202 SOILS 



open ditches to dry out the marsh until the shrink- 

 age has occurred. Get a crop started upon the 

 marsh as soon as possible, as it hastens decay. 

 Later these ditches may be deepened and tile 

 drains laid in the bottoms of them. 



According to King, another occasion when open 

 ditches are feasible is in draining very level land 

 underlaid by a very fine clay. These places are 

 usually found where a lake once existed. Water 

 moves through the fine clay so slowly that tile drains 

 would not be effective unless laid so close that the 

 expense would be prohibitive. Such soils should 

 be plowed into lands from twenty to thirty feet 

 wide with the dead-furrows emptying into shallow 

 ditches. 



Ditches are also useful to provide an outlet for 

 under-drains, and to catch surface drainage on 

 slopes, or at the foot of slopes. In other words, 

 ditching is useful mainly for taking care of surface 

 water, and for removing the excess of water in the 

 first foot or two of soil. Deep and thorough 

 drainage, such as most farm crops demand, can 

 usually be best secured by under-drainage. 



HOW TO DIG A DRAINAGE DITCH 



The depth, width and grade of a ditch depends 

 chiefly upon the amount of water to be removed, 

 the lay of the land and the nature of the soil. In 

 marsh lands the ditch may usually be cut to a 

 depth of four or six feet, and with almost vertical 

 sides. Peat or muck soil is not liable to wash or 

 cave in, being more or less fibrous, especially if 

 the water-table is not lowered sufficiently to dry 

 out the soil so deep that it will shrink and crumble 

 the banks. Ditches in an upland soil, however, 



