Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/9/2007
Publication Date: 9/6/2007
Citation: Papiernik, S.K., Lindstrom, M.J., Schumacher, T.E., Schumacher, J.A., Farenhorst, A., Malo, D.D., Stephans, K.D., Lobb, D.A. 2007. Variability of soil properties and crop yield in landscapes affected by long-term tillage. In: Proceedings of the 50th Manitoba Soil Science Society Meetings, February 8-9, 2007, Winnipeg, Manitoba, Canada. p. 31-40.
Technical Abstract: Intensive tillage moves large quantities of soil, resulting in a pattern of soil redistribution where topsoil is depleted from convex slope positions and deposited in concave positions. In these experiments, the variation in erosion estimates, soil properties and crop yield were determined in a hilly landscape subject to annual moldboard plowing. Wheat yields were lowest in areas of high soil loss by tillage erosion, demonstrating yield reductions of 50% or more. Wheat yields were highest in areas of soil accumulation by tillage and water erosion (depressions). These soils had lower pH and inorganic carbon contents, but higher organic carbon, total nitrogen and extractable phosphorus contents throughout the profile compared to areas of soil depletion. The mean surface soil organic carbon and total nitrogen contents in cultivated areas (regardless of erosion status) were less than half that measured in an adjacent uncultivated area, indicating that intensive tillage and cropping has significantly depleted the surface soil organic matter in this landscape. These results indicate that the observed variation in crop yield in hilly landscapes may be significantly influenced by removal of topsoil through repeated intensive tillage, and point to opportunities for landscape restoration to reduce yield losses.