Vol. LVI. No. 2465. 
NEW YORK, APRIL 24, 1897. 
*1.00 PER YEAR. 
WHY DO WE PLOW? 
WHAT IS THE OBJECT OF TILLAGE ? 
PAKT IT. 
The pulverizing' capacity of the plow lies wholly in 
the moldboard which, by its shape, determines 
whether the furrow shall stand on edge or lie flat, 
and whether the soil brought to the surface shall be 
left much in the condition it was found or be made 
fine and fit for seed. Sometimes there are soils on 
which the plow can only begin the work of pulveriz¬ 
ing, especially if they are not in the right condition. 
Then the work must be carried on by the harrow ; 
yet without the beginning by the plow, the harrow is 
of no practical use. There are soils, too, where the 
same plow with differently shaped moldboards will 
leave the furrow slice finely, coarsely, or even hardly 
pulverized at all. An example of such 
a soil is shown in Fig. 117, which is a 
photograph of a piece of land on the 
Cornell University farm. This soil is a 
clay loam, bearing a very loose clover 
sod, with very few stones and, at the 
time of plowing—April, 1896—con¬ 
tained about 22 per cent of moisture. 
An Oliver chilled plow, letter E, having 
four interchangeable moldboards, was 
used for the work. The four furrows 
to the right of each lettered stake show 
the quality of work done by the mold- 
board corresponding to the number on 
the stake, the moldboard bearing the 
numbers E I, E II, E III and E O, re¬ 
spectively. 
Notes taken at the time of plowing 
state : E I turns the furrows very flat. 
E O leaves them a little more inclined, 
but breaks them more, making the soil 
in a better condition for seed and not 
requiring so much harrowing as E I. 
E II leaves the furrow slice still more 
inclined than E I, but does not pulverize 
so well. It leaves, however, a ridge of 
loose soil which is easily attacked by 
the harrow. E III does the roughest 
work of all, in some places leaving the 
furrow almost perpendicular, and were 
it not that the jointer turns under the 
upper edge of the sod, it would be 
almost impossible to reduce the soil to 
a good seed bed. As it is, the mold- 
board does little pulverizing, and from 
the point of economy of time, would 
not be a profitable one to use, because 
it necessitates so much harrowing. 
However, for fall plowing where it is 
desirable to leave the soil as rough 
as possible to prevent puddling, this 
moldboard would be most excellent. 
This illustrates well the effect pro¬ 
duced by moldboards of different shape, and shows 
how the farmer, by studying the needs and conditions 
of his soil and having plows adapted to the various 
needs, can so plan his plowing as to accomplish the 
most work in the shortest time, and also keep his soil 
in the best physical condition. For spring plowing, 
use a moldboard like E O, and the seed may be 
planted with but very little harrowing. For heavy 
lands which are benefited by fall plowing, use a 
moldboard like E III, and the soil is left in a con¬ 
dition to be best acted on by the winter weather, with 
no danger of running together into a pasty mass. 
The general shape of these moldboards i6 well known 
to plowmen, and almost at a glance they can tell 
whether one is going to turn a furrow fiat or leave it 
on edge. We have also seen that it is equally advanta¬ 
geous to know whether it will pulverize or not; but 
this is most readily told by actual practice in the field. 
Further experiment at the University farm showed 
that only a small portion of the power needed to pull 
the plow is consumed by the action of the moldboard 
in turning the furrow. This experiment found that 
55 per cent of the total draft of the plow is used in 
cutting the furrow, 33 per cent in the friction of the 
sole and landside. and but 12 per cent in turning the 
furrows. We are more assured of the correctness of 
these proportions since the Hon. J. Stanton Gould, in 
1867, found 55 per cent due to cutting the furrow, 35 
per cent to friction, and 10 per cent to turning. Seeing 
that the shape of the moldboard will not materially 
influence the draft of the plow, there is one more 
point added to the desirability of shaping the mold¬ 
board so as to do the best work. 
The Relation of Plowing to Movements of Soil 
Moisture. —In this connection, we need regard the 
soil water in but two of its conditions, viz., as free, 
and as capillary water. Free water is that which 
moves only by force of its weight, or gravity, and 
capillary, that which moves by force of capillary at¬ 
traction or surface tension. Bulletin 120, by L. A. 
Clinton, of the Cornell Station, treats clearly of the 
movements of soil moisture, and all who have not a 
copy should send for one at once. A diagram like 
the following may help to see how these two forces, 
gravity and capillarity, act: 
CAPILLARITY 
A 
CAPILLARITY <- BOIL WATER > CAPILLARITY 
\> 
CAPILLARITY AND GRATITY. 
Thus while gravity draws only downward upon the 
soil water, capillarity may pull the water in any or 
every direction. Capillarity is the movement of the 
water in passing from a moist to a drier portion of 
soil. Thus, if the drier soil be above the moister, as 
is usually the case, the water will move upward If 
the drier portion be at the side or below the moister, 
then the water will move to the side or downward, as 
the case may be. Gravity, in its action, affects mostly 
the free water of the soil; still it assists capillarity 
when that is working downward, but hinders it when 
working upward. 
Aside from the effect produced upon the movements 
of the water by the various amounts of moisture 
present in different portions of soil in contact, there 
are conditions affecting these movements which are 
dependent on the physical texture of the soil. These 
may be briefly stated somewhat as follows : Gravity, 
in taking the rain water down through 
the soil, will move it faster through a 
mellow than a compact soil and, there¬ 
fore, get more water into the soil in a 
given time, or while the rain lasts. 
Capillarity works slower in a mellow 
than in a compact soil, because the 
pores are larger than in the compact 
soil, and thus the land having a mellow 
surface soil not only receives more 
water but, also, retains it longer be¬ 
cause capillarity cannot take it so 
rapidly to the surface to be evaporated. 
A loose surface soil above a compact 
subsoil keeps the moisture for the use 
of plants. On the other hand, a com¬ 
pact surface soil permits the moisture 
to evaporate through the soil at a loss 
to vegetation. The looser the surface 
soil, the more completely is capil¬ 
larity broken between it and the 
subsoil, and the more quickly does 
the surface soil lose its own moisture. 
The water-storing power is greater in 
a fine-grained than a crumbly soil. 
Thus the condition in which to have 
the most water available to the plants, 
is a moderately compact subsoil to store 
water, and a loose surface soil to pre¬ 
vent its escape by evaporation. 
To see the relation of the above to 
the art of plowing, let us turn again to 
the sample of plowing shown in Fig. 
117, but this time to look at the end of 
the furrows as in Fig. 118. In the pen 
sketch, the furrows are shown in dif¬ 
ferent order for better comparison. In 
each of the four cases, seven inches of 
earth are turned up loosely on top of 
the remaining soil. The reader will 
readily observe which of the four kinds 
of furrows will receive the most water 
in a given time. From this standpoint, 
E III is the most desirable furrow, and E II stands 
next. But except for fall plowing as above men¬ 
tioned, we seldom care for such extreme looseness in 
a furrow. In the majority of cases, the desire is to 
get the seed in as soon as possible, and thus the 
farmer looks not at the amount of water the soil will 
catch, but how soon he can sow. He knows, too, that 
furrows like E I and E 0 are loose enough to receive 
sufficient water for practical purposes. In each of 
these instances, also, the plow has broken the capil¬ 
larity to a greater or less degree, between the furrow 
slice and the subsoil. In E I, the furrow is turned 
practically upside down and, unless a large amount 
of coarse manure or rubbish be plowed under, capil¬ 
larity will act again in a short time, for it will not 
take long for the furrow to become packed against 
the lower soil. For spring plowing, this will keep 
the furrow cool and moist by the coming up of the 
WHAT TEOSINTE DOES ON POOR SOIL. Fig. 116. See Page 274. 
