By another form of irrigation, the fields are divided at regular intervals by wide wooden troughs from which water is directed between the rows of plants. Main canals leading from the streams and intersected by short canals extend in all directions through the fields and orchards, and are distributed in various ways. This system is in general use throughout the arid portions of the West. The methods are said to be the most scientific and varied in southern California.
When water for irrigation is supplied from wells some underground system is generally used. One common method is to lay continuous pipes from the wells all over the fields and distribute from hydrants, plugs and standpipes.
By still another system, the water is carried below the surface through pipes which are broken every few inches and laid in beds of charcoal.
In the eastern states irrigation is only employed in dry weather to increase the yield of vegetable crops. In the arid western region it transforms what would otherwise be a dreary desert into fertile valleys.
William J. Bryan, speaking at the first Conservation Congress, said, "Last September, I visited the southern part of Idaho and saw there a tract that has been recently reclaimed. I had been there before. I had looked upon these lands as so barren that it seemed as if it were impossible that they could ever be made useful.
"When I went back this time and found that in three years 1,700,000 acres of land had been reclaimed, that where three years ago nothing but sage-brush grew, they are now raising seven tons of alfalfa to the acre, and more than a hundred bushels of oats; when I found that ten thousand people are living on that tract, that in one town that has grown up in that time there are more than 1,900 inhabitants, and in three banks they had deposits of over half a million dollars, I had some realization of the magic power of water when applied to these desert lands."
The same thing might be said of other regions throughout the West. In the Salton district of California a marvelous change has been brought about by irrigation. A few years ago that was one of the most desolate and forbidding regions on our continent. Now it is covered with several thousands of acres of alfalfa and other crops, and it bids fair to be a great fruit region. Of southern California it is said, "The irrigation systems of this part of the state are known all over the world, and have created a prosperous commonwealth in a region which would be a scene of utter desolation without them."
This locality presents a better opportunity for the scientific study of farming by irrigation than exists anywhere else in the world. Here all land values depend directly on ability to obtain a water supply. So precious is the water and so abundant are the rewards that follow its application to the soil that the most careful consideration is given to the various sources of supply and distribution.
As land becomes scarcer and the cost of living greater on account of the increase in population, men are turning more and more to irrigation to solve the problem of food supply.
As showing what may be accomplished by irrigation, the report of the last census says: "The construction of large irrigation works on the Platte, Yellowstone and Arkansas Rivers would render fertile an area equal to that of some eastern states. Engineers are grappling with the great problems of conserving the flood waters of these streams, which now are wasted and help to increase the destructive floods of the Mississippi. The solving of these problems will change a vast area of country, now practically worthless, into valuable farms."