MANURING AND WORN-OUT SOILS 325 



had worked up mellower on this spot. This gave 

 him an idea. The chemist had also told him that 

 he could buy of a fertiliser dealer all the plant food 

 that there is in a ton of good cow manure for two 

 dollars, yet this farmer knew from experience that 

 he could get better results on his land from one ton 

 of manure than from five dollars' worth of any 

 commercial fertiliser he had ever bought. Per- 

 haps the manure had other values besides its plant 

 food value. 



He went to the cow pasture and kicked over a 

 heap of dry cow dung that had lain there many 

 months. Evidently the rains must have washed 

 out practically all its plant food. The substance 

 that remains is mostly indigestible vegetable mat- 

 ter that the cow has eaten; it is fibrous, holds 

 water like a sponge, and is easily incorporated with 

 the soil. He knows that it is good for plants, 

 though it contains little or no plant food. 



Following this clue, the farmer went to his wood- 

 land. Beneath the living plants about him are 

 the dead and decaying trees, underbrush, herbage, 

 leaves. He can barely trace upon the ground the 

 outline of a one-time forest monarch that is slowly 

 passing into mould, and already nourishes a thrifty 

 colony of mosses and ferns. Beneath the carpet- 

 ing leaves is the rich, black, forest mould. It is 

 made of the leaves, branches and trunks of a genera- 

 tion ago. It holds water like a sponge. Upon it 

 Nature is growing a crop that must be many 

 times more exhaustive of plant food than any crop 

 of maize. 



The farmer came to this conclusion: "It is 

 this decaying vegetation that my soil needs. My 

 farm has been cropped with corn, oats and pota- 

 toes for fifty years. No vegetation has been 



