HINTS ON SOILS AND FERTILIZERS 33 
climates. Still there are other sections of the 
country, such as in some of our western states, 
where considerably less than twenty inches fall 
in one year. These sections are known as dry 
or arid climates. 
Splendid results would obtain if we could 
have our rains just at the time when they would 
do the most good. Owing to the fact that rain 
comes at irregular intervals, the farmer must 
conserve the moisture as best he can, by proper 
tillage operations, supplying sufficient humus 
to soak up the water, etc. After a heavy rain, 
the farmer usually gets out on the land as 
soon as it is dry enough to work, and breaks 
up the hard crust formed by the rain, and leaves 
a crumbly mass by means of his cultivating im¬ 
plements. This prevents the moisture from 
evaporating too rapidly. 
Soil water may exist in the soil in three 
different forms. It may be present in the soil 
as hygroscopic water. This form is present in 
soil that is air-dried, and is of no special im¬ 
portance. It may also be present as gravita¬ 
tional water. This form is also known as free 
water, and is characterized by its tendency to 
run off the soil, or seep down through the 
soil due to the force of gravity. We see illus¬ 
trations of this form when we get a hard rain. 
Not all of the water has time to be absorbed by 
the soil, and a great quantity runs off the high 
land into brooks and streams at the lower 
levels. 
The third form of soil water is the one with 
which we are most concerned. This form is 
known as capillary water, and it is this form 
