40 DRY FARMING 



Thus the process went on, the rock materials supporting 

 plant life, and the latter contributing further to soil 

 building. 



The ultimate outcome was the soil, made up as we now 

 know it, of stones, gravel, sand, silt, clay and organic 

 matter. These then were the final products, though we 

 must not think of the process as being finished. Nature 

 is constantly at work levelling mountains, disintegrat- 

 ing rocks, and transporting and depositing the ma- 

 terials without heed to the desires of man, indeed often 

 contrary to his wishes. 



29. Soil Classification. — According to the manner of 

 formation and deposition and the agencies that played 

 the leading part, soils are classified as indicated in the . 

 following outline — 



(1) Sedentary, formed in place: 



(a) Residual, formed in place from disinteg- 

 ration of rocks. 



(b) Cumulose, formed in place by the partial 

 decay and accumulation of vegetable 

 matter. 



(2) Transported Soils: 



(a) Glacial soils, deposited by glaciers. 



(b) Loessial soils, deposited by the wind. 



(c) Alluvial soils, deposited by the action of 

 water. 



Sedentary Soils. — As the name indicates, these are 

 formed in place, no appreciable transportation from the 

 location of the original rock upon which they rest having 

 taken place. Sedentary soils are further subdivided in- 

 to (1) residual, soils formed in place from the disinteg- 

 ration of rocks; and (2) cumulose, soils formed in place 

 by the partial decay and accumulation of vegetable mat- 



