138 DRY LAND FARMING 



brings up soil from below the sole of the furrow made 

 by the first plowing and places it on top of the furrow 

 slice first made. It is simply deep plowing, the addi- 

 tional depth being gained by running the plow twice in 

 the same place, the second plowing being deeper than 

 the first. Where the elements in the subsoil are very 

 similar in kind and condition to those in the top soil/ 

 the practise is to be commended, but where the food ele- 

 ments in the lower soil are in a raw and undigested con- 

 dition, the practise is to be strongly condemned, as it 

 will certainly be followed by a lessened production. The 

 inert plant food thus brought to the surface cannot be 

 taken up by plants until it has been made available by 

 what are termed weathering influences. 



There are different kinds of subsoil plows. One of 

 these simply tears through the lower soil much after the 

 fashion of a curved harrow tooth. It consists of a steel 

 bar attached to and running below the plow that turns 

 the top furrow. In other instances it consists of a wedge- 

 like shoe attached to the lower part of the steel bar, 

 which is drawn forward through the lower soil. In 

 many instances the subsoiler is not attached to the or- 

 dinary plow, but more commonly it runs in the furrow 

 made by the former. 



The objects sought in subsoiling are: (1) to deepen 

 the area which the roots of plants may readily penetrate 

 in search of food; (2) to increase the capacity of soils. 

 for receiving and storing water more readily that comes 

 in the form of precipitation; (3) to facilitate the libera- 

 tion of plant food in the lower soil by allowing air and 

 water the more readily to penetrate it. It will be readily 

 apparent, therefore, that the benefits resulting from sub- 

 soiling will be largely dependent on the character of the 

 soil and especially the subsoil, also the character of the 

 crops as deep or shallow rooted. Subsoiling is not help- 

 ful in very open subsoils, as in these it would only tend 



