Dr. Ni’s research interest is in methodology and technology in air quality study, bioenergy from agricultural wastes, and air and water pollution abatement, such as measurement and control for research facilities, data acquisition and control software programming, sensor development, biogas technology, pollution assessment, and mathematical modeling. His extension is in livestock and rural waste systems engineering, including state-wide animal manure management, water and air quality protection, and on-farm biological waste treatment using technologies such as anaerobic digestion, bioreactors, and best management practices for reducing environmental impacts from animal agriculture.