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UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 997 
Joint contribution from the Office of Farm Management and Farm Economics, 
H. C. TAYLOR, Chief; Bureau of Public Roads, THOS. H. MacDONALD, Chief; 
and Bureau of Animal Industry, JOHN R. MOHLER, Chief 
Washington, D. C. 
December 21, 1921 
THE COST AND UTILIZATION OF POWER ON 
FARMS WHERE TRACTORS ARE OWNED 
286 FARMS— OHIO, INDIANA, ILLINOIS— 1920 
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By 
H. R. TOLLEY, Agricultural Engineer, and 
L. A. REYNOLDSON, Junior Farm Economist 
CONTENTS 
Page 
Introduction 1 
Summary 2 
Areas in Which Investigation Was Made . 5 
Size and Age of Tractors 9 
Workstock 10 
Size of Farm 11 
Work Done by Tractors 13 
Work Done by Horses • 26 
Horse Labor Equivalent of Tractor Work . 34 
Proportion of Work Done by Horses and 
by Tractors 35 
Number of Workstock Used on Different 
Operations 37 
Page 
Cost of Keeping Workstock 39 
Cost of Using Tractors 45 
Reliability of Tractors 53 
Cost of Power as Furnished by Horses and 
by Tractors .54 
Annual Cost of Drawbar Work . . . . 54 
Changes in Size of Farm and Number of 
Workstock 56 
Increase in Investment Due to Purchase 
of Tractors . . . , 59 
Saving of Man Labor Due to Use of 
Tractors 60 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1921 
