46 MANURES FOR FRUIT TREES 



season's fruit, etc. It pays the cultivator not 

 only to add such manures as potash, nitrates, and 

 phosphates, but the minor constituents (such as 

 salts of iron and manganese) in the form of soluble 

 compounds. 



There is little doubt that many fruit trees are 

 failures because the soil is incapable of properly 

 nourishing them. It may be mentioned en 

 passant, that Prince Salm-Hortsmar in 1849 

 (after a long series of interesting investigations) 

 came to the conclusion that oats demand for 

 complete development all the mineral constituents 

 found in their ashes. 



If the mineral constituents are absent in the 

 soil — or cannot be utilised by the living roots — 

 such a soil becomes barren. 



On the following page are examples of barren or 

 sterile soils. ^ 



Nos, 1 and 2 are sterile heath soils contain- 

 ing only traces of potash, soda, sulphuric acid 

 and phosphoric acid. No. 3 is a sterile sandy 

 soil, containing much humus, and No. 4 is 

 also a barren sandy soil ; both contain only traces 

 of potash, phosphoric and sulphuric acids, and 

 very little lime and magnesia. Nos. 5 and 6 



' The " ager inf ecundus arbore " of Sallust, and the "sterilitas 

 agrorum " of Cicero. 



