46 LAND DRAINAGE 



the more compact the soil becomes, until finally all the 

 mellowing effects brought about by capillary water, tools, 

 roots, and the burrowings of animal forms, are overcome 

 and the mass of soil and subsoil have their pore-space 

 reduced to a minimum, and are left in the poorest possible 



FIG. 19. The appearance of a recently plowed soil mass when the 

 plowing has been performed with the soil in proper capillary mois- 

 ture condition. 



condition of structure to support plant growth. This 

 is the condition of all soils upon or in which water stands 

 for extended periods. 



68. Increased labor required to fit puddled soils for 

 crops. A soil whose physical condition has been thus 

 compacted by the presence of standing water is subject to 

 more rapid evaporation losses when relieved of its gravita- 

 tional water. As a result, it is difficult, sometimes impos- 



