EGYPTIAN COTTON AS AFFECTED BY SOIL VAKIATIONS. 



23 



were several areas of greater or less size where the plants either had 

 failed to appear or had subsequently died. The electrical resistance 

 of the soil was determined in different parts of this field on October 

 23, and notes were made upon the character of the plants where the 

 respective soil samples were taken. The results of these observa- 

 tions are summarized in Table IV. The percentages of total salts 

 indicated by the electrical resistances as given in this table are 

 computed from Table III, page 14, Bulletin 61 of the Bureau of Soils, 

 which applies to a type of alkali consisting of one-half chlorids and 

 one-half sulphates. 



Table IV. — Electrical resistance of the saturated soil, indicated percentage of total salts y 

 and condition of Egyptian cotton plants, at Bard, Cal., in 1911. 



Bor- 

 ing 

 No. 



Depth. 



Character of 

 soil. 



Elec- 

 trical 

 resist- 

 ance. 



Indicated 



total 

 salts in 

 percent- 

 age of dry 

 weight 

 soil. 



Condition of plants. 



1 



Feet. 



< 1 



2 



3 



4 



Sandy loam... 



do 



do 



Fine sandy 

 loam. 



Ohms. 

 45 

 63 

 113 

 117 



0.75 

 .53 

 .29 



.28 



•No plants; boring m center of a small hare spot. 





.46 







i i 



( l 



2 

 3 



4 



Sandy loam. . . 

 do 



Sandy loam... 

 do 



Fine sandy 



loam. 

 do 



33 

 63 



63 

 91 

 62 



59 





2 



1.12 



.53 



1 Between two good-sized, healthy, fruitful plants bear- 

 > ing abundant fiber of excellent quality, strong, If 

 1 inches long. 



3 



.53 

 .37 

 .53 



.56 



Among small scattered plants (less than half normal 

 height) mostly dead. Plants shallow-rooted here. 





.50 







f 1 



2 

 3 

 4 



Sandy loam... 

 do 



55 

 50 

 69 



85 







.60 

 .67 

 .48 

 .39 



Between two good-sized, healthy, fruitful plants bear- 



4 



do 



> ing strong, abundant, silky fiber. Root system 

 comparatively shallow. 





.53 







I 1 



2 

 3 

 4 



Average. 



Sandy loam... 



do 



do 



55 

 81 

 75 

 97 





5 



.60 

 .41 

 .45 

 .34 



Beside a dying plant at edge of spot in center of 

 1 which boring No. 3 was made. This plant bore a 

 [ few open bolls, the fiber in which was coarse and 

 weak. 









.45 











Inspection of this table shows no close relation between the salt 

 content of the soil and the growth of the cotton plants. Thus, at 

 boring No. 2, located midway between two plants which were about 

 as good as any in the field, the first foot of the soil contained con- 

 siderably more soluble salts than the first foot of borings Nos. 1, 3, 

 and 5, where there were either no plants at all or the plants were evi- 

 dently suffering. 1 



1 Much of this alkali had doubtless accumulated in the upper soil after the cotton was planted, the ground 

 water table in this field having reached the surface of the soil during the high-water stage of the Colorado 

 River in June. It had lowered by the date when these borings were made, saturated soil having been 

 encountered at a depth of about 4| feet in the neighborhood of boring No. 3. 

 [Cir. 112] 



