138 FERTILIZERS 



QUESTIONS 



1. Show the need of soil improvement. 



2. Name and describe the general classes of fertilizers. 



3. Name some of the natural fertilizers. 



4. Discuss the value of (a) lime, (6) salt, (c) gypsum. 



5. Discuss the value of (a) marl, (&) wood ashes, (c) salt. 



6. What is leather meal ? Felt waste ? Hair waste ? 



7. Discuss the value of muck and peat. 



8. Discuss the importance of (a) leaves and straw, (6) barnyard manure, 

 (c) stable manure. 



9. What is compost? 



10. Discuss commercial fertilizers. 



11. Discuss the nitrogenous fertilizers. 



12. Describe briefly the potassic fertilizers. 



13. Discuss (a) the bone phosphates, (6) the mineral phosphates. 



14. What can you say of (a) iron phosphate, (6) guano phosphate? 



15. Discuss the manufacture of commercial phosphates. 



16. Discuss the use of fertilizers. 



17. Enlarge upon the necessity of field tests. 



REFERENCES 



Fertilizers, Voorhees. 

 Talks on Manure, Harris. 



Soil Fertility and Permanent Agriculture, Hopkins. 

 Barnyard Manure, Farmers' Bulletin No. 192. 

 r Renovation of worn-out Soils, Farmers' Bulletin No. 245. 



