1186 
6. It is interesting to note that the 
average cost of water from the govern- 
ment works is about $12 per acre less 
than from the recent private works of 
comparable size. The real difference is 
still greater because of the fact that de- 
ferred payments on government works do 
not draw interest. 
7. This difference is further accentu- 
ated by the greater probability of the 
water users under the government proj- 
ects receiving an adequate water supply, 
as this matter has been given more care- 
ful consideration and deficiency guarded 
against with greater care than in the 
private investments. In fact it is known 
that in a few cases at least there is not 
water enough for the entire area of land 
included in these private projects. Also 
on the government works provision in 
many cases has been made for drainage 
such as has not been provided by the 
private works and the water is, as a rule, 
brought nearer to the land to be irri- 
gated, still further reducing the cost to 
the water user. 
8. Summing up all of these advantages 
—lower first cost, absence of interest, 
more dependable water supply, and more 
complete works—it would appear to be 
fair to state that water from the govern- 
ment projects is obtained at from half 
to two-thirds the cost of that from pri- 
vate works here listed, including those 
built under the terms of the Carey act. 
WINTER IRRIGATION 
In a general way lands in irrigated 
districts are not irrigated in the late 
autumn, winter or early spring. The 
water is turned out of the irrigating 
ditches in October or November and then 
turned on again in March or April, de- 
pending on the climate, the amount of 
rainfall during the winter, the soil and 
the kinds of crops grown. While the wa- 
ter is out of the ditches is an opportune 
time for repairs, cleaning the ditches and 
other work for the irrigation of grounds 
the following year. However, there are 
conditions where irrigation would be 
practicable in winter, and there are some 
reasons why it is desirable. One reason 
why it is desirable is that there is a 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
larger water supply in winter than in 
summer, and this, in places where water 
is scarce, is an important item. 
Another reason is that there is less 
evaporation in winter than in summer, 
and this is another important item where 
water is scarce, a larger per cent being 
left to percolate through the soil. 
A third reason is that in winter irri- 
gation the land does not bake and need 
cultivation as in summer. 
A. fourth reason is that there is suffi- 
cient time for a deep, thorough wetting, 
which in some soils is much needed. 
A. fifth reason is that an amount of 
water which in summer would injure the 
little root hairs will do little if any in- 
jury in winter during the dormant pe- 
riod of the tree. 
A sixth reason is that heavy winter 
irrigation will retard the blooming pe- 
riod for a few days in spring and tend 
to lessen the injury from frosts. 
Winter irrigation to be of any consid- 
erable value must be given when the 
ground is not frozen. 
It is not here argued that winter irri- 
gation is to take the place of summer 
irrigation, but that it might be made to 
supplement it and, in some places, a good 
irrigation in winter is all that would be 
needed for a crop and the summer irri- 
gation might be dispensed with alto- 
gether. For instance, in a country where 
there is approximately 25 inches of rain- 
fall per annum a good deep irrigation 
before the ground freezes in winter or 
after it thaws in the spring would enable 
the fruitgrower to develop a good crop 
of apples, whereas that amount of rain- 
fall is not sufficient in ordinary soils. 
GRANVILLE LowTHER 
IRRIGATION IN HUMID REGIONS 
J. EF. Duaaar 
The size of the crop is more dependent 
upon the amount and distribution of the 
rainfall than upon soil, fertilizer, or any 
other factor. Man cannot entirely regu- 
late the supply of moisture, but by means 
of irrigation and drainage he can do 
much to make the moisture conditions in 
the soil such that crops will make their 
largest growth. Irrigation and drainage 
