A growing U.S. agricultural biomass industry can help meet the catapulting energy and fuel demands of a global population that the United Nations predicts could reach 9 billion by 2050.
“We need to envision and implement biomass-based, highly productive food, fuel, and energy production systems with available land and water to meet the increasing demands of the growing world population,” says Dan Putnam, University of California Cooperative Extension forage specialist.
Terrestrial biofuels produced from crops, he says, is one way to meet those demands.
Biomass production is a developing industry in the U.S., gaining favor and interest among farmers and other agricultural entrepreneurs.
The industry, still in its infancy, involves growing plants for biomass that are trucked to a conversion facility, where plant wall cellulose is broken down for conversion to glucose sugar and then cellulosic ethanol. Biomass can also be co-fired with coal and wood to produce heat, steam, and electricity at bioenergy refineries.
Existing grain-based ethanol will continue to serve as an important farm-grown fuel in the future; additionally, there are benefits from the high quality distiller’s grain produced in the conversion process, which can be used for livestock feed. Cellulosic conversion is viewed as the next generation of liquid farm fuel technology.
The list of current and potential biomass crops include the grasses switchgrass and miscanthus, plus high biomass sorghum, energycane (high biomass sugarcane), alfalfa, and other crops. These can offer farmers the opportunity to diversify their cropping systems and boost their income stream.
Opponents argue that biomass production is a food-versus-fuel issue — taking land out of food crop production to provide fuel and energy.
“Biomass crops are engineered for production on marginal land and require significantly less water and fewer crop inputs,” says Frank Hardimon, sales manager for Ceres, Inc., a biomass seed and technology company based in Thousand Oaks, Calif. “Biomass crops can bring life to marginal land.”
Ceres is in the race to develop and market low carbon, non-food grasses and other crops for advanced biofuels and biopower. Its trait pipeline includes drought- and salt-tolerance plus improved nitrogen utilization.
“These are some of the key traits necessary to build the biomass industry to scale and to facilitate the wide-scale adoption of energy grasses,” Hardimon says.
Ceres sells seed varieties of perennial switchgrass and annual crop high biomass sorghum to farmers under its Blade Energy Crops brand. The company has lines of sweet sorghum, miscanthus, and energycane in the developmental pipeline.
The switchgrass lines were developed under a partnership with the Samuel Roberts Noble Foundation, headquartered at Ardmore, Okla.
Texas A&M University provided input into high-biomass sorghum, a crop which towers 15 feet to 18 feet in height and generates yields in 90 to 100 days.
Switchgrass takes two to three years to reach maturity, Hardimon says. The crop stand longevity is seven years to 10 years.
Hardimon said, “After five to seven years, a farmer should evaluate the stand. If a new variety on the market can increase yields by 30 percent or more, the rotation of some acreage to a newer variety should be considered.”
Switchgrass is widely adapted to the Southeast, Midwest, and Southwest, where it is currently grown as a pasture plant for forage for cattle.
Switchgrass is a C4 grass, which means it has an efficient biochemical system for fixing carbon dioxide from the atmosphere via photosynthesis. Switchgrass also has a modest demand for nitrogen fertilizers.Switchgrass is probably the most widely tested biomass crop in the U.S.
Genera Energy LLC this year opened one of the world’s first cellulosic ethanol demonstration plants at Vonore, Tenn., where switchgrass and corncobs are converted to cellulosic ethanol for liquid fuels.
Switchgrass relatively new California crop
Switchgrass is a relatively new crop in California. Putnam has four research trials under way, testing varieties from Ceres and Mendel Biotechnology, Inc. He calls switchgrass and miscanthus the top contenders so far in his trials.
“The switchgrass yields, especially in the Central Valley, California trials, are quite impressive on good soils with irrigation,” Putnam says. “Yields have reached 18 tons per acre — some of the highest switchgrass yields recorded in the nation.”
He says commercial switchgrass yields in California could average 8 tons to 15 tons per acre. His research is also measuring switchgrass performance under deficit irrigation.
“Switchgrass may not need its full year-round water requirement,” Putnam says. “We have seen a 30 percent to 40 percent reduction in water compared to its seasonal demand and still generate reasonable yields. This is very encouraging, especially in California where water supplies are an ongoing concern.”
Hardimon says biomass crops generally require a minimum of 20 inches of water annually. The plants naturally have deep root systems. Ceres’ switchgrass varieties have root systems three times larger than the above-ground plant.
“This gives switchgrass a tremendous ability to survive in low water conditions where other crops could have difficulty,” he says. “It also accounts for the large carbon sequestration potential of the plants.”
Much of the growing interest in biofuels is spurred by the federal Energy Independence and Security Act of 2007, plus the adoption of new state energy standards.
The U.S. law, in part, requires taxpayer funding for increased biofuels production. Biofuels added to gasoline must total 36 billion gallons by 2022, up from 4.7 billion gallons in 2007.
The federal law requires that 21 billion gallons of the 2022 requirement be derived from non-cornstarch products, including cellulose ethanol.
As the many needs of a burgeoning world population continue to evolve, Hardimon says foreign governments are seriously evaluating climate change and weighing a stronger commitment to cleaner-burning fuels. There is strong interest overseas in U.S.-grown biomass exports, Hardimon says, including U.S.-produced biomass pellets for European countries and the United Kingdom.
How would the basic biomass production premise work for U.S. farmers?
They would grow biomass under contract to a company for conversion at a biorefinery for cellulosic ethanol or at a biopower utility for bioenergy.
Hardimon suggests biomass farmers choose a facility within 50 to 60 miles of the farm — the closer the better to reduce transportation costs.
Putnam urges farmers to cautiously investigate biomass and how it may fit into their diversification portfolio.
“The first thing to consider is whether a local market exists for the product,” Putnam says. “If you can’t completely answer that question, then treat limited biomass acreage primarily as an experiment.”
He urges interested growers to gain the assurance of at least a short-term market (several years) with a local buyer.
The biomass industry, as with any new venture, is experiencing growing pains and many in agriculture are watching to see how it develops.
The next few years should be an exciting ride for U.S. agriculture in terms of new opportunities in the energy sector.