Impact of tillage on water transformation and runoff-sediment-yielding characteristics on slope land

Serious soil and water loss from slope land was the main causes for soil degradation and eco-environmental degradation on the Loess Plateau. Experiments were conducted on soil water transformation and runoff-sediment-yielding characteristics on loessial soil slope land for tillage and compaction under simulated rainfall conditions. Results showed that: (1) comparing soil tillage with compaction, the infiltration rate decreased by 40%～60%, runoff-yielding intensities increased by one to three times, and the transforming ratio from rainfall to soil water decreased by over 50%; (2) Under tillage conditions, the average sediment concentration in lost runoff increased by 70%, sediment-yielding amount increased by three times, and runoff volume doubled. So the application of no-till fallow could reduce the loss of soil and water and even control soil quality degradation on slope land. (3) With the extension of runoff-yielding time during the rainfall process, the sediment loss from slope tended to accelerate more rapidly than runoff volume increased. So the applications of suitable measures to prolong the initial runoff-yielding time, reduce runoff-yielding volume, and increase the transformation ratio from rainfall to soil water will be effective in reducing soil loss from slope land.