ORCID
0009-0006-7873-5885
Date of Award
2025
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Natural Resources
First Advisor
Joshua Faulkner
Second Advisor
Andrew Schroth
Abstract
Agriculture in Vermont is a major non-point source contributor of phosphorus to freshwater bodies such as Lake Champlain, which can generate algal blooms due to the high influx of nutrients. Clay agricultural soils and their dispersive nature, combined with higher levels of magnesium, have the potential to contribute to a greater loss of phosphorus. Preferential flow pathways in the form of cracks can form in expansive clays that exist in agricultural regions. These pathways, when present in tile drained agricultural soils, can allow for runoff to have a direct pathway to surface waters. Sediment containing legacy phosphorus can be transported through these preferential flow paths. Here, we designed an experiment to simulate and quantify the impact that higher levels of magnesium in clay rich agricultural soils collected have on sediment and phosphorus loss. Target ratios of Ca:Mg solutions, 10:90, 30:70, 50:50, and 70:30 were applied to soil columns that were collected from Panton, Vermont. Seven simulated rain events were administered to the intact soil columns and the effluent was analyzed for total suspended solids (TSS), total phosphorus (TP), soluble reactive phosphorus (SRP), and particulate phosphorus (PP). It was found that treatments with high magnesium levels had greater levels of sediment and phosphorus loss when compared to the high calcium treatment. When examining TSS loads, the loads for the 10:90 treatment were significantly higher than the 70:30 treatment (p = 0.033). Other high magnesium treatments showed higher trends of TSS, SRP, and TP when compared to the 70:30 high calcium treatment. Higher contents of magnesium contribute to increased dispersion of clay soils, contributing to greater levels of phosphorus and sediment loss. The clay type also provides insight for how a soil might function chemically and physically. Through clay characterization using X-ray diffraction, it was determined that the makeup of the clays present in the soils collected were vermiculite, muscovite, and kaolinite.
Language
en
Number of Pages
91 p.
Recommended Citation
Menice, Katarina Anna, "Effect Of Soil Base Cation Ratios On Subsurface Phosphorus And Sediment Loss: A Column Study" (2025). Graduate College Dissertations and Theses. 2066.
https://scholarworks.uvm.edu/graddis/2066