Water and the Plant 85 
A fine, loose condition of the soil also allows the 
roots to penetrate more deeply and to spread more 
widely, thus increasing the water supply available to 
the plant. 
Conserving the soil moisture. Water evaporates from 
the surface of a soil into the air. Then more water 
rises from below, through capillary action, and this also 
is lost to the air. Thus in time the soil becomes dried 
out, and plants often suffer because the water they need 
has evaporated into the air. 
If a mulch of fine manure, straw, or leaves is placed 
over the soil, the evaporation from the surface is checked, 
and the soil moisture is conserved; celery, eggplant, 
Chinese cabbage, endive, and lettuce are benefited by 
such mulches, especially in dry periods or when grown on 
dry, sandy soils. e 
A mulch may also be made of a layer of loose surface 
soil. If the top inch of soil is raked loose and fine, it 
quickly dries out, and because its connection with the 
soil below is somewhat broken, the water does not 
readily rise into it by capillary action. This loose sur- 
face soil, therefore, acts as a covering for the lower soil, 
keeping the moisture that is in it from being lost to the 
air. Frequent shallow cultivation of growing crops is 
very essential to maintain a surface mulch. 
Watering the garden. Crops use large amounts of 
water, and even under the best methods of culture the 
natural supply may be insufficient for their needs. It is 
then often advisable to supply water by irrigation. This 
subject will be discussed in the chapter on “‘ The Care of 
Growing Crops ” (page 207). 
