RANGE PRESERVATION AND EROSION CONTROL. 31 



REMEDIAL MEASURES WHERE THOROUGH REVEGETATION BY ORDINARY MEANS 



IS IMPOSSIBLE. 



TOTAL- EXCLUSION OF STOCK". 



On the more important fan-shaped basins at high elevations, 

 where the original vegetative cover, including the seed plants, has 

 for the most part disappeared; and where the fertility of the soil has 

 been seriously depleted as a result of erosion, the best plan i- to 

 discontinue -grazing entirely. The small amount of forage pro- 

 duced, consisting, as it usually does, of annual weeds and many 

 poisonous species, by no means compensates for the further skim- 

 ming off of the already deficient organic matter and tearing down 

 into the gullies of the loose soil. In most instances stock will not 

 have to be excluded longer than during the period required to re- 

 establish the fertility of the soil and the incoming of the deep-rooted, 

 permanent type of perennial vegetation, provided, of course, that 

 light grazing and proper handling of the stock are at all times 

 resorted to. On the other hand, where the soil fails to regain its 

 former productivity within a reasonable length of time, as indicated 

 by the character and density of the vegetative cover following the 

 exclusion of stock, grazing should be permanently discontinued. To 

 graze such lands after a few years of rest, even though they pro- 

 duced a little feed, would be to undo in a season all that nature has 

 accomplished in building up the soil during the seasons that stock 

 was excluded. 



TEBBACING AND PLANTING. 



There are local areas, mostly of small size, where the proper regu- 

 lation of grazing and, indeed, the total exclusion of stock from seri- 

 ously eroded lands is delayed until the vegetative cover can not be 

 effectively reestablished and the erosion thus eliminated. The estab- 

 lishment of a dense cover of vegetation should not be hoped for on 

 the bottdm and along the sides of deep, vertically cut gullies where 

 the water rushes by after each rainstorm of appreciable size. The 

 force of the water does not permit many seeds to lodge, and in the 

 beginning the soil is too thin and dry to favor growth. Depressions 

 of the more prominent gullies which have been revegetated, how- 

 ever, would still serve as drainage . channels following heavy rain- 

 storms, but the resistance afforded by the vegetation would tend to 

 hold the water back ; and since the soil would be held firmly by the 

 roots, the channels would terfd to flatten out rather than become 

 more prominent. 



Where it is no longer possible for the vegetation to hold the soil 

 intact, some means of artificial control is necessary. The gully 



