Management options for farmers facing saltwater intrusion along the Chesapeake Bay’s Eastern Shore

View the project final report

Commodities

Practices

• Crop Production: cropping systems, nutrient cycling, nutrient management
• Natural Resources/Environment: soil stabilization
• Production Systems: agroecosystems

Coastal agricultural systems are vulnerable to saltwater intrusion as sea levels continue to rise along the U.S. Eastern Seaboard. Saltwater intrusion negatively impacts plant productivity and soil health by altering biogeochemical cycling, resulting in the loss of nutrients and soil dispersion. My overall objective is to identify best management practices for farmers facing saltwater intrusion by quantifying the effects of different species on sodium (Na) and phosphorus (P) dynamics. Sodium is an element moving onto fields via saltwater intrusion and P is an element that can move off fields and into waterways following saltwater intrusion. Landowners may respond to saltwater intrusion by altering their management practices. Farmers may adapt by planting a salt-tolerant crop, attempt to remediate soils with trap crops, restore native marsh grasses, or abandon fields altogether. My work will examine the influence of these management practices on biogeochemical cycling, specifically Na and P along a salinity gradient, over time, in a replicated field experiment. My project will focus on quantifying accumulation of Na and P pools in plant biomass and drawdown in soils under four treatments: (1) adaptation [salt-tolerant soybean (Glycine max) and sorghum (Sorghum bicolor)]; (2) remediation [switchgrass (Panicum virgatum)]; (3) restoration [saltmarsh hay (Spartina patens)]; and (4) abandonment [native grasses (weeds)]. The goal of this research is to guide local best management practices and potential easement policies for landowners facing sea level rise and saltwater intrusion. We will conduct outreach through farmer field days, workshops, and stakeholder meetings, and disseminate findings through presentations and publications.

The specific objectives of this research are to:

(1) Quantify how soil total P and available Na and P concentrations and pools vary among adaptation, remediation, restoration, and abandonment species along a salinity gradient.

Q1.A Does field management (e.g. adapt, remediate, restore, abandon) affect soil total P and available Na and P concentrations and pools?

Q1.B How do field management practices change soil total P and available Na and P concentrations and pools along a salinity gradient?

(2) Quantify how leaf tissue total Na and P concentrations and pools vary among adaptation, remediation, restoration, and abandonment species along a salinity gradient. 

Q2.A Does field management (e.g. adapt, remediate, restore, abandon) affect plant biomass pools of Na and P? 

Q2.B How do field management practices change plant biomass Na and P pools along a salinity gradient?