Solomon Ghezehei

Greenhouse, field, and AI optimization of germplasm for poplar and hemp are needed to address economic and environmental challenges to sustainable bioeconomies in the South's highland or mountain regions.

World energy demand has been continuously increasing, with no indication of slowing down in the coming years. There exists an imperative need for cleaner, sustainable, renewable energy sources that can be locally produced. Biomass is identified as a sustainable long-term plan to reduce the dependency on imported energy and as a national security strategy, and wood pellet is identified as an important biomass product with growing demand and an established expert market mainly in Europe. Many bioenergy-focused field studies conducted by NC State University have shown the efficacy of Populus as short rotation woody crops (SRWC) when clones are matched to site conditions. The objectives of this project are to develop a novel preprocessing during pellet production, assess its effects on the technical feasibility of wood pellet production, and evaluate potential of utilizing Populus clones that are suitable and highly productive in NC for producing the next generation of solid fuels. The expected outcomes include validity of the modified production method to improve the quality of wood pellets and identification of poplar clones for producing high-quality and durable pellets.

In North Carolina, poultry is the top agricultural industry with an economic impact of more than $37 billion, employing over 146,000 people. Although, the main heating fuel for poultry houses is propane, recent pilot studies in the state have shown that wood pellets may be a cheaper heating fuel. Anecdotal evidence also suggests that wood pellet-heated poultry houses also produce better chicken survival, health, and growth. Our goal is to comprehensively assess the technical and economic feasibility of producing pellets specifically for the poultry industry in the Western NC, where a great proportion of broiler and ‘backyard’ poultry farms are located. As the economics of poultry farming is heavily dependent on mortality and overall growth/productivity of chicken, we will examine how wood pellet-based heating affects indoor air quality and health of the broiler chickens in the poultry houses. Our project results will demonstrate if this fuel is cost-effective and sustainable for poultry production to facilitate decision-making about poultry house fuel selection. Additionally, our project will generate information about potential income enhancements associated with pellet-based poultry heating.

Forestry is the largest manufacturing industry in North Carolina (NC). Yet, opportunities for silviculture of hardwood plantations in western NC, where hardwood sawtimber industries are primarily located, have been missing. From our extensive experience of growing short-rotation woody crops for bioenergy and environmental clean-up in different parts of NC, we understand the importance matching species/clones to site conditions and their establishment and management, know expected production costs and yields under various scenarios, and have observed high growth and survival rates of many Populus clones. We have been identifying poplar clones for their potential for high-value veneer production. Our goal is to study feasibility and development of Populus clones as veneer crops by establishing a Populus-veneer demonstration and research site in western NC Piedmont, develop species, clonal and silvicultural recommendations and enterprise budgets for such plantations, and examine post-coppicing potential of Populus clones for veneer-log production. We will collaborate with Columbia Forest Products to test log quality for veneer processing. A successful launching of Populus for veneer would join in existing markets without the requisite of new mills and offer landowners in the western Piedmont and mountains of NC with smaller stands/fields who tend to “try” new promising crops with an opportunity to produce viable high-value hardwoods.

Producing feedstocks for bioenergy remains a national long-term priority. The congressionally-mandated Renewable Fuel Standard remains in effect and targets will increase with time. Many states have Renewable Portfolio Standards while the European Union increasingly is relying on the U.S. for feedstocks to support their energy and carbon policies. With low feedstock prices and high costs of establishment and production for purpose-grown energy crops, few landowners will engage in production until the enterprise is more profitable. We believe that using a modified short-rotation woody crops (SRWC) system, a high-value Populus veneer can be co-produced with energy feedstocks in North Carolina with little yield loss for feedstocks by growing high biomass-yield clones selected for the specific site based on our research with clones selected for veneer. Columbia Forest Products Inc. has expressed great interest in using Populus logs for veneer production following the outcome of processing Populus logs for veneer at their Old Fort facility in North Carolina. We propose to evaluate the efficacy of the hybrid feedstock/veneer SRWC system and evaluate the potential landowner incomes and investment quality using our established plantations, the enterprise budget and decision tool already developed, and the Populus productivity model (3PG) under development for North Carolina. We will screen and evaluate available clones for biomass yield and potential for veneer, determine optimum spacing and rotation regimes for the modified SRWC system to maximized economic returns and conduct investment quality analyses of such projects for North Carolina.

Woody feedstocks are expected to play a major role in the future sustainable renewable energy production. Economically viable short rotation woody crop (SRWC) production is particularly significant in North Carolina due to prominent wood pellet exports to Europe and evolving bioenergy markets. Extrapolating field-scale studies to state-scale assessment of feedstock productivity for North Carolina is a necessary tool to facilitate stakeholder decision making for SRWC procurement and for recommending best management practices to landowners. Our on-going studies have demonstrated that Populus can be grown productively throughout North Carolina, yet individual landowners will need to assess the merit of growing SRWCs on their own land based on their specific site conditions. Potential industrial users of wood feedstocks also need regional assessments of regional-scale potential for sustainable provision of adequate feedstocks before investing in new facilities. We will refine and validate an existing forest productivity model (3-PG model) for SRWCs including poplar, sweetgum, green ash, sycamore, and loblolly pine depending on their productivity performances at our sites. We will also perform plantation-level and regional-scale economic analyses based on the productivity predictions. Data from existing plantations in the coastal plain, piedmont, and mountain regions of North Carolina will be used for model validation.

There is enormous potential for a robust bioeconomy in western North Carolina (NC). Short-rotation woody crops (SRWCs) can be a major regionally grown feedstock if they can be profitable for landowners. Ongoing NCDA-funded projects have shown that weed control cost is a key factor that determines whether SRWCs can be profitable. Denser plantings typically reach canopy closure sooner thus reducing weed control costs. Nutrient availability is critical to SRWC productivity, but it enhances weed growth and control costs. Determining what combinations of weed control treatments and fertilization will maximize SRWC productivity, profitability and viability is needed for a robust bioeconomy in Western NC. We propose to: (1) establish a large-scale planting of Populus, high intensity pine, and sycamore for public demonstration in Western NC; (2) establish an adjacent randomized trial to demonstrate responses of three best-performing Populus clones to different combinations of spacing, chemical and mechanical weed control methods, and fertilization; and (3) coppice part of our existing Populus stands in western NC to compare four-year production with and without coppicing. With data from these and existing trials, we will calibrate a productivity model for Populus and complete an enterprise budget for public dissemination and use specific to Western NC.