8 WILSON & TOOMER FERTILIZER COMPANY 



Humus Humus increases the water storage by absorp- 

 tion and also by its particles being finer than the sand 

 particles, which are the bulk of our soils. By holding 

 the water it saves from leaching any plant food the 

 water has in solution and also keeps the land from ex- 

 cessive heat in summer. It regulates the air supply, as 

 it fills in coarse soils and opens up fine ones; it is 

 a source of plant food, particularly of our most expen- 

 sive element, nitrogen; and is both a food and a dwell- 

 ing place for bacteria. The content of humus decides a 

 soil's fertility. That there be no misunderstanding, I 

 will explain: Vegetable matter, though popularly called 

 humus, is not humus until properly decomposed; the 

 peat-like substances found in some swamps, though of 

 vegetable origin, are not humus and neither are they 

 fertile. Humus is the fine dark dust of the soil; it is 

 easily used by plants and much of it is drained away. 

 The addition of humus matter to soil is necessary not 

 alone for building up the soils but to preserve their nat- 

 ural fertility. The great crops we produce impoverish 

 the land just as surely as drawing checks lessens a bank 

 account. Eight management of the soil makes the fer- 

 tility greater each year. 



