454 



Reading-Course for Far:^iers. 



cost of maintenance and do not interfere with tillage. In all these re- 

 spects they are preferable to open drains. 



However, there are some situations where it is desirable or even 

 necessary to use the surface drains, — for example, where there is no 

 proper outlet as in very low river bottoms ; where the soil is especially 

 fine textured and dense or where only a temporary effect is desired. 



On all land requiring drainage, the local peculiarities of the soil, sur- 

 face topography and outlet will determine just the kind of system which 



Fig. 374. — A thorough system of surface drains in a nczdy seeded grain held. 



should be established. Y&ry frequently the advice of one acquainted 

 with the peculiarities of soils is necessary in choosing the correct system. 



Types of drai)iagc systems. 



Contrary to common opinion, it is not necessary to install a regular 

 system of drains to secure large and profitable returns. I mean by 

 this lines of tile regularly placed at intervals of 50 or 100 feet. The 

 expense of such a system is great and a considerable period of time is 

 required for the improvement to pay the cost. In fact, only a small 

 part of the land in need of drainage requires such systematic treatment 

 because the surface is generally uneven, the water accumulates in a few 

 places or comes from a single limited source. A line of tile intercepting 

 the supply or laid in the center of the area of accumulation, will usually 

 remove the surplus water quickly before it has a chance to affect the 



