|SCHUMACHER, THOMAS - South Dakota State University|
|LOBB, DAVID - University Of Manitoba|
|MOLLINEDO, JAVIER - South Dakota State University|
|CHINTALA, RAJESH - South Dakota State University|
Submitted to: Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 1/5/2014
Publication Date: 6/8/2014
Citation: Schumacher, T.E., Papiernik, S.K., Lobb, D.A., Mollinedo, J., Chintala, R. 2014. Physical restoration of eroded soils in the Northern Great Plains (NA). Proceedings of the 20th World Congress of Soil Science, June 8-13, 2014, Jeju, Korea.
Technical Abstract: Management of agricultural lands often seeks to modify or control non-human environmental factors so as to support diverse (and often conflicting) objectives, such as extraction of resources, profitability, human survival, soil and water conservation, maintenance of wildlife habitat, food security, etc. Agricultural management objectives have short and long term consequences that must be considered in devising global and national food security goals. Past soil management practices have emphasized resource extraction and profitability at the expense of the physical integrity of soils. Soil profile changes due to topsoil translocation and reduced quality of soil structure from truncated soil pore size distribution and simplified pore geometry are especially prevalent in eroded agricultural landscapes. Historically soil management in the Northern Great Plains in North America (NA) was an exploitive technology and as a result 40% of the soil organic matter has been lost resulting in reduced structural stability. Additionally extensive soil profile changes have occurred from extensive mechanical translocation of soil by tillage on convex hilltops and from water erosion on backslopes. Soil management practices evaluated for physical restoration of soil structure on eroded landscapes within the Northern Plains (NA) included the physical replacement of topsoil on eroded hilltops, the addition of amendments such as biochar to eroded soils, and the use of native prairie grasses to improve degraded soil structure. Soil replacement of topsoil on eroded soil significantly increased soil water contents at -0.03 MPa compared to the control. However water contents at -1.5 MPa also increased resulting in a reduced effect on plant available water holding capacity. Wet aggregate stability also improved with topsoil replacement. Studies with biochar addition to eroded soils showed an increase in plant available water holding capacity for two eroded soils, a coarse textured and a fine textured soil. This was primarily related to an increase in the upper end of the water retention curve near the air entry value of the coarse texture soil. Native grasses improved wet aggregate stability on an eroded soil three years after establishment. However a comparison with a nearby native prairie remnant indicated that significant progress is still needed to match the high structural stability of the original prairie. The efficacy of soil management practices to restore eroded soil to soil structure approaching that of the original soil will depend on the difference in composition between the eroded soil and the original soil, and the degree to which soil management practices reinforce mechanisms that increase soil pore development, complexity, and stability.