296 SOILS 



gullies. Tools of this character are often indis- 

 pensable, but the furrows they make should be 

 levelled off with a shallow- working implement, as a 

 spike-tooth cultivator. 



The practice of ridging corn, potatoes, cotton, 

 and other crops is responsible for much gullying. 

 Unless ridging is made necessary by poor drainage, 

 it is rarely a profitable practice. Deep plowing 

 and deep planting may accomplish the same re- 

 sult, with less danger. Level culture should be 

 practised wherever erosion is likely to be serious. 



The somewhat detailed attention given to ero- 

 sion in this chapter is not out of proportion to its 

 importance in the farm economy of this country. 

 Erosion is stealing from many farms the fertility 

 that should have been bequeathed to posterity. 

 There should be an increasing concern among 

 farmers about this phase of soil fertility. 



FALLOWING AND SOIL FERTILITY 



Fallowing leaving land uncropped for one or 

 more seasons was a common farm practice up to 

 the beginning of the last century. The Mosaic 

 law commanded that land should be fallowed one 

 year in seven. At present it is rarely practised in 

 America, except in the arid regions, although still 

 quite popular in many parts of Europe. The 

 chief reason for this is the rapid improvement of 

 tillage tools. The crude tillage tools of earlier 

 years pulverised the soil so imperfectly, that the in- 

 crease in available plant food by weathering was 

 very slow; hence crops quickly exhausted the 

 soil. It was soon noticed that if land was 

 cultivated while it was being rested it would be 

 more productive thereafter. The chief advantage 



