TILLAGE METHOD AND DEPTH EFFECTS ON FURROW IRRIGATION INFILTRATION

Methods of primary tillage between annual crops of corn or sorghum on the Southern High Plains commonly include disking followed by chiseling or occasional deeper loosening by ripping or moldboard plowing. This study was conducted during 1992-1994 at Bushland, Texas, to evaluate the effect of tillage method and depth on furrow irrigation infiltration, soil water storage, grain yield, and water use efficiency (WUE). Treatments included both chiseling and sweep undercutting to 150 and 250 mm (6 and 10 in.) depths. Extending tillage depth from 150 to 250 mm (6 to 10 in.) increased irrigation infiltration from 20 to 28% for the first irrigation after primary tillage, but had little effect during successive irrigations. The deeper tillage increased power requirements by about 60%. Sweep tillage was as effective as the more common chiseling for soil loosening and required only about 75% as much power. Tillage method and depth did not significantly affect average sorghum yield or WUE for the years studied which received average to above average precipitation.