THE EARTH'S BOUNTY 



downward had scarcely reached 12 inches, and 

 6 inches from the hill no roots were nearer the 

 surface than 2 inches. Twenty-seven days 

 after planting, the greatest depth reached by 

 the roots was 18 inches, and the greatest lateral 

 extension 24 inches from the hill, witH the tips 

 4 inches below the surface. The depth of the 

 roots at 6 inches from the hill was the same as 

 9 days before. 



In similar work along this line the North 

 Dakota Station found that 30 days from 

 planting, the main roots appeared to have de- 

 veloped laterally and but few had penetrated 

 to a depth of 12 inches, the bulk of the roots 

 lying within 8 inches of the surface of the 

 soil. An examination 55 days from planting, 

 when the plants were 54 inches high, showed 

 that the primary roots had penetrated to a 

 depth of 2% feet, and that many of the hori- 

 zontal roots now extended from hill to hill. 

 The lateral roots frequently sent up feeders 

 within 2 inches of the surface. A third sample 

 was taken 90 days from planting, and soon 



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