Irrigation

Categories: MISCELLANEOUS

Irrigation is the name given to the plan of supplying water in large

quantities to growing crops. Since the dawn of history this practice has

been more or less followed in Asia, in Africa, and in Europe. The

Spanish settlers in the southwestern part of America were probably the

first to introduce this custom into our country. In New Mexico there is

an irrigating trench that has been in constant use for three hundred

ye rs.






The most common source of water for irrigating purposes is a river or a

smaller stream. Artesian wells are used in some parts of the country.

Windmills are sometimes used when only a small supply of water is

needed. Engines, hydraulic rams, and water-wheels are also employed. The

water-wheel is one of the oldest and one of the most useful methods of

raising water from streams. There are thousands of these in use in the

dry regions of the West. Small buckets are fastened to a large wheel,

which is turned by the current of a stream. As the wheel turns, the

buckets are filled, raised, and then emptied into a trough called a

flume. The water flows through the flume into the irrigating ditches,

which distribute it as it is needed in the fields. In some parts of

California and other comparatively dry sections, wells are sunk in or

near the beds of underground streams, and then the water is pumped into

ditches which convey it to the fields to be irrigated.



Engines are often used for pumping water from streams and transferring

it to ditches or canals. The canals distribute the water over the land

or over the growing crops.






None of these methods, however, can be used for watering very large

areas of land. Hence, as the value of farm lands increased other methods

were sought. Shrewd men began to turn longing eyes on the wide stretches

of barren land in the West. They knew that these waste lands, seemingly

so unfertile, would become most fruitful as soon as water was turned on

them. Could water enough be found? New plans to pen up floods of water

were prepared, and immense sums were spent in carrying out these plans.

Enormous dams of cemented stone were thrown across the gorges in the

foothills of the mountains. Behind these solid dams the water from the

rains and the melting snow of the mountains was backed for miles, and

was at once ready to change barrenness into fruitfulness. The stored

water is led by means of main canals and cross ditches wherever it is

needed, and countless acres have been brought under cultivation.



Water is generally applied either by making furrows for its passage

through the fields or by flooding the land. The latter plan is the

cheaper, but it can be used only on level lands. Where the land is

somewhat irregular a checking system, as it is called, is used to

distribute the water. It is taken from check to check until the entire

field has been irrigated.






The furrow method is usually employed for fruits and for farm and garden

crops. In many places the grass and grain crops are now supplied with

water by furrows instead of by flooding.



Irrigated lands should be carefully and thoroughly tilled. The water for

irrigation is costly, and should be made to go as far as possible. Good

tillage saves the water. Moreover, all cultivated crops like corn,

potatoes, and orchard and truck crops ought to be cultivated frequently

to save the moisture, to keep the soil in fit condition, and to aid the

bacteria in the soil. It was a wise farmer who said, "One does not need

to grow crops many years in order to learn that nothing can take the

place of stirring the soil."





METHODS OF IRRIGATING CROPS



_Tree fruits._ Water is conducted through very narrow furrows from three

to five feet apart, and allowed to sink about four feet deep, and to

spread under the ground. Then the supply is cut off. The object is to

wet the soil deeply, and then by tillage to hold the moisture in the

soil.



_Small fruits._ The common practice is to run water on each side of the

row until the rows are soaked.



_Potatoes._ A thorough soaking is given the land before planting-time,

and then no more than is absolutely necessary until blossoming-time.

After the blossoms appear keep the soil moist until the crop ripens.



_Garden crops._ Any method may be employed, but the vital point is to

cultivate the ground as early as it can be worked after it has been

irrigated.



_Meadows and alfalfa._ Flooding is the most common method in use. The

first irrigation comes early in the spring before growth has advanced

much, and the successive waterings after the harvesting of each crop.