Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. PROFESSIONAL PAPER June 23, 1916 
CARRYING CAPACITY OF GRAZING RANGES IN 
By HK. O. Wooton, Agriculturist, Office of Farm Management. 
CONTENTS. 
Page. | Page 
AIT RO GUC GIO Mens see hana le eee ae ie ie Hay-cut tine Operations) ss eee aes. o5ce 23 
BMI ATC CON MILION Sea saa eee re One Grazin gexpeniMentS ema scee eee eee 28 
Character and distribution of forage... -.-...-- 9 Miscellaneous; mo teStess sere see eee eae 3 
| Nature and rate of the recovery. .--.-------- 16 | Ruaturedmvestigahionss cesses 36 
Cankyil ica pacitya- a-2- ssa oe ee ose 18 | Summary and conclusions. .....--.--.------- 3 
The most important factor governing possible List of publications relating to this subject- - 40 
improvement of the range .....-..-.--..--. 22 
INTRODUCTION. 
This bulletin presents the results of several years’ experimentation 
and measurements leading to the determination of the carrying 
eapacity of certain kinds of stock ranges in southern Arizona. The 
climatic and soil conditions under which the experiments have been 
carried on are those of the lower foothills and the sloping belt of 
grassland 8 or 10 miles wide which surround all the mountains of 
that region. The altitudinal variations are between 2,800 and 5,500 
| feet. All the area studied has been under control and observation 
| for 11 years. Forty-nine sections which were badly run down by 
overstocking at the beginning of the study have been under a condi- 
tion of complete rest from stock. Approximately nine additional 
sections (the most productive part of the area) have been grazed 
according to the judgment of four men who are acquainted with the 
region. Three of these men have been in the business of raising 
cattle; the fourth has had a few head of horses and burros in his 
pastures. The policy of each of the cattle raisers has been to stock 
his area as heavily as it would bear, allowing a small margin for 
slow improvement. The nicety of adjustment of the various factors 
involved in such a plan has depended upon each man’s judgment 
of what was the best thing to do under all circumstances. By this 
arrangement the pastured area inside the fence has been subjected 
28465°—Bull. 367—16——1 
