Holding and Increasing Fertility of Soil 



tility; probably it will lack that most important 

 element of productive soil — hmnus. Humus, be 

 it understood, is that element in the soil that 

 causes it to appear dark. What it really consists 

 of is decayed vegetable matter and it is always 

 found forming the top soil of virgin, or unculti- 

 vated land. It is present in large amounts in 

 woodlands where the falling leaves and surface 

 growth lie on the ground, year after year, and de- 

 cay and form what is technically known as leaf 

 mould. We know how admirably it is adapted 

 to the growing of house plants, and its value is 

 often erroneously attributed to the plant food it is 

 supposed to contain, but its great value is not so 

 much in its food content as its influence on the 

 soil with which it is combined; by its presence it 

 makes the soil retentive of moisture and this 

 moisture in turn unlocks the chemical elements 

 ,of the soil so that they become available for food. 

 Soils that are deficient of humus, though other- 

 wise fertile, dry out so badly in summer that un- 

 less artificially watered, they will produce little, 

 and even where a sufficient water supply is avail- 



65 



