SUMMARY 



A study was made to evaluate the effect of tractor traffic on 

 yields of alfalfa and red clover. Eight hasic treatments were 

 applied hy using two tractors, one with new tires and one with 

 smooth tires. 



The tests were conducted on a Paxton loam soil. Plots were 

 seeded in August of 1959 and 1960. The following spring the 

 first crop was harvested by hand. The traffic treatments were 

 applied to the second growth when the plants were approxi- 

 mately four inches high. The area between the tractor tracks 

 was kept cleanly mown, consequently, only those plants which 

 had been run over by the tractor were allowed to grow. 



Results show that tractor traffic does injure and kill young 

 plants. A smooth tire does more damage than a new tire. Stem, 

 leaf and crown damage was prevalent following all treatments. 



This research was supported in part by funds from regional project 

 NE-13. The Mechanization of Forage Crops, Harvesting, Processing, Storing 

 and Feeding, a cooperative study, including Agricultural Experiment Sta- 

 tions in the Northeastern Region, of the United States Department of 

 Agriculture. 



The authors wish to express their appreciation to Richard D. Merritt 

 and John P. Adams, University of New Hampshire photographers, for 

 their asssitance in taking and preparing the pictures in this bulletin. The 

 contribution of R. H. Kilpatrick, Plant Pathologist and Merle Ct. Wright, 

 technical assistant, is gratefully acknowledged. 



Cover Ph(»t4»: Effect of increasing drawbar pull on alfalfa and red 

 clover plants — center plants arc from the control 

 plot — degree of pull increases from center to left 

 and right. 



