Creating Local Circular Systems: Bioenergy using Switchgrass, Miscanthus, and Poultry Litter

Commodities

• Agronomic: grass (misc. perennial)
• Animals: poultry

Practices

• Animal Production: manure management
• Crop Production: nutrient cycling
• Education and Training: extension
• Energy: anaerobic digestion
• Farm Business Management: new enterprise development

Project Focus:

Economic growth is often linked to resource extraction, leading to a decoupling of material cycling between sources and sinks. Transition pathways away from extractive, linear economies toward more local, circular systems can create resilient, nutrient-based circular bioeconomies. Key progress has been made globally in identifying and enacting bioeconomy approaches, yet challenges remain to effectively implement biobased systems in the US that are economically viable for farmers. This project focuses on utilizing marginal lands and waste products to generate new revenue streams for farmers. We focus on bioenergy crops (switchgrass and giant miscanthus) grown on lands in the Delmarva region affected by saltwater intrusion that are combined with regional waste products, i.e., poultry litter and poultry processing waste, in anaerobic digestion systems to create bioenergy in localized and economically viable systems.

The proposed work builds on our previous farmer engagement in crop growth, saltwater intrusion, anaerobic digestion, and regulations. Farmers interested in growing switchgrass requested a framework on the implications of contractual agreements and mitigating potential risks associated with entering this emerging market, which our legal team provided. The team's Extension programs on giant miscanthus production on saltwater-intruded areas included numerous workshops, presentations, and webinars on the bequest of farmers. Our annual stakeholder meetings have provided local landowners, Extension agents, and agricultural service providers with strategies to address saltwater intrusion, including planting of switchgrass and giant miscanthus. But these disparate research and Extension efforts have not been combined to go from bioenergy crop growth through to renewable energy production and planning, which this project will accomplish.

Solution and Approach:

The overall goal is to scale circular bioeconomy approaches by using saltwater-intruded lands, bioenergy crops, and waste for renewable energy production. This overall goal will be achieved through implementing four objectives (Fig 1):

1. Quantify biomass production and chemical properties of bioenergy crops grown on prime and salt-intruded soils.
2. Determine the energy potential of bioenergy crops with co-digestion of localized waste resources.
3. Use GIS to show feedstock availability, salt-intruded land, co-digestion potential, regulatory and electric company jurisdictional boundaries, and grant opportunities to drive scaling and future project implementation based on locational analytics.
4. Provide field days, Fact Sheets, and training for farmers on bioenergy crops, anaerobic digestion, and regulations to encourage effective system implementation and economic gain.

Field days and Extension efforts will be integrated to show the entire process from crop production and digestion technology to navigating regulatory hurdles for system implementation. The bioenergy and bioproduct development created through this project will improve the resiliency and circularity of the bioeconomy supply chains while improving soil and human health, economic prosperity, and energy security through bioenergy production that complements existing local agricultural production systems.

The goal is to scale saltwater-intruded land use, bioenergy crops, and renewable energy through implementation of four objectives and testing their associated hypotheses (H):

1. Quantify biomass production and chemical properties of bioenergy crops grown on prime and salt-intruded soils.

H1: 80% yield of miscanthus and switchgrass on salt-intruded soil compared to prime lands, with higher annual biomass with miscanthus.

2. Determine the energy potential of bioenergy crops with co-digestion of waste resources.

H2: Equal ratios of miscanthus, poultry litter, and processing waste will be optional for energy and C:N:P ratio of digestate for crop production.

3. Use GIS to show feedstock availability, scaling options, and regulatory boundaries to drive the implementation based on localized analysis of transport distances and economics of scaling co-digestion systems within the Delmarva region.

H3: Land closest to poultry processing plants on the Delmarva Peninsula will have the highest economic opportunity based on the least distance traveled for co-digestion substrates.

4. Provide field days, Fact Sheets, and Extension training for farmers on bioenergy crops, anaerobic digestion, and regulations to encourage effective system implementation and economic gains.

H4: We intend to reach at least 300 farmers through our in-person or virtual programs.