Author
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WANG, LINHUA - Chinese Academy Of Sciences |
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YEN, HAW - Texas A&M University |
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WANG, XIANG - China Agricultural University |
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Huang, Chi Hua |
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SUN, JIAMEI - Purdue University |
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Hammac Ii, Warren |
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WANG, YAFENG - Chinese Academy Of Sciences |
Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/14/2020 Publication Date: 8/15/2020 Citation: Wang, L., Yen, H., Wang, X., Huang, C., Sun, J., Hammac II, W.A., Wang, Y. 2020. Deposition- and transport-dominated erosion regime effects on the loss of disolved and sediment-bound organic carbon: Evaluation in a cultivated soil with laboratory rainfall simulations. Science of the Total Environment. 750:141717. https://doi.org/10.1016/j.scitotenv.2020.141717. DOI: https://doi.org/10.1016/j.scitotenv.2020.141717 Interpretive Summary: The loss of soil organic carbon (SOC) from processes of surface runoff and erosion is the primary cause of soil degradation. On the other hand, the transport of SOC during runoff events is a complex process because it depends on the selectivity of different particle sizes and the placement of erosion control practices on a hillslope. In this research, we used simulated rainfall to quantify the particle size distribution of eroded sediments from soil surfaces where the amount of surface cover and its placement were varied. Due to the interactive nature of the treatments, we used a statistical procedure called Grey Relational Analysis to identify the most probably cause between different eroded particle sizes and surface coverage and placement. The results showed that an increased surface cover and the location of the cover at the lower portion of the hillslope produced the most runoff and sediment reductions. Sediment enrichment, i.e., increased finer fractions as compared to the original soil, decreased when both runoff and erosion were increased, indicating larger sized particles were transported during more erosive events. The results are useful to those interested in quantifying soil particle and SOC transport on the landscape and in relating runoff and erosion processes to soil degradation. Technical Abstract: Organic C loss caused by erosion results in degradation of surface soil fertility. An evaluation of the effect of spatially structured coverage and sediment particle size distribution on soil organic C (SOC) enrichment was conducted. Soil boxes receiving simulated rainfall with various levels of soil coverage were used in a laboratory setting. The results showed that higher coverage and lower position cover had greater reductions in SYR (with mean reductions of 98.6% and 95.2% in lower and upper position cover slopes, respectively) and RYR (with mean reductions of 95.4% and 76.9% in lower and upper position cover slopes, respectively). ERSOC values varied between 1.90 and 4.99, on the lower position cover slope with a mean value of 3.52, and 2.54 on the upper position cover slope. ERSOC had negative power relationships with SYR and RYR. ERSOC was determined by sediment particle size selectivity in erosion process, ERSOC had linear relationships with particle size content, with higher correlation with smaller particles (<2 µm and 2-50 µm particle size classes). Grey relational theory was processed to analyze the sediment particle size classes contents for ERSOC. Particle content of 2-50 µm had the highest association degree of ERSOC, then was the particle size class of below 2 µm. The results of comparison of grey relational grade (GRG) to traditional research showed that grey relational analysis (GRA) is efficient for solving multiple attribute agriculture problems. |