A264-919—5M

BULLETIN

OF THE

AGRICULTURAL AND MECHANICAL
CCLLEGE OF TEXAS

(In cooperation with‘ the United States Department of Agriculture)

JUNE 1, 1919 EXTENSION SERVICE No. B—51

TERRACING IN TEXAS

Terrace carrying water to the fence in a. relatively broad and
shallow stream at a low velocity.~

ADDRESS

T. 0. WALTON L - .
DIRECTOR OF EXTENSION SERVICE, COLLEGE STATION, TEXAS

 

 

 

 

  

 

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FOREWORD

 

Usually soil erosion is so gradual that few farmers realize the great loss
through depletion of soil fertility. T00 often the perceptible reduction in acre
production is attributed to adverse seasons, insect injury and other causes when
the washing of the available plant food content from the soil by heavy rains
has been the controlling factor, and the error is not realized until the rolling
hillside is eventually washed away. In fact, many farms are damaged as much
as five dollars an acre in soil fertility by one washing rain. This estimate
does not include the heavy tax levied on crop production in future years.

There are no more cheap lands in ’l‘exa.s. More attention must be given to
the conservation of the soil as Well as soil rebuilding, if the people of today and
their descendants are to be prosperous as tillers of the soil.

Poor soils encourage poor farming. Poor farming engenders discontent
among farm people. resulting in dissatisfied citizens. A prosperous man is
usually a contented citizen, While a prosperous and contented citizen is gen-
erally a good citizen.

Should additional evidence be needed to convince anyone of the importance
of having- his “rolling” land terraced, it may be found in the provisions of
the Federal Land Bank not to make loans on lands which are not properly ter-
raced unless the prospective borrower will agree to have terraces properly con-
structed and keep them in good condition during the life of the loan, as evi-
denced by the following extract taken from the loan agreement:

“It is agreed that during the term of this loan that the land herein described
shall be at all times fully protected from deterioration by washing or lack of
drainage, by the construction and maintenance of reasonable, proper and ade-
(juate terracing and drainage, and, if at any time during the period of this
loan such terracing and. drainage is not constructed and maintained as will
fully protect said land from deterioration, of which fact The Federal Land Bank
of Houston is to be the sole judge, the said bank may, at its option, declare the
entire indebtedness secured hereby immediately due and payable.”

When a banker who makes a loan of not over one-half the value of the land
cannot afford to take chances on the soil deteriorating i_n value from “washing,”
is it sound business judgment for the owner to take such risks?

It is not the purpose of the author of this bulletin to give an exhaustive
treatise on the subject of terracing, but rather to bring the importance of the
subject to the attention of the Texas farmers and give sufficient information
to enable the farmer, after a little practice, to survey and construct terraces
on his own farm.

Those desiring a more comprehensive treatise on the subject should write to
the Extension Service of the A. and M. College of Texas for the following bul-
letins and circulars:

Farmers’ Bulletin No. 997.
Ciwmlzirs

No. 262. Filling Gullies in Advanced Stages of Erosion.
No. 208. The Soil Saving Dam for Large Gullies.
No. 258. The Concrete Drop for Large Gullies.

N0. 259.
N0. 261.
N0. 257.

racing.

No. 260.
N0. 256.

FOREWORD.

Tile Drainage to Prevent \\'asl1ing.
The Level Bench Terrace. -

Relation of Cultivation, Plowing, Cover Crops, and Humus t0 Ter-

Home-made Farm Levels.
Special Pointers on Terracing.
I '1'. O. WAlxrox,
Director.

TERRACING IN TEXAS

J. C. OLSEN, TERRACING SPECIALTST, EXTENSION SERVICE, A. AND LI. COLLEGE OF
TEXAS.

Soil-saving and soil-building are two of the important problems confronting
farmers 0n the hilly lands in Texas. At least 75 per cent. of the cultivated
hilly farm lands of 'l‘exas (slopes over 2% feet per 100 feet) are subject to seri-
ous erosion. This great loss may be stopped at a relatively low cost by ter-
racing. u

The shaded area on the map shown in Figure 1 constitutes about 60 per cent.
of the area of the State (l00_.0O0,000 acres). Practically all of this is affected
more or less by soil erosion. The Gulf Coast and Plains Region are very level
and need little terracing. The mountainous and ranch country in Southwest
Texas receives very little rain, is principally range land and being sparsely
settled will probably not receive very much attention in terracing work.

About 40 to 50 per cent. of the shaded area, amounting to about forty or
fifty million acres, may be greatLy benefited by tel-racing so as to prevent erosion
and provide for holding rain water. A

CONSERVATION OF MOISTURE.

Unfortunately, the benefits of terracing have been considered mainly from the
standpoint of soil erosion, whereas the drouth of the past two years has demon-
strated that splendid results came from holding the water on the land where
it fell. On many fields the crop yield was doubled, due to terracing, by hold-
ing and uniformly distributing the rain water; and on many places a small
crop was raised on terraced fields, whereas on similar adjoining hilly fields not
terraced the crop was practically a complete failure.

In a great portion of West Central Texas the average annual rainfall is 20
to 25 inches. The precipitation in this section is very erratic. The rainfall is
usually intense and. falls in heavy downpours of short duration. The result is
a heavy run-off and very destructive erosion on the steep slopes; consequently,
much of the rain water is lost to the fields. The seasonal distribution of mois-
ture is also bad in this section. Long drouths often follow these "intense down-
pours with the result that the soil compacts and prevents the land from ab-
sorbingthe water as it should. The conservation of this moisture would be
Worth several million dollars to West Texas annually, and this may be done
to a greater or less extent on nearly every farm in the semi-arid section of the
State by building terraces and small levees at a cost ranging from one to three
dollars per acre.

COST OF TERRACING.

Six mules on a V-drag, two mules on a plow and two men can build from
one-third to one-half mile (1760 to 2640) of terraces, or an average of five-
twelfth miles (2200 feet) a day; The cost of this equipment at present prices
is probably about $12) a day. The cost of 100 feet is therefore about 45 cents.
By reference to the terracing table on page l9 it will be seen that about- 75

6 AGRICULTURAL AND MECHANICAL COLLEGE or Thsxlas.

per cent. of the land in need of terracing requires from 400 to 500 feet
of terraces per acre. The cost at 45 cents per 100 feet will, therefore, range
from $1.80 t0 $2.25 an acre. In some cases it may range up to $5.00 an acre
and in others may be below $1.00 an acre.

SUGGESTIONS BEFORE TERRACING.

The best time to do terracing work is in the late summer and fall, after the
crops have been harvested. Work done then will be well established before the

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Fig. l.—Shaded area especially affected by erosion. The figures indicate
, the rainfall in inches.

springi operations begin, and will also protect the land against heavy fall and
Winter rains. The expense of building terraces at this time is usually not as
great as at other seasons, and by selecting a period for the Work when the land
is considered too dry to plow, a large acreage may be terraced in a day.

When possible it is advisable to sow the field to small grain preparatory to
terracing.

It is better not to flat break or use the middle buster on land until after the

  
    

'I‘ERRA(:1N<1 IN "'l‘1~1x/\s. '7‘

Fig. 2.—Gu11ying of the water fall typc in Eastland County shows how the water
undermines the surface soil when it is more resistant to washing than
the soil below. Soil saving dams of concrete, tile or wood will
often solve the problem economically.

Fig. 3.——Th_e combination of sheet erosion and gullying shown in the above cut has
practically ruined part of this field. The surface soil is devoid of humus or
other water holding material, and the soil is baked so hard that
most of the water is lost as run-off. Kaufman, Texas.

8 AGRICULTURAL AND MECHANICAL GoLLEeE or TEXAS.

terraces are located or built, because the plowing should be done with the ter-
races.“ This will help to fill up the washes, and the fact that the plowing is
with the contour of the hill will also aid the terraces materially by protecting
them and making the water go into the ground. Also, that part of the field
represented by the terraces is plowed. Always fiat-break and never use a middle
buster on the terraces. The rows should be laid off on the terraces with a cul-
tivator in such manner as to make them come_ out even with the middle buster
rows between ithe terraces.

‘Kill. all the Johnsongrass and Bermuda grass on a cultivated hillside before
terracing, because it is more diflicult to kill it on the terrace.

In stony or stumpy land, xvhen possible, all the stones and stumps should be
removed twelve feet each way from the center line of the terrace before building
the terrace.

A permanent system of crop rotation should be maintained on the terraced
land. Terracing is only the first step in building up a worn-out hillside.

Fig. 4.—-The break in this terrace caused by an insufficient outlet occurred 20 feet from
the outlet after the water had been carried 1200 feet. The two foot outlet
through a hog wire fence should have been 8 to 1O feet wide.

Overloading the top, terrace, by giving it too large a drainage area, is one
of the common mistakes of "the inexperienced in terracing.

Where the drainage from adjacent farms comes through a field which is to
be terraced _an effort SllOLild be made to get the owner of the land to terrace in

_ order to" avoid digging a hillside ditch to intercept this water.

In the extreme northwestern part of ‘Fexas considerable difliculty in terracing
is caused by. “gas mounds.” YVhen these are located on the terraceiline a slip
scraper or fresno is used to cut through them. When they are too large to cut
through the terrace should be relocated above or below these places.

When it is necessary for a farm road to cross a terrace try to make the road
conform to the terracing system by locating the road at the dividing point of
the water along the terraces. Should this be impossible the terrace must be
built extra large and. strong where the crossing occurs. Sometimes culverts are
used for crossing the terraces. \

It is extremely hard to make an outlet for the terraces in a field where a
round knoll projects up in the center. In such cases, where the soil is very

Tiammcilve IN TEXAS. e 9

porous, terraces may be located close together on a level and built extra high
until a lower elevation is reached which wi.ll permit the terrace to empty
properly. If the terrace will not be too long, it may sometimes circle from one
to one and a hztlf times around the hill before it is-emptied.

It is a mistake to attempt to cultivate land where the slope is much over
twelve "feet per 100 feet. A narrow’ high terrace should be constructed and the
land put in pasture.

Before setting out orchards on a hillside, it should be terraced and the trees
set out on the terraces.

TWO CLASSES OF TERRACE-S.

There are two general classes of terraces. In the first class the terrace is
run on a level around. the hillside with the purpose of ‘making the land retain

l Fig. 5.—A terrace through a pecan grove near Corsicana. Note the
trees on the terrace line.

and take up all the water that falls ‘on it. The bench terrace belongs to_ this
class.

In the second class the terrace is given a slight fall, which permits the water
that will not soak into the ground to run off at a very low velocity. This is
the type that is adapted to the greater part of Texas. Theibroad terrace and
the modifications of the broad terrace come under this class. These are dis-
cussed fully in the following pages.

THE BENCH TERRACE.

The level bench terrace—the true terrace—is adapted to Texas conditions to
a limited extent. Its use is recommended for deep porous soils which are too
steep to permit the use of a cultivated terrace (slopes exceeding 12 to 15 feet
per 100 feet).

10 AGRICULTURAL AND MECHANICAL COLLEGE or TEXAS.

THE BROAD BASE TERRACE.

The broad base terraec-—contoi1ring a field with a light grade to_ conduct the
surplus water away slowly—--is the type of terrace to build in most parts of
Texas. The graded road is a splendid illustration. _

lVhen the terrace is first built and the soil is loose, it should be at least 21
inches high (knee high) in order that it may be 15 to l6 inches high, after set-
tling. From 20 to 30 per cent. should be allowed for settling.

The base width ‘of the terrace for ordinary slopes should not be less than 20
feet. This Width is necessary in order to give it suflicient strength to hold the
weight of the water above and to make it possible to cultivate six rows of
cotton on the terrace satisfactorily. Each year the plowing is started along
the crest of the terrace and the base Width increased until it is from 25 to 30
feet. .

The broad base does not permit the water to cut or denude any part of the

Fig. 6.—One of the thirteen terraces on this slope in Milam County on the farm of J. C.
_ Hardy where the broad base terrace is sown to sorghum the first year.

field. After the ground is fairly well soaked the balance of the water is car-
ried away in a shallow, broad stream, at a low velocity, toward some natural
watercourse where the terrace may drain. The terrace gives the‘ water a dif-

ferent course, causing it to move slowly and permits the soil to absorb more

moisture. Should the hillside slope 4 feet per 100 feet? which is very common,
and the terrace is given 4 inches fall per 100 feet, the water, instead of having
48 inches fall per 100 feet, has only =1 inches fall per 100 feet, after terracing.

The common practice of building terraces ten to twelve feet iuide at the base
must be corrected. These ridges cannot be expected to withstand even an ordi-
nary rain. They possess many of the bad features of the hillside ditch, and
many farmers who have built these small terraces have discouraged others who
might have terraced if they had not seen these narrow terraces.

One of the greatest advantages of the broad terrace is that it permits the use
of all improved machinery. The gang plow, the section harrow, riding culti-
vator and grain binder may be used successfully. There is no waste land be-
cause the best crop in the field is usually found on the terrace.

TERRACING- IN TEXAS. _ 11

MODIFICATION OF THE BROAD TERRACE.

In a few places in Texas a narrow terrace——a modification of the broad ter-
race—is used quite successfully. iVhere the soil “melts” down after a heavy
rain, making cultivation impracticable, their use is recommended. This type
of terrace Works very well in blow sand and when located on a level or with
fall to meet the conditions, it is very Well adapted to pasture land; however,
they have many of the disadvantages of the hillside ditch. They are usually
built from 18 to 20 inchesfhigh and 7 to S feet wide.

FARM LEVEL FOR TERRAGING.

A simple, eflicient and inexpensive farm level, costing from $15 to $25, with
telescope, rod and target, is suitable for locating farm terraces. As satisfac-
tory work may be clone with these levels, when properly used, as with the more
expensive ones. Three or four farmers may use the same level and help each
other in locating and building terraces. By cooperating in this manner the
cost of terracing is reduced and more satisfactory results are obtained.

Everyone who uses a farms level should lcnnw how to adjust and test it be-
cause accurate work can-not be done unless the level is in adjustment. This is
necessary in the best instruments and requires only a few minutes when the
method of performing the work is understood.

ADJUSTING LEVEL WITH A POND OF WATER. _

Farm levels may he adjusted with. the surface of a small pond of water as
accurately as is necessary for terracing purposes.

First A djztstmeut.——To make the bubble tube perpendicular to the vertical
axis. This adjustment is only a matter of convenience and it will not be neces-
sary to “level up” the instrument in sighting in different directions. Turn the
telescope over one pair of foot screws a11d level up the instrument. Then turn
the telescope a half turn or 180 degrees about the vertical axis. If the bubble
changes its position, raise or "lower the adjustable end of the bubble tube until
the bubble is brought half way back to its former position. This operation
should be repeated until the bubble stays in the center While the telescope is
rotated 180 degrees.

Second Adjustmeutr-To make the bubble tube and the telescope parallel.
This adjustment is mzyle with a pond of water. The water must be still and
should be at least 200 feet across it. A stake with a smooth top is driven flush
with the water surface on one edge of the pond. The level is set up over this
stake and the distance from the top of the staked to the center of the telescope
is measured. This reading can be taken by sighting through the telescope in
the reverse direction. When the target is properly located, it is clamped at that

reading and carried to the other side of the pond, where another reading is v

taken on top of a stake driven flush with the surface of the water. If the cross-
hair does not coincide with the center of the target, something is wrong and
the telescope must either be raised or lowered with the adjusting screws until
this condition. is met. The level will then be ready for use.

PRELIMINARY SURVEY OF FARM.

Before attempting to locate any terraces a preliminary survey should be
made of the entire farm. Poor forethought a11d judgment are shown if the

12 AGRICULTURAL AND hIEoHANIeAL GoLLEer; or TEXAS.

whole farm is not terraced as a unit. It is a mistake to terrace individual
slopes Without regztrd to the entire farm. The entire terracing‘ system,- i.nclud-
ing the drainage ditches, on a series of hills on the farm must be made to dove-
tail and fit together.

The boundary lines of the farm should be located, the slope of the land and
the direction the water runs across the fields, should be noted. The drainage
from adjacent fields and farms should be determined and controlled, and all
the possible outlets for the terraces should be studied, after which the best and
netvessary ones are selected a11d used. '

There is very little choice in the selection of the outlets when a large acreage
drains through the farm from above. In this case, the natural drainage course
of this water through the. farm should be selected as a ditch and an emptying
place for the terraces. This ditch should be made as straight as possible.
Usually terraces on. the hillsides on either side of this drain may empty into

this ditch.

Fig. 7.——This is a very typical condition where there were tour ditches on a 30 acre
field near West. After the field was terraced only one ditch was left.

As. a general rule, the upper terraces are the shortest and often the most
difficult to locate with good outlets. It is very oftem necessary to carry the
water from the upper terraces to a fence on one side of the field, and from
this point in a small shallow ditch, the water must be carried along the fence
down the slope to the main ditch. After the upper two‘ or three terraces are
located, the rest of the terraces are easy to locate and usually empty directly
into the main ditch where the water can do no damage. They run more or
less parallel with the upper terraces. The steeper the land, as a rule, the more
nearly parallel they run, and the flatter the land the more irregular they run.
On round. hillsides that slope two ways it is best to carry. the water out to each

‘side of the field if good outlets can be secured. .A terrace carrying water 800

feet is an average length terrace. If possible keep the length under 1200 feet.
Of course if a terrace empties both ways from the center it may be 2400 feet
long.‘ The shorter the terraces, the less water they will have to handle, and the
easier they can be maintained. If the area to be terraced is large and several
have to be-crossedpbefore a good outlet can be secured it may be necessary, in

TERRACING IN Texas. 13

order not to make the terraces too long, to use one of these depressions as an
outlet for terraces from either side, and thus relieve the strain o-n long irregular
terraces. This ditch should be seeded. to grass in order to hold the soil together
and to check the velocity of the water down the slope, or perhaps, a soil-saving

dam, described in circular No. 208, can be installed at a' reasonable cost which

will prevent the ditch from washing too deep.

In order to give the least possible length, the terraces have to be located so .

as to empty the water at_ an angle upstream into the main drainage channels, in
a direction more or less opposite to the flow of the ditch, or stream it empties.
The water is often carried and emptied into the main channel at an angle of
less than 4.5 degrees upstream with the main channel. If the terraces were
riin so as to carry the water more or less in the same general direction as the
main channels. in most cases the outlets would not be as good and the terraces
would be much longer". The fact that the natural drainage channels and creeks,

. as a rule, have more fall than the terraces, accounts for the difliculty. Of

course, terraces cannot be located to carry the water'out of its natural course
through the neighbor’s field, nor should the terrace be located to carry the
water out of its natural course and emptied into a public road where. it "may
do damage. The public road is being used too much now as drainage channels.
In many cases a house, barnyard, orchard, or garden will prevent running the
terraces in the most desirable direction. To properly terrace some farms may
affect a neighbor’s property, in which case a collective operation in reclaiming
land by terracing should be resorted to in much the same Way as is required
in irrigation and drainage projects.

If the terrace should pass any particular point, such as an orchard or a very
irregular place in the field, the starting point should be selected just above or
below such points. If there are several large gullies in the field, the location
of a terrace just above the sharp breaks in these gullies will often save consid-
erable work and the next lower terrace ‘will usually’ intersect the gullies at
favorable points. Sometimes it is desirable to have the terrace empty at some
particular place along the side of the field,'and in that case it should be the
starting point in locating the terrace. To avoid crossing abrupt knolls in a
field, terraces should be located just above and below such places. By avoiding
as many of these irregularities as possible, a neat job of terracing may be done
while if carelessly done, it would have many ugly twists and turns. In ter-
racing a field it “is not necessary to locate the top one first". In fact, it is often
better to start half way dpwn the slope where the terraces run more regular and
work in the upper and lower ones later. When they are allowed to discharge
into a woodland, it often happens that in the future, when it  desired to put
that area in cultivation, there will be considerable difficulty in adapting the
terracing system to this new land. All the possible future changes should be
kept in mind, when locating terraces. A careful inspection of the field and a
little forethought in the location of terraces very often results in a better loca-
tion and reduces the labor of terracing.

LOCATING THE BROAD TERRACE WITH A FARM LEVEL.

After the preliminary survey has been made, a starting point must arbitrarily
be selected on the first proposed terrace. Usually the first terrace located is
the upper terrace on the hillside. In this case, the level may be set up on a
slightly lower elevation about midway between the ends of the terrace line in

14 AGRICULTURAL AND lllncniinrcuu. COLLEGE OF TEXAS.

a position Where the rodman will be Within range of at least one end of the
terrace line and usually both ends. Sometimes two terraces can be located with
one set up of tl1e level. Long sights over- S00 feet should be avoided as much
as possible. The rodman places his rod at the proposed starting point and the
instrument man sights through the telescope at the target, motioning the rod-
man to move the target up or down until the horizontal cross-hair in the tele-
scope coincides with the middle of the target. Here the target is clamped and
a stake driven into the ground to locate the place. Broken corn stalks, weeds
or other convenient material may he used for stakes to mark these points on
the terrace line. A bundle of light Wire stakes 2%- feet long-with a red ribbon
six inches long tied to a loop at the top of the stake, makes a very distinct
mark and may easily be seen 6,00 feet between high cotton or corn stalks.

In an open field, free from vegetation, piles of dirt, made with a hoe, make
good marks. Sometimes stakes are not set, but it is not good practice to do
such slip-shod Work. Even the most experienced men can do much more satis-

Fig. 8.—This cut illustrates how completely a gully eight feet deep and ten to twelve
feet wide has been filled up. This man is standing on the site of the
original gully. Gallatin, Texas.

factory work when the line is marked as outlined above. The terraces will be
there for a long time, and we should all try to do the Work the very best we
can. If the stakes are fifty feet apart. and the fall per 100 feet is 4 inches,
it will be necessary for the rodman to raise the target two inches at each
station in locating the terrace down. grade. Seventeen good ‘steps are equivalent

to fifty feet, and a variation of three or four feet in distance is 11ot serious-

The rodman is motioned up and down the hill by the instrument man, but still
keeps approximately fifty feet from the first stake, until the target again coin-
cides with the cross-hair of the instrument. Here another stake is driven and
the target again raised for the third position. If the rodman gets out’ of sight

{around the hill, or toe long a sight is required, i.t will be necessary to move the

instrument to a new position where the terrace may he finished. The first read-
ing with this new set up of the instrument must be taken at the point where
the last stake was driven and the target raised or lowered until it coincides

TERRAOING IN TEXAS. 15

with the cross-hair. After this the target is raised. two inches at each station.
lf the rodman is locating the terrace up grade, the target must be lowered two
inches for each reading instead of raising it.

When the fall per 100 feet along the terrace is 5 inches, stakes are ilsually
set 60 feet apart {20 good steps), and the target is raised three inches at each
station in locating the terrace down grade, and vice versa in locating up grade.

The vertical drop between terraces is determined as follows:

Take a reading at any one of the stations which have been marked on the
last terrace and set the target so as to coincide with the horizontal cross-hair
in the level. Suppose the rod reading is 4. feet. If the vertical drop is to be
3 feet between terraces, 3 feet must be added to 4 feet, making a T-foot rod
reading for a lower terrace, and for the next upper terrace 3 feet must be sub-
tracted from 4 feet and the rod reading will be 1 foot. In either case the rod-
man goes up or down the slopes as the case may be until the target coincides
again with the horizontal cross-hair, and the first point on the next terrace is
located. From this beginning point the target is now raised or lowered at
every station as described in the two preceding paragraphs.

There is more or less variation in the slope of all hills. Very few have uni- ~

form slopes. As a general rule, terraced hillsides which have only one general
slope have less slope near the outlet of the terraces than at any other place.
This is also true to a certain extent with round hillsides. The terraces are,
therefore, usually farther apart near the outlet of the terraces than at any
other place. They are closer together where the hill is steepest. Therefore, if
the proper spacing and vertical fall is taken at the outlet end of the terraces,
they may be too close together at the other end and vice versa.

As a general rule, it is better to get the vertical fall and spacing between
terraces at some point on the slope which is as representative of the average
slope as possible. This position is usually about half way around the terrace.

The upper end of a terrace for short distances (100 to 300 feet) may be run
on a level or on a grade up to 8 inches ‘fall per 100 feet safely. Good strong
terraces can be located on grades of 3 inches or even 2 inches per 100 feet safely,
if their length does not exceed 600 to 700 feet. Sometimes the top terrace may
be located with a 5-inch fall, the second one with a 4-inch fall per 100 feet, etc.,
and vice versa. By taking advantage of these facts the terraces will run more
nearly parallel in many instances and lots of point rows will be eliminated.

MARKING THE TERRACE WITH A PLOW.

After staking ofi‘ the terrace line, the real terrace line is marked off with a
plow. The stakes are to be used as guides only because i11 looking back over
the course the stakes will usually show a very broken line. To avoid the irreg-
ularities shown by these stakes, it is necessary to miss some of the stakes sev-
eral feet so as to make easy rounding curves for the terraces. A variation of
two feet from the line of stakes on hillsides which slope 4 feet per 100 feet only
means a difference of elevation of one inch. Variations of from four to five
inches in elevation for short distances can safely be made if additional work is
done at the fills and cuts. it is ilsually’ best to haw: a competent man walk
ahead. of the team in plowing the first furrow in, order to lead the way and
make these variations. If a riding plow is used to mark the lines, sometimes
the driver can stand up on the plow and make these corrections himself. It is
not good practice to mark the lines off directly behind the rodman. A little

16 AGRICULTURAL AND,MEOHANICA.L COLLEGE or TEXAS.

experience and good judgment are necessary in plowing the first furrow, and
especially so if the land is seriously washed and gzillierl.
J

LOCATING THE TERRACE OVER A GULLY.

In taking rod readings in rough places average ground should always be se-
lected. Readings should not be taken on ridges, knolls, holes, gullies 0r washes.
If the first rod reading is taken between the rows the succeeding readings should
be taken there also. Where elevations or depressions are sharp and the terraces
turn and twist considerably, the rod readings should be taken closer together
than fifty or sixty feet in order to give the terrace the proper curve. In very
rough places where the terrace curves considerably, it is advisable to increase
the fall along the terrace slightly. In crossing a gully, stakes should be set
on each side in such a way as to make it necessary to grade dirt from the high
places to fill in the gully where the terrace crosses. These gullies, of course,
need, a dam which will be higher at the first than the terrace on either side,
because the loose high bank will settle considerably. These banks must also

Fig. 9.—A large terrace- in Milam County. The terrace was five feet high across the
gully. These terraces were located by County Agent Mr. Geo. Banzhaf.
Note ._how the gully is filling up where he is standing.

stand the strain of the water which concentrates above and softens the bank.
These depressions fill up with sediment very rapidly to the grade of the water

Vcourse of the terrace. Most farmers want to eliminate as many crooks across

small draws and large gullies as possible by making extra heavy fills across
these places. The amount of variations to make at these points depends entirely

on the extent of work the owner is willing to do. Usually it is best to compro-

mise, making a partial fill and curwing the terrace line slightly up grade. If
the draw is 100 feet or more in width, the curve of the terrace line should be
followed pretty closely, because too much work is required to straighten the
terraces. In making heavy fills over’ gullies, if possible, they should be tested
with a level or a string which can be stretched clear across the gully to points
on top of the completed terrace on either side of the gully which are safe. About
25 per cent. settling should be allowed.

It is also advisable to put in extra fills with a scraper across the gullies half -

Way between the terraces. These places will fill up much faster if this is done.

TERRACING IN TEXAS. 17

Sometimes short, small, cross terraces from 100 to 200 feet long With a fall
of from 8 t0 12 inches per 100 feet, located just above very bad breaks in the
hillside between the regiilar terraces to carry the water to the terrace in the»
reverse direction, are very helpful. ‘

PRECAUTIONS IN BUILDING TERRACES.

in building" terraces, the Work should begin at the top of the hill on the upper
terrace. If the top terrace is not completed before Working on the‘ lower terrace,
a heavy rain might ruin part of the work already done. The terraces are ex-
pected to handle only a small water shed each, and if one of the upper terraces
should break, the mud and water will probably clog up and “smash” the ter-
races directly below and break the terraces all the Way down the hill. The crest

and the Water course of the terrace must both have a uniform grade and a dif--

ference, when the soil is settled, of from sixteen to eighteen inches along the
entire course. _ i
The first year the terraces should receive careful attention. If the first rains

Fig. 10.—Deposit of _soil in gully above watercourse of terrace. The water along the
terrace 1s flpwlng to the foreground. The far end of the terrace shows
clearly that the fall was too great.

on the loose, soft terrace are slow, they will probably not cause any trouble;
however, should the first rain be very intense and break the terrace, the break
should be repaired immediately. After the first year the terraces will need
little attention, other than beginning the ploxving at the center each year and
throwing it toward the center of the terrace each time the land is plowed.
Insufiicient outlets often cause the terraces to break and eat back into the field.
When the terrace 1s carrying water to its ‘full capacity, the top width of the
stream should be at least eight feet, as a rule, and from eight to ten inches deep.
It is a very common occurrence to find the outlet only ‘from two to four feet wide,
and of course the water must have double velocity to pass this narrow point and
carry the. water. If the water piles upvtoo much at this point it will break the
terrace a short distance from the outlet. If, at the outlet, the water has a con-
siderable vertical drop, the increased velocity at the outlet will naturally cause
the water to eat out a ditch back into the field. In order to eliminate all this
difiiculty the outlet should be broad so as to spread the water as much as pos-

18 AGRICULTURAL AND NIEOHANICAI. COLLEGE OF TExAs.

sible and decreaseits velocity. It is also a very good-plan to sod the outlet
immediately, if there is not already a turf there. Sometimes the outlet ditch
can be protected with big fiat rocks. These rocks should be placed at the lower
end first and laid up grade. The ditch should be slightly rounding and the rocks
at the edges should be laid firmly in the ground so that the water cannot eat
around them at the edges.

SPACING TERRTACES.

Failure in. terracing often results from spacing the terraces too far apart.
On steep hillsides a vertical drop of less than four feet places them too close to-
gether, while on gently sloping land a drop of two feet may place them amply

far apart. About 75 per cent. of the hilly land of this State requires from two-

and one-half to four feet vertical drop between terraces. This places them from

a 80 to 115 feetapart, giving the terraces as much Water _as they can handle, while
placing" them as far apart as is safe to keep the hill from washing. The spac-'

ing of-terraces depends on the slope of the land; the length, height and regularity
of the terraces, and the type of soil. A steep hill, an irregular terrace and a
soil which washes easily requires close spacing of terraces. Usually the hillside

QIFig. 11.——Gross section of terrace when completed.

is steeper just below the brow of the hill and flattens out above and below this
point; therefore, different vertical falls and distances must be used on the same
slope. The vertical drop varies from one to eight feet. The terracing table on
page 19 may serve as a guide for directing the work of the inexperienced.

IFALL- TO GIVE ALONG THE TERRACES.

The fall to give a terrace depends primarily on the slope of the land and the
capacity of the surface soil and subsoil to absorb water. As a general rule
sandy soils require about 1 inch less fall per 100 feet than heavier soils of the
same slope, and the higher the state of cultivation the less fall necessary. Four
inches fall per 1040 feet for light soils and 5 inches fall perlOO feet for black
land and heavy soils in Central and East 'I‘exas gives good results. Five inches
should be the maximum fall under all conditions. For the steepest slope in
West Central Texas 4 inches fall per 100 feet is suflicient fall. See terracing
table on page 19.

In West Central Texas many cultivated hillsides have slopes not exceeding
l8 to 24 inches per 100 feet. Under these conditions the terrace may be located

TEBRACING IN TEXAS. ' 19
on a level to hold all the water where it is so badly needed. Where the slope
is less than 15 to l8 inches per .100 feet, the terrace may be located on a level,
and in many places some of the run-off water from adjoining pastures may be
diverted over the land. This might be termed “Providence Irrigation?”

For slopes of 3 to 4 feet per 100 feet a fall of 2 to 3 inches per 100 feet along
the terrace is ample fall with a strong terracing system.

TERRACING TABLE.

Vertical Fall between Terraces, Distance between Terraces, and Fall along Terraces for different Soils. Base Width
and Height of Terrace, Width of Water Course, and Acres Terraced per Day for various Slopes.

Vertical Fall Between Terraces in Feet.

l1.)
511%22%33§¢44%55%66%7
Distance between terraces for— q
heavy black land and
soils with a large per cent '
0f clay ................................ .. A 200' 165' 135' 115' 100' 94' 88' 83’ 78' 74' 70’ 67' 65'
Distance between terraces for —_ l
sandy soils that wash
easily .................................. .. B 185' 140' 115’ 95' 89' 84' 80' 76’ 72' 68' 65' 62' 60’
Fall per 100’ along the _ 3”-4” sand yloos e soil 4" for s andy and 1 oose s oil.
terrace ................................ .. C 0"-3" 1"-4" ’-4” 4"-5" for h eavy soils. 5" for s andy and 1 ooses oil.
Base width to build terraces
first year ............................ .. D 22' 22' 22’ 21' 21' 20' 20' 19' 19’ 18' 18' 17' 16'

Heighth to build terraces
above the water course
when dirt is loose. Settles
25percent ........................ .. E 15" 16" 18" 20" 21" 21" 22" 22" 23" 23" 23" 24" 24"

Minimum top width of water
in water course when
water is 9" deep ................ .. F ................. .. 11' 10' 9' 9' 8' 8' 8' 7' 7' 7' 7'

Lineal feet of terrace per acre
for distance between ter-
racesgiven 0n lineA ........ .. G 218' 261' 323' 380' 435' 462' 495' 526' 559' 588' 620' 650' 672'

Acres terraced per dav with _
4 to 6 mules on V-drag ’
2 mules on plow ................ .. H 8-12 6§—l0 5%—8 4%—7 4-6 3%—5% 3%—5% 3%—5 3—4% 34% 3—4% 2%—4 2%—3%

See cut on "Cross section of terrace when completed,” on Page 18, Fig. 11. It may simplify the use of above table.

RUNNING ROWS WITH THE TERRACES.

l The best method of cultivating row crops on a terraced field is to run the
rows parallel with the terraces. Practically all the Work is then done on level
ground. It is wry hard on a team to climb up and down a steep hill all day
long. If the distance bet-ween the terraces varies a great deal, there will be a
number of short point rows. The first row should be planted right on top of
the terrace. If the terrace is 2] feet wide, and the rows 3% feet apart, there will
be six rows on the terrace. About half of the long rows between two terraces
should be located above and below each terrace. To prevent having all the
short rows running out together, sometimes it is best to work in two short
rows occasionally before locating all the long rows and avoid having too
many point rows together, which would concentrate too much water at one point.

20 AGRICULTURAL LAND MECHANICAL COLLEGE OF TEXAS.

Fig. 12.—Cotton.rows contoured with terraces inhMilam County. Note the two point rows
half way between the terraces. The arrows indicate location of terraces.

Fig. l3.-—Corn rows crossing terraces in Navarro County. If the slope exceeds two and
‘ one-half feet per 100 feet this system is usually not successful.

TERRACING IN TEXAS. 21

RUNNING ROWS OVER THE TERRACE.

’lhere are a number of farmers in Texas who are running the rows at a slight
angle over the terraces successfully, where the slope of the hill does not exceed
2% feet per 100 feet. A good many farmers are trying to cross the terraces on
steeper slopes, but in most cases the terraces give way and cause considerable
trouble. If the rows cross over the terraces they should be run in such a direc-
tion that the rows will cross the terrace at a small angle. The ideal condition
is reached when the rows cross the terrace at such an angle that the rows have
the same fall as the terraces in the reverse direction, so that they will carry the
water to the terraces opposite to the direction it flows in the terraces. The
rows should never be run straight across the terraces. ‘It is useless to Waste
time trying to cross terraces when a middle buster is used, “because they will
almost certainly cause trouble. Many farmers expect to lift these plows slightly
in crossing the terraces. but it does not work out in practice.

Contouring the rows with every other terrace in some places is an excellent
method for slopes of less than 3 feet per 100 feet, and often eliminates many
point rows. This is a compromise between crossing and contouring the rows.
Where they do cross the terraces they usually do so at a very slight angle. If
a hillside has five terraces which run fairly uniform the middle terrace is more
representative of the general curve of all the terraces and can sometimes be
used as the guide for all the rows on the hillside. On steep slopes the terraces
run more regularly than on moderate slopes a.nd the rows should always be con-
toured with each terrace. If the rows cross the terraces slightly, they should
be at least 24 feet wide at the base. A little less time and labor is ‘required in
plowing, less difficulty is encountered in turning in the field when the crop is
large and farm machinery can be handled a little easier when the point rows
are eliminated by this method. Care must be taken to fill up all dead furrows
made in plowing as well as tracks made in crossing with other farm implements.
If the terraces run nearly parallel it is better to contour the rows with the ter--
races, because the rows will hold more water and the terraces will be so much
easier to maintain.

EQUIPMENT FOR BUILITING TERRACES.

Terraces may be built with a plow alone, a plow and a home-made V-drag, a
plow and a steel ditcher, a plow and a road grader. a reversible disc plow, or a
combination of the above methods. The home-made V-drag, the steel ditcher,
and the road grader should be reversible. Usually two men and from four to
eight mules are required for either of these three methods and from sixteen to
twenty-four rounds are usivlly necessary to put up a first class terrace when
the soil is in first class condition. (See terracing table on page 19.) When the
vertical fall between the terraces is under two and one-half feet the dirt may
be shoved toward the center of the terrace from both sides until it is completed.
When the vertical fall is from two and one-half to four feet the dirt may be
shoved toward the center from both sides of the terrace until it is nearly com-
pleted. At the finish three or four rounds should be made by shoving the dirt
do\vn hill entirely. This makes a flatter,‘ wider watercourse, which is so neces-
sary for a strong terracing system. When the vertical fall between terraces is
from fourto six feet, the dirt may be shoved to the center from both sides until
it is half built. After this it is more satisfactory to work only from the upper
side. For steeper slopes than a six-foot fall between terraces, practically all

22 AGRICULTURAL AND MECHANICAL COLLEGE or TEXAS.

the work must be down hill. The dirt is shoved up hill only enough to round
ofl‘ the terraces.
TI-IE HOME-MADE V-DRAG. '

The V-drag, shown in Figure l4, when used in connection with a good walk-
ing plow, is one of the best implements that is used in building terraces. It is
simple, eflicient, and may be made in an hour. It is very useful in opening up
small ditches, after the soil has been loosened with a plow. It is so constructed
as to shove the loosened dirt toward the center of the terrace. When the soil
is in fairly good condition, six mules on the V-drag and two mules on a good
turning plow can build from one-third to one-half a mile of terrace in a day.

The short wing of the V-drag corresponding to the mold board of a plow is
7 feet 6 inches long, and the long wing corresponding to the landslide is 12 feet
6 inches long. For these Wings a good grade of 2xl2-incl1 lumber should be
used. One side should be planed, turned toward the dirt and used on the wear-
ing side of the V-drag. The spread between the wings for black land should
be about four feet, while for sandy land four and a half feet is satisfactory.
To hold the wings rigid, two 2x6-inch braces, as shown in illustration, spiked
to the i-xlil-inch wings three inches from each edge of the wings, allows three
inches clearance for the drag and makes it reversible when it is tipped over at
the end. The hitch should be located in the center of the 2xl2-inch for the
same reason as shown in the cut. Usually an iron 3-l6x2 inch by 6 feet 6
inches, bent into form as shown in cut and bolted to each wing, makes a very
convenient hitch. A six-horse evener should be hitched to the V-drag by means
of a chain two and one-half to four feet from the point of the drag. Usually one
team is put in the lead- The short wing should. be faced with a piece of steel
3 to 4 inches wide by 3-16 to i; inch thick, by 7% feet long. This cutting edge

is put on both outer edges of the short wing. It is well to do this if the V-drag »

is reversed a good deal, but if the dirt is shoved up from both sides three-quarters
of the time the cutting edge on both edges is hardly necessary. If only one wing
is provided with the cutting edge, it should be put on the V-drag so that the
drag will shove the dirt in the same direction as the plow. In sandy land, the
wear on the plank wings is very rapid, and it sometimes becomes necessary to
place a strip of iron along the long wing too, so as to protect it. The following
table gives dimensions for a 2, 3, 4, 6, or S-horse V-drag:

DIMENSIONS FOR HOME-MADE ‘V-DRAG.

?Numb_er of Horses or Mules.

Length of Short Wing .............................................................. .. 4%’ 5’ 6%’ 7’ 3:
Length of Long Wing ......................  ...................................... .. 8 ’ 9' 11%’ 12%’ I, 14;,
Size of Material for Wings .. 2" X 3" 2" X l0" 2" X 12" 2" X 12" 2 X 1,2 l,
Spread between Wings for black land (33 degrees) .......... .. 2%’ 3’ 3%’ 4' 4 4
Spread between Wings for sandy land 3-5 of length of , I
short wing (37 degrees) .................................................. .. 2%’ s’ 3' 11" 4' 6" 4 10'

Sometimes the short wing is hinged-to the long wing, but there is little advan-
tage in making it that way if the terrace is properly started. The spread be-
tween the hinged wings in this case should be varied, but usually the drag is
not as strong or rigid. The simpler the (lrag can be made the more effective
it will be.

23

T'I~JRR.ACING IN TEXAS.

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24 AGRICULTURAL AND MECHANICAL CoLLEeE or TEXAS.

With one man riding on the V-drag six good mules will have a full load. By
shifting theweight the proper pressure can be put on the wings to hold it in
place and cause it to shed the dirt properly.

CONSTRUCTING THE TERRACE WITH A HOME-MADE V-DRAG,

Either a disc plow or a mold board plow may be used with the home-made
V-drag in building terraces. After the first furrow has been run, marking the
terrace line, a second furrow is plowed three or four feet from and toward the
first furrow. This leaves a solid strip for the center of the terrace. Usually
four furrows wo from each side-are thrown together before the V-drag is
used. The long wing runs in the furrow and acts as the landslide of the plow,

while the short wing is the mold board, which shoves the dirt three or four feet

Fig. 15.—Small tractor pulling steel ditcher and four horses on road plow terracing in
Bosque County. A half mile of terraces can be built in one
day with this equipment.

toward the center of the terrace. From this stage the V-drag follows each plow
furrow and the terrace gradually widens out with each round until the proper
width has been reached. In order to get the terraces high enough the operation
is repeated again by beginning at the center of the terrace as in the beginning.
The plowing this time should extend about a foot further to each side, making
the base width two feet wider. Sometimes a third and even a fourth operation
is necessary to put the terraces up properly. One time over will rarely put it
high enough. Two careful operations are generally sufficient. The size of the
V-drag, the type and condition of the soil, determine the number of operations
necessary. ‘ Sometimes a plow with an extra long wing attached to it is used
very effectively ,in putting up terraces.

TETRRACING IN TEXAS. 25

THE STEEL DITCHER.

The steel ditcher is one of the best machines that can be secured for building
terraces. It is usually necessary to plow ahead of the ditcher in the same man-
ner as for the home-made V-drag. In sandy or loose land only about one-half
as much plowing is necessary. For terracing, the small to medium-sized should.
be used, and it requires from six to eight mules to handle them efliciently. In
terracing a large acreage it will pay any farmer to buy one of these machines.

They are also very fine for cutting small ditches from two to two and a half,

feet deep.
THE ROAD GRADER.

The road grader is used considerably to put up terraces. i If the soil is in
good condition they work splendidly. and when eight good mules are hitched to
a small reversible road grader probably no better outfit can be secured for p'ut-
ting up terraces. A plow is often needed to loosen the dirtahead of the grader.

Fig. 16.——-A good way to stop and fill up gullies especially along fence lines. Rocks, if
they can be secured, are permanent and much niore satisfactory. -Th-e wall
of rocks should be level sol the water may filter through
and over evenly all along the line.

USING THE PLOW QNLY FOR BUILDING TERRACES.

Some of the best terraces in the State of Texas were built by using no other
implement than a plow. This system simply requires replowing a sufficient
number of times to bring the terrace to the retjuired height and width. The
double disc plow is especially fine. The size of the plow, the condition and type
of soil. the depth of plowing, the kind of plow and the speed of the plowman
determine the number of plowlings necessary to put up a good terrace. The
terrace line is used as a center line and the furrows are thrown toward this
center line from both sides until a land 2O feet wide is plowed. The center line
of the terrace is again used as a beginning point and the land is replowed in
this manner about half a dozen times or until a terrace of the required height
and strength is built. The ground, after the second or third plowing, may be
very loose and in that case farmers sometimes wait and. allow a rain to settle

26 AGRICULTURAL AND MECHANICAL COLLEGE or TEXAS.

the terrace. This is quite risky because a heavy rain may not only settle the
terrace, but may injure and undo some 0f the work which required a lot of hard
labor. Either of the previously described methods of building terraces is better.

THE FRESNO AND SLIP SCRAIPER.

For making fills at the gullies the fresno is the best implement to use. A
slip scraper is often used, but it is a slow, hard and tedious Way to finish the
terrace at the high and low lalaces. The fresno is easy to fill, dump and handle,
and the four-horse fresno will move about three times as much dirt as the ordi-
nary scraper.

FILLING. GULLIES IN ADVANCED STAGES OF EROSION.

I
For filling gullies in advanced stages of erosion the soil-saving dam and the
concrete, stone or wooden drop are effective means for checking and filling them

Fig. 17.—-Soil saving dam at Bruceville, Texas. The inlet end is shown on the
right and the outlet end on the left.

up. Both take up the excess ‘grade and fill the gully at the expense of the
adjoining upper slopes. The rushing Water “is checked above, its sediment de-
posited and the water is carried through the pipe of the soil-saving dam or over
the concrete, stone or wooden drop.

The table on page 271 gives the approximate number of acres a soil-saving dam
will drain. If the storage alnove the dam is large, slightly smaller pipes may
be used, and if the storage is small it may be necessary to increase the size of
the pipe. ~

For filling gullies three to five feet deep the banks should be plowed down just
before terracinv. Sometimes five or six rounds will fill it up half full and make
it possible to cross with farm machinery. \

TERRACING LN TEXAS. 27

NUMBER OF ACRES DRAINED BY SOIL-SAVING DAM.

Diameter of Tile in Inches.

Fall in Feet. "

10 | 12 | 15 I 1s I 20 | 22 | 24 | sq
3 4% 1 13 17 25 31 53
3 42 71 141 1s1 17% 34 ss
3* 5 sl 152 20 291 362 62%
3% 5; 10’ 11’ 25 31% 39 67
4 6 11 11s 21 23% 41% 71
4 6 11% 1s2 2s as 43% 15