
of new methods have eliminated much of the drudgery of silo
filling and, with the increased use of farm tractors, have been
important factors in promoting individual farm ownership of
such machinery. These developments have made the choice
of equipment and methods more difficult for the individual
farmer, however, since much labor is replaced by power and
equipment. The farmer must consider, with respect to con-
editions on his farm, the ownership of silo-filling machinery, the
type and size of equipment, and the size and organization of
the crew. On farms on which the necessary equipment is al-
ready owned there is little alternative so far as machine owner-
ship or type of equipment is concerned since the cost of making
a change would more than offset any advantage gained. On
farms on which no equipment for filling is owned, or on which
the old equipment is so depreciated that it cannot be used
further, a choice must be made between buying new equip-
ment or hiring a machine, and if the operator decides to pur-
chase new equipment the choice of type and size is important.
The most economical size and organization of the crew may
vary from farm to farm, and from year to year on the same
farm, with changes in the supply of labor, relative prices of
labor and power, and other factors.
SCOPE AND PURPOSE OF STUDY
This study is based on data collected in 1928 and 1929 by
the Department of Farm Organization and Management, Uni-
versity of Illinois, in cooperation with the Bureau of Agri-
cultural Economics, United States Department of Agriculture.
Records of the cost of filling upright silos were obtained on
87 farms in Illinois on which stationary cutters were used and
on 118 farms on which field harvesters were used. Practices
and equipment in silo filling have not changed appreciably
since the data were gathered. It is believed the conclusions
are approximately applicable to most parts of the country
where upright silos are used. They are particularly applicable
to conditions in the North Central States.
Since then the wages of farm labor have fallen to about
48 percent, the cost of horsepower to about 50 percent, and
the cost of tractor power to 85 percent of the rates obtaining
during the years of the study. These changes and changes in
the future should be taken into account by farmers in using the
figures given in this bulletin.
The purpose of this bulletin is (1) to show the elements of
cost involved in filling upright silos by different methods and
practices, (2) to show the relative importance of these elements
of cost and the factors affecting them, and (3) to present a
basis for selecting and combining them in such manner as best
to fit conditions on the individual farm. As it is assumed that
the farmer is committed to the practice of making and feeding
silage, no attempt is made to show its advantages or disad-
vantages. Nor is the cost of producing the corn crop con-
sidered since in most areas the methods used in producing
silage corn are similar to those used in producing corn for
TYPES OF EQUIPMENT AND INITIAL COST
\Two methods in which the equipment is entirely different
are used for filling silos in the United States. The most com-
mon method is that in which corn is cut in the field, hauled
to the silo, and cut up for silage with a stationary cutter. The
field silage harvester was first put on the market in 1918 and is
not widely used. It cuts the standing corn and chops it into
silage lengths in one operation, after which the material is
elevated into the silo by means of a blower.
The stationary cutters are all of the same general type, vary-
ing only in mechanical construction, and, more important, in
size. There are wide variations, however, in the equipment
and methods used in cutting the corn in the field and hauling
it to the silo. jThe maximum cutting capacity of stationary
cutters varies largely with the size, but on most farms the rate
of filling depends on the number of men hauling the corn to
the silos. The field harvester is made in only one size, and
the only equipment used with it are box wagons for hauling
the cut corn to the silo and a blower to elevate it. The small
amount of strenuous labor required in filling with this machine
makes it possible to utilize a class of labor that cannot be used
around a stationary cutter.
The newer field harvesters are drawn and operated by a
tractor equipped with a power-take-off device. They have
proved more efficient and satisfactory than the earlier ma-
chines, which were drawn by horses, the cutter mechanism
being operated by a gasoline motor mounted on the frame of
the machine. The older type of cutter was used on nearly two
The farm tractor has been an important element in promot-
ing farm ownership of belt-operated equipment. Many tractors
are bought with a view of reducing the cost of hiring power
and equipment for belt work and with the knowledge that they
would otherwise not be used enough to justify the investment.
If power for filling silos has to be hired its cost may more than
offset any advantage of owning silo-filling equipment.
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The kind of knife used in cutting corn for silo when a corn
harvester is not available.
Cooperative ownership of equipment often solves the prob-
lem of securing the initial capital and of providing labor and
power for silo filling. Overhead costs decrease as the amount
of corn cut by each machine increases, and the investment per
thirds of the farms studied, and there seemed little difference
in the cost of filling.
The amount of capital required to buy silo-filling equipment
is relatively large in relation to the amount of use that can be
made of such equipment on many individual farms. Insuf-
ficient capital, or alternative uses for that which is available,
lead many farmers to hire custom outfits to fill their silos, or
leave little choice as to type of equipment to be purchased.
This is particularly true in the case of tenant operators, whose
capital is closely limited or whose terms of occupancy may
The amount of capital required depends on the methods and
equipment used in cutting the standing corn, and on the type
of equipment used in cutting the corn into silage length. The
average initial cost of the silo-filling equipment used on the
farms studied was as follows: Stationary cutter, $375; corn
binder without elevator, $175, and with an elevator $225; field
harvester, $625; blower, $225. Most of the equipment used
on these farms was bought during the 8 to 10 years previous to
the time the study was made. Small stationary cutters may
be bought for less, however, and if the corn is cut by hand the
necessary investment per farm may be kept at a much lower
figure than is indicated by these prices.
Private ownership of silo-filling equipment has become com-
mon, and the relatively high investment has been justified by
a saving in labor costs and amount of time used in filling. In
many instances the necessary capital is supplied by two or more
farm operators, and the equipment is owned and operated co-
operatively. In localities in which silos are common the neces-
sary equipment may be hired, frequently at less cost than if
a machine were owned. In addition to regular custom outfits
operated entirely for profit, many farmer-owned machines are
used on neighboring farms in exchange for power or labor,
and some custom work often is done to provide profitable work
for the regular labor and at the same time reduce the over-
head cost of filling the home silo.
farm is lower when the machine is owned cooperatively. The
number of farms included in such an agreement, however,
should be no more than are needed to provide the necessary
capital, labor, and power.
The choice of equipment may be influenced and the relative
costs of filling determined by the amount available or by alter-
native uses for the available capital, labor, and power. No
capital is invested if a custom machine is hired, but the cash
costs are higher. The effect on the farm income, if these ele-
ments of production are used in other phases of the farm busi-
ness, may determine their value in filling silos. Capital in-
vested in other equipment or improvements may return a
greater ine.ome than if used to purchase a silo filler. Family
labor and horse work are important items of cost only if they
may be used in other work, at that time, which would increase
the farm income or decrease the operating expenses of the
The ease of filling or amount of leisure. time may be con-
sidered on farms where costs by different methods appear
similar. The usual custom in the community or consideration
for neighbors may also be important in some instances. On 1
farm 2 silos, each with a capactiy of 256 tons, were filled.
The large quantity of silage made it almost impossible for this
man to exchange labor with his neighbors. A new field
harvester would have necessitated hiring another tractor and
would not have reduced the time used very much. The operator,
2 regularly hired men, and 2 extra hired men filled these silos
in 125 hours with a 16-inch stationary cutter, cutting the corn.
in the field with a binder equipped with an elevator.
The effect of these factors on the total cost of filling by
different methods and on the distribution of costs may be
seen more easily by making some estimates on a single farm.
On one of the farms, studied a custom machine was hired to
fill a silo holding 175 tons. A custom charge of $4 per hour,
plus the cost of fuel, was paid for the tractor and cutter, and
the labor of two men. Labor was exchanged with four other
farmers in the community and, in order to fill as rapidly as
possible, a crew of 15 men was used in addition to the machine
men. A total of 67.5 hours was required to fill the 5 silos, and
since only the operator was on the farm at this season of the
year it was necessary to hire 2 men for the entire period. The
costs of filling with the custom machine and the estimated
costs if a stationary cuttor or a field harvester had been owned
are shown in table 4. It is estimated that with his own sta-
tionary cutter this farmer can cooperate with only 3 other men
and fill the 4 silos in 72 hours with a crew of 10 men. In case
the field harvestei was owned, the cooperation of only 1 other
is desirable, and with 6 men the 2 silos will be filled in 48
hours. One difficulty with individual ownership of the field
harvester is the necessity for two tractors In this case it may
be agreed that each farmer will furnish a tractor and that the
farmer cooperated with will pay the estimated depreciation
costs on the field cutter and blower in filling his silo. As
these costs will about equal the cost of hiring a trctor, neither
is included in the costs shown.
The estimated costs, based on prices prevailing in 1929, were
$1.17 per ton when a custom machine was hired and would have
been $1.08 if a stationary cutter had been owned and $1.05 if a
field cutter had been purchased. Cash costs were even more
in favor of th field harvester, being 77 cents per ton when a
custom machine was used, 45 cents with an owned stationary
cutter, and 36 cents with a field harvester. Depreciation and
interest, however, are greatest when the field harvester is used
and amount to only a small part of the total cost when a ma-
chine is hired. Under these conditions costs are in favor of the
field harvester. What will be the effect on these costs and
their distribution (1) if only half as much silage is cut; (2)
if the yield of corn per acre is materially different; (3) if
more unpaid labor is available, and (4) if labor and material
costs are changed?
Table 4.-Cost of filling a 175-ton silo with a custom machine on
one farm in 1929, and estimated costs if a stationary cutter
and field harvester had been owned
When hired If owned If owned
stationary stationary field
Item cutter was cutter had harvester
used been used had been
IDollars Dollars Dollars
Cash costs ----- --.....-- ....... ..... ( 135.28 78.21 63.02
Unpaid costs -..................---------- 1... 53.85 57.20 36.60
Depreciation .--- - .................... 10.21 29.49 49.96
Interest ------- ..------. ------. --.- -.. -.. -- ........ 5.67 23.34 34.89
Total -- -------- ---- -----.. --.... 205.01 188.24 184.47
If only 87.5 tons of corn were cut, all costs, with the excep-
tion of interest, presumably would be reduced accordingly.
But interest makes up only 2.8 percent of the total when a
machine is hired, 12.4 percent when a stationary cutter is
owned, and 18.9 percent when a field harvester is owned. So
far as total costs are concerned, therefore, the custom machine
would be the most economical method, while the field harvester
is the most expensive. Cash costs, likewise, are reduced by
half when a field harvester is owned unless the smaller quantity
of corn enabled the operator to return a greater part of the
exchange labor with unpaid labor, in which case the costs
would be reduced more than half.
A lower yield of corn per acre would increase the acreage
of corn required. More labor and power would be used in
cutting the corn and depreciation on the binder would be in-
creased accordingly when stationary cutters are used. The rate
of filling would also be reduced unless additional labor is hired
for cutting and hauling corn. If the yield is reduced one third,
the cost of filling with the custom machine is increased about
12.4 percent and with an owned cutter about 14.1 percent. In
the case of the field harvester, however, depreciation on the
tractor and field cutter would be increased 50' percent, and
nearly 50 percent more fuel would be used. Not more than
five men would be needed, since the rate of cutting would be
lower, but the total labor bill would be increased nearly 10 per-
cent, while slightly less horse work would be used. The total
cost, however, is increased about 22.5 percent and is more than
if a stationary cutter is owned and nearly as much as if one is
hired. Yield is important, therefore, in determining the rela-
tive economy of the field harvester.
The amount of family labor available does not affect the
total cost but does affect the amount of hired labor and thus
the cash cost of filling. If there were two unpaid members
of the family, the cash cost of filling with the custom machine
would be reduced $27, with the owned stationary $28.80, and
$19.20 if a field cutter is used. Not only family labor but
regular hired labor, which would be paid even if the silo were
not filled, should be considered in this way.
The cost of hired labor affects both total costs and their
distribution. Labor costs make up a larger proportion of the
total when stationary cutters are used; so low-cost labor re-
duces the advantage of the field harvester. If labor can be
obtained at 25 cents an hour instead of 40 cents, the cost of
filling with the stationary cutters on this farm is reduced
nearly 15 percent but less than 12 percent in the case of the
field harvester. The possibility of using less-able labor, boys,
or elderly men, with the field harvester, however, always offers
a chance of further reducing the cost of filling with the field
ORGANIZATION OF CREW FOR FILLING SILOS
The size and organization of the crew used in filling silos
should be determined by the type of equipment used, the
amount of unpaid labor and exchange labor available, the cost
of hired labor, and the amount of time available for filling.
The rate of filling with the field harvester is determined by
the capacity of the field cutter, and three or four men with
teams can almost always haul the chopped corn from the field
to the silo as fast as it is cut. One man usually is kept at the
silo to tend the tractor and blower, help unload, and put doors
in the silo. Tramping is considered unnecessary in filling with
the field harvester since the lower rate of filling usually gives
sufficient time for the material to settle from its own weight.
The most efficient number of men is not so difficult to deter-
mine when this type of equipment is used.
The organization of the crew used in filling with the sta-
tionary cutter is not so simple. Except in cases where very
small cutters are used or where sufficient power is not avail-
able, the number of men hauling corn from the field is the
limiting factor in determining the rate of filling. The neces-
sity or desire of the silo owner to fill slowly or rapidly should
determine the size of the crew in most cases (fig. 4). Where a
custom machine is hired and the cost determined by the amount
of time used, a large crew is economical in most cases. If a
machine is owned, however, and no other work at which the
regular labor can be more effectively used is available, the
cash cost usually is reduced by filling more slowly with a
small crew in order to use unpaid or exchange labor as much
TABLE 5.-Approximate quantities of corn handled per unit of man
labor and power in corn yielding 8 tons
of silage material per acre*
OnQan- Expect- Quan- Expect-
Operation and tity ed Operation and tity ed
method per range in method per range in
unit quan- unit quan-
tity I tity
Tons Tons ITons Tons
Cutting corn in field IHauling corn cut
by hand 1.6 1.0-2.2 with binder with
Cutting corn in field elevator:
with binder: Without extra
Without elevator 5.4 I 4.4-6.4 drivers | 1.5 1.2-1.8
With elevator 4.4 3.4-5.4 With extra I
Hauling corn cut by Idrivers 1.6 I 1.4-1.8
hand: Cutting corn with
Without extra power-take-off
pitchers ---- 1.0 .7-1.3 field harvester I 5.8 I 4.0-7.6
With extra Cutting corn with I
pitchers I 1.2 .9-1.5 motor-mounted I
Hauling corn cut I field harvester I 5.2 4.2-6.2
with binder with-
pitchers I 1.3 1.0-1.6
With extra 1
pitchers I 1.4 I 1.1-1.7
*One unit of man labor, and power consists of 1 man plus 2 horses in
hauling corn, 3 horses in cutting with a binder or motor-mounted
field harvester, or 1 tractor in the case of the power-take-off field harvester,
the combination working 1 hour.
The approximately quantity of corn that one man with the
usual power unit may be expected to handle per hour in shown
in table 5. The rate of cutting corn in the field is especially
affected by the yield per acre, but the quantity of corn hauled
per man is also affected, so the data in table 5 are adjusted
for corn yielding about 8 tons of silage per acre. As the rate
of performance is also affected by other factors such as the
distance the corn is hauled, the type of corn, and size of crew
in relation to size of cutter, the expected range, due to these
factors, is also shown.
Given a farm on which a medium-sized stationary cutted is
owned with sufficient power and labor available to fill a 180-
ton silo in 2 days or about 18 hours; how many men will be
needed, and how must they be distributed if the corn is cut with
a binder and the bundles dropped on the ground?
A study of the figures in table 5, indicates that 2 binders are
necessary to complete the job in the time specified, or 1, if it
cuts 1 entire day before filling is started. Since 1 man can
haul about 1 ton per hour, 10 men with teams and wagons are
necessary, or if 2 or 3 extra pitchers are provided to help load
the wagons in the field, 8 men may be sufficient. Two men
should be kept at the silo when cutting at this rate, 1 to feed
the cutter and 1 to tend the tractor and cutter. In order to
fill he silo fairly full at least 2 men should tramp; and there
probably should be 1 man to put in doors, tend the water, and
do other miscellaneous tasks.
This arrangement makes a crew of at least 17 men. More
will be needed if the distance from the field to the silo is
unusually great or if the yield of corn per acre is lower. If
the corn is cut by hand, 6 men are necessary in cutting unless
some corn is cut the day before. If binders with the elevator
attachments are used, three binders probably will be necessary,
but not more than 7 men will be needed for hauling.
The size of crew probably is more often determined by the
number of men available than by the speed at which it is
desired to fill. Suppose 10 men are available on this farm;
what should be their distribution? One man must tend the
cutter and tractor, 2 men should tramp, put in doors, etc.,
while 1 man with a binder can cut the c.orn. This would leave
6 men to haul corn, and the silo would be filled at the rate of
about 6.5 to 7.5 tons an hour. Since one binder can cut only
about 5.5 tons an hour some cutting must be done the day be-
fore. If elevator attachments are used on the binders, two
binders would be necessary, and 5 men would be left to haul
corn to the silo. The 5 men could not keep both binders cutting
steadily, but this would be preferable to using one binder and
delaying the haulers.
The organization of the crew is an important factor in
obtaining economic and efficient operation. The choice of
equipment is made only once in several years, but the most
efficient crew must be determined each year, on the basis of
SIZES AND CAPACITIES OF CYLINDRICAL
In Tons of Corn Silage
silo. feet Inside diameter of silo, feet
10 12 14 15 16 18 ,20
20 26 38 51 59 67 85 105
21 28 40 55 63 72 91 112
22 30 43 59 67 77 97 120
23 32 46 62 72 82 103 128
24 34 49 66 76 87 110 135
25 36 52 70 81 90 116 143
26 38 55 74 85 97 19.3 1
27 40 58 78 90 103 130 160
28 42 61 83 9 5 108 137 169
29 45 64 88 100 114 144 178
30 47 68 93 105 119 151 187
SIZES AND CAPACITIES OF TRENCH SILOS
To determine the size of silo you need, multiply the number
of cows to be fed by the number of days they are to be fed.
This will give the number of cubic feet needed, because a cow
will feed about one cubic foot of silage per day. Example:
20 cows to be fed 150 days; 20x150 is 3,000 cubic feet, or 30x
3,000 is 90,000 pounds or about 45 tons of silage necessary.
No. of cows it will
Width at top Width at bottom Depth Length feed for 109 days
6 4 5 24 6
6 4 5 32 8
6 4 5 40 10
7 5 6 34 12
7 5 6 39 14
and so on, the table can be carried out indefinitely.
ADVANTAGE OF SILAGE
The following facts have been summarized from various
Experiment Station reports on silage feeding as compared to
dry field cured roughage::
(Quoted from Mississippi State College circular, by L. A.
Olson and L. A. Higgins.)
"From many tests, silage reduced the feed cost per pound
of butterfat 10c."
"Illinois, comparing silage with corn fodder, found silage
worth 31% more."
"Nebraska, comparing silage with corn stover, found silage
worth 20% more."
"Kansas, comparing Kafir. silage with Kafir fodder, found
the silage worth $37.00 more per acre."
"Pennsylvania, comparing cows receiving silage with same
not receiving silage, found silage increased yearly production
150 gallons per cow."
"Kansas, where silage was fed obtained an average greater
yearly return per cow of $19.03."