TITLE:
Southeastern Missouri Phosphorus and Sulfur Soil Concentrations in Mississippi River Floodplain Environments
AUTHORS:
Michael Aide, Christine Aide
KEYWORDS:
Legacy Phosphorus, Sulfate, Mississippi River Quality, Gulf Mexico Hypoxia, Eutrophication, Forest Soils
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.8,
August
31,
2026
ABSTRACT: Nitrogen and phosphorus fertilizer amendments increase the nutrient content of soils to support plant growth and development. With overland and subsurface water flow, wind and water induced erosion, and other transport pathways, waterways will become impacted by these nutrients. In the Gulf of Mexico, nitrogen and phosphorus contributed to the prevailing hypoxia zone. We investigated two soil locations on the floodplain of the Modern Mississippi River in Missouri. One soil location had two pedons of the Commerce soil series (Endoaquepts) and the other soil location had two pedons of the Caruthersville soil series (Udifluvents). Soil analysis indicates that both soil sites exhibited labile phosphorus exceeding 100% soil phosphorus index values. Aqua regia digestion indicates that appreciable quantities of phosphorus and sulfur exist. Plant tissue analysis confirms that these soils provide ample nutrients for the existing vegetation. We conclude that maintaining forested acreages along the floodplains of the Mississippi River mitigate phosphorus riverine transport to the Gulf of Mexico, reducing the severity of the hypoxia zone.