UNITED STATES DEPARTMENT OF AGRICULTURE 



In Cooperation with the 

 North Dakota Agricultural College 



DEPARTMENT BULLETIN No. 1170 



Washington, D. C. 



July, 1923 



EFFECTS OF DIFFERENT SYSTEMS AND INTENSITIES OF GRAZING 

 UPON THE NATIVE VEGETATION AT THE NORTHERN GREAT 

 PLAINS FIELD STATION. 



By J. T. Saevts, Assistant Agronomist. Office of Dry-Land Agriculture Investi- 

 gations, Bureau of Plant Industry. 



CONTENTS. 



Page. 



Introduction 1 



Plan of the grazing experiment 3 



Land used for the experiment 5 



Relation of precipitation to native 



forage production 7 



Deferred and rotation system of 



grazing 8 



Period of grazing and cattle used 10 



Weighing the cattle 11 



Gains of the cattle 12 



Percentage of vegetation annualiy 



removed by grazing 15 



Measure of efficiency of a pasture 



or system of grazing 17 



Page. 



Botanical studies in connection with 

 the experiment 10 



Other studies bearing upon the ex- 

 periment 33 



Soil moisture 



Palatability of the vegetation 35 



Causes of the deterioration of native 



pastures by grazing with cattle 38 



Grazing capacity based upon the 

 native vegetation 39 



Salient points revealed by the graz- 

 ing experiment 42 



Conclusions and summary 42 



INTRODUCTION. 



During the period when the beef-cattle industry on the free ranges 

 of the Great Plains area was in a thriving condition, meager authentic 

 information was recorded regarding the best utilization of the native 

 vegetation. This information is lacking because there was little 

 demand at that time for the investigation of the subject through a 

 systematic study of grazing problems. The range was looked upon 

 as an inexhaustible supply of forage for all classes of stock. If the 

 range became short in one place, it was only necessary to move to a 

 new area. With the advent of the dry-land farmer and the conse- 

 quent splitting up of the range, however, grazing became more in- 

 tensified, and a demand arose for information regarding range and 

 pasture management. The problem was not only how to restore 

 overgrazed areas, but also how to graze an area that was still in a 

 high state of production in order to afford the best utilization of the 

 forage and to maintain the range in good condition. This problem 



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