EANGE 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 

 implanted 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- 



