REMOVAL OF WATER BY PLANTS 



265 



for evaporation. It would be unwise, as a rule, to roll 

 the soil when it is excessively wet, because of the injury 

 to the structure of the soil which would result. But the 



Fig. 95. A well-constructed outlet for a line of drain tile. 



land may be rolled in anticipation of a wet period, which 

 condition of the soil will facilitate the formation of that 

 compact surface which most favors evaporation. In the 

 spring, in regions of cold winters, bare or fallow land has 

 usually settled into this condition, which, if permitted 

 to continue, will most rapidly dry the soil. 



Ridging increases evaporation by exposing a larger 



