52 



THE PRINCIPLES OF SOIL MANAGEMENT 



Table V, continued 



Chemical Composition of Soils Deposited by Water. 



Strong Hydrochloric Acid Analyses. 



1. Insoluble 



2. Silica (SiO,) 



3. Alumina (A1X> 3 ). .. . 



4. Ferric iron (Fe 2 3 ) . . 



5. Ferrous iron (FeO) . 



6. Sulfur trioxid (S0 3 ) . 



7. Phosphoric acid (P 2 5 



8. Lime (CaO) 



9. Carbon dioxid(C0 2 ). 



10. Magnesia (MgO). .. 



1 1 . Soda (Na,G) 



12. Potash (K,0) 



13. Water 



14. Organic matter 



15. Volatile matter 



XXIII 



a 



o 



-M 03 



M s 



O 



a -a 



o 



T) 03 



O 

 o 

 o 



02 



79.99 

 7.76 

 2.78 

 3.40 



0.15 

 0.06 

 0.95 



0.21 

 0.31 

 0.44 

 4.10 

 0.51 



* Soluble. 



be. It embraces large areas of the most productive soils. 

 Properly drained, bottom lands are generally regarded 

 with favor for several of the staple crops. Corn is prob- 

 ably the most grown. Wheat is important on the heaviest 

 soils. They are generally rich in organic matter to an 

 unusual depth because they represent largely the wash 



