613 Keport of the Department of Field Crops of thb 



testimony so far secured is conflicting. In many cases the quality 

 of the tubers as expressed by the percentages of dry matter and 

 starch has been found to be lower with the use of the muriate 

 than where the sulphate was applied. In a recent number of Die 

 landicirtsckaftlichen Yersuchs-Statlonen, Pfeiffer and others re- 

 view the data bearing upon this point and give results from well- 

 planned experiments of their own. Their conclusionis are that 

 the muriate free from other compounds has no injurious effect 

 upon the composition of the potato tuber, but that the depression, 

 in the proportion of starch which has been noticed is due to the 

 impur-ities in the commercial potash salts, notably magnesium 

 chloride. These authors even claim that the addition of chlorine 

 to the soil may under some circumstances be beneficial to the 

 quality of the tubers. 



The Proportion of Dry Matter and Starch. 



About one bushel of potatoes was sent to the Station from each 

 one of the experimental plats on the Hallock and Fleet farms. 

 Tubers to the amount of about ten pounds were carefully selected 

 from each lot, were sliced and dried at a temperature between 

 50° and 60° C. Determinations were made in each sample of the 

 dry matter, starch, nitrogen, phosphoric acid and potash. These 

 results are given in detail in Table III and are summarized in 

 the succeeding tables, Nos. VII, VIII and IX. 



