Robert Kröger

Graduate Student(s):  Elizabeth Usborne

This project is funded through the Soil Processes Program office of the Agricultural Food Research Initiative (AFRI, now NIFA), USDA-CSREES. The project was funded in September, 2009, and is expected to be completed by September, 2011.

The central hypothesis of this project is that hydrological variability and influent P loads from agricultural soils will predictably interact with the contribution of P loads from drainage sediments to aquatic systems. The long term goal of this project is to allow the development of a broader scale research program that will develop strategies which enhance our understanding of drainage sediments (i.e. primary aquatic systems) associated with the agricultural landscape, and the complex nature of nutrient dynamics therein. The overall objective of this application, which is the first step towards attainment of my long-term research goal, is to identify the contribution drainage sediments make to P loads under typical agricultural circumstances. The research proposed is significant, because application of this preliminary data will result in more substantial development of knowledge in this field that will eventually lead to new approaches to management of nutrient contamination from production agriculture to aquatic receiving systems. Determining relationships between hydrology, P sediment dynamics and influent P loads is expected to have significant environmental impacts to adjacent agricultural aquatic systems at a fine scale, to hydrologically connected coastal ecosystems at a broad scale.

Outputs

• Kröger, R., R.E. Lizotte Jr., F.D. Shields Jr., E. Usborne. 2012. Inundation Influences on Bioavailability of Phosphorus in Managed Wetland Sediments in Agricultural Landscapes. Journal of Environmental Quality 41 (2):604-614
• Lizotte Jr., R.E., F.D. Shields Jr., J.N. Murdock, R. Kröger, S.S. Knight. 2012. Mitigating water quality impacts of agricultural runoff using a managed riverine wetland. Science of the Total Environment 427-428: 373-381
• Usborne, E.K.A. Littlejohn, S.C. Pierce, RKröger. 2012. Nutrient reduction capabilities of agricultural drainage ditch wetlands: creation and policy implications In: Wetlands: Ecology, Management and Conservation. Nova Publishers, New York, NY, pp. 185-202.
• Kröger, R., M.T. Moore. 2011 Phosphorus dynamics within agricultural drainage ditches in the Lower Mississippi Alluvial Valley. Ecological Engineering 37:1905-1909.
• Usborne, E., R. Kröger. 2011. How weirs in agricultural drainage ditches alter conditions for sediment accumulation and phosphorus retention. National Society of Environmental Toxicology and Chemistry Meeting, Boston, MA, November 11-17th, 2011.
• Kröger, R., E.L. Usborne, R.E. Lizotte, F.D. Shields Jr., M.T. Moore. 2010. Inundation influences on bioavailable phosphorus in wetland sediments. Soil and Water Conservation Society National Conference, St Louis, MO.
• Usborne, E.L., R. Kröger, S.C. Pierce. 2010. Effects of weirs on phosphorus, sediment accumulation and pH in agricultural drainage ditches over time. SWS-South Central Chapter Regional Meeting, Oxford, MS.
• Usborne, E.L., R. Kröger. 2010. Weir effects on physicochemical sediment properties and phosphorus retention in agricultural drainage ditches. National Society of Environmental Toxicology and Chemistry Meeting, Portland Oregon.

Gulf of Mexico Research

• Gulf of Mexico Research
• Efficacy of Best Management Practices as an Approach to Water Resource Conservation in the Mississippi Delta Region

Completed Projects

• MASGC - Decreasing nitrate-N loads to coastal ecosystems with innovative drainage management strategies in agricultural landscapes
• EPA-GMPO: Evaluation of innovative, low-technology water management structures as important tools in nutrient reduction strategies
• Monitoring for short term success of BMP structures in the Harris and Porters Bayou 319 watersheds for altering hydrology and reducing sediment and nutrient concentrations.
• BMP evaluations in Wolf Lake
• Understanding nitrate delivery within the Big Sunflower River, Mississippi: implications for nutrient loads to the Gulf of Mexico
• Assessing complexity of hydrology, nutrient inputs and phosphorus dynamics with agricultural drainage sediments
• Drainage canal vegetation management plan for the city of Jonesboro
• EPA 319h Wolf Lake turbidity and total suspended sediments
• Hill Country Aquaculture
• Sport Fisheries Restoration in Puerto Rican Reservoirs - Water Quality
• Denitrification in agricultural drainage ditches under various hydrologic management regimes
• Understanding the influence of Annamox and denitrification in agricultural drainage ditch sediments in potential nitrogen removal
• Review of best management practice efficiencies in the Lower Mississippi Alluvial Valley
• Integrative Aquatic Research on Southfarm
• Soil media compositions for water quality improvements and stormwater management in urban flow-through facilities
• Oxbow lake fisheries and water quality
• Evaluating changes in diversity and functional gene abundance of denitrifying microbe communities to nutrient concentrations in run-off following the implementation of low-grade weirs in agricultural drainage systems
• Examining the role of organic carbon amendments as a possible best management practice to improve nitrogen removal in agricultural drainage ditches
• Assessment of evaporation rates of tailwater recovery and on-farm storage reservoirs to establish the potential use of these BMPs to reduce agricultural impacts to water quality while promoting surface water re-use in the Mississippi Alluvial Valley
• Monitoring changes in nutrient and sediment concentrations and loads to downstream aquatic systems to assess the use of cover crops as an in-field BMP in a HUC 12 watershed
• REACH (Research & Education to Advance Conservation & Habitat)