Characterization of the effect of tillage on furrow irrigation hydraulics for the Dire Dawa Area, Ethiopia

Soil water infiltration is one of the most important processes affecting the volume, transport route and water quality of agricultural drainage. Tillage method and depth have also effects on the ability of soil to store water and the furrow irrigation hydraulics of irrigated fields. A study was conducted to evaluate the effect of tillage method and depth on furrow irrigation hydraulics and soil water storage during the dry season at Dire Dawa, Eastern Ethiopia. Treatments in the study included were chisel, moldboard and disk ploughing to 150 mm and 250 mm depths; and “Maresha” (local plough). Data obtained through field measurement and/or observations and laboratory analysis included soil data, irrigation water, advance and recession times, inflow–outflow volumes, available soil moisture, and infiltration rate at each irrigation event. Extending tillage depth from 150 mm to 250 mm significantly increased irrigation infiltration (mm) from 34 to 38%, increased irrigation water advance time from 55 to 75%, increased application efficiency from 33 to 55%, and increased saturated hydraulic conductivity from 23 to 48%; and significantly decreased tail water ratio and distribution uniformity (p < 0.05) in the first two irrigations, but had little effect during the successive irrigations.