|Dabney, S - USDA-ARA, NSL, OXFORD, MS|
Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 31, 2001
Publication Date: September 6, 2005
Citation: Raper, R.L., Schwab, E.B., Dabney, S.M. 2005. Measurement and Variation of Site-specific Hardpans for Silty Upland Soils in the Southeastern United States. Soil and Tillage Research. 84(1):7-17. Interpretive Summary: Compacted soil layers limit yield and reduce overall productivity of many Southeastern U.S. soils. Three Southeastern U.S. fields from Northern Mississippi were sampled to determine the depth to the root-impeding layer that was found in these soils. We determined that conventional tillage moved this layer significantly closer to the soil surface. The effect of vehicle traffic in a no-till field was minimal except for reducing the variation in the root-restricting layer that is commonly found. Farmers that adopt conservation tillage systems may find reduced areas of their field being severely stressed in short periods of drought due to the increased depth of soil available for root growth and moisture retention.
Technical Abstract: Cone index profiles taken in several Southeastern U.S. fields with upland soils were used to measure the hardpan depth and to predict their spatial variation. Continuous treatments of these fields for several years included conventional tillage, no-tillage, segregated traffic, and random traffic. Conventional tillage systems were found to bring the hardpan significantly closer to the soil surface, even in no-trafficked row middles and directly beneath the rows. Little difference in depth of hardpan was found between a no-till field subjected to random traffic and a field where traffic was segregated. The least amount of variation in hardpan depth was found in trafficked row middles in a no-till field.