160 AGRICULTURE 



these are consumed by stock the potash is 

 restored to the ground ; but it is now in the 

 surface layers, and therefore within the 

 feeding range of such shallow-rooted plants 

 as White Clover. 



There is only one class of manure that 

 contains in considerable quantity all three 

 of the more important elements of plant 

 food, namely Guanos. The most important 

 guano is that which comes from Peru, of 

 which, however, the imports are now much 

 less than in the middle and earlier half of 

 last century. Good Peruvian guano is an 

 excellent fertilizer, offering to plants nitrogen 

 (7-12 per cent.), phosphates (20-40 per 

 cent.), and potash (3-4 per cent.) in an easily 

 available form. Worked out on a unit 

 basis, however, it will be found that the 

 price looks high (7-lO a ton), a position 

 that it has attained partly on its intrinsic 

 merits, and partly as an inherited tradition 

 of the good agricultural times, when high 

 profits and Peruvian guano were closely 

 linked in the farmer's mind. Ichaboe guano, 

 a South African product, has much the same 

 composition and value as Peruvian. There 

 are, however, other guanos on the market 

 which hold much less nitrogen (2-3 per 

 cent.) and much more phosphate (50-70 per 



