Prof. Julia Lu
Department of Chemistry and Biology, Toronto Metropolitan University, 350 Victoria Street, Toronto, ON M5B 2K3 CanadaSpeech Title: Nitrogen (N) species in marginal land soils: is N-fertilizer necessary for biomass production on marginal land in Ontario, Canada?
Abstract: Nitrogen-fertilizer application is one of the most common agricultural practices that helps plant growth and increase crop yields. Plants, however, take up only a fraction of the N applied and the unused N can be carried into the surface environment with unintended consequences for water and emitted to air, as nitrous oxide, contributing to global warming. This research focuses N-species in soils during the sorghum growing season on marginal lands in Ontario, Canada. Soil samples were collected from agricultural and marginal land fields at three different times during the growing season: Before Planting (BP), After Fertilizer Application (AFA), At (biomass) Harvest (AH). Plant-usable (as water leachable N-species) and unusable N-species in the soil samples were analyzed using calorimetric and Kjeldahl methods. The results show that the plant-usable N-species only account for a small portion of the N content in the soil and that the concentrations of the plant-usable N-species in the soils varies with the land type and soil collection time. N-fertilizer significantly increased the level of the plant-usable N-species in the soils shortly after its application but the increase was not proportional to its rate of application and did not significantly enhance the biomass production. More research is needed to confirm the findings of this research and to develop techniques to make the plant-unusable N-species usable by plants.
Biography: Dr. Julia Lu is a professor in the Department of Chemistry and Biology, Toronto Metropolitan University, Canada. She received her PhD degree from Carleton University, Ottawa, Canada. Her research focuses on the development, evaluation, validation and application of novel techniques to identify and quantify different physical and chemical forms of toxic substances in water, air, soil and biological tissue; environmental pollution; biogeochemistry of toxic substances in the natural environment and their effects on ecosystem and human health. She has so far co-authored 58 papers published in various (>30) scientific journals including “Analytical Chemistry”, “Environmental pollution”, “Environmental Science and Technology”, “Nature”, …