CHARACTERIZATION OF TILLAGE AND TRAFFIC EFFECTS ON UNCONFINED INFILTRATION MEASUREMENTS

This study was conducted to develop new methods needed to characterize the effects of wheel traffic and tillage on pore structure as measured by water flow through macropores. Unconfined (three-dimensional) saturated and unsaturated infiltration measurements at the soil surface were taken sequentially at field sites to determine the steady-state rate of water flow through different pore-size classes on a Tama silty clay loam. A tension infiltrometer was used to obtain the unsaturated infiltration rates. Wheel traffic reduced infiltration rates in tillages, but caused a greater decrease in infiltration rates in a chisel-plow system than in a no-till. Increasing tension caused proportionately smaller decreases in infiltration rates for wheel-trafficked positions. -from Authors