EMBRACE-EAR-Growth: Coupling In-situ Probing and Modeling Moisture-Related Soil Carbon and Nitrogen Cycling and Transport

Agriculture has a large footprint on Earth’s natural systems and cycles. Agricultural activities have impacted the cycling and transport of two important nutrients: carbon (C) and nitrogen (N). Alterations in C and N cycles have led to many challenges within agroecosystems, including contaminated ground and surface waters, changes in soil health, and increased greenhouse gas emissions. The cycling of nutrients in soils depends on various environmental conditions, such as soil water content and precipitation. However, the extent to which these factors impact C and N transport to groundwater is not fully understood. This research seeks to unpack the links between soil-water levels and the cycling and transport of N and C in soils subjected to agricultural practices. The project will create transformative research experiences for undergraduate students and early career scientists and inform general farming and scientific communities. This project will provide students at University of Wisconsin-River Falls, an undergraduate institution, with research opportunities and training in environmental science and engineering to prepare them for future careers. This project will support an early career researcher in conducting independent research, building a wider network, and mentoring undergraduate students. Intellectual reciprocity between academic researchers and agricultural producers is crucial for finding opportunities to mitigate agricultural impacts on natural resources and global nutrient cycles. Through existing relationships and initiatives, the results of this study will be presented directly to farmer groups to inform land use and crop management decisions. The two specific objectives of the project are (1) to decipher redox-related soil C and N cycling, mobilization, transport, and emissions in soils subjected to two different sources of these nutrients in agricultural soils: manure and crop residue, and (2) to model the transport of C and N organic and inorganic species under different hydrological conditions using chemical transport models. Organic biomolecules and nutrient species will be characterized in soil and leachate to capture hydrobiologically-driven N and C dynamics in soils. By bridging the molecular scale to the mesoscale, this study will advance understanding of soil N and C dynamics coupled with transport modeling and will capture the variability and transformation of C and N cycling in highly human-impacted soil conditions. This award is co-funded by Hydrologic Sciences, Geobiology & Low-Temperature Geochemistry, and the Division of Earth Sciences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.