48 



MASS. EXPERIMENT STATION BULLETIN 232 



pounds of kainit must be applied. Conceivably, too much of soluble salts 

 may have been applied and resulting injury may have overbalanced in- 

 creases which might otherwise have been produced. 



2. The remaining sources of potash were about equallj' effective. 

 Differences in yields arising from their use are well within the limits of 

 experimental error. There were neither markedly injurious nor beneficial 

 results from the use of any one of these as compared to the others. 



Muriate versus Sulfate of Potash 



The most important of the comi)arative data just presented are those 

 which bear on the use of muriate of potash versus the sulfate, these two 

 being standard sources of fertilizer potash. In addition to these data 

 tiiere are many from Field B, devoted to a comparison of these two salts. 

 This field was originally laid out in 1883; and was formally devoted to a 

 comparison of these salts in 1893, with records from that year which are 

 considered trustworthy and fairly representative of normal experience. 

 Fertilizer other than potash consisted of 600 ))ounds per acre of fine ground 

 bone. At the beginning potash was applied at the rate of 400 pounds per 

 acre of muriate, or the same quantity of sulfate. These amounts were 

 reduced in 1900 to 2.'50 pounds per acre; and further reduced in 1917 to 150 

 poimds per acre. Tiiere were five j^airs of differentially treated plots, not 

 cropped in definite rotation. 



The following table summarizes the more significant results, and 

 presents averages from Field G for com])arison. 



Comparison of Muriate of Potasii with lligh-Crade Sulfate of Potash 

 Averuiie Yields per Acre 



a One planting. 



b Two plantings . 



