Water conservation and economic impacts when integrating irrigation with no tillage

Experiments in the early 1990s in the Texas High plains compared a no-tillage (NT) irrigated corn and sorghum farming system with a conventional tillage (CT) system in typical wheat/fallow/feedgrain/fallow rotations. Mechanical tillage between wheat and feed grain crops in the CT farming system was replaced by herbicide weed control in the Nt farming system. Additionally, the commonly practiced preplant irrigation in the CT system was eliminated in the NT system. Tillage comparisons were made for each of four seasonal irrigation strategies that varied the amount and timing of applications for each crop. In the case of sorghum irrigation strategies, NT reduced most seasonal irrigation quantities, Seasonal intake and net irrigation water use were reduced for all irrigation strategies. In contrast, corn irrigation quantities during the growing season were largely unaffected by NT, a likely result of in-season lay-by fertilization and furrow clearing. Yields of both crops were unaffected by Nt; yet costs were reduced and net returns (profits) increased.