Proceedings of the 2023 Mississippi Water Resources Conference

Year: 2023 Authors: Simek V., Joeksema J., Taylor J.

The global human population continues to grow exponentially, and agriculture will need to become more productive to meet growing food demands. Humans also need clean water and other services that ecosystems provide. This requires future agriculture production to reduce environmental and wildlife impacts through improved efficiencies and best management practices. Migratory shorebirds rely on wetlands throughout North and South America as stopover habitat for rest and refueling during migration. Temporarily flooded farmlands in the Mississippi Delta have proven to be beneficial locations for shorebirds during migrations along the central flyway. This conservation practice also enhances wetland properties that promote excess nitrogen (N) retention or removal. However, little research has been conducted to evaluate how shorebird activity influences N cycling in these temporary wetland habitats on agricultural lands. Shorebirds potentially influence N cycling through several pathways including top-down control of sediment properties via movement and foraging as well as bottom-up processes by recycling nutrients via the deposit of fecal matter. The proposed study will investigate the influence of migratory shorebirds on N cycling in fallow agricultural fields flooded for migratory habitat. We will collect soil cores from plots that either exclude or allow access to shorebirds to assess bird effects on soil properties and invertebrate biomass, as well as different N cycling processes including denitrification and N uptake. Nitrogen cycling processes will be measured using intact sediment core incubations coupled with dissolved inorganic nitrogen (DIN) and dinitrogen (N2) gas measurements. Results from the proposed experiment will provide a better understanding of how interactions between wildlife and habitat created through best management practices may enhance ecosystem services in managed agroecosystems.