Research

1. Legacy Phosphorus Dynamics in Agricultural Landscapes

Legacy phosphorus stored in agricultural soils represents a long-term source of nutrient loading to surface waters. This research integrates long-term soil test datasets, geospatial analysis, and statistical modeling to quantify temporal trends in phosphorus accumulation and depletion, identify persistent hotspots, and evaluate the implications of legacy phosphorus for watershed restoration and nutrient management.

2. Topographic Controls on Nutrient Accumulation and Transport

Landscape position exerts a fundamental control on hydrologic connectivity, nutrient cycling, and pollutant transport. Using high-resolution terrain analysis, LiDAR-derived topographic indices, and spatial modeling approaches, this research investigates how landscape organization influences nutrient accumulation, runoff generation, and critical source area development across agricultural watersheds.

3. Nutrient Mass Balance and Nutrient Management

Sustainable nutrient management requires a quantitative understanding of nutrient imports, exports, storage, and losses. This research develops nutrient mass balance frameworks at field, farm, watershed, and regional scales to identify nutrient surpluses, evaluate nutrient use efficiency, and support strategies that promote nutrient recycling and circular nutrient economies.

5. Denitrifying Bioreactors for Legacy N Treatment

Denitrifying bioreactors offer a promising approach for mitigating nitrate losses from legacy source from groundwater. Research efforts focus on understanding bioreactor performance under varying hydrologic and environmental conditions, quantifying nitrogen removal efficiency, developing monitoring protocols, and advancing approaches for nutrient crediting and performance-based conservation.

6. Performance-Based Water Quality Management

Traditional conservation programs typically compensate implementation of practices rather than measured environmental outcomes. This research develops and evaluates performance-based frameworks that link financial incentives to observed nutrient reductions, with particular emphasis on nonpoint source pollution control, environmental markets, and outcome-based conservation programs.

7. Climate Change, Hydrology, and Water Quality

Climate change is altering hydrologic processes, nutrient transport pathways, and watershed responses to management. This research combines climate projections, watershed modeling, and monitoring data to evaluate future water quality risks, assess system resilience, and identify adaptive management strategies for agricultural and mixed-use watersheds.

8. Data-Driven Watershed Science

Advances in environmental monitoring and computational methods have created new opportunities for understanding watershed function. This research applies statistical modeling, machine learning, data assimilation, and geospatial analytics to characterize nutrient dynamics, identify emerging trends, and improve prediction of watershed responses to environmental change.

9. Agricultural Conservation Effectiveness

The effectiveness of conservation practices varies across environmental settings and management contexts. This research quantifies the performance of conservation practices and systems using monitoring data, experimental studies, and modeling approaches to improve practice targeting, increase environmental benefits, and reduce uncertainty in conservation planning.

10. Decision Support Tools for Environmental Management

Effective environmental management requires tools that translate complex scientific information into actionable guidance. This research develops open-source modeling frameworks, forecasting systems, and decision-support applications that support nutrient management, watershed planning, conservation implementation, and policy evaluation.