222 Salt Proportions [420 



A STUDY OF SALT PROPORTIONS IN A NUTRIENT 



SOLUTION CONTAINING CHLORIDE, AS RELATED 



TO THE GROWTH OF YOUNG WHEAT PLANTS 



By S. F. TRELEASE 



Chlorine has been considered an unnecessary element in the 

 nutrition of most plants,, but it seems to have produced a 

 beneficial influence in certain cases that have been recorded. 

 There is some practical as well as scientific interest in the 

 question thus raised, since potassium chloride is frequently 

 used as an agricultural fertilizer, and the influence of the 

 chlorine thus put into the soil may not be without impor- 

 tance. In the experiments of which this is a preliminary 

 report the chlorine ion was introduced into nutrient solutions 

 that already contained all the essential elements usually ab- 

 sorbed by plant roots. These essential elements (N, S, P, 

 Ca, Mg, K, and Fe) may be supplied to the young wheat 

 plants as a nutrient solution containing the three salts 

 Ca(N0 3 ) 2 , MgS0 4 , and KH 2 P0 4 , with a trace of iron as 

 FeP0 4 . To ' introduce chlorine, KC1 was added to the 

 list just given, thus making a 4-salt solution. A solu- 

 tion made from these four salts was used by Knop and 

 Nobbe, and Grafe * recommends these same salts as most gen- 

 erally useful. Detmer 2 employed one set of proportions of 

 these -four salts, and this solution has been designated by Tot- 

 tingham 3 as Detmer^s solution. In the experiment s consid- 

 ered in this paper the same general methods were used as were 



1 Grafe, V. " Ernahrungsphysiologisches Praktikum der hoheren 

 Pflanzen." Berlin, 1914. 



2 Detmer, W., " Practical plant physiology." Translated by S. A. 

 Moor. London, 1898. 



3 Tottingham, W. E., "A quantitative chemical and physiological 

 study of nutrient solutions for plant cultures." Physiol Res. I : 

 133-245. 1914. 



