Irrigation Means And Ends
While few can have failed to realize the important part played by Water
in the economy of vegetation, I judge that the question--"How can I
secure to my growing plants a sufficiency of moisture at all
times?"--has not always presented itself to the farmer's mind as
demanding of him a practical solution. To rid his soil and keep it free
of superfluous, but especially of stagnant water, he may or may not
accept as a nece
sity; but that, having provided for draining away
whatever is excessive, he should turn a short corner and begin at once
to provide that water shall be supplied to his fields and plants
whenever they may need it, he is often slow to apprehend. Yet this
provision is but the counterpart and complement of the other.
I had sped across Europe to Venice, and noted with interest the
admirable, effective irrigation of the great plain of Lombardy, before I
could call any land my own. I saw there a region perhaps thirty miles
wide by one hundred and fifty along the east bank of the Po, rising very
gently thence to the foot of the Austrian Alps, which Providence seems
to have specially adapted to be improved by irrigation. The torrents of
melted snow which in Spring leap and foam adown the southern face of the
Alps, bringing with them the finer particles of soil, are suddenly
arrested and form lakes (Garda, Maggiore, Como, etc.) just as they
emerge upon the plain. These lakes, slowly rising, often overflow their
banks, with those of the small rivers that bear their waters westward to
the Po; and this overflow was a natural source of abiding fertility. To
dam these outlets, and thus control their currents, was a very simple
and obvious device of long ago, and was probably begun by a very few
individuals (if by more than one), whose success incited emulation,
until the present extensive and costly system of irrigating dams and
canals was gradually developed. When I traversed Lombardy in July, 1851,
the beds of streams naturally as large as the Pemigewasset, Battenkill,
Canada Creek, or Humboldt, were utterly dry; the water which would
naturally have flowed therein being wholly transferred to an irrigating
canal (or to canals) often two or three miles distant. The reservoirs
thus created were filled in Spring, when the streams were fullest and
their water richest, and gradually drawn upon throughout the later
growing season to cover the carefully leveled and graded fields on
either side to the depth of an inch or two at a time. If any failed to
be soon absorbed by the soil, it was drawn off as here superfluous, and
added to the current employed to moisten and fertilize the field next
below it; and so field after field was refreshed and enriched, to the
husbandman's satisfaction and profit. It may be that the rich glades of
English Lancashire bear heavier average crops; but those of Lombardy are
rarely excelled on the globe.
Why should not our Atlantic slope have its Lombardy? Utah, Nevada, and
California, exhibit raw, crude suggestions of such a system; but why
should the irrigation of the New World be confined to regions where it
is indispensable, when that of the Old is not? I know no good reason
whatever for leaving an American field unirrigated where water to flow
it at will can be had at a moderate cost.
When I first bought land (in 1853) I fully purposed to provide for
irrigating my nearly level acres at will, and I constructed two dams
across my upland stream with that view; but they were so badly planned
that they went off in the flood caused by a tremendous rain the next
Spring; and, though I rebuilt one of them, I submitted to a
miscalculation which provided for taking the water, by means of a
syphon, out of the pond at the top and over the bank that rose fifteen
or twenty feet above the surface of the water. Of course, air would work
into the pipe after it had carried a stream unexceptionably for two or
three days, and then the water would run no longer. Had I taken it from
the bottom of the pond through my dam, it would have run forever, (or so
long as there was water covering its inlet in the pond;) but bad
engineering flung me; and I have never since had the heart (or the
means) to revise and correct its errors.
My next attempt was on a much humbler scale, and I engineered it myself.
Toward the north end of my farm, the hill-side which rises east of my
lowland is broken by a swale or terrace, which gives me three or four
acres of tolerably level upland, along the upper edge of which five or
six springs, which never wholly fail, burst from the rocks above and
unite to form a petty runnel, which dries up in very hot or dry weather,
but which usually preserved a tiny stream to be lost in the swamp below.
North of the gully cut down the lower hill-side by this streamlet, the
hill-side of some three acres is quite steep, still partially wooded,
and wholly devoted to pasturage. Making a petty dam across this runnel
at the top of the lower acclivity, I turned the stream aside, so that it
should henceforth run along the crest of this lower hill, falling off
gradually so as to secure a free current, and losing its contents at
intervals through variable depressions in its lower bank. Dam and
artificial water-course together cost me $90, which was about twice what
it should have been. That rude and petty contrivance has now been ten
years in operation, and may have cost $5 per annum for oversight and
repairs. Its effect has been to double the grass grown on the two acres
it constantly irrigates, for which I paid $280, or more than thrice the
cost of my irrigation. But more: my hill-side, while it was well
grassed in Spring, always gave out directly after the first dry, or hot
week; so that, when I most needed feed, it afforded none; its herbage
being parched up and dead, and thus remaining till refreshed by generous
rains. I judge, therefore, that my irrigation has more than doubled
the product of those two acres, and that these are likely to lose
nothing in yield or value so long as that petty irrigating ditch shall
be maintained.
I know this is small business. But suppose each of the hundred thousand
New-England farms, whereof five to ten acres might be thus irrigated at
a cost not exceeding $100 per farm, had been similarly prepared to flow
those acres last Spring and early Summer, with an average increase
therefrom of barely one tun of Hay (or its equivalent in pasturage) per
acre. The 500,000 tuns of Hay thus realized would have saved 200,000
head of cattle from being sent to the butcher while too thin for good
beef, while every one of them was required for further use, and will
have to be replaced at a heavy cost. Shall not these things be
considered? Shall not all who can do so at moderate cost resolve to test
on their own farms the advantages and benefits that may be secured by
Irrigation?