16,6 Espino: Salt Requirements of Young Rice Plants 497 
considred (0.0016 gram-molecule per liter, or 0.08 atmosphere) 
the diagram for top yield (fig. 4) shows five sets of salt propor- 
tions as of the high group, all lying in the forward left portion 
of the lowest triangle. No set of proportions in the lowest 
triangle is indicated for the low group, but three sets are shown ; 
one in the second, one in the third, and one in the fourth 
triangle, all at or adjacent to the forward right apex. The 
corresponding diagram for root yield (fig. 5) shows about the 
same low region in the lowest triangle as is shown for top yield, 
but here also there are three high sets of proportions; in the 
KHjPO^ 
HM 
Fig. 6. Root-yield values for the thirty-five different sets of salt proportions, with low- 
medium total concentration. 
