COMPOSITION or READILI IMFROVEABLE S0IL3. 



S89 



100 



100 



100 



100 



The first of these soils produces naturally beautiful red clover — the 

 second produces very bad red clover. On comparing the constitution of 

 the two soils, we see the second to be deficient in sulphuric acid and 

 chlorine. A dressing of gypsum and common salt would supply these 

 deficiencies, and render it capable of producing this kind of clover. The 

 third soil is remarkable for growing luxuriant crops of pulse, when ma- 

 nured with gypsum. The almost total absence of sulphuric acid ex- 

 plains this effect. The fourth soil was greatly improved by soap-boiler's 

 ash, which supplied it with lime, magnesia, manganese, and other sub- 

 stances. 



I need not further multiply examples to show you how much real 

 knowledge is to be derived from a rigidly accurate analysis, not only in 

 regard to the agricultural capabilities of a soil, but also in regard to the 

 natural and necessary food of plants, and to the manner in which 

 mineral manures act in promoting and increasing their growth. The 

 illustrations I have already presented will satisfy you — 



1°. That a fertile soil must contain all the inorganic constituents which 

 the plant requires, and none that are likely to do it an injury. 



2°. That if the addition of a given manure to the soil render it more 

 fertile — it is because the soil was defective in one or more of those sub- 

 stances which the manure contained. 



3°. That if a given application to the land fail to improve k — of gyp- 

 sum, of bone-dust, of common salt, for example — it is because enough of 

 the substance applied is already present, or because something else is 

 still wanting to render the previous additions available. 



4°. That the result of extended experience in our country, that the 

 clay soils are best for wheat, and sandy soils, such as that of Nor- 

 folk, for barley, is not to be considered as anything like a law of nature, 

 setting aside the clay land for the special growth of wheat, and denying 



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