1907.] PUBLIC DOCUMENT — No. 33. 33 



Should furtlier exj^eriment confirm what now appears to bo 

 probable in regard to the varying effect of these two potash 

 salts upon the ability of the canes of these frnits to resist 

 the winter's cold, the point demonstrated will be one of 

 much importance, for winter-killing is one of the most seri- 

 ous obstacles to the successful j)roduction of some of the 

 most desirable varieties of these fruits. 



The Hay Crops. — The hay crop of the past year occu- 

 pied four plots. Clover seed alone was sown, but the clover 

 did not make a good stand, and the vacancies were filled in 

 part by timothy, in part by weeds. Where the clover was 

 best, a considerable superiority in favor of the sulfate of 

 potash was manifest. Aside from this observation, the re- 

 sults of the year with the hay crop did not ajjpear to have 

 much significance. 



Potatoes. — It will be noted that the yield of merchant- 

 able potatoes upon the sulfate of potash was materially 

 larger than on the muriate. This result is in accordance . 

 with the results which have usually been obtained in experi- 

 ments upon our grounds; and, in spite of the fact that the 

 season during which the potatoes made their chief growth 

 was this year characterized by a considerable deficiency of 

 rainfall, the soil where the sulfate has been continuously 

 used shows its superiority over that where the muriate has 

 been similarly used. 



III. ■ COMPAKISON OF DlFFEEEJSTT PoTASH SaLTS FOR 



Field Crops. (Field G.) 

 This experiment is designed to show the ultimate effect 

 upon the soil, as well as the current effect upon the crops, 

 of continuous use of different potash salts. We have under 

 comparison kainit, high-grade sulfate, low-grade sulfate, 

 muriate, nitrate, carbonate and silicate. The field includes 

 forty plots, in five series of eight plots each. Each series 

 includes a no-potash plot, as well as the seven potash salts 

 which have been named. The experiment is therefore car- 

 ried out each year in quintuplicate. The area of each plot 

 is one-fortieth of an acre. The potash salts under compai'i- 

 son are used in quantities which will supply annually actual 



