CHAPTER IX 



DRAINING THE SOIL 



Underground Water. As was stated in the last 

 chapter, the plant makes use of the capillary water in 

 the soil, and this capillary water is being continually 

 supplied from the free water in the ground below. 

 There is a level to this underground water, just the 

 same as there is a level to the water in a pond. On 

 low, flat land this level is usually near the surface. It is 

 at or above the surface on swampy ground, and usually 

 many feet below the surface in high places. Ordinarily, 

 high ground needs little attention so far as drainage is 

 concerned, as the water which falls upon it either soaks 

 in or runs rapidly off as surface water. 



Water Level Must Be Below Surface of Soil. 

 Low ground, however, does need attention. Plants 

 cannot grow without air, and much water in the soil 

 keeps out the air. The level of the underground water 

 must therefore be below the depth to which the roots 

 of the crop ordinarily penetrate the soil. In other 

 words, a crop will not do well on a field where the free 

 water level is too near the surface. You have all seen 

 crops "drowned out," as the farmer says. If you dig 



