Research

    Research Vision

    Over the past two decades, our research has expanded from nutrient management in agricultural primary production to nutrient stewardship across the entire agrifood system. This evolution reflects a growing recognition that improving environmental sustainability requires understanding nutrient flows beyond the farm gate, from food production and consumption to waste recovery and circular resource use.

    Research Theme 1: Circular Feeds and Livestock Production

    Food loss and waste represents one of the greatest inefficiencies in the global food system, with major implications for food security, climate change, and resource sustainability. Recovering suitable food waste as livestock feed captures substantially greater value than most other recycling pathways while reducing reliance on conventional feed resources. Our research evaluates the nutritional suitability of diverse food waste and residual biomass streams, develops preservation and processing strategies, and conducts laboratory and animal-feeding studies to assess their impacts on animal productivity, nutrient use efficiency, enteric emissions, and environmental sustainability. Together, these studies provide scientific evidence supporting the development of circular feed systems for sustainable livestock production.

    Publication #3, 5-9

    Diagram of food loss waste.

    Fig. 2. Food loss/waste – Feed as top priority – Animals for food – Circular Systems. Adapted from Dou et al., ES&T Letters. https://doi.org/10.1021/acs.estlett.6c00186, 2026.

    Research Theme 2: Food Waste End-of-Life Pathway and Food System Sustainability

    Food waste management is a critical component of climate change mitigation and circular bioeconomy development. Our research combines field data, life-cycle assessment, and systems-based analysis to quantify greenhouse gas emissions and resource implications of alternative end-of-life pathways, including landfilling, composting, anaerobic digestion, and conversion to animal feed. These studies demonstrate that diverting food waste from landfill substantially reduces greenhouse gas emissions while generating important co-benefits, including sparing land, water, fertilizer, and energy resources. Our work provides science-based evidence to support policy development and investment in circular agrifood systems.

    Publication #8, 10, 11

    Diagram of Distribution of studies documenting LCA-based GHG mitigation potential of food waste recycling options.
    Diagram of carbon footprint of AC, AD, Re-Feed, and landfill disposal, in terms of (a) operation-related emissions, (b) emission offset credits, (c) systems-based emissions, and (d) emission mitigation factors (system-based emissions minus landfill emissions).

    Fig.3. Top: Distribution of studies documenting LCA-based GHG mitigation potential of food waste recycling options: composting (AC, blue), anaerobic digestion (AD, yellow), and re-purposing to animal feed (Re-Feed, green), compared with landfill (red).  Bottom: carbon footprint of AC, AD, Re-Feed, and landfill disposal, in terms of (a) operation-related emissions, (b) emission offset credits, (c) systems-based emissions, and (d) emission mitigation factors (system-based emissions minus landfill emissions).  Adapted from Wang et al., Nature Food, https://doi.org/10.1038/s43016-025-01140-z, 2025

    Research Theme 3: Nutrient Flow Modeling in the Food Supply Chain

    Carbon, nitrogen, and phosphorus are continuously transformed as food moves through production, processing, distribution, consumption, and end-of-life management. Our research develops quantitative methods to track these nutrient flows across the food supply chain and identify opportunities to reduce losses, recover valuable resources, and improve system efficiency. By integrating material flow analysis, life-cycle assessment, and systems modeling, we provide evidence that supports more circular, resilient, and environmentally sustainable food production and consumption.

    Publication #3, 5-9

    Diagram of the best-use framework for prioritizing macronutrients (C, N, P) embedded in food waste streams across recycling pathways.

    Fig. 4. A best-use framework for prioritizing macronutrients (C, N, P) embedded in food waste streams across recycling pathways. Pre-consumer food waste is preferentially directed toward higher-value uses such as animal feed; heterogeneous, contamination-prone post-consumer food waste is more suitable for land-based non-feed uses. Consumer-interface food waste occupies an intermediate position due to constraints such as de-packaging and variable composition. Adapted from Dou et al., ES&T Letters. https://doi.org/10.1021/acs.estlett.6c00186, 2026.