Tile Drainage Research   

Greg Brenneman, FS-Ag Engineering, Southeast Iowa      


The use of yield monitors has increased crop producers’ awareness of the need for proper drainage of crop ground.  One of the most frequent questions asked is, ‘what is the proper spacing of tile drainage on different types of soils?’  The Iowa Drainage Guide published in 1987 is available with this information, but frequently producers ask if this information is still applicable to today's agriculture.     


A tile spacing drainage study was installed near the Southeast Research Farm in the late summer of 1999.  Tile spacing of 30, 45, 60, and 75 feet were installed.  Based on the Iowa Drainage Guide, 60 to 100 ft. spacing would be recommended.  Crop yields, tile flow, and water table depth measurements have been collected over the past 5 years.     


Both crop yields and water table measurements have shown very little advantage for closer tile spacing when compared to the 75 ft. spacing.  This information compares favorably with the tile spacing recommended by the Iowa Drainage Guide.  Based on this information, one tile contractor has told me that he has modified some of the spacing installations he is making, often times saving money for the landowner.


March 16, 2005   
150 -- Environmental Stewardship 

Page last updated: July 9, 2006
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