The Role of Hydraulic Connectivity and Management on Soil Aggregate Size and Stability in the Clear Creek Watershed, Iowa
The role of tillage practices on soil aggregate properties has been mainly addressed at the pedon scale (i.e., soilscape scale) by treating landscape elements as disconnected. However, there is observed heterogeneity in aggregate properties along flowpaths, suggesting that landscape scale hydraulic...
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MDPI AG
2018-12-01
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| Series: | Geosciences |
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| Online Access: | https://www.mdpi.com/2076-3263/8/12/470 |
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| author | Kenneth M. Wacha A. N. Thanos Papanicolaou Christos P. Giannopoulos Benjamin K. Abban Christopher G. Wilson Shengnan Zhou Jerry L. Hatfield Timothy R. Filley Tingyu Hou |
| author_facet | Kenneth M. Wacha A. N. Thanos Papanicolaou Christos P. Giannopoulos Benjamin K. Abban Christopher G. Wilson Shengnan Zhou Jerry L. Hatfield Timothy R. Filley Tingyu Hou |
| author_sort | Kenneth M. Wacha |
| collection | DOAJ |
| description | The role of tillage practices on soil aggregate properties has been mainly addressed at the pedon scale (i.e., soilscape scale) by treating landscape elements as disconnected. However, there is observed heterogeneity in aggregate properties along flowpaths, suggesting that landscape scale hydraulic processes are also important. This study examines this supposition using field, laboratory and modeling analysis to assess aggregate size and stability along flowpaths under different management conditions: (1) tillage-induced abrasion effects on aggregate size were evaluated with the dry mean weight diameter (DMWD); (2) raindrop impact effects were evaluated with small macroaggregate stability (SMAGG<sub>STAB</sub>) using rainfall simulators; and (3) these aggregate proxies were studied in the context of connectivity through the excess bed shear stress (<i>δ</i>), quantified using a physically-based landscape model. DMWD and SMAGG<sub>STAB</sub> decreased along the flowpaths for all managements, and a negative correspondence between the proxies and <i>δ</i> was observed. <i>δ</i> captured roughness effects on connectivity along the flowpaths: highest connectivity was noted for parallel-ridge-till flowpaths, where <i>δ</i> ranged from 0⁻8.2 Pa, and lowest connectivity for contour-ridge-till flowpaths, where <i>δ</i> ranged from 0⁻1.1 Pa. High tillage intensity likely led to an increase in aggregate susceptibility to hydraulic forcing, reflected in the higher gradients of aggregate size and stability trendlines with respect to <i>δ</i>. Finally, a linear relationship between DMWD and SMAGG<sub>STAB</sub> was established. |
| first_indexed | 2024-12-21T21:33:57Z |
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| issn | 2076-3263 |
| language | English |
| last_indexed | 2024-12-21T21:33:57Z |
| publishDate | 2018-12-01 |
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| series | Geosciences |
| spelling | doaj.art-23e1695925874718a46069d10e4d44302022-12-21T18:49:33ZengMDPI AGGeosciences2076-32632018-12-0181247010.3390/geosciences8120470geosciences8120470The Role of Hydraulic Connectivity and Management on Soil Aggregate Size and Stability in the Clear Creek Watershed, IowaKenneth M. Wacha0A. N. Thanos Papanicolaou1Christos P. Giannopoulos2Benjamin K. Abban3Christopher G. Wilson4Shengnan Zhou5Jerry L. Hatfield6Timothy R. Filley7Tingyu Hou8USDA-ARS (United States Department of Agriculture-Agricultural Research Service) National Laboratory for Agriculture and the Environment, Ames, IA 50011, USAHydraulics and Sedimentation Laboratory, Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USAHydraulics and Sedimentation Laboratory, Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USAHydraulics and Sedimentation Laboratory, Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USAHydraulics and Sedimentation Laboratory, Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USAHydraulics and Sedimentation Laboratory, Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, USAUSDA-ARS (United States Department of Agriculture-Agricultural Research Service) National Laboratory for Agriculture and the Environment, Ames, IA 50011, USADepartment of Earth, Atmospheric and Planetary Sciences, Purdue University, West Lafayette, IN 47907, USADepartment of Earth, Atmospheric and Planetary Sciences, Purdue University, West Lafayette, IN 47907, USAThe role of tillage practices on soil aggregate properties has been mainly addressed at the pedon scale (i.e., soilscape scale) by treating landscape elements as disconnected. However, there is observed heterogeneity in aggregate properties along flowpaths, suggesting that landscape scale hydraulic processes are also important. This study examines this supposition using field, laboratory and modeling analysis to assess aggregate size and stability along flowpaths under different management conditions: (1) tillage-induced abrasion effects on aggregate size were evaluated with the dry mean weight diameter (DMWD); (2) raindrop impact effects were evaluated with small macroaggregate stability (SMAGG<sub>STAB</sub>) using rainfall simulators; and (3) these aggregate proxies were studied in the context of connectivity through the excess bed shear stress (<i>δ</i>), quantified using a physically-based landscape model. DMWD and SMAGG<sub>STAB</sub> decreased along the flowpaths for all managements, and a negative correspondence between the proxies and <i>δ</i> was observed. <i>δ</i> captured roughness effects on connectivity along the flowpaths: highest connectivity was noted for parallel-ridge-till flowpaths, where <i>δ</i> ranged from 0⁻8.2 Pa, and lowest connectivity for contour-ridge-till flowpaths, where <i>δ</i> ranged from 0⁻1.1 Pa. High tillage intensity likely led to an increase in aggregate susceptibility to hydraulic forcing, reflected in the higher gradients of aggregate size and stability trendlines with respect to <i>δ</i>. Finally, a linear relationship between DMWD and SMAGG<sub>STAB</sub> was established.https://www.mdpi.com/2076-3263/8/12/470aggregate stabilitydry aggregate size distributionhydraulic connectivityagricultural management practicesrainfall simulatorerosion processes and mechanicsclimatic and human impacts |
| spellingShingle | Kenneth M. Wacha A. N. Thanos Papanicolaou Christos P. Giannopoulos Benjamin K. Abban Christopher G. Wilson Shengnan Zhou Jerry L. Hatfield Timothy R. Filley Tingyu Hou The Role of Hydraulic Connectivity and Management on Soil Aggregate Size and Stability in the Clear Creek Watershed, Iowa Geosciences aggregate stability dry aggregate size distribution hydraulic connectivity agricultural management practices rainfall simulator erosion processes and mechanics climatic and human impacts |
| title | The Role of Hydraulic Connectivity and Management on Soil Aggregate Size and Stability in the Clear Creek Watershed, Iowa |
| title_full | The Role of Hydraulic Connectivity and Management on Soil Aggregate Size and Stability in the Clear Creek Watershed, Iowa |
| title_fullStr | The Role of Hydraulic Connectivity and Management on Soil Aggregate Size and Stability in the Clear Creek Watershed, Iowa |
| title_full_unstemmed | The Role of Hydraulic Connectivity and Management on Soil Aggregate Size and Stability in the Clear Creek Watershed, Iowa |
| title_short | The Role of Hydraulic Connectivity and Management on Soil Aggregate Size and Stability in the Clear Creek Watershed, Iowa |
| title_sort | role of hydraulic connectivity and management on soil aggregate size and stability in the clear creek watershed iowa |
| topic | aggregate stability dry aggregate size distribution hydraulic connectivity agricultural management practices rainfall simulator erosion processes and mechanics climatic and human impacts |
| url | https://www.mdpi.com/2076-3263/8/12/470 |
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