Trends and seasonal patterns of nitrogen and phosphorus concentrations and loads in two Mississippi Alluvial Plain watersheds following nutrient reduction efforts during 2010–22 book cover
Environment · 2026 · English

Trends and seasonal patterns of nitrogen and phosphorus concentrations and loads in two Mississippi Alluvial Plain watersheds following nutrient reduction efforts during 2010–22

by Stephen E. DeVilbiss, Matthew B. Hicks, Emily Gain

About this book

Stephen E. DeVilbiss and colleagues examine long-term nutrient patterns in two agricultural watersheds of Mississippi's Alluvial Plain. Focusing on Harris Bayou and Porter Bayou, the report follows nitrogen and phosphorus concentrations and loads during 2010–22 after efforts to reduce the effects of agricultural runoff.

Monthly sampling and samples collected during high-flow events provide the basis for analyses at three locations in each watershed. Several statistical approaches explore seasonal differences, changes across the flow distribution and trends adjusted for variations in streamflow.

The findings distinguish changes in nutrient concentrations from changes in the amount of material transported through the watersheds. Nitrogen and phosphorus do not respond identically, and patterns differ among sampling sites. By bringing those contrasts together, the report offers a detailed example of how water-quality monitoring can assess conservation efforts over time while accounting for the importance of season and runoff conditions.