470 THE PRINCIPLES OF SOIL MANAGEMENT 



results will be obtained. Any departure from this 

 moisture content will result in less efficient work. It 

 has been said that, in proportion to the amount of energy 



Fig. 130. Sulky Lister 



required, the plow is the most efficient pulverizing 

 implement available to the farmer. The optimum 

 moisture content for plowing is indicated by that nicely 

 moist condition in which a mass of the soil when pressed 

 in the hand will adhere without puddling, but may be 

 readily broken up without injury to the intimate 

 soil structure. This is a much more critical stage for 

 fine-textured soils than for coarse-textured ones. Sandy 

 soils are not greatly altered by plowing when out of 

 optimum moisture condition. On the other hand, if a 

 clay soil is plowed when it is saturated with water, it 



