ASH ABSORPTION BY SPINACH FROM CONCENTRATED 



SOIL SOLUTIONS 



By Rodney H. True, Physiologist in Charge, Otis F. Black, Chemical Biologist, and 

 James W. Kelly, Laboratory Technician, Office of Drug-Plant, Poisonous- Plant, 

 Physiological, and Fermentation Investigations, Bureau of Plant Industry, United 

 States Department of Agricultiire 



INTRODUCTION 



In 1 91 5 when the authors were engaged in a study of the possible 

 causes of spinach-blight, the theory was advanced that the disease was a 

 form of "malnutrition" due, in a measure, to the accumulation of an 

 excess of fertilizer salts in the soil solution. 



FERTILIZER SUBSTANCES USED 



In the hope of reproducing the symptoms seen, beds of spinach (Spi- 

 nacia oleracea) grown on the grounds of the Virginia Truck Experi- 

 ment Station,^ in cooperation with which this work was carried on, were 

 given large applications of the commoner fertilizer salts, singly and in 

 the usual mixtures. The so-called "acid mixture" was that generally 

 employed by the truck farmers of the Norfolk region for use in their 

 spinach fields. The "basic mixture" was made up of substances which 

 would likely be neutral or basic in the soil. The constituents of each 

 were approximately as follows : 



ACID MIXTURE. 



Pounds. 



Ammonium sulphate 340 



Acid phosphate 830 



Potassium muriate 170 



Dried blood 260 



Tankage 400 



BASIC MIXTURE. 



Pounds. 



Sodium nitrate 450 



Basic slag from Birmingham, Ala. 720 



Potassium sulphate 170 



Dried blood 260 



Tankage 400 



Single salts were supplied in two proportions : One was intended to be 

 near the maximum; the other to cause clear injury. The substances 

 applied are listed below in terms of pounds per acre : 



SXIBSTANCES. QUANTITY USED. 



Calcium carbonate 3 and 6 tons per acre. 



Magnesium carbonate i and 2 tons per acre. 



Potash 750 and 1,500 pounds per acre. 



Sodium nitrate Do. 



Sodium chlorid Do. 



Sodium sulphate Do. 



1 The authors are indebted to the Director of the Virginia Station and to his assistants for help in many- 

 ways. To Mr. J. A. McClintock, at that time Plant Pathologist of the Station, they owe an especial 

 debt for careful notes made from time to time and for help rendered in other ways. 



Journal of Agricultural Research, 



Washington, D. C. 



qw 



(X5) 



Vol. XVI, No. I 

 Jan. 6, 1919 

 Key No. G-171 



