Soil Biogeochemistry, Land Management, and Environmental Sustainability:  Nitrogen and carbon biogeochemical cycles; Greenhouse gas and air pollutant emissions; Nitrate leaching and runoff; Innovative manure and nutrient utilization; Composting; Climate change mitigation and adaptation; Ecosystem services and carbon markets; Dairy environmental sustainability; Novel methods in isotopic techniques; Mechanistic exploration of soil-plant-microbe interactions; Process-based modelling. Zhu-Barker Soil Biogeochemistry Laboratory.