RANGE IMPROVEMENT BY DEFERRED GRAZING. 11 
of the annual plants, of which cheat constituted the greater part. 
The perennial species, despite the seed crop produced, had revege- 
tated only to a very limited extent. On the medium and high plots, 
with the exception of porcupine grass, the seed of which is planted 
by means of a bristle or awn, there was practically no reproduction. 
Plate V shows the increase in herbage of the original plants on the 
mountain lands after three years of protection. Even after five sea- 
sons of protection, however, practically no new perennial plants were 
found. This lack of seedlings was not due to low fertility of the 
seed, for after two seasons of protection the large seed crop pro- 
duced had at least average viability, the seed of many species germi- 
nating more than 50 per cent. In each locality it was evident that 
the failure to produce new plants from seed was due to the fact that 
the seed did not penetrate the soil. The larger-seeded species, such 
as mountain bunch grass, failed almost completely to reproduce where 
the soil was not stirred, while the seedlings which originated from 
unplanted seed soon died from drought. Small areas, artificially 
planted, were revegetated by all species regardless of the size and 
character of the seed. 
This shows conclusively that (1) yearlong protection from graz- 
ing restores the vigor of the impoverished vegetation and promotes 
the forage production of the plants in existence; (2) the annual 
species with strong seed habits reproduce satisfactorily, but the more 
desirable and nutritive plants, especially the large-seeded species, re- 
produce only to a limited extent; and, (3) while yearlong protection 
is favorable to the growth of the vegetation, it does not accomplish the 
planting of the seed, which is essential if the range is to be revege- 
tated. 
Aside from failure to insure revegetation with the most desirable 
species, the method entirely wastes the forage during the period of 
protection. Nonuse of the herbage is a serious drawback, and year- 
long protection could not be economically carried out on a large 
scale. Furthermore, the accumulation of inflammable material 
during the period of protection would result in increased fire danger. 
DEFERRED GRAZING. 
In contrast to the two grazing systems discussed, deferred grazing 
is based upon the growth requirements of the vegetation from the 
germination of the seed until new plants have been established. The 
essential principles of the system are: (1) An overgrazed portion of 
the range, sufficiently large to supply the forage from the time of 
seed maturity until the end of the grazing season, is protected from 
stock until the seed crop has matured; (2) upon maturity of the 
seed crop the forage is grazed closely during the first season, but not 
to the extent of injuring the seed plants; (3) the same area is pro- 
