73 



superiority was chiefly due to the greater degree of moisture in the 

 soil of this plot as compared with the others which received fertili- 

 zers. This larger water supply may have been, in part, due to the 

 physical effect of the manure, but it was, undoubtedly, in part also a 

 natural difference due to location. Neither lime nor plaster produced 

 results of any significance. 



On this soil the fertilizer recommended on page 56 should prove well 

 adapted for the potato. 



GENERAL SUMMARY. 



For convenience of comparison the figures showing the average 

 effects of the several ingredients of the fertilizers used are brought 

 together. 



These figures together with others showing the grand average effect 

 apparently due to each of the three ingredients are shown in the 

 table below. 



AVERAGE EFFECTS OF THE INGREDIENTS OF THE FERTILIZER UPON THE 

 POTATO CROP. 



It will be observed that the potash of the fertilizers in every 

 experiment, save one, (Shelburne) proved much more beneficial in 

 its average effect upon the crop than either nitrogen or phosphoric 

 acid and the indication is, therefore, that it should be relatively more 

 abundant in fertilizers especially designed for this crop than is 

 usually the case. The twelve special potato fertilizers, the analyses 

 of which are given in the Eighth Annual Report of the State Exper- 

 iment Station contain, on the average: nitrogen, 3.4 ; phosphoric 

 acid, 10.69 ; and potash, 6.36 per cent. With one exception, they 

 do not differ widely from each other in the proportions of these 



