APPLICATION OF GRAPHITIC NANOPARTICLES IN REDUCING NITROGEN LOSS FROM AGRICULTURAL SYSTEMS

Our preliminary data showed encouraging results wherein 2-D graphene added with NPK fertilizers can reproducibly, across three grow seasons, reduce nitrogen application requirements (kg N/ha) and leaching into groundwater without impacting plant productivity. However, the preliminary study wasn't designed to probe the mechanisms responsible for this encouraging outcome. This proposed project aims to experimentally investigate the efficacy and mechanisms of engineered graphitic nanoparticles (GNP) in affecting the mobility and transformation of inorganic nitrogen species in soil/plant systems. The overall objective is to understand the biogeochemical mechanisms responsible for this dramatic benefit in improving nitrogen use such that we can more fully utilize the unique size-dependent properties of graphitic nanomaterials to increase nutrient uptake efficiency, decrease environmental impact from synthetic fertilizer, and assess the exposure levels and environmental/health risk of GNP application in agricultural systems.The specific objectives are following:Objective #1 - Characterize interactions of GNP with inorganic nitrogen species and soil components (e.g., mineral and organic matter) that affect nitrogen transformation and distribution in soil.Objective #2 - Evaluate GNP mobility in soil systems and transport of nitrogen species upon simulated irrigation events in soil columns.Objective #3 - Determine the change of biogeochemical N transformation in a soil-plant system and optimize N uptake efficiency and N loss reduction from conventional fertilizer application.Objective #4 - Examine soil respiration and N transformation resulting from changing microbial functional activities.