Extent of Root Urowth. 157 



The coarse branches shown with the winter wheat roots 

 are the roots of a red oak tree which was growing in a 

 pasture 33 feet away, and they serve to show how far forest 

 trees send their roots foraging through the soil for water 

 and food, and through what long lines the water must be 

 pumped after it has been gathered. 



185. The Total Root of Plants. In the preceding sections 

 the samples simply show the amount of root found in a 

 given volume of field soil. In Fig. 51 is shown the total 

 root of four stalks of corn, while Figs. 52 and 53 show the 

 same thing for oats and medium clover. These were se- 

 cured by growing the plants in cylinders 42 inches deep 

 and 18 inches in diameter, filled with soil. When the 

 crops were mature the cylinders were cut down and the soil 

 washed away. 



In each case the roots extended to the bottoms of the 

 cylinders, forming a dense mat there, as the engravings 

 show. 



The roots shown with the clover, and which gathered the 

 moisture for the top, forced from the soil water enough to 

 cover the space to a depth of 29 inches. It will be seen 

 that the stand of clover is very close, fully three times as 

 heavy as a good clover crop in the field. This was made 

 possible by having a rich soil and supplying all the water 

 the plant could use at just the right time. 



The length of all these roots is less than it would have 

 been had the cylinders been deeper, as proven by the mat- 

 ting at the bottom. 



