STERILE SOILS 49 



Lime is necessary for successful fruit growing — 

 especially for stone fruits (plums, etc.). It 

 strengthens the stem, hastens ripening of the fruit, 

 and shortens period of growth — a valuable 

 property in a precarious climate, like that of Great 

 Britain. 



Heavy clays are greatly improved by the 

 addition of lime in any form, by shortening the 

 period of growth, and thereby preventing the 

 damaging action of frost. 



In addition, it may be stated that the minor 

 constituents of the soil also play a most important 

 part in the nutrition and growth of trees ; con- 

 sequently, if a soil is deficient in the minor 

 constituents, or they are not in such a form that 

 they can be readily absorbed by the roots, the 

 trees are bound to suflPer from imperfect nutrition. 

 Many soUs are sterile because they are devoid of 

 certain minor constituents ; and a fruit-growing 

 soil may contain an abundance of lime, potash, 

 nitrogen, phosphoric acid, iron, etc., and still be 

 almost barren if these substances exist as insoluble 

 compounds. To prevent sterility or soil exhaustion 

 it is necessary to add, year by year, a quantity 

 of the mineral and other ingredients of plant-food 

 at least equal to that which has been removed in 

 the form of fruit, flowers, wood, etc. If more 



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