THE SOIL— ITS PROPERTIES, Etc. 



Any national system of agriculture must be based on a correct 

 knowledge of the nature and proportion that exist in the soil; and 

 the manner in which those properties which are wanting may be 

 most economically supplied ; the object of tillage in general, being, 

 to produce in the most advantageous manner, certain results in the 

 growth and maturation of the various crops grown. We must pro- 

 ceed here in the culture of plants prcisely in the same manner as 

 we do in the fattening of animals. The increase or dimunition of 

 the vital activity of vegetables depends on heat and solar light, 

 which we have not at our disposal. It is our especial province to 

 supply substances adapted for assimilation, by the power already 

 present in the organs of the plant. But what are some of these 

 substances. 



The soil which covers the surface of the earth, is composed of the 

 pulverized matter of the different rocks, the primary ingredients of 

 which are silex, alumina, lime, magnesia, iron, and a few other salts. 

 This is called the primary soil, and according as either of the com- 

 ponent ingredients preponderates, it may be sandy, clayey, calcare- 

 ous, ferruginous, saline. The soil also contains a greater or less 

 proportion of vegetable remains, such as the decomposed leaves and 

 trunks of trees, or the remains of cryptogamic and other marsh 

 plants. Some soils, indeed, are almost entirely composed of vege- 

 table remains, and constitute the rich dark mold, which duly dilat- 

 ed, is esteemed so valuable in our fertile alluvial bottoms, and which 

 are so well adapted to the growth of our Indian corn. Some plants, 

 however, thrive best in one kind of soil, and some in another. — 

 Hence it is the business of the skillful agriculturist, to adapt his soil 

 to the peculiar kind of plant he wishes to rear in perfection. 



The pure earth it is thought by many, do not afford any nourish- 

 ment to plants ; at all events, they enter but very sparingly into 

 their compositions. They serve, however, as a medium by which 

 water, carbon, and some of the gases, are conveyed into their Juices 

 and also as a convenient means by which the fibrous or bulbous root 

 are attached to, and held firm and stationary in the ground. The 

 true nourishment of plants is water and decomposing organic matter, 

 whether vegetable or animal. The constituent parts of the soil 

 which give tenacity and coherence, are the minutely divided particles, 

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