38 MASSACHUSETTS HOKTICULTURAL SOCIETY 



tain, to the direction of their transport and movement as percolating 

 ground waters, and to the place of ulterior evaporation of these 

 waters, e. i, the precipitation of their salts. It is needless to add 

 that to the form of the surface drainage and the underdrainage 

 system and to the effects of irrigation channels on the horizontal, 

 vertical or lateral movement of such ground waters on peat land 

 the greatest of care should be given. 



Observations on peat lands with a water level 30 to 40 inches 

 below the surface and which are not exposed to floods show that 

 evapoi'ation is relatively active during the summer season. This 

 renders the surface soil when under cultivation liable to saline 

 incrustations due to salt constituents of various kinds in solution 

 drawn from the deeper beds. The action is strongly marked in 

 ditches on peat lands with a water table fluctuating during the 

 seasons for plant growth. 



In deep and broad peat basins the imbibition and transport of 

 soil waters is on the whole horizontal and dependent for its position 

 upon those strata of peat materials whose composition and proper- 

 ties favor a lateral movement. This is readily observed in open 

 ditches with peaty strata which permit underground water drainage 

 along the cleavage lines and (upon estuarine peat land) which 

 contain beds of diatomaceous earth or heavy layers of ash owing 

 to severe and extensive clearing fires. The ash is chalk-like in 

 color at the inner portions of the peat basin due to the removal of 

 iron compounds to which the yellow and red ash at the marginal 

 areas normally owes its color. 



In shallow peat lands and those of small size and depth the 

 transport of ground waters appears to be vertical and lateral. 

 During floods, however, the abundance of water reduces the move- 

 ment of the saline constituents and from the appearance of the 

 characteristically bleached sands underlying the peat lands it may 

 be concluded that the transport is then lateral and downward 

 where under-drainage is free. 



We are lacking data showing the increase in evaporation and 

 vertical salt deposition due to specific crops, such as corn, potato, 

 certain truck crops, and grasses for hay or pasture, but there is 

 little doubt that onion would show an excess. 



Fogs and other forms of humidity should be closely observed 



