MANURES FOE POTATOES. 261 



" Potatoes," says Mr. Hunter, " were largely grown on the farm, 

 and in the absence of a sufficiency of farm-yard manure, potash 

 naturally suggested itself as a necessary constituent of a chemical 

 potato-manure. The soil was light and gravelly, with an open 

 subsoil, and the rainfall from 29 to 38 inches a year." 

 ' The first series of experiments was made in 1867. The follow- 

 ing are some of the results : 



m7ielspcr acre. 



No manure 221 



4 cwt. mineral superphosphate 225 



4 cwt. mineral superphosphate and ) 040 



4 cwt. of muriate of potash \ 



15s tons farm-yard manure 293 



" That does not say much for potash nud superphosphate," said 

 the Deacon. " The superphosphate only produced four bushels 

 more than the no manure, and the potash and superphosphate 

 only fifteen bushels more than the superphosphate alone." 



It may be worth, while mentioning that one of the experimental 

 plots this year was on a head-land, " where the cattle frequently 

 stand for shelter." This plot was dressed with only eight and a 

 half tons of manure, and the crop was over 427 bushels per acre, 

 while a plot alongside, without manure, produced only 163 bushels 

 per acre. 



" That shows the importance," said the Deacon, " of planting 

 potatoes on rich land, rather than to plant on poor land and try to 

 make it rich by applying manure directly to the crop." 



The following are some of the results in 1868 : 



Ihishels per acre. 

 1. No manure 232 



)4 cwt. superphosphate ) 

 2 " muriate of potash V340 

 2 " sulphate of ammonia ) 



3 . 20 tons farm-yard manure 342 



j 4 cwt. superphosphate ( 074. 



4 - I 4 " muriate of potash J 



"Here again," said the Doctor, "superphosphate and potash 

 alone give an increase of only forty-two bushels per acre, while on 

 plot 2, where two hundred weight of muriate of potash is substi- 

 tuted by two hundred weight of sulphate of ammonia, the increase 

 is 108 bushels per acre. It certainly looks as though a manure for 

 potatoes, so far as yield is concerned, should be rich in available 

 nitrogen." 



