766 



SUCCESSFUL FARMING 



absence of stones, roots or other obstructions, ditches may be excavated 

 at a cost of from 7 to 13 cents per cubic yard. The contract is frequently 

 made on the basis of material removed. 



It is essential that such water courses be made as straight and as deep 

 as conditions will permit. The straight course makes the shortest possible 

 ditch and provides for the maximum fall. Good fall and straightness both 

 accelerate the flow of water and make possible adequate drainage with a 

 smaller ditch than would be possible with a longer and more circuitous 

 route. 



The ditch embankments, after weathering for a year, may be gradually 

 leveled down and worked back into the adja- 

 cent fields by the use of plows and scrapers. 

 The banks of the ditch need not be as sloping, 

 as formerly thought, although the slope will 

 depend on the character of soil. In heavy, ten- 

 acious soils, a slope of f to 1 is sufficient, that 

 is 6 inches horizontal to 1 foot vertical. The 

 fall of the ditch may range from 6 inches to 3 

 feet or more per mile. With 3 feet of fall per 

 mile, the velocity of the water will keep the 

 ditch fairly free from sediment, provided it is 

 not allowed to become filled with growing grass, 

 weeds or willows. If these grow in the ditch 

 during the dry portion of the year, they should 

 be cut and removed annually. Where the 

 fall is too great, the banks of the ditch are 

 apt to erode and cave in. The caved earth 

 will be carried and deposited in lower portions 

 of the stream course and cause trouble. The 

 banks of the ditch should be kept covered 

 with grass to prevent erosion. 



Tile Drains. — The first step in tile drain- 

 age is an accurate survey of the land to be 

 drained. This will determine the fall and the best position for the main 

 drains. It should also include an estimate of the water shed, that is, the 

 amount of water to be carried away, whether falling on the land to be 

 drained or flowing on to it from adjacent higher lands. The lines of 

 drainage should be as straight as conditions will permit. The mains 

 should be in the lowest portions of the field. Laterals may extend from 

 them into more elevated portions. In case of very level land, this makes 

 provision for the greatest possible fall in the drainage lines. 



Running the Levels. — This work may be done by the farmer. In 

 large systems or on very level land, the employment of an engineer is 

 advised. A farm drainage level that is sufficiently accurate may be pur- 



1 Courtesy of U. S. Dept. of Agriculture, Farmers' Bulletin 187. 



Grading the Ditch and 

 Laying Tile. 1 



A — Depth gauge. B— 

 Cross piece. C and D — Stakes 

 driven in ground to give 

 proper slope to grading line. 

 E F — -Hollow tile drain. 



