CHAPTER XVII 



GRAZING CAPACITY AND PASTURE INSPECTION 

 GRAZING CAPACITY 



The grazing capacity of a pasture area may be defined as the 

 number of stock of one or more classes which the area will sup- 

 port in good condition during the time that the forage is pala- 

 table and accessible, without decreasing the forage production 

 in subsequent seasons. The determination of the grazing ca- 

 pacity of a pasture area is one of the most difficult yet important 

 tasks that the stockman and pasture technician have to solve. 

 It is hardly necessary to say that the grazing-capacity equation 

 has not been worked out on any range unit with mathematical 

 precision. Furthermore, in view of the numerous variable and 

 uncontrollable factors that present themselves nearly every 

 season, it is not likely that the grazing-capacity factor will 

 ever be worked out to a high degree of scientific accuracy. 

 Many of the variables in forage production, as well as in seasonal 

 grazing and grazing for longer periods, are due to what may be 

 termed "human" factors — factors which may be modified 

 or controlled by human effort. Among such factors may be 

 mentioned: (i) Overgrazing; (2) undergrazing; (3) pasturing 

 by the wrong class of stock; (4) turning the stock on the pasture 

 too early in the spring; (5) methods of handHng the stock; 

 (6) condition of flesh in which it is desired to keep the stock; 

 and (7) failure to develop watering places with a view to ob- 

 taining the fullest possible utilization of the forage crop over 

 the area as a whole. 



Basis for Estimating Grazing Capacity. — In the investi- 

 gation to determine grazing capacity two distinct methods have 

 been employed. The studies of grazing capacity by the Bureau 

 of Plant Industry of the United States Department of Agri- 

 culture—probably the pioneer work along this line in the 

 United States — were confined chiefly to fenced range reserves 



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