152 FIELD CROPS FOR THE COTTON-BELT 



to a distance of 16 to 18 inches and that by the time the 

 plants are coming % in to tassel the root-system may cover 

 a radius of 4 feet. 



The depths at which the greater part of the primary 

 roots of corn develop varies somewhat in accordance with 

 (1) the moisture content of the soil during the growing 

 season, (2) the depth at which the seed-bed has been pre- 

 pared and (3) the distance of the roots from the plant. 



FIG. 20. Root distribution of corn at silking time. 



In wet seasons the tendency is for the roots to develop very 

 near the surface of the soil. This is especially true in cases 

 of protracted rainy weather during the first part of the 

 growing season. On a deeply prepared seed-bed the feed- 

 ing zone of the roots is much deeper than where shallow 

 preparation has been practiced. As a rule, the upper roots 

 6 inches from the plant are about 3 inches below the sur- 

 face and gradually increase in depth to 4 or 5 inches at a 

 distance of 2 feet from the plant. 



