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CHAPTER IV. 



THE SOIL AND ITS FUNCTIONS. 



The soil is the supplier of the inorganic constituents of plants. 

 The condition in which these inorganic substances must 

 be present. Their mere presence does not prove the fertility 

 of a soil. The fallacy of judging by a chemical analysis 

 of the capabilities of a soil. Tables to "measure" the 

 fertility of a soil. The injury done to scientific agriculture 

 by hasty conclusions drawn from imperfect experiments. 

 The constituent parts of the soil are in their original form 

 insoluble in water. The action of moisture, heat, and 

 atmospheric air renders them soluble. The peculiar 

 absorptive power of the soil to abstract the elements of 

 inorganic plant-food from their solutions. The capillary 

 absorbing power of the soil. Its bearing upon vegetable 

 life. The physical force of attraction of the soil is stronger 

 than the solvent power of water ; but yields when " Endos- 

 mose" comes into play. To judge of the capabilities of a 

 soil, it is necessary to distinguish between the assimilable 

 and unassimilable portion of inorganic plant constituents 

 present in it. 



Inorganic plant-food in physical and chemical combination. 

 Inorganic plant-food necessary in physical combination 

 for the immediate requirements of the soil, in chemical 

 combination for its lasting fertility. A sufficient quantity 

 of plant-food in the first state indispensable for the purposes 

 of husbandry. Fallowing. Its meaning, purport, and 

 action upon the component parts of the soil. An analysis 

 of a soil should exhibit the physical condition as well as 

 the chemical composition of its ingredients. Necessary 

 details of a soil analysis to render it useful and interpretable 

 for the purposes of agriculture. Surface and subsoils of 

 the Concan. Their relative bearing power. Subsoils, at 

 first sterile, become fertile. The subsoil of India contains 



