492 FORAGE CROPS 
plowing causes too great loss of it, since it breaks 
the capillary connection with the lower layers at a 
too great depth from the surface. A dried-out 
plowed surface, not having proper connection with 
the lower layers, does not contain sufficient mois- 
ture to cause the rapid germination of seed and to 
provide what is necessary for immediate and con- 
tinuous growth. 
COVER - CROPS 
To keep the land constantly occupied with 
growing plants is particularly important, both in 
the hot summer months and in fall and spring. 
The covering of the land in summer prevents the 
temperature from rising so high as to destroy the 
organisms in the soil, while the covering in fall 
and spring prevents the mechanical losses that 
occur from wind and rain, and by the carrying 
away of food in the soil-water. Owing to the fact 
that cértain crops, as, for example, barley or late- 
seeded oats, are harvested too late to permit of 
seeding other cover-crops, it has been found prac- 
ticable to seed either rye or wheat with the barley 
or oats; and the rye, if the nurse crop is removed 
by the latter part of October, will usually make 
growth enough in the central states to prevent 
the losses referred to, and to be used in spring 
for green manure or for forage, as may be most 
convenient. 
