Van Dyke, who may always be quoted with confidence, says
that the ground should never be flooded; that water must not touch the
plant or tree, or come near enough to make the soil bake around it; and
that it should be let in in small streams for two or three days, and not
in large streams for a few hours. It is of the first importance that the
ground shall be stirred as soon as dry enough, the cultivation to be
continued, and water never to be substituted for the cultivator to
prevent baking. The methods of irrigation in use may be reduced to
three. First, the old Mexican way--running a small ditch from tree to
tree, without any basin round the tree. Second, the basin system, where
a large basin is made round the tree, and filled several times. This
should only be used where water is scarce, for it trains the roots like
a brush, instead of sending them out laterally into the soil. Third, the
Riverside method, which is the best in the world, and produces the
largest results with the least water and the least work. It is the
closest imitation of the natural process of wetting by gentle rain. "A
small flume, eight or ten inches square, of common red-wood is laid
along the upper side of a ten-acre tract. At intervals of one to three
feet, according to the nature of the ground and the stuff to be
irrigated, are bored one-inch holes, with a small wooden button over
them to regulate the flow. This flume costs a trifle, is left in
position, lasts for years, and is always ready. Into this flume is
turned from the ditch an irrigating head of 20, 25, or 30 inches of
water, generally about 20 inches. This is divided by the holes and the
buttons into streams of from one-sixth to one-tenth of an inch each,
making from 120 to 200 small streams. From five to seven furrows are
made between two rows of trees, two between rows of grapes, one furrow
between rows of corn, potatoes, etc. It may take from fifteen to twenty
hours for one of the streams to get across the tract. They are allowed
to run from forty-eight to seventy-two hours. The ground is then
thoroughly wet in all directions, and three or four feet deep. As soon
as the ground is dry enough cultivation is begun, and kept up from six
to eight weeks before water is used again." Only when the ground is very
sandy is the basin system necessary. Long experiment has taught that
this system is by far the best; and, says Mr. Van Dyke, "Those whose
ideas are taken from the wasteful systems