Improving land for irrigation

              NElf ![E,TICO COI.LEGE OF AGRICUTTUNE AND IIECHANIC ARTS
AND AGMCI}LTURAT EXPERI}MM STATION
Press Bulletin 981
IUFN,O\rui{G IAND FOR IRRTGATION
The United States has never before in the history of agriculture been faced
wlth the opportunity of doing as much for the ueLfare of the world as it i-s today,
Great emphasis has been p.Laced upon the importanee that food will have, both in
winning the lvar and vuhen terns of peace are under consideration. Large quantities
of food, feed, seed, clothing, alld livestock, as weIL as of nachi-nery, will be
needed by the fighting nabions for sorne time after hostilities cease, in order that
their people nay be suppJ.ied with the necessities of Ij.fe.
To meet the responsibility of providing as many of these rnaterials as practi-cable,
it is necessary that unusual efforts be put forth to lncrease production and
reduce waste. With the farm machinery and labor conditions so serious, farrn oper-ators
are severly handicapped in meeting the production goal-s assigned to them. It
soems that about the only neans left is to increase the efficiency of present fa-cilities.
Careful thought and planning should be exercised, in order that efforts
rnay be expended most effectively.
Observation of condi.tions i-n the irrigated areas indlcates that there are
many things that can be done to lncrease the yields and the efficiency of operation
on manlr of the farrns, Much of the land is not properly prepared for the most satis-factory
irrigatioh of cultivated crops. Sone of it is so rough that only a poor
stand of crops can be secured. This can result only Ln Iow yields of poor-quality
products obtaj.ned through the inefficient use of water, labor, and machinery. In
other cases, where the land was prepared fairly well, insofar as the surface son-dition
of.the soil vras concerned, satisfactory yi"elds have been obtained. This has
been done inefficiently, however, through the use of too much irrigation water and
with a waste of time and labor in irrigating; and certainly, efficient labor for
irrlgating has this year been very scarce,
During the winter months, nany things can be done on the irrigated farm that
will increase the production of crops the conuing season. An analysis of the irri-gation
system and methods should be made at ihis ti.me. Plans should be developed
lhat will result in a higher annual efficiency in the use of water, labor, and
machinery. Available facilities can sometimes be used in the winter so that less
effort will- need to be expended in naking the crops in the months that follow. In
nany cases, the d:itches have been i,nproperly constructed or located and a revision
of the entire system may be lndicated by an analysJ.s of their use and location.
Perhaps it is desirable to enlarge the ditches, so that the stream of water being
used can be prop'"lrly accornmodated, thus reducing actual waste of water as well as
of labor lost in ropairing the banks. In other cases it nay be advisable to reduce
the sizes of the ditclies. Ditches larger than necessary result in a loss of water
and require an excessive a.mount of labor for r,veed-cleani-ng operati.ons. They also
oocupy land that should be used for, growing food, feed, or fiber. In still other
instances it nay be desj.rable entirely to relocate the distribption systern.
At present on many farms the irrigation runs are not of the proper length. In
so$p cases they are too long; in others, too short. While long runs are desirable
insofar as certain farrn operations are concerned, they may result in the use of an
excessiveJ-y large amount of water. llrlhere the runs are too 1ong, the water rernains
on the ground so long that large quantlties of i.t pass beyond the normal root zone
of the crops being grovrn. This results not only in the loss of water and time,
but also in the leaching of the plant nutrients.
In sorne fields, rurs have been made so short that inadequate penetration of the
water ie obtained. Where thj"s is the case, the crops nay suffer for water, or j.rri-gati"
nq has to be don: more frequently than where adequate penetration is obtained.
T"Jri,i t' :iur:ir or.)ltditions thc runs should be lengthened, so that fewer irrigations and
less labor will be required and larger yields of higher-quality crops will be ob.
tained. As a rule, runs of 500 to 800 feet in length are the most desirabl-e. Gen-eral
topographic conditions, slope of the 1and, soiJ- texture, and the size of the
irrigating strea.n are factors which must be given proper consideration i.n pilanning