16, 5 Espino: Salt Requirements of Young Rice Plants 509 
and green weight of tops may be expected to be better than 
occurs for what may be termed the optimal range of total con- 
centration. The three less concentrated series nearly agree 
with one another in this regard, but the series with highest 
concentration shows less than half the number of discrepancies 
that any one of the other three shows. This fact may or may 
not be important; of course it is to be understood that, if the 
total concentration were made high enough to injure the plants 
seriously, each of the various dry yields must approach the 
KH, PO, 
c 
High yield 
(NH, ),S0, 
Fic. 8. Distribution of low, medium and high green-weight values for series 16 and 19 
combined. 
