Intercept drain tile installation and subsequent sand topdressing applications can provide a built-up sand-based system. There are a number of different intercept drain tile spacing and sand layer depth recommendations. The objectives of this research were to determine the effects of intercept drain tile spacing on the surface runoff, soil water content, and surface shear strength of a compacted sandy loam with sand topdressing. A single factor, RCBD field study in East Lansing, Michigan, was seeded May 29, 2007, with a Kentucky bluegrass (Poa pratensis L.)-perennial ryegrass (Lolium perenne L.) mixture. Intercept drain tiles were spaced 2.0, 3.0, 4.0, and 6.0 m apart and were compared with an 8.1-m-long control without intercept drain tiles. Well-graded sand (90.0% sand, 7.0% silt, and 3.0% clay) was used for topdressing. After the accumulation of a 2.4-cm sand layer, simulated traffic at two applications per week was applied to all treatments using the Cady traffic simulator from October 10 to November 3, 2007. In 2008, topdressing, providing a 4.8-cm depth accumulated during a 2-year period, and traffic were repeated on the same experimental treatments. When a 2.4-cm sand layer is present, surface runoff and soil water content are generally directly related to intercept drain tile spacing, and drain tiles, spaced 2.0, 3.0, and 4.0 m apart, will provide increased surface shear strength. As topdressing depths were accumulated to a 4.8-cm sand layer depth in 2008, no differences in surface shear strength were observed regardless of drain tile spacing.
1School of Agriculture and Natural Resources, Abraham Baldwin Agricultural College, ABAC 6, 2802 Moore Highway, Tifton, GA 31793. Mr. Alexander Robert Kowalewski is corresponding author. E-mail: email@example.com
2Crop and Soil Sciences Department, Michigan State University, 162 PSSB, East Lansing, MI 48824.
Received May 3, 2010.
Accepted for publication January 4, 2011.