324 MAN'S USE AND CONSERVATION OF SOILS 



much better than plants grown on undrained land where 

 the water table has not so uniform a depth. The too fre- 

 quent surface watering of plants is bad for them, as it keeps 



RICE SWAMP 

 A valuable plant growing in water. 



their roots so near the surface that the plants are unable to 

 withstand slight drought. 



Certain kinds of plants need more water than others. 

 Water lilies, reeds, rice, and other plants grow with their 

 roots submerged in water. Other plants, such as the cactus,. 



