POSSIBILITIES OF WORN-OUT FARMS. 41 



matter, or "humus." It is this organic matter which makes the 

 soil mellow, dark colored, and rich; which changes a sterile 

 clay-bank into a fertile clay-loam field. It makes the soil soft 

 and sponge-like, enabling it to hold moisture and air, thereby 

 lessening extremes of temperature and hastening chemical activ- 

 ity. It also, in itself, supplies plant food. 



"When land is brought under cultivation, its virgin condition 

 is gradually lost. The humus is gradually used up, and if not 

 replaced, the land becomes hard and "dead." If clay, it 

 bakes and turns up in great clods or lumps when plowed; if sand, 

 it "leaches." This is the result which may be expected when 

 hoed crops or grain crops are grown on the same land for a long 

 series of years. One great value of stable manures is the supply 

 of humus which accompanies the plant food. 



Whether a soil is deficient in humus, is usually evident with- 

 out experiment; the texture of the soil being a sufficient guide. 

 If there is a deficiency, it may be supplied by stable manure, muck, 

 leaves, or by turning under a green crop. But in the absence of 

 the spongy texture which the presence of humus insures, the appli- 

 cation of excessive amounts of commercial fertilizer is useless 

 and wasteful. Many so-called worn-out soils contain an abun- 

 dance of plant food, but it is not available because of the physical 

 condition of the land. 



Lack of humus may result from too little cultivation, as well 

 as from "running" the land. One of the greatest drawbacks, 

 to successful agriculture in some parts of New England, has been 

 the blind reliance upon hay as the money crop. There are, within 

 sight of my office, hay fields which to my own knowledge have not 

 been plowed or fertilized for fifteen years, and it is not uncommon 

 for fields to be mown for twenty or twenty-five consecutive years 

 without renewal. Such fields not only use up the available supply 

 of humus, but the grass plants themselves die or are crowded out. 

 The remedy for such fields is evident. 



Lack of Plant Food. 



The only sure way to determine whether plant food of a certain 

 kind is needed, is to ask the question directly of the land. In 

 certain cases the chemist may render assistance; but in general 



