132 ELEMENTS OF AGRICULTURE 



The manure is covered with a layer of earth, another 

 layer of manure placed on the earth, and this in turn 

 covered. The compost heap is made up of alternate 

 layers of manure -and earth, the earth layers absorb- 

 ing the nitrogen compounds formed in the manure. 

 For the earth may be substituted plaster, the old mor- 

 tar from buildings, or swamp muck. The manure may 

 have mixed with it old straw or hav, dead leaves and 

 any other refuse matter that can be utilized. Before 

 applying to the soil the compost heap should be thor- 

 oughly worked over and fermentation allowed to start. 



Questions 



1. What is a manure? 2. Into what two classes are 

 manures divided? 3. Name some well-known natural ma- 

 nures. 4. What is marl? 5. Why are marls applied to 

 soils? 6. What is gypsum, and why is it used for a ferti- 

 lizer? 7. Why are wood ashes valuable as a fertilizer? 

 8. What is swamp muck, and what makes it valuable as a 

 fertilizer? 9. What part of wood's mold, rotting straw, or 

 dead leaves is of value as a fertilizer? 10. What is barn- 

 yard manure? 11. On what does the value of barnyard 

 manure mainly depend? 12. What is stable manure? 

 13. Why is stable manure which is allowed to accumulate 

 in the stable of more value than that which is thrown out 

 into the weather? 14. What causes the loss of ammonia 

 from manure piles? 15. How may the loss of nitrogen be 

 prevented? 16. Tell how a compost heap is made. 

 17. What substances besides manure may be used in form- 

 ing a compost heap? 



