Sun Grant Research Articles

Environmental limitation mapping of potential biomass resources across the conterminous United States

AbstractSeveral crops have recently been identified as potential dedicated bioenergy feedstocks for the production of power, fuels, and bioproducts. Despite being identified as early as the 1980s, no systematic work has been undertaken to characterize the spatial distribution of their long‐term production potentials in the United states. Such information is a starting point for planners and economic modelers, and there is a need for this spatial information to be developed in a consistent manner for a variety of crops, so that their production potentials can be intercompared to support crop selection decisions. As part of the Sun Grant Regional Feedstock Partnership (RFP), an approach to mapping these potential biomass resources was developed to take advantage of the informational synergy realized when bringing together coordinated field trials, close interaction with expert agronomists, and spatial modeling into a single, collaborative effort. A modeling and mapping system called PRISM‐ELM was designed to answer a basic question: How do climate and soil characteristics affect the spatial distribution and long‐term production patterns of a given crop? This empirical/mechanistic/biogeographical hybrid model employs a limiting factor approach, where productivity is determined by the most limiting of the factors addressed in submodels that simulate water balance, winter low‐temperature response, summer high‐temperature response, and soil pH, salinity, and drainage. Yield maps are developed through linear regressions relating soil and climate attributes to reported yield data. The model was parameterized and validated using grain yield data for winter wheat and maize, which served as benchmarks for parameterizing the model for upland and lowland switchgrass, CRP grasses, Miscanthus, biomass sorghum, energycane, willow, and poplar. The resulting maps served as potential production inputs to analyses comparing the viability of biomass crops under various economic scenarios. The modeling and parameterization framework can be expanded to include other biomass crops.

Biomass production of herbaceous energy crops in the United States: field trial results and yield potential maps from the multiyear regional feedstock partnership

AbstractCurrent knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small‐scale and short‐term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock yield for each of the herbaceous species evaluated. The Feedstock Partnership expands our previous understanding of the bioenergy potential of switchgrass, Miscanthus, sorghum, energycane, and prairie mixtures on Conservation Reserve Program land by conducting long‐term, replicated trials of each species at diverse environments in the U.S. Trials were initiated between 2008 and 2010 and completed between 2012 and 2015 depending on species. Field‐scale plots were utilized for switchgrass and Conservation Reserve Program trials to use traditional agricultural machinery. This is important as we know that the smaller scale studies often overestimated yield potential of some of these species. Insufficient vegetative propagules of energycane and Miscanthus prohibited farm‐scale trials of these species. The Feedstock Partnership studies also confirmed that environmental differences across years and across sites had a large impact on biomass production. Nitrogen application had variable effects across feedstocks, but some nitrogen fertilizer generally had a positive effect. National yield potential maps were developed using PRISM‐ELM for each species in the Feedstock Partnership. This manuscript, with the accompanying supplemental data, will be useful in making decisions about feedstock selection as well as agronomic practices across a wide region of the country.

Summary Report on the 2012 Sun Grant National Conference: Science for Biomass Feedstock Production and Utilization

Abstract The 2012 Sun Grant National Conference on Science for Biomass Feedstock Production and Utilization was held on 2–5 October 2012, in New Orleans, LA, USA. The Sun Grant Initiative set out to highlight recent advances in science and technology contributing to the deployment of conventional and advanced biofuels and bioproducts from agricultural and forest systems. The Initiative, with sponsorship from the Department of Energy’s Bioenergy Technologies Office (BETO), assembled an agenda focusing on promoting collaboration between academic, industry, non-profit, and government partners. This special issue is comprised of a small sample of conference presentations selected to reflect important research progress and to highlight the range of issues that must be considered as the transition to biomass energy takes hold.

Switchgrass Response to Nitrogen Fertilizer Across Diverse Environments in the USA: a Regional Feedstock Partnership Report

The Regional Feedstock Partnership is a collaborative effort between the Sun Grant Initiative (through Land Grant Universities), the US Department of Energy, and the US Department of Agriculture. One segment of this partnership is the field-scale evaluation of switchgrass (Panicum virgatum L.) in diverse sites across the USA. Switchgrass was planted (11.2 kg PLS ha−1) in replicated plots in New York, Oklahoma, South Dakota, and Virginia in 2008 and in Iowa in 2009. Adapted switchgrass cultivars were selected for each location and baseline soil samples collected before planting. Nitrogen fertilizer (0, 56, and 112 kg N ha−1) was applied each spring beginning the year after planting, and switchgrass was harvested once annually after senescence. Establishment, management, and harvest operations were completed using field-scale equipment. Switchgrass production ranged from 2 to 11.5 Mg ha−1 across locations and years. Yields were lowest the first year after establishment. Switchgrass responded positively to N in 6 of 19 location/year combinations and there was one location/year combination (NY in Year 2) where a significant negative response was noted. Initial soil N levels were lowest in SD and VA (significant N response) and highest at the other three locations (no N response). Although N rate affected some measures of biomass quality (N and hemicellulose), location and year had greater overall effects on all quality parameters evaluated. These results demonstrate the importance of local field-scale research and of proper N management in order to reduce unnecessary expense and potential environmental impacts of switchgrass grown for bioenergy.

Erratum to: Crop Residue Considerations for Sustainable Bioenergy Feedstock Supplies

Two regrettable errors occurred in citing a critical funding source for the multi-location research summarized in the 2014 article entitled “Crop Residue Considerations for Sustainable Bioenergy Feedstock Supplies” by Douglas L. Karlen and Jane M. F. Johnson (BioEnergy Research 7:465–467 DOI 10.1007/ s12155-014-9407-y). Within the abstract, the sentence stating that: “This overview highlights ... as part of the National Institute for Food and Agriculture Sun Grant Regional Feedstock Partnership Corn Stover Team” should read “This overview highlights ... as part of the Department of Energy Bioenergy Technologies Office’s Regional Feedstock Partnership Corn Stover Team (as part of the Sun Grant Initiative). Also, in the second paragraph of the article, the sentence stating that: “The SOC and GHG concerns ... Therefore, working through the Office of Biomass Products” (now known as the Biomass Energy Technology Office the DOE... through the NIFA Sun Grant Association to address those needs” should read “The SOC and GHG concerns ... through the DOE Bioenergy Technologies Office, the DOE ... through the Sun Grant Initiative to address those needs.” We deeply regret these errors and want the readers of BioEnergy Research to know that the USDA-ARS Resilient EconomicAgricultural Practices (formerly theRenewable Energy Assessment Project) REAP team is very grateful for the collaborative research that was enhanced by these DOE fiscal resources.

Distribution of Structural Carbohydrates in Corn Plants Across the Southeastern USA

Quantifying lignin and carbohydrate composition of corn (Zea mays L.) is important to support the emerging cellulosic biofuels industry. Therefore, field studies with 0 or 100 % stover removal were established in Alabama and South Carolina as part of the Sun Grant Regional Partnership Corn Stover Project. In Alabama, cereal rye (Secale cereale L.) was also included as an additional experimental factor, serving as a winter cover crop. Plots were located on major soil types representative of their respective states: Compass and Decatur soils in Alabama and a Coxville/Rains-Goldsboro-Lynchburg soil association in South Carolina. Lignin and structural carbohydrate concentrations in the whole (above-ground) plant, cobs, vegetation excluding cobs above the primary ear (top), vegetation below the primary ear (bottom), and vegetation from above the primary ear including cobs (above-ear fraction) were determined using near-infrared spectroscopy (NIRS). The distribution of lignin, ash, and structural carbohydrates varied among plant fractions, but neither inclusion of a rye cover crop nor the stover harvest treatments consistently affected carbohydrate concentrations within locations. Total precipitation and average air temperature during the growing season were strongly correlated with stover composition indicating that weather conditions may have multiple effects on potential biofuel production (i.e., not only yield but also stover quality). When compared to the above-ear fractions, bottom plant partitions contained greater lignin concentrations. Holocellulose concentration was consistently greater in the above-ear fractions at all three locations. Data from this study suggests that the above-ear plant portions have the most desirable characteristics for cellulosic ethanol production via fermentation in the southeastern USA.

Crop Residue Considerations for Sustainable Bioenergy Feedstock Supplies

The anticipated 2014 launch of three full-scale corn stover bioenergy conversion facilities is a strong US market signal that cellulosic feedstock supplies must increase dramatically to supply the required biomass in a sustainable manner. This overview highlights research conducted by the USDA-Agricultural Research Service Renewable Energy Assessment Project (now known as the Resilient Economic Agricultural Practices) team as part of the National Institute for Food and Agriculture Sun Grant Regional Feedstock Partnership Corn Stover team. Stover and grain yield, soil organic carbon, soil aggregation, greenhouse gas, energy content of the stover, and several other factors affecting the fledgling bioenergy industry are addressed in this special issue of the journal.

Influence of High Protein Digestibility Sorghums on Free Amino Nitrogen (FAN) Production during Malting and Mashing

The International Sorghum, Millet and Other Grains Collaborative Research Support Program (INTSORMIL), Sun Grant Program, US Department of Transportation, Project No. DTOS59-07-G-00056 to D.B. Hays, Novozymes SA, Mr J. van Aswegen, Mr I. Kennedy and Mr B. Higgins.

Corn stover feedstock trials to support predictive modeling

AbstractTo be sustainable, feedstock harvest must neither degrade soil, water, or air resources nor negatively impact productivity or subsequent crop yields. Simulation modeling will help guide the development of sustainable feedstock production practices, but not without field validation. This paper introduces field research being conducted in six states to support Sun Grant Regional Partnership modeling. Our objectives are to (1) provide a fundamental understanding of limiting factor(s) affecting corn (Zea mays L.) stover harvest, (2) develop tools (e.g., equations, models, etc.) that account for those factors, and (3) create a multivariant analysis framework to combine models for all limiting factors. Sun Grant modelers will use this information to improve regional estimates of feedstock availability. A minimum data set, including soil organic carbon (SOC), total N, pH, bulk density (BD), and soil‐test phosphorus (P), and potassium (K) concentrations, is being collected. Stover yield for three treatments (0%, 50%, and 90% removal) and concentrations of N, P, and K in the harvested stover are being quantified to assess the impact of stover harvest on soil resources. Grain yield at a moisture content of 155 g kg−1 averaged 9.71 Mg ha−1, matching the 2008 national average. Stover dry matter harvest rates ranged from 0 to 7 Mg ha−1. Harvesting stover increased N–P–K removal by an average of 42, 5, and 45 kg ha−1 compared with harvesting only grain. Replacing those three nutrients would cost $53.68 ha−1 based on 2009 fertilizer prices. This first‐year data and that collected in subsequent years is being used to develop a residue management tool that will ultimately link multiple feedstock supplies together in a landscape vision to help develop a comprehensive carbon management plan, quantify corn stover harvest effects on soil quality, and predict regional variability in feedstock supplies.

The Sun Grant Initiative... A new integrative role for science and education

The Sun Grant Initiative... <i>A new integrative role for science and education</i>

The Sun Grant Initiative—A New Day for Agriculture

The Sun Grant Initiative is a new Act of Congress (Sec. 9011 of Title IX of the Farm Security and Rural Investment Act) that reflects a new vision for the future in agriculture. The Sun Grant Initiative is driven by a national consortium of land grant universities, in coordination with the U.S. Department of Agriculture and the U.S. Department of Energy. The mission of the Sun Grant Initiative is to 1) enhance national energy security through development, distribution, and implementation of biobased energy technologies; 2) promote diversification and environmental sustainability of America's agriculture through land-grant based research, extension, and education programs in renewable energy and biobased products; and 3) promote opportunities for biobased economic diversification in rural communities. Bioenergy produced on American farms represents an opportunity to both reduce dependence on imported oil and provide a significant source of income to American farmers.