Monday, November 13, 2006
111-2
3D Soil Electrical Resistivity for Indexing Soil Rooting Volume of Loblolly Pine under Upland Tillage.
Brian Adams and Daniel Markewitz. Univ of Georgia, DW Brooks Dr, Athens, GA 30602
Soil tillage (disk-harrowing, bedding, sub-soiling or combinations) is not a common practice in loblolly pine plantations within upland soil conditions of the Peidmont. The benefits of tillage include competition control, concentration of topsoil and improved nutrient availability, improved moisture conditions, and improved soil physical properties. Results from recent studies on upland sites generally indicate small or inconsistent responses to tillage. The benefits of tillage, however, associated with changes in soil physical properties may significantly increase growth on certain sites and cannot be replaced by herbicide or fertilizer amendments. Roots cannot exploit soils of high mechanical resistance that lack continuous pores of sufficient size. It has remained extremely difficult, however, to directly assess changes in the volume of soil exploitation by individual trees in response to tillage. The goal of this study is to evaluate the effects of soil tillage (control, coulter + subsoil, and coulter + bedding + subsoil) on soil physical properties and soil rooting volume utilizing 3D soil electrical resistivity. Soil electrical resistivity was measured four times from March 2005 to May 2006 in replicated tillage treatments on a Orangeburg (Typic Kandiudult) in southwestern Georgia. Soil electrical resistivity did not differ significantly among the treatments with depth.
Handout (.pdf format, 125.0 kb)