SOIL IMPROVEMENT 177 



for a roof. Spread on the ground a layer 

 of stable manure 8 by 10 feet, six inches deep. 

 Over this spread one hundred pounds of acid 

 phosphate or ground phosphate rock. The 

 ground phosphate rock answers about as well 

 as the acid phosphate and costs about half as 

 much. Continue these layers until all the 

 manure is used up or until the pile has become 

 conveniently high. To these layers might be 

 added straw, leaves, mold, or other litter, add- 

 ing one hundred pounds of ground phosphate 

 rock to each ton of material used. Be sure to 

 wet all thoroughly. When the heap is com- 

 pleted cover it about four inches deep with 

 good loam, or with forest mold, to prevent 

 evaporation of the ammonia and other ele- 

 ments. This should remain in the heap for 

 several weeks, thoroughly mixing when cutting 

 down, and before hauling to the field for ap- 

 plication. 



The judicious use of commercial fertilizers 

 in combination with barnyard manure and 

 green crops will aid in soil building, and will 

 be found profitable in the increased production 

 of crops. 



With the best methods of conserving the 



