LIST OF TABLES 



TABLE PAGE 



1. Elements, Symbols, and Atomic Weights 10 



2. The More Important Elements : Occurrence . ... 13 



3. Composition of Silicates 48 



4. Composition of Rock 49 



5. Composition of Fresh Limestone and Residual Clay . . .51 



6. Soils: General Groups 55 



7. Recognized Soil Types 5^ 



8. Relative " Supply and Demand " of Seven Elements ... 59 



9. Composition of Productive and Nonproductive Soils ... 63 



10. Composition of Adobe and Coral Limestone Soils . -65 



1 1 . Composition of Loess Deposits 69 



12. Composition of Ten Residual Soils .... -73 



13. Mineral Plant Food in Wheat, Corn, Oats, and Clover . . 75 



14. Composition of New York Soils ....... 75 



15. Fertility in Illinois Soils: Surface .82 



16. Fertility in Illinois Soils : Subsurface 84 



17. Fertility in Illinois Soils: Subsoil ....... 86 



18. Composition of Southern Indiana Surface Soils .... 88 

 18.1. Plant Food in Surface Soils of Iowa 91 



19. Composition of Surface Soils of Tennessee 93 



19.1. Composition of Georgia Soil 94 



19.2. Average Composition of Some Texas Soils ..... 95 



19.3. Composition of Some Louisiana Soils ...... 96 



20. Composition of Some Michigan Soils . . . . . .98 



20.1. Composition of Canadian Soils 103 



20. 2. Certain Plant-food Elements in Illinois Surface Soils . . . 105 



21. Annually Available Fertility in Illinois Soils no 



22. Composition of Various Extensive Soil Types of the United States 138 



23. Fertility in Farm Produce 154 



24. Fertility in Manure, Rough Feeds, and Fertilizers . . . . 157 



25. Pennsylvania Experiments with Lime ...... 165 



25.1. Maryland Experiments with Lime ...... 167 



26. Experiments with Magnesium Carbonate ..... 171 



27. Losses of Calcium Carbonate from Broadbalk Field . . .174 



28. Losses of Calcium Carbonate from Hoos Field . . . 175 



29. Digestibility of Common Food Stuffs *99 



