May29. i9i6 Root Systems aiid Leaf Aveas of Covu and Sovghum 325 



which have already been described. The moisture equivalent, together 

 with the wilting coefficient obtained from it by the formula of Briggs and 

 Shantz (i, p. 56-73) for each foot of soil, is also included therein. 



Table VII. — Soil-moisture content and depth of root penetration of corn, kafir, and 

 niilo in 1914 and igiS at Garden City, Kans. 



Date. 



1914. 



June s 



July 2 



10 



21 



29 



Aug. 9 



22 



Sept. 6 



Wilting coefficient 

 of Briggs and 

 Shantz 



Moisture equiva- 

 lent 



1915. 

 June 18 



29 



July 12 



24 



Aug. 6 



16 



25 



Wilting coefEcient 

 of Briggs and 

 Shantz 



Moisture equiva- 

 lent 



Percentage of moisture at a depth of- 



foot. 



22.9 

 14- 6 

 II. 8 

 10. 6 

 8.7 

 9.4 

 8.4 

 7- 7 



20. 3 

 16. 2 



13-3 

 24-4 



feet. 



22. S 

 20. 2 

 17- I 

 13-3 

 13- I 

 13- S 

 13-4 



12. 2 



feet. 



21. 1 

 21. 2 



14-5 

 26. 7 



14. I 

 25-9 



14- S 

 26. 7 



21. 7 

 20.8 

 20. 2 



17-8 

 15-4 

 17-7 

 15-9 



14.9 

 27-5 



feet. 



22.8 

 23.6 

 19.4 

 16.8 

 14- S 

 14.4 

 12. 9 



16.3 

 30.0 



18. 5 

 17-9 

 17.8 

 17- 2 

 i5. o 

 17. 2 



13-6 

 25- I 



feet. 



17- 1 

 31-5 



IS- 5 

 16.8 



19.0 

 17-4 

 16. I 

 16. 4 

 IS. 6 



13-4 

 24. 6 



6 

 feet. 



16. 1 

 29-6 



16.0 

 16. 7 



IS- 5 

 16.5 

 15-4 

 IS-S 

 16. 2 



II. 9 



21. 9 



feet. 



feet. 



15-7 

 29.0 



16.6 



17. 1 



19. 8 



18.9 



15-7 

 2S. 9 



19-1 

 19-3 



18.6 

 19.0 

 19. 9 



12. I 



22. 3 



feet. 



16. 4 



16. 7 



18.4 



20. 6 

 19- S 



15.0 

 27. 6 



19. 2 

 19-7 



20. 2 

 20. 4 

 20. 9 



13.0 

 23-9 



Greatest depth of 

 rcotj. 



Feet. 



1% 

 '434 

 6 



Feel. 



2Va. 



6 



.Mi!o. 



Feet. 



1% 

 3 



4^4 

 6 



The season of 1914 was especially favorable for such an observation, 

 since the rainfall for the last half of June amounted to only 0.44 inch, and 

 for July and August 0.56 and 0.64 inch, respectively. This amount of 

 rainfall, a little over 1% inches for the 2^ months, came at 12 different 

 periods, so that with the exception of the first foot of soil no influence was 

 exerted by the rainfall upon the original soil-moisture content. The sea- 

 son of 1 91 5 was not so favorable for an observation of this kind, but the 

 results, while not so striking as those of 1914, show the same facts. It 

 should be borne in mind in studying Table VII that in 191 4 the soil sam- 

 ples which were taken on July 2 and 21 were procured from five to six 

 days after the isolation of the root systems whose depths are recorded for 

 that date. Furthermore, in 191 5 the samples for July 12 and August 6 

 were taken two and six days, respectively, after the recorded depths of 

 the root systems. 



The results of these experiments for both seasons seem to show that 

 there was little if any depiction of the soil moisture below the depth to 

 which the roots penetrated. 

 36290°— 16 3 



