FLORIDA ,STATE HORTICULTURAL SOCIETY. 
161 
afterwards giving the ground a thor¬ 
ough working or cultivating. 
The second system, or sub-irriga¬ 
tion, has been considered satisfactory 
where the land is low and requires 
draining, or where cheap artesian wells 
can be had, as no power is required to 
distribute the water. Recent experi¬ 
ments, however, show that with this 
system, the soil, or ground, closely sur¬ 
rounding this tile becomes too wet and 
s °ggy before sufficient moisture has 
reached the more distant parts. This 
moisture from beneath also drives the 
heat upwards and out of the soil, there¬ 
by causing the soil to become cold. 
The third system, or spraying, is 
highly recommended, and gives satis¬ 
factory results under most conditions, 
and makes trucking and fruit-growing 
successful and profitable on land that 
otherwise would be a failure. When 
using this system it is unnecessary to 
cultivate the ground after each irrigat¬ 
ing, as proper spraying does not pack 
the soil. The water supply can be eas¬ 
ily controlled, and by applying the 
moisture to the surface, the heat is not 
forced out of the soil, but into it. I 
have in mind a celery grower on Terra 
Ceia Island, who last year installed a 
plant of the Skinner System of Irriga¬ 
tion. He also had sub-irrigation and 
used the two systems on adjoining 
land, or practically the same land. The 
celery received the same attention and 
nder both systems. The 
result was that the celery grown under 
the Skinner System of spraying not 
only made a larger yield, but matured 
from three to four weeks earlier than 
that on the sub-irrigated land. 
Another feature in favor of the 
spraying system is the ability for spray¬ 
ing with fungicides, insecticides and 
soluble fertilizers, as this can readily be 
done with but little additional cost. 
A plant must have not only water, 
but air, and when we appreciate how 
much air a plant requires and how 
much water the soil will hold, we have 
the danger of too much water. The 
tendency frequently is to water too 
much. Each farmer or gardener must 
learn this from experience. Conditions 
must be carefully studied, and the 
water supply be under control to per¬ 
mit its being applied carefully and 
properly. We know the soil is not 
made up of a solid mass, but of par¬ 
ticles laid together with air space be¬ 
tween. If we magnified the soil we 
would find it more like a box of or¬ 
anges, and authorities say that 50 per 
cent, of the space of soil is air, or only 
50 per cent, of what is apparently soil 
is solid matter. This bears on irriga¬ 
tion in one way, and that is the capacity 
of soil to hold water. Extensive tests 
have brought out the fact that soils 
will hold water by saturation to a great 
extent before the water will run off. 
This, of course, varies according to the 
kind of soil. According to tests made, 
plant growth stops absolutely, in clay 
land, when the saturation goes as low 
as 8 J 4 per cent., or when there is 8 
per cent, as much water by weight as 
soil. In red clay this is 12.4 per cent., 
in sandy clay 13.5 per cent., and in 
sand 9.35 per cent. 
