TY - JOUR T1 - Field-scale watershed evaluations on deep-loess soils: II. Hydrologic responses to different agricultural land management systems JF - Journal of Soil and Water Conservation SP - 705 LP - 710 VL - 54 IS - 4 AU - L.A. Kramer AU - M.R. Burkart AU - D.W. Meek AU - R.J. Jaquis AU - D.E. James Y1 - 1999/10/01 UR - http://www.jswconline.org/content/54/4/705.abstract N2 - The deep-loess hills in Iowa and Missouri are susceptible to erosion and disruption of the balance between infiltration and runoff due to row-crop production. More than 30 yr of precipitation, runoff baseflow, and sediment discharge measurements near Treynor, Ia., showed conservation tillage improved important hydrologic responses. Conservation tillage produced smaller amounts of storm-driven runoff and more baseflow. Accompanying this was reduction in sediment discharged annually and during peak storm events. Sediment discharge also was reduced between rough fallow and crop development. The watershed with ridge-till had reduced annual runoff seasonal runoff and seasonal sediment discharge compared to ridge-till and terraces. This raises questions about the efficacy and value of widely-spaced terraces in this region. It is clear that ridge-till and terracing provide multiple benefits to soil and water management. The reduced runoff resulting from maximum storm events decreases the loss of sediment derived from sheet and rill erosion. The reduction in annual runoff and accompanying increase in base-flow provides for additional potential soil moisture available for crops. This is particularly important in these relatively well-drained soils. ER -