170 Nebraska Agricultural Exp. Station, Research Bui. 6. 
to see sunflower plants in cornfields as large as those grown in the 
potometers. Such a plant uses approximately as much water as 
a hill of corn with three plants. 
RELATION OF ASH CONTENT TO TRANSPIRATION UNDER 
VARIOUS CONDITIONS OF GROWTH. 1 
There are two common theories relative to the relationship 
between the transpiration rate and the intake of soil solutes. 
According to one theory the amount of solute taken up by the 
plant from the soil solution is proportional to the amount of 
water transpired, and the amount of transpiration is in inverse 
ratio to the density of the solution. According to the second 
theory, the amount of solute taken in by the plant may be in- 
dependent of the density of the solution and the amount of water 
transpired. 
In order to secure information regarding these relationships, 
ash determinations 2 were made of a large number of the plants 
harvested in 1913 and 1914. Altho the ash left on incineration 
has not the composition of the inorganic compounds taken up 
by the plant from the soil, nevertheless it may serve as an index 
of the relative absorption of soil solutes. In these determinations 
every precaution was taken to insure the highest degree of accu- 
racy. The whole plant was reduced to a fine powder, thoroly 
mixed, and sampled. The samples were ashed in a carefully 
regulated electric furnace, so that loss by volatilization was re- 
duced to a minimum. In all cases duplicate determinations 
were made. The following tables contain data concerning the 
relation between transpiration and ash content, as affected by: 
(1) Atmospheric humidity, (2) seasonal climatic differences, (3) 
soil fertility, (4) soil moisture, (5) kind of crop and variety, and 
(6) limitation of the amount of soil thru the size of the potometer. 
The complete plans and other detailed results with these 
plants have been given earlier in this bulletin, reference to the 
related data being given below each of these tables. 
EFFECT OF CLIMATIC DIFFERENCES UPON RELATION OF TRANSPIRATION TO 
ASH CONTENT. 
The plants grown in the dry and humid greenhouses in 1912 
furnish excellent material to determine the effect upon the 
1 References relative to transpiration and the intake of salts: Daszewski 
(1900), Fittbogen (1873), Hasselbring (1914a, 1914b), Il'enkov (1865), Lawes 
(1850), Preul (1908), Wilfarth and Wimmer (1902), and Wimmer (1908). 
2 The ash determinations were made under the direction of Dr. F. W. 
Upson, Station Chemist. 
