Furrow Infiltration on Nontilled Beds with Cracking Soils

Abstract

A recirculating furrow infiltrometer is used to determine the effect of three flow rates on infiltration for nontilled beds established on a red‐brown earth soil (heavy clay soil) in the Goulburn‐Murray irrigation region of southeastern Australia. Flow rates are 0.13 L/s (low), 0.38 L/s (medium), and 0.61 L/s (high). Tests are repeated four times at two‐week intervals over the irrigation season. Infiltration measurements are made over 10‐m long furrows for a minimum of five hours of outflow. Increasing the flow rate, with commensurate increases in wetted perimeter and depth of water in the furrow, increases the volume infiltrated into the nontilled beds on these soils. Because of this effect, the depth of water in the furrow should be maintained as high as possible without flooding the surface of the beds. Narrow spacing between furrows and the presence of crop residues in the furrow may also be beneficial. The volume infiltrated, calculated from the Kostiakov‐Lewis equation, decreases with time during the season and is especially evident at the high flow rate.