Depths at Which Plants Absorb Water and Nutrients. 



99 



little change in water-content of the check container (No. 10) during the inter- 

 val from June 15 to July 16, but a marked loss from the ones with crops, espe- 

 cially at depths of 2 to 3 feet. Thus, the activity shown by the deeper portions 

 of the roots on June 28 is here confirmed. Indeed, the total water absorbed 

 at the several levels (May 19 to July 16) is about the same in amount to a 

 depth of 3 feet (table 33, last column). Further evidence for this conclusion 

 is given in table 34, which shows the water-loss from the sealed containers 7 

 and 8 during this interval. 



Table 34. — Water-content of sealed containers, May 19 and July 16. 



Container No. 7, eight plants, roots quite uniformly- 



Container No. 8. no olants. 



distributed throughout the container. 









Depth of sample. 



May 19. 



July 16. 



Loss. 



May 19. 



July 16. 



Loss. 



Jeet. 



p. ct. 



p. ct. 



p. ct. 



p. ct. 



p. ct. 



p. ct. 



to 0.5 



25.6 



15.9 



9.7 



26.0 



28.3 



+2.3 



0.5 to 1 



25.7 



14.3 



11.4 



28.1 



27.9 



0.2 



1 to 1.5 



26.3 



16.4 



9.9 



29.5 



30.0 



+0.5 



1.5 to 2 



26.9 



20.7 



6.2 



29.0 



30.4 



+ 1.4 



2 to 2.5 



28.3 



22.8 



5.5 



28.2 



28.7 



+0.5 



On July 29 the barley was nearly ripe. The plants in the remaining con- 

 tainers were 2.2 feet tall and were rather badly rusted with Pvxcinia graminis 

 tritici. The roots in both the sealed and unsealed soil were rather uniformly 

 distributed to near the bottom of the containers, a depth of 3.5 feet. Only in 

 the deepest soil were they less numerous. The plants had tillered extensively 

 and the dense mat of roots was most pronounced to a depth of 2 feet. None of 

 the 4 containers had been disturbed in any way since May 21, except that on 

 June 28 a liter of water was slowly added to each through the slit in the roof 



Table 35. — Total water lost at the several levels from May 21 to July 29. 



Depth of 

 sample. 



feet. 



to 0.5 

 0.5 to 1 



1 to 1.5 

 1.5 to 2 



2 to 2.5 

 2.5 to 3 



3 to 3.5 



Container No. 12. 



p. ct. 

 30.9 

 32.0 

 31.8 

 30.4 

 30.4 

 31.3 

 30.6 



p. ct. 

 28.3 

 30.4 

 30.7 

 30.6 

 30.3 

 31.3 

 31.8 



p. ct. 

 2.6 

 1.6 

 1.1 



+0.2 

 0.1 

 0.0 



+ 1.2 



Container No. 14. 1 



p. ct. 



32.6 

 33.3 

 33.0 

 32.0 

 31.7 

 32.9 

 30.6 



p. ct. 



30.2 

 33.0 

 33.6 

 32.9 

 32.5 

 31.9 

 30.3 



p. ct. 

 2.4 

 0.3 

 +0.6 

 +0.9 

 +0.8 

 1.0 

 0.3 



Container No. 13.* 



p. ct. 



32.5 

 34.5 

 32.7 

 34.0 

 33.7 

 32.6 

 30.8 



p. ct. 

 13.5 



p. ct. 

 19.0 

 17.8 

 16.4 

 16.6 

 13.2 

 9.1 

 6.9 



Container No. 15. 3 



p. ct. 

 33.3 

 33.3 

 31.5 

 32.5 

 31.9 

 31.5 

 34.6 



p. ct. 

 13.1 

 14.5 

 15.8 

 16.9 

 17.9 

 19.5 

 23.3 



p. ct. 

 20.2 

 18.8 

 15.7 

 15.6 

 14.0 

 12.0 

 11.3 



1 No plants. 



* Eight plants, average height 2.2 feet; 2 to 6 tillers each; roots normally distributed to 

 bottom of container. 



•Fifteen plants, average height 2.2 feet; 2 to 8 tillers each; roots normally distributed to 

 bottom of container. 



