THE POTATO. 



CHAPTER V. 



MANURES AND MANURING. 



THE subject of manuring land for potato cultivation is one 

 of considerable interest to potato growers, and we propose 

 in the following notes .to give a digest of the opinions ex- 

 pressed by various authorities, in order that some tangible 

 idea may be formed as to what kinds of manures are best 

 adapted to yield the most satisfactory results. 



The manures advised by the leading authorities are 

 farmyard dung, superphosphate, basic slag, bone-meal, 

 phosphatic Peruvian guano, kainit, muriate and sulphate 

 of potash, sulphate of ammonia, nitrate of soda, sulphate 

 of iron, sulphate of lime, magnesium salts, and soot. The 

 farmyard dung may be said to be an all-round manure, 

 because it contains small quanties of phosphates, potash, 

 and nitrogen, the three chief elements required as food 

 by the potato. Superphosphates, basic slag, bone-meal, 

 and phosphatic guano are phosphatic manures; kainit, sul- 

 phate, and muriate or chloride of potash are potash 

 manures; while sulphate of ammonia and nitrate of soda 

 are purely nitrogenous manures. We will now deal briefly 

 with the merits of each manure, so far as they apply to 

 the potato. 



Farmyard Manure. This is generally agreed to be 

 an indispensable manure, partly from a chemical, and 

 partly from a mechanical point of view. Chemically, its 

 small quantities of phosphoric acid, potash, and nitrogen 

 are helpful to the crop, but they are not sufficient, or so 

 readily accessible, to aid materially in the development of 



