Author
Wuest, Stewart | |
Williams, John | |
Johlke, Tami |
Submitted to: Columbia Basin Agricultural Research Annual Report
Publication Type: Experiment Station Publication Acceptance Date: 5/12/2006 Publication Date: 6/1/2006 Citation: Wuest, S.B., Williams, J.D., Johlke, T.R. 2006. Effects of tillage on water infiltration. Dryland Agricultural Research Annual Report. Oregon Agric. Exp. Sta. Special Report 1068. Interpretive Summary: Soils in the dryland wheat-growing region of the Pacific Northwest are very susceptible to water erosion when tilled and left bare of crop residue. In cropping systems that do not involve tillage, organic matter accumulates on and near the soil surface, and structural changes develop deeper in the soil. Both of these features allow more rapid infiltration of water, greatly reducing the chances of runoff or erosion. Even with tillage, if depth of tillage and burial of surface residues is minimized, increased organic matter at the soil surface results in greater infiltration capacity than traditional moldboard-plow tillage. Technical Abstract: Soils in the dryland wheat-growing region of the Pacific Northwest are very susceptible to water erosion when tilled and left bare of crop residue. In cropping systems that do not involve tillage, organic matter accumulates on and near the soil surface, and structural changes develop deeper in the soil. Both of these features allow more rapid infiltration of water, greatly reducing the chances of runoff or erosion. Different degrees of tillage leave different amounts of residue on the surface and change the stratification of organic matter over time. Shallow tillage decreases organic matter at depths below tillage, and increase it near the surface. If depth of tillage and burial of surface residues is minimized, increased organic matter at the soil surface results in significantly greater infiltration capacity than traditional moldboard-plow tillage. In one long-term experiment, the maximum infiltration rate was approximately doubled where the sweep-plow was used at 6-inch depth compared plowing at 8-inch depth. |