Bioenergy Feedstock Development Program Status Report

ORNL/TM-2000/292

L. A. Kszos, M. E. Downing, L. L. Wright, J. H. Cushman, S. B. McLaughlin, V. R. Tolbert, G. A. Tuskan, and M. E. Walsh

2000

Prepared for the U.S. Department of Energy Office of Fuels Development Budget Activity Number EB 52 03 00 0 and Office of Power Technologies Budget Activity Number EB 24 04 00 0 Prepared by OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831 managed by UT-BATTELLE, LLC. for the U.S. DEPARTMENT OF ENERGY under contract DE-AC05-00OR22725

The full report is available as a PDF file (603k).

Executive Summary

The U.S. Department of Energy’s (DOE’s) Bioenergy Feedstock Development Program (BFDP) at Oak Ridge National Laboratory (ORNL) is a mission-oriented program of research and analysis whose goal is to develop and demonstrate cropping systems for producing large quantities of low-cost, high-quality biomass feedstocks for use as liquid biofuels, biomass electric power, and/or bioproducts. The program specifically supports the missions and goals of DOE’s Office of Fuels Development and DOE’s Office of Power Technologies.

ORNL has provided technical leadership and field management for the BFDP since DOE began energy crop research in 1978. The major components of the BFDP include energy crop selection and breeding; crop management research; environmental assessment and monitoring; crop production and supply logistics operational research; integrated resource analysis and assessment; and communications and outreach. Research into feedstock supply logistics has recently been added and will become an integral component of the program.

Crop Selection and Breeding

The BFDP’s energy crops research emphasizes short-rotation tree crops in the genus Populus (primarily poplars and cottonwoods) and switchgrass (Panicum virgatum). These species were chosen as crop development models based on performance in screening trials, potential for broad distribution, ease of propagation, environmental benefits, and status of genetic information. Many other species are also suitable feedstocks for bioenergy and bioproducts and could become energy crops. Our objective is to improve and protect yields of the model crop species through breeding and sustainable management systems. High, dependable and sustainable yields are key to reducing crop production costs. Genetic improvement and appropriate cultural practices provide the most reliable means of obtaining long-term gains in yield.

The strategy used by BFDP for developing Populus and willow as model woody crops is based on traditional breeding programs linked to plant physiology, molecular genetics, pest and disease resistance, and silviculture practices. Our breeding programs are located in the Pacific Northwest, and in the north-central, southeastern, and northeastern United States. Each regional breeding effort is at a different stage of development. The Pacific Northwest poplar hybridization program started earlier and achieved great success, and the ongoing molecular genetics work is heavily supported by industry. The north-central poplar breeding and testing effort is just beginning to demonstrate in field sites the rewards of hybridization and selection for disease resistance. In the north-central regions, new non-commercial hybrid poplar clones have demonstrated growth rates that are significantly greater than those of commercial controls. In the southeastern region, eastern cottonwood clone bank nurseries and clonal breeding trials have been established. In the northeastern region, selection and breeding of hybrid willow involves native germplasm collection, breeding and selection, and field trials. Growth data indicate that some of the new clones will outperform those previously planted in field trials.

Several woody crops studies have relevance nationwide. Detailed physiological studies of growth limitations in several hardwood species were conducted in the Southeast. Evaluations of the mechanisms of drought stress resistance among several hybrid poplar clones are providing input to industry breeding programs. Applying the tools of biotechnology to woody crop selection and breeding is expected to accelerate progress in woody crop improvement.

The BFDP is a participating member in two biotechnological cooperatives. Recently, researchers with the Poplar Molecular Genetic Cooperative isolated the gene that confers resistance to an important Populus disease, leaf rust caused by Melampsora medusa. The Tree Genetic Engineering Research Cooperative is currently transforming commercially important hybrid poplar clones with sterility genes, insect resistance genes, and herbicide resistance genes. At ORNL, researchers are using mathematical models and molecular genetic assays to understand the genetic mechanisms of sexual differentiation and wood formation in willow.

Switchgrass development is centered around breeding programs in Nebraska, Oklahoma, and Georgia. Current breeding projects build upon early work that identified chromosomal and cytological differences between upland and lowland switchgrass cultivars and emphasize genotypic recurrent selection. Thus far, many of the experimental synthetic varieties bred over the past few years are producing significantly more biomass than commercial controls. New molecular tools are being developed to explore the biology of switchgrass, to improve classical breeding, and to set the stage for potential gains through genetic transformation (if deemed desirable). These tools include development of tissue culture techniques for clonal reproduction of parent plants, molecular fingerprinting, genetic mapping, and linking physiological traits to specific genotypes. Significant advances have been made in tissue culture technology since 1993, including the development of plantlets from a wide variety of plant parts, production of flowers in culture, and techniques for producing plantlets from cells in suspension cultures.

Crop Management Research

Woody crop management research has been an integral component of the BFDP since its inception. Although many silviculture issues are sufficiently resolved to result in successful establishment and production, most management issues — such as rapid increase of preferred clones, fertilization, weed control, and disease and insect control — must be optimized at the region-or site-specific level and thus are not resolved at all locations. Insects and disease have the potential to seriously hinder the development of woody species as energy crops. Research at several institutions is focused on developing new cottonwood clones that are resistant to the cottonwood leaf beetle, Septoria stem canker, and Melampsora leaf rust.

Crop management research for switchgrass focuses on improving practices or conditions that constrain the use of switchgrass for energy. These constraints may be related to planting, stand establishment, use of chemicals for fertilizer, weed or pest control, soil quality, or harvest regime. Establishment issues, such as seed dormancy, seed scale-up, and the use of herbicides and/or insecticides, are important because of their potential impacts on cost. Successful stand establishment practices have been developed for the Southeast, including use of methods to break seed dormancy, effective application of fertilizers (N, P, and K), and herbicide regimes. Although much progress in establishment has been accomplished, research efforts are continuing to optimize establishment in all regions.

Environmental assessment and monitoring

In the process of developing feedstocks, it is important to develop the quantitative data needed to identify the environmental benefits and risks associated with establishment, management, and harvest of bioenergy crops and their use for energy. Water quality issues are increasingly becoming a concern because of the potential transport of herbicides and nutrients into surface water and groundwater. Studies in small watersheds have been conducted in the Southeast to evaluate erosion, surface water quality and quantity, and subsurface movement of water and nutrients from woody and herbaceous crops. A watershed study in South Carolina is evaluating the effects of water level manipulation on water quality and quantity, soil quality, and short rotation woody crop productivity.

An integral component of environmental studies of biomass crops is to quantify the changes that occur in soil quality and soil carbon storage for a variety of management practices, soil types, and climates. Soil carbon sequestration and soil quality in areas with switchgrass plantings are currently being investigated in the southeast. In the near future, similar research will be initiated in the northern Great Plains region. Early indications are that soil improvement may be occurring in areas planted with switchgrass. In the Southeast, a model based on soil organic carbon measurements has been developed to predict the rate of increase in soil organic carbon after switchgrass establishment.

Recently, BFDP has worked with the United States Department of Agriculture (USDA) Agricultural Research Service to begin studies on the use of agricultural residue, particularly corn stover, for energy production. This research will be part of an effort to identify stover availability and harvest potential while maintaining soil cover, soil stability, and soil quality.

The role of energy crops in enhancing biodiversity has been an area of research since 1992. From 1992 to 1996, bird and mammal surveys were conducted in areas that contained various types, sizes, and ages of energy crops and undisturbed habitats. In general, established hybrid poplar plantings were used more extensively by birds and small mammals than common row crops but less extensively than natural mixed forests. In the Southeast, bird community structure and diversity in industrial plantings of sweetgum and sycamore were comparable to community structure and diversity in similarly aged hardwood forests.

Operational Research

Operational research involves the collection and analysis of data from commercial-scale or demonstration-scale plantings. The objective is to understand and improve overall system efficiency and reduce costs of feedstock supplies. The BFDP has been engaged in operational research since the North Central Hybrid Poplar Regional Planting established approximately 130 acres of hybrid poplar in the late 1980s. In 1994 and 1995, the BFDP and others collaboratively established approximately 5000 acres of hybrid poplar in two Minnesota projects. Production and operational data from these plantings are being collected and published for use by the bioenergy community. The BFDP is working with collaborators in projects established through the DOE Biomass Power Program. For these switchgrass and willow production systems, the planting, field preparation, harvesting, transporting, and processing costs are being tracked and recorded.

Supply logistics research, only recently added as a component of the BFDP program, focuses on the equipment, systems, and infrastructures required to move biomass from where it is grown to where it is used, in a form needed by the end-user. We are collaborating with the National Renewable Energy Laboratory (NREL) on a model of the logistics and costs of collecting, transporting, and processing corn stover for use as an ethanol feedstock. The results will be linked to the ethanol conversion models developed by NREL to obtain full supply-chain economics.

Integrated Resource Analysis and Assessment

Integrated resource analysis and assessment research uses information from BFDP tasks and DOE programs to analyze economic factors associated with biomass production. The work involves creation of tools, models, and databases that can be used by firms, government agencies, and other institutions to conduct analyses pertinent to their needs. Our analysis focuses on regional and national issues and provides information in the form of databases and user-friendly models that can be used by individual firms to conduct screening and pre-feasibility analysis. The Oak Ridge Energy Crop County Level Database (ORECCL) includes county-level land-use information and information about three energy crops, including expected yields and range and estimated production costs. The Multi-Feedstock Biomass Resource Database contains estimated price and quantity data for forest residues, mill residues, urban wood wastes, agricultural residues, and dedicated energy crops. Economic models that have been developed include (1) BIOCOST, a model used to estimate regional costs of producing switchgrass, hybrid poplar, and willow; (2) the Oak Ridge Integrated Biomass Assessment System (ORIBAS), a geographic information system (GIS)-based transportation model; and (3) the Policy Analysis System (POLYSYS), an agricultural sector model used to estimate the cost-competitiveness and impacts of biomass crops with traditional agricultural land uses.

Economic and policy analyses

The databases and economic models are currently being used in several economic and policy analyses. One recent analysis indicates that if biomass could be sold at a $40/dry ton farmgate price, approximately 42 million acres (producing 188 million dry tons of biomass) could produce energy crops at a profit greater than that from existing uses of the land. In a joint analysis with the USDA Forest Service, we are evaluating the potential role for hybrid poplar in fiber markets. Corn stover is an existing form of biomass that could be collected and processed to produce ethanol as a liquid transportation fuel. A study is currently analyzing the potential economic impacts of a corn-stover-to-ethanol industry in the ten Midwestern states that produce the greatest quantities of corn. The analysis, conducted for each state, will include one-time impacts associated with the construction of ethanol plants, as well as annual impacts associated with plant operation, the agricultural sector, and the transportation sector.

Partnership and Outreach

The BFDP strives to provide useful, accurate information on energy crop research, biomass resources, and biomass production. All BFDP staff communicate with public and technical audiences through such activities as farm show participation, International Energy Agency task participation, contribution to web sites, BFDP’s Energy Crops Forum newsletter, and fact sheets or Frequently Asked Questions sheets. In addition, staff members have participated actively in meetings with environmental constituencies across the country to provide input and to identify, define, and document the interests and concerns that internal and external stakeholders have about bioenergy crops and agricultural residues, cultivation, and harvesting practices.