FLORIDA STATE HORTICULTURAL SOCIETY. 
163 
the plot consisted of a mulch six inches 
deep. This was done after the fifth 
day, and it was found the evaporation 
from the sixth to the eleventh day, in¬ 
stead of being 11.4 per cent, was re¬ 
duced to 5.6 per cent. 
In another experiment, eight inches 
of water was applied in ten hours. The 
evaporation in three days was 10 per 
cent; from four to six days in the part 
not cultivated it was 3.6 per cent. At 
the end of the third day, part of the 
soil was cultivated, and with a six-inch 
mulch, the evaporation was reduced in 
the second period of from four to six 
days to 1.2 per cent. 
In both these experiments the 
ground was so wet it was several days 
before it could be cultivated. 
In another locality, more exhaustive 
experiments were made, and the water 
applied in a way that the effect on the 
mulch could be observed from time the 
water was applied. The evaporation 
in a fourteen-day experiment where 
there was no mulch and the ground 
was not cultivated was found to be 45 
lbs. of water. An identical pl'ot with a 
four-inch mulch lost 13 lbs., with an 
eight-inch mulch 5 lbs., and with a ten- 
inch mulch 1 lb. In other words, the 
uncultivated soil remaining in the con¬ 
dition in which the water was applied 
lost forty-five times as much as the 
plot under similar conditions, which 
was protected by a ten-inch mulch. 
It has been found that the equivalent 
of one to one and one-quarter inches of 
rainfall is evaporated from the soil in 
a growing season. 
Regarding the temperature as affect¬ 
ed by water. It is readily understood 
that soils with excessive moisture are 
cold soils. Plant growth stops when 
the temperature reaches approximately 
45 degrees. When it is recognized that 
germination at 72 degrees soil temper¬ 
ature in three days equaled the germi¬ 
nation through a period of sixteen days 
under the same conditions except the 
temperature being reduced to 60 de¬ 
grees, we can appreciate the effect an 
undue amount of water in the soil 
would have on the growth and ma¬ 
turity of a crop. 
Frost protection is a very important 
question. We know that groves and 
farms near large bodies of water are 
not so liable to frost as those farther 
away from the water. It is an interest¬ 
ing fact that the condensation of at¬ 
mospheric moisture into dew liberates 
a vast amount of heat. In condensing 
from vapor into water, a pound of dew 
liberates enough heat to raise five 
pounds of water to the boiling point. 
Also a ton of water crystallized into 
ice would liberate enough heat to raise 
an equal amount of water from 32 to 
112 degrees. In some of the colder sec¬ 
tions of the country, winter irrigation 
has given satisfactory results. The pur¬ 
pose is not only to store water in the 
soil, but to prevent winter killing of 
the trees. Experience has shown that 
it is not best to apply too much water 
to orchards during the latter part of 
the growing season as it produces an 
immature growth which is easily dam¬ 
aged by frost. 
Growers are beginning to realize the 
importance of correct water distribu- 
