MANAGEMENT OF THE SOIL 21 



tends to pile up the dirt around the borders and to 

 hollow it out in the middle of the field, where the 

 center or so-called "dead furrow " comes. Occasional 

 back furrowing remedies this trouble. To back fur- 

 row it is necessary to begin plowing in the middle of 

 the field and turn in the opposite from the usual di- 

 rection so as to continuously turn the furrows toward 

 the center. By using skill in laying out the lands 

 for plowing and by back furrowing when necessary 

 a field may be kept quite level or high places may be 

 leveled down and low ones filled up, or if the land 

 is low and wet, it may be gradually built up into nar- 

 row beds with open Avater furrows between them in 

 such a wa,y as to greatly improve the drainage. It 

 is usually better to take long narrow lands rather 

 than those that are short and nearly square as there 

 will be much less time lost in turning. 



Great care should always be taken to see that 

 plows are so adjusted as to run level and even, 

 and that they turn the soil to the desired depth. 

 On sulky plows these adjustments are made by 

 means of the various levers. On walking plows 

 the depth is regulated by adjusting the clevises at 

 the end of the beam by which the team is attached. 

 The lower the point of attachment, the shallower 

 the plow will run. Elevating the point of attacli- 

 ment correspondingly deepens the furrow. Short- 

 ening the traces or elevating them by adjusting the 

 back bands will also serve to lessen the depth of 

 the furrow. On many plows there is a secondary 

 clevis by means of which the width of the furrow 

 may be regulated. When the ground is in good 



