Jan. 6, 1919 



Ash Absorption by Spinach 



23 



relative values, especially in the tops, in the plots to which the complete 

 fertilizers were applied. 



The relation of potash and soda is of particular interest in view of the 

 halophytic nature of the spinach plant. It is perhaps worth noting in 

 this connection that the sodium-potassium ratio varies over a wider 

 range, something to be expected perhaps in view of the greater variability 

 in the quantities of these constituents present. In Table III these 

 ratios are given, soda being unity, the values of potash appearing in the 

 appropriate columns. 



Table III. — Soda-potash ratio in spinach ash. Soda {Na02)=i 



Fertilizer. 



Sodium nitrate. .. . 

 Sodium sulphate . . 

 Sodium chlorid . . . 

 Potassium chlorid . 

 Calcium carbonate 

 Acid phosphate . . . 

 Acid complete .... 

 Basic complete . . . . 



Manure 



Control 



It will be seen that in a broad way, when the potash is high in the 

 ash, soda is low, and vice versa. Potash, however, is always higher 

 than soda, the excess being greater in the leaves than in the roots. 

 High potash seen in the plot receiving sodium sulphate is accompanied 

 by a very low soda content. The same is seen in the control as well as 

 in both acid and basic complete mixtures and in stable manure. High 

 soda is seen in the plots treated with sodium chlorid, in which potash 

 reaches its minimum, and in that receiving sodium nitrate. The control 

 culture and that receiving acid phosphate show the same less strikingly. 

 Potash is in greatest relative excess in the plots receiving the complete 

 fertilizers. 



These results suggest the possibility that sodium may be able to 

 perform some functions in the plant which are usually performed by 

 potassium. It seems likely that by giving proper mixtures of the alkalis 

 it might be possible without detriment to the plant to get along with 

 less of the expensive potassium constituent, thus protecting the potassium 

 in the soil. 



In view of the fact that calcium is usually found in the ash of a great 

 majority of plants in considerably greater quantity than magnesium* it 

 is of interest to note the quantities found in these spinach plants. 



' LoEw, Oscar. Liming of soils from a PBtYSiowKiiCAi, standpoint. In U. S. Dept. Agr. Bur. Plant 

 Indus. Bui. I, p. 9-35. 1901. 



