1905.] 



PUBLIC DOCUMENT — No. 33. 



135. 



with fairly liberal ainomits of muriate of potash, it is essential 

 to use lime freely on many of our soils, if their productive- 

 ness is to be maintained. This field contains four plots, to 

 which neither manure nor fertilizer of any kind has been 

 applied during the sixteen years that the experiment has 

 contiimed. These plots have now become very highly ex- 

 hausted, producing crops which are practically valueless so 

 far as the production of grain is concerned, although the 

 nominal yield is at the rate of about 3.5 to 8 bushels per 

 acre. The following table shoAvs the fertilizers used on the 

 several plots, the rate of yield, and the gain or loss per acre 

 compared with the nothing plots : — 



Coryi. — South Acre Soil Test, 1904. 



It will at once be noticed that the potash is the element 

 which determines the crop, almost to the exclusion of all 

 others. Where potash has been used alone during sixteen 

 years, the yield is almost as great as it is with potash and 

 any of the other combinations. Nitrate of soda alone does 



