184 The Principles of Fruit-growing. 
COVER CROPS. 
A cover crop* is one which is used for the par- 
ticular purpose of securing its mulching and_ phys- 
ical effect upon the land in the intervals between 
the regular crops or the normal seasons of tillage. 
A sowed crop in the orchard may be valuable in 
two ways: by affording a cover to the land, and by 
improving the soil when it is plowed in. As a 
cover, it may keep down weeds, and protect the land 
from injurious effects of frost. As a green manure, 
it may add fiber to the soil, and thus augment its 
power of holding fertility and moisture, and it may 
add directly to the fertility of the land. This late 
crop catches and holds the leaching nitrates which 
the tree-roots utilize earlier in the season. Taken 
as a whole, the cover crop may be said to improve 
the soil in eight ways: 
I. It directly improves the physical condition of 
the land: 
Prevents hard soils from cementing or pud- 
dling ; 
Holds the rains and snows until they have 
time to soak away into the land; 
Dries out the soil in spring, making early 
tillage possible ; 
Sometimes serves as a protection from frost. 
*Term first used in this connection in Bull. 61, Cornell Exp. Sta. 333 
(Dee. 1893). 
