450 GRASSES AND HOW TO GROW THEM. 



through ploughing occasionally { This would not be 

 practicable under range conditions except in a limited 

 way because of the great extent of the ranges. Third, is 

 it possible to supplant other grasses by these without 

 ploughing the land % When a turf now covers the 

 ranges, this is doubtful. If the land has to be ploughed 

 to make such substitution possible, the element of im- 

 practicability comes again to the front. 



Substitution through sowing the seed of blue grama 

 grasft is more hopeful, especially in the central and 

 southwestern range states, where the turf is not usu- 

 ally dense. This grass would seem to have special 

 power to establish itself under such conditions, even 

 when the precipitation is light. But the impossibility 

 of getting supplies of seed in a large way, at the pres- 

 ent time, is ^n insurmountable obstacle in the way of 

 such substitution ; sometime in the future, however, 

 this may be different. All the evidence points to the 

 conclusion, under existing conditions, that the best w^ay 

 of improving range grasses, at present, is by some sys- 

 tem of alternation in grazing, which makes possible the 

 re-seeding of the land by grasses now growing upon 

 the same. The production of lands, that can be tilled, 

 can almost invariably be improved by substitution, but 

 it is not so of nuicli of the land that cannot be tilled. 



THE FUTUKE OF THE WESTER X RAXOES. 



The changes that are being brought about by the irri- 

 gation of irrigable lands will exercise an important in- 

 fluence upon the productive ])o\ver of the ranges. The 

 vast quantities of food tlius grown, along with the pri- 



