446 



PRACTICAL BOTANY 



Terraced farms sometimes are desirable for vineyards, but it 

 is obvious that for ordinary crops such elaborate care will 

 prove profitable only where available land is extremely scarce. 



FIG. 347. Landward slope of an Italian promontory, the loose, loamy soil 



terraced to prevent erosion when under cultivation as a vineyard 



Modified from a photograph 



111 localities with moderate slope of the surface, underground 

 drains may prevent erosion except at times of extremely heavy 

 rains. Many ditches that were formerly supposed to be too 

 large to be taken underground have been so placed with great 

 advantage. 



