|Frederick, James - CLEMSON UNIV, FLORENCE|
Submitted to: International Soil Tillage Research Organization Proceedings
Publication Type: Proceedings
Publication Acceptance Date: June 26, 2003
Publication Date: November 1, 2003
Citation: BUSSCHER, W.J., BAUER, P.J., FREDERICK, J.R. VARYING CONE INDICES FOR DEEP TILLAGE AND SOUTHEASTERN USA COASTAL PLAIN HARDPAN SOILS. INTERNATIONAL SOIL TILLAGE RESEARCH ORGANIZATION PROCEEDINGS. 2003. p. 242-247. Technical Abstract: We evaluated double-crop wheat (Triticum aestivum L.) and drilled soybean (Glycine max L. Merr.) in deep-tilled hardpan soils. Soybean and wheat were drilled in 19-cm-row widths in plots that had different coastal soils at either end. Treatments included surface tillage (disked or none), deep tillage (paratilled or none), additional treatments that were rotated with maize (Zea mays L.) and winter fallow, and a final treatment that was disked, deep tilled with a conventional in-row subsoiler, and planted in 76-cm-wide rows. Rainfall was erratic throughout the experiment with long dry periods. Cone indices were measured at two places in each plot 120 m apart to assess soil strength differences within and among treatments. Cone indices were higher for non-deep tilled treatments vs. deep tilled treatments. They were also higher in wheel tracks vs. non-wheel tracks and in soil types with shallower B horizons. Cone indices of subsoiled treatments were not significantly different from paratilled treatments. Yields were greater for deep tilled soils. Yields were also greater for paratilled than for subsoiled or non-paratilled treatments partly as a result of the more complete disruption of the paratill and partly because the paratilled treatments were managed with narrow rows. Different soil types did not have yield differences despite the fact that they had different cone indices. Tillage was a more dominant factor than soil type during this study because it softened the soil for potential root exploration during times of water stress.