THE BEET-SUGAR INDUSTRY IN THE UNITED STATES. 23 



will run lengthwise of the field, thereby avoiding the crossing of the 

 ditch in the usual farming operations. The size and depth of the 

 open ditch will depend upon the length and fall of the ditch, the 

 location of the subsoil, the amount of water to be carried, and the 

 position of the outlet. It should always be deep enough to prevent 

 any interference of the water table with the crop to be grown. 



The Uind ditch.— The most satisfactory method of artificial drain- 

 age is the blind ditch. In the construction of this ditch tile is used 

 most commonly. Many fields that otherwise would not yield profit- 

 able crops have been reclaimed by the blind ditch. These ditches 

 should be laid out very carefully with reference to direction, depth, 

 and slope, so that the entire area under consideration will be drained 

 thoroughly. The size of the tile is very important. Tiles that are 

 too small must never be used. This is false economy, and it frequently 

 results in added expense in that the small tiles must be taken up and 

 replaced with larger ones. The tile should be large enough to carry 

 off the water quickly in times of excessive rainfall, deep enough not 

 to be disturbed by the plow or other implements, and laid so care- 

 fully that the ends will fit against each other evenly and a gentle 

 and continuous fall provided, without depression or elevation. 

 The outlet of the blind ditch should be kept open that the water 

 may flow freely. 



SEEPAGK 



Seepage is closely related to drainage. Many fields or areas that 

 otherwise might be profitable for crop production are rendered use- 

 less by seepage. This is especially noticeable in those areas where 

 irrigation is practiced. Seepage is detrimental to the soil in several 

 ways: (1) As a loss of water, especially in cases where water has 

 been stored for irrigating purposes, and (2)' through a loss of the 

 use of the land, either because the soil is too wet for crop production 

 or because of the accumulation of soluble minerals which are brought 

 to the surface through seepage. The injurious soluble minerals 

 usually are known as alkali. 



Seepage from strea7ns.— Some streams are so located naturally that 

 a portion of the water seeps out into the adjacent soil, forming 

 marshes or waste places due to excessive moisture ; this is especially 

 true where the fields adjacent to the stream are low, level, or under- 

 lain with an impervious subsoil. The nature of the bank of the 

 stream is of importance in this connection. If the overflow at flood 

 time is prevented by the construction of dikes the land may be 

 made productive by drainage. Usually these marshlands when 

 drained are very fertile and produce good crops, though they are 

 not always the best for sugar-beet production, since they sometimes 

 produce large roots low in sugar. 



