(17) 



acid, and especially magnesia, added to the soil. For these 

 last two substances this (calculation) is easily made. More 

 difficult is the question of the potash which has been re- 

 moved by the crop. Manuring with potash salts is fre- 

 quently undervalued, and undoubtedly because large and 

 tangible results were expected which failed to appear, while 

 the chief end of potash manures is neither in augmenting nor 

 bettering the crop, but in causing it to hold its own. This re- 

 sult is especially noticeable from the fact that no diminution 

 takes place in the yield, which would certainly be the case 

 in a greater or less number of years if the compensation 

 was not complete. ***** 



A further consideration, and such an one as would greatly 

 modify the results, lies in the form of the potash compound 

 employed. There is no other point on which the opinions 

 of practical men so much differ as in this, and continually 

 are new compounds declared to be the best; but of universal 

 application alone is the rule above, that we should always 

 mix the potash salts with common salt (NaCl), in order to 

 insure their being conveyed to the lower soil ; also the ad- 

 mixture of magnesia salts, when these have not been ap- 

 plied in some other way. l!^one of the potash salts from 

 natural deposits possess any peculiar merit above the others. 

 But those having an admixture of organic matter seem to 

 me to be preferable. * * * * For this pur- 

 pose, that potash coming from the beet itself — the residue 

 rich in lime, the molasses, &c. — is most valuable and 

 should be returned to the field when possible. One 

 should not believe, however, that potash sufficient for 

 the development of the plant has been added when the 

 molasses and other waste products of the beet harvest have 

 been returned to the field. Without taking into considera- 

 tion the leaves, which may have been left upon the field, a 

 very large amount of potash is still necessary, and the mo- 

 alone does not restore the amount needed by a good 



