Natural runoff plots on which maize was produced were laid out at Cedara on a well-drained clay loam Doveton soil and showed, over a six-year period, the benefits to be gained from adopting conservation tillage practices. The four tillage and crop utilization practices compared were: no-till with all crop residues retained; chisel ploughing after simulated light grazing (which left half of the crop residues on the surface); mouldboard ploughing in spring after simulated light grazing; and mouldboard ploughing in autumn after the removal of all plant residues. Mean annual soil loss and runoff (in parentheses) for the respective tillage practices were 0.41 (18 mm); 1.11 (25 mm); 3.01 (38 mm) and 5.91 (66 mm).