RANGE MANAGEMENT ON THE NATIONAL FORESTS. 29 



reduced about 30 per cent below the average for the year, to give the 

 vegetation a chance to grow. - Otherwise, grazing was yearlong. 

 Utilization was closer than can be expected on open range. 



Studies of grazing capacity on the Jornada Range Reserve in 

 southern New Mexico led to the conclusion that the grass range will 

 support one cow on 20 to 30 acres, depending upon the acreage 

 of poorer range types which occur within the grass type. 1 These 

 figures are computed on a yearlong basis, but with the understanding 

 that the number of stock will be reduced during the main growing 

 season, July to October, to about one-half the average number for 

 the year. With the relatively close utilization possible under fence 

 on the Jornada Range Reserve it is figured that approximately 8 

 forage acres per cow yearlong will be sufficient. 



In general, the grazing-capacity figures indicate that about 2 to 2J 

 acres per cow per month is as near an average as can now be arrived 

 at for cattle range suited to this class of stock within the National 

 Forests. This, of course, is the acreage required exclusive of lands 

 of no value for grazing except the occasional small patches of waste 

 within usable range. With this average as a guide, the examiner can 

 judge whether range is exceptionally good or inferior and can adjust 

 his estimate accordingly. Where available forage is estimated in 

 terms of forage acres, an average of about 0.8 forage acres per cow 

 per month should be allowed. If utilization is complete and close 

 over the entire area, as it usually is in pastures, O.T of a forage acre, 

 or a little less, per head per month should be sufficient. 



COMPARISON OF ACREAGE REQUIRED TOR SHEEP AND FOR CATTLE. 



Considering the general difference in the forage suited to sheep and 

 cattle, it is evident that there is no constant relation between the 

 grazing capacity of a range for sheep and the grazing capacity of 

 the same range for cattle. By careful division of the range between 

 different classes of stock, as outlined on page 3, the justification for 

 change in class of stock on a general range is largely done away with. 

 Some ranges, however, may be used to advantage by either sheep or 

 cattle. A change from one class to the other can never safely be 

 made in an individual case on a previously decided or fixed ratio. 

 The ratios used in the Grazing Manual of the Forest Service 2 are 

 based on general averages and are intended for application to the 

 special case of change in class of stock, provided the grazing capacity 

 of the range in question for the new class of stock warrants the use of 

 the standard ratio. The grazing capacity of the range in question for 



1 Jardine, James T., and Hurtt, L. C, Increased Cattle Production on Southwestern 

 Ranges, U. S. Dept. of Agriculture, Bui. 588, 1917. 



2 U. S. Forest Service. National Forest Manual ; Regulations and Instructions, Grazing 

 Section. 



