THE CALL OF THE LAND 



forthwith after every rain, harrowing or 

 cultivating must be incessant, not only to 

 mulch the top soil, interrupting capillarity, 

 but also to kill all weeds, for weeds perni- 

 ciously use up your precious moisture as 

 well as the nutrition needed by your crop. 



The above are the absolutely essential 

 principles of the dry-culture system. There 

 is another consideration which, though sub- 

 ordinate, is of no small importance. I refer 

 to the creation and maintenance of humus 

 in the soil. Humus is immensely valuable 

 as a holder of moisture. It is a sort of 

 sponge, taking in water and retaining it. 



Normal prairie is rich in humus. This 

 is why it will carry crops through a drouth 

 that would be fatal to them on older soils. 

 For centuries the grasses on our great prai- 

 ries grew up and died annually. The dead 

 grass partly rotted where it fell and rains 

 washed it into the earth, where the decom- 

 position was completed. Roots, too, died 

 from time to time and decayed. This is the 

 way the primitive humus of the plains was 

 formed, a provision of Nature for massing 



74 



