SOILS. 15 



12. Why are some soils adapted to one kind of crop and not to 

 another? 



13. Where are the soils of greatest value in your vicinity? What 

 makes them so? 



14. Specify the crops considered best adapted to the different soils 

 of your locality. 



15. Discuss the loss of fertility in the sale of eggs, milk and meat, 

 as compared with the loss of fertility in selling clover, alfalfa and corn. 



16. Which is the better method of conserving the natural resources 

 of the farm; to sell grain and hay or to sell eggs, meat and milk products? 



17. An analysis of various soils in the United States showed on an 

 average the presence of 3,000 pounds of nitrogen, 4,000 pounds of phos- 

 phoric acid, and 16,000 pounds of potash, in the upper foot of earth per 

 acre, what would be the effect on agriculture if these elements were im- 

 mediately available for plant food? 



Books For Reference. 



1. First Principles of Soil Fertility Vivian, 7-10 Orange Judd Co., 

 $1.00. 



2. The Soil King, 8-12 Macmillan Co., $1.50. 



3. Principles of Soil Management Lyon & Fippin, 8-12 Macmillan 

 Co., $1.75. 



4. Soils Hilgard, 8-12 Macmillan Co., $4.00. 



5. Soil and Crops of the Farm Morrow & Hunt, 8-12 Webb Pub. 

 Co., $1.00. 



6. Soil Fertility and Permanent Agriculture Hopkins, 8-12 Ginn and 

 Co., $2.25. 



7. The Soil Hall, 8-12 E. P. Dutton & Co. 



8. Soils Burkett, 8-12 Orange Judd Co. 



9. Soils Fletcher, 8-12 Doubleday, Page and Co. 



10. Soils and Fertilizers Snyder, 8-12 Macmillan Co. 



11. Fertilizers and Crops Van Slyke, 8-12. 



12. Talks on Manures Harris, 8-12. 



13. The Farm that Won't Wear Out Hopkins, 7-10. 



Bulletins by the U. S. Department of Agriculture. 



FARMERS' BULLETINS. 



Number. 



257. Soil Fertility. 



406. Soil Conservation. 



421. Control of Blowing Soils. 



