Discipline: Ecology Environmental and Earth Sciences
Subcategory: Geosciences and Earth Sciences
Elizabeth Osota - University of Georgia
Co-Author(s): Aaron Thompson and Rachel Ryland, University of Georgia, Athens, GA
Up until the last hundred years, most of the land in the Southeast region of the United States was heavily farmed for cotton. The popularity of single-cropping of cotton and little to no use of Best Management Practices (BMPs) during this period led to high rates of runoff and soil erosion. Understanding how much of the top soil (A Horizon) eroded during and after cotton farming in relation to slope is essential to understanding erosion severity. We hypothesized higher degrees of slope will have lower depth to the argillic horizon relative to slopes of lower degrees. Particle size analysis was conducted on soil samples of varied ranges of depths from augured locations of different slopes from Watersheds 3 and 4 of the Calhoun Critical Zone Observatory. From there, the depth to the argillic horizon (Clayey B) or simply the top soil was quantified. In relation, the samples were also scanned with a VNIR (Visible and Near-Infrared) to test the effectiveness of using VNIR soil reflectance to predict clay content in situ instead of the long process of ex situ particle analysis. Overall, the data showed that as slope increased, the depth to the argillic increased showing decreased rates of erosion of the top soil in the upland position. With a wavelength of 2203, the soil reflectance data gave a .61219 R squared value concluding that the VNIR data and the clay content of the soil samples gave an above average correlation. Future research involves understanding how the characteristics Southeastern soil has improved or changes since the end of the cotton farming era. This will help to understand why the results gathered may have misaligned with the hypothesis.
References: Costa, J. E. (1975). Effects of agriculture on erosion and sedimentation in the Piedmont province, Maryland. Geological Society Of America Bulletin, 86(9), 1281-1286.
Soriano-Disla, J. M., Janik, L. J., Viscarra Rossel, R. A., MacDonald, L. M., & McLaughlin, M. J. (2014). The Performance of Visible, Near-, and Mid-Infrared Reflectance Spectroscopy for Prediction of Soil Physical, Chemical, and Biological Properties. Applied Spectroscopy Reviews, 49(2), 139-186.
Trimble, S. W.. (1985). Perspectives on the History of Soil Erosion Control in the Eastern United States. Agricultural History, 59(2), 162-180.
Funder Acknowledgement(s): I thank Rachel Ryland for helping me with the collection and analysis of the soil samples. Thank you to Aaron Thompson for guiding me on the creation of the research poster. Funding was provided by the University of Georgia College of Agricultural and Environmental Sciences, National Sciences Foundation (B51C-0444), and Calhoun Critical Zone Observatory.
Faculty Advisor: Aaron Thompson, AaronT@uga.edu
Role: I was a part of every step of the project. I was already helping Soil Science Graduate Student, Rachel Ryland, with her project so I developed a project that was an extension to hers. With previous class knowledge and other resources, I helped in the development of the method which was finalized by Rachel and Professor Thompson. Rachel and I retrieved and analyzed all of the soil samples together. I created the poster myself but Rachel and Professor Thompson gave tips and additional help on how to improve the poster.