PROPERTIES OF MANURES 231 



stove and greenhouse shrubs, climbers, etc. In 

 many cases it ensures healthy growth of fruit trees, 

 vines, bushes and flowering shrubs. 



Guanos are phosphatic manures, and are 

 divided into two classes — nitrogenous and non- 

 nitrogenous guanos. They are valuable manures 

 for fruit and other trees, and they enter into the 

 composition of special manures. A good guano 

 contains in 100 parts : — 



Water 17-79 



Organic matter and anunonial salts 42 '62 = 10 '04% N. 



Calcium and earthy phosphates . . . 25 '45 



Alkaline salts 11-92 



Sand . 2-22 



Guanos are excellent for various soils, but 

 Peruvian guanos are not suitable for supplying 

 nitrogen to calcareous soils — better to use a 

 manure containing nitrate of soda and phosphates. 

 Chrevreul found that frequently guano contains 

 ammonium subcarbonate. 



Peruvian guanos are better suited for heavy 

 lands than light soils — if used on the latter, they 

 are best applied in the form of composts. It 

 must be remembered that if the soil is deficient 

 in potash, iron, etc., no amount of guano wUl 

 produce a full yield of fruit or perfect blooms. 

 The intellectual cultivator must know the ash 



