Sub-irrigation in California. 185 
until they are injured by severe frosts. On the other hand, it is 
often desirable to give deciduous trees a draft of water alter the 
fruit has been gathered, if the soil is so dry that-the tree is 
likely to drop its leaves too soon, and wake from its dormancy 
with the first rains. Many times the fall blooming of deciduous 
trees, which is very undesirable, may be prevented by keeping 
them growing later in the summer by moderate irrigation. 
If trees or vines, in regions usually irrigated, are to be 
grown without irrigation, it is important that the grower be 
more than usually thorough and constant with his summer cul- 
tivation. In trying the non-irrigation experiment, one should, 
of course, begin with young trees which have not been irrigated, 
and not usually expect success by withdrawing the water from 
trees which have been accustomed to it, and have developed a 
root system accordingly. 
SUB-IRRIGATION IN CALIFORNIA. 
The word “sub-irrigated” is freely used in California to de- 
scribe land which is moistened below by underflow or seepage 
from streams or springs, or from open irrigation ditches, trav- 
ersing higher levels. This land is sub-irrigated, it is true, but 
there is no system about it, except the natural distribution of 
water, which is disposed to run down hill. Some of our most 
productive lands are of this character, and where the soil and 
subsoil are fitted to the movement of this living water, and not apt 
to retain it up to the point of saturation, most satisfactory growth 
of deep-rooting field crops and of trees and vines are secured. 
But this is not sub-irrigation in the ordinary signification of the 
term. 
Several systems of sub-irrigation have been devised by Cali- 
fornia inventors, but none have passed beyond the ‘experimental 
stage, and no considerable acreage is yet in place. 
“DRAINAGE IN CALIFORNIA. 
There was for a long time a very erroneous popular gen- 
eralization that California soils do not need drainage; that in a 
dry State the aim should be to retain the moisture, not to part 
with it. It is, of course, true that we have vast areas of natu- 
rally well-drained soil, upon which any money spent for drain- 
age would be in great part thrown away, but we have, also, 
both in the valley and on the hillsides, locaiities where, by pecul- 
iar character and conformation of the subsoil, water is held in 
the soil until evaporated from the surface, and the result is a 
boggy, miry condition, which prevents proper winter cultivation, 
and at the same time injures the roots of the trees.or vines. This 
defective cultivation, added to the puddling effect of standing 
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