EFFECTS OF SUBSOILING AND IRRIGATION ON CORN PRODUCTION

Deep tillage and irrigation are two soil management techniques that have been used separately to alleviate water shortage for crops growing on soils having root restricting tillage pans. The purpose of this study was to evaluate the effects of in-row-subsoiling (S), irrigation (I), and in-row-subsoiling plus irrigation on corn (Zea mays L. ) production on Wagram soil (fine-loamy, siliceous, thermic Arenic Paleudults) having a dense tillage pan. Main plot treatments were: CD(conventional tillage left bracket double disking right bracket , dryland); CI (conventional tillage, irrigated when soil water pressure left bracket SWP right bracket at the 0. 25-m depth reached - 40 kPa); SD (in-row-subsoiled and bedded, dryland); and SI(in-row subsoiled and bedded irrigation when SWP less than minus 40 kPA at 0. 30-m depth).