536 NATURE AND PROPERTIES OF SOILS 



A permanent system of agriculture evidently cannot be 

 established by merely returning all the manure possible to 

 the land, as approximately only 25 per cent, of the organic 

 matter, 30 per cent, of the ammonia, 50 per cent, of the phos- 

 phoric acid, and 30 per cent, of the potash of the food con- 

 sumed on the farm ever reach the land in the manure. Never- 

 theless, it is certainly worth the while of a farmer to use 

 some care in handling this product and some thought as to 

 its rational utilization in the field. Even if the manure 

 should aid only in the up-keep of organic matter, the effort 

 would be worth while. Reasonable care in the handling of 

 farm manure will save this country thousands of pounds of 

 manurial fertility which are now utterly lost and at the same 

 time increase by thousands of dollars the food production. 



