8 SOILS OF THE EASTERN UNITED STATES. 



of the enterprise. When in addition to the agricultural value of 

 such improvements their value to the health of the community through 

 the drainage of swamps is considered and the aid to the navigation 

 of rivers, thus restrained within their proper channels, is taken into 

 account, the reclamation of lands of this character, through proper 

 embankments and drainage, is seen to be very desirable. In the rec- 

 lamation of such lands, however, each particular case must be studied 

 both from an agricultural and from an engineering standpoint. 



The complete drainage of areas of the "NYabash clay, even in those 

 localities where proper protection from overflow has been provided, 

 is a serious problem. Very little effort has been made to install tile 

 underdrains in such areas, but sufficient has been done to show that 

 the stiff, plastic nature of the subsoil requires lines of tile laid at no 

 great distance from each other and at a 1 considerable depth, in order 

 properly to lower the water table. In fact it is a general opinion 

 among those who have attempted to drain soil of this character in 

 connection wdth their farming operations that frequent open ditches 

 are fully as effective in the removal of surface water and in the 

 lowering of the subsoil water as the more expensive tile-drain sys- 

 tems. Thousands of acres of the Wabash clay have been drained 

 with good results through the establishment of open ditches. Owing 

 to the position of this soil somewhat below the level of the front 

 lands, and usually intervening between these and the deeper sloughs 

 to the rear, this surface drainage is not infrequently effected through 

 open ditches which empty, not into the main stream, but into the 

 sloughs or deeper depressions to the rear of the type. Through the 

 adoption of this practice a gentle slope, which does not give rise to 

 the erosion of the bottom or the sides of the ditches, is obtained, and 

 any difficulty with culverts or carrying the ditches across main high- 

 ways or with the outflow of these ditches through embankments or 

 levees is obviated. In general, it is recommended that open ditches 

 be used rather than tile drains, and that wherever possible the grade 

 of these ditches be sufficiently low to prevent erosion, but sufficiently 

 steep to give thorough surface soil drainage. It is frequently possi- 

 ble to dig these ditches in the form of broad, shallow excavations 

 which will not interfere seriously with communication between the 

 tilled areas separated by the depressions. Such ditch forms have 

 two advantages over the steep-sided narrow open ditch frequently 

 used. In the first place, less labor is required to keep the ditch open, 

 since this can be done by horsepower and the use of a slip scraper. 

 In the second place, little or no damage results from erosion of the ;; 

 banks and the caving in of soil to obstruct the flow of water. As an f 

 additional advantage, communication between different portions of 

 the field is not interrupted, as has been noted. 



