THE PLAINS ASSOCIATION. 



67 



of the quadrat cut smooth and perpendicular. Then by the use of a 

 hand-pick the soil was carefully removed from the roots in the trench 

 wall along the edge of the quadrat to a horizontal distance of 4 inches. 

 WTiile this was under way the roots were carefully measured and 



Table 17. 



drawn in position to scale. This gives a picture of the exact root 

 distribution in a block of soil a meter long, 4 inches wide, and 7 feet 

 deep, in this particular case. Dotted Unes indicate the exit or entry 

 of roots from or into this soil area respectively. This plains bisect 

 shows the complete occupancy of the soil by roots and the intense com- 

 petition for moisture and soil solutes that must result. 



