The fields of the Sunbelt Ag Expo in Moultrie, Ga., have become a proving ground of sorts for crops that have the potential to be converted into energy and feed sources.
While there is still much work to be done, especially in the area of establishing markets, some of these energy crops are showing promise for Georgia and the Southeast.
While much of the biofuel focus has been on corn in recent years, switchgrass is a crop that appears to be gaining favor with some growers.
“The USDA conducted a study on which crop in the United States sequesters the most carbon, and switchgrass came out No. 1,” says Frank Hardimon, director of sales for Blade Energy Crops/Ceres.
Switchgrass is a perennial crop, he says. “It can last at least 10 years in your field, and it’s a low-input crop. It’ll die back towards the fall of the year. It takes all of the nutrients it has received throughout the season, and the carbon, and it sequesters that back into the soil profile,” he says.
The Blade Energy Crops product line includes the world's first switchgrass varieties developed specifically for bioenergy production — EG 1101 and EG 1102. These varieties have shown double-digit increases over similarly adapted cultivars in trials, as well as improved vigor/establishment.
“Usually, a grower will get about 30 percent of maximum biomass in the first year. Then, you’ll get 75 to 80 percent in the second year. By the third year, you should have reached maximum
As for markets, they are starting to be developed, he says.
In Tennessee, 6,000 acres are being grown for ethanol. There is a working pilot plant where biomass is being converted from switchgrass into cellulose-derived ethanol. There’s also a movement to pelletize the material and co-fire it with coal, using it as an option to reduce greenhouse gas emissions, says Hardimon.
“The market for switchgrass could be a cellulosic ethanol market or a market for bio-power. With cellulosic ethanol, you harvest the entire plant, break it down through enzymes, and the sugar produces ethanol. You can also go out and harvest this, take it to a pelletizer, process the material, and it goes from there to a utility where they mix it with coal,” he says.
University of Georgia Extension agronomist Dewey Lee is one of a team of researchers evaluating the potential of bio-mass crops. “We’re looking at crops and perennial grasses that we hope will be converted into some form of energy. We’re all concerned about our use of foreign oil, and we want to become less dependent on it. With corn, we’re able to produce 12 to 13 billion gallons of ethanol per year, and we can produce even more than that. The gasoline you’re using now may have 10 percent ethanol in it, and maybe in the next year it’ll go up to 12 to 15 percent. This is giving us a start,” he says.
Researchers are hoping to find crops from which bio-mass can be converted into some form of energy, says Lee. One of those is miscanthus, a tall Asian perennial grass that grows rapidly in temperate climates. It has been widely used as an energy crop in Europe for the past 20 years.
“We can convert grasses and perennial grasses, and we can convert corn, corn stovers, and even sorghum into some form of energy,” he says.
Looking at pellets
There isn’t a market in Georgia right now for the grasses, but Lee says he hopes markets will develop. “The first markets in Georgia will probably be for pellets,” he says.
University of Georgia researchers also are looking — for the fifth year at the Expo site — at improved alfalfa varieties. “This is a crop that has been long forgotten in Georgia,” says Dennis Hancock, UGA Extension forage specialist. “Back in the 1950s and 1960s, there were about 60,000 acres of alfalfa in Georgia. We can grow it well. The challenge has been in getting varieties that are well-developed and other technology such as insecticides.”
Now, growers have very good tools for growing alfalfa, he says, and they are relatively low-cost tools. This has led to a resurgence in growing alfalfa, for commercial hay operations, the horse hay market, and dairy operations. In addition, alfalfa is being grown for beef cattle producers who are using it as a supplemental feed and also as a diet for their forage-finished animals, says Hancock.
University of Georgia has developed Bulldog 805 and Bulldog 505 improved alfalfa varieties, he says. “These varieties are highly resistant to a lot of disease problems, and we have a lot of control over insect problems as well.”
Researchers also have been looking at gypsum applications on alfalfa, says Hancock. “Alfalfa is very sensitive to low soil pH and aluminum toxicity in the soil. Gypsum is very good at developing roots. We’ve taken soil samples at about 3 feet deep and found that there are more than 100 more roots in the gypsum-treated alfalfa than in that which has not been treated. Even at the shallow root depths, there’s a significant increase in root development. It improves the potassium efficiency fertilization of alfalfa. It also translates into yields, about a 10 to 20-percent increase in yield where we’re using gypsum,” he says.
Gypsum is being applied on the alfalfa at a rate of 4 tons per acre when the crop is planted, says Hancock.
“This is not a crop for the faint of heart. It takes good management and good soil, but the results are good in terms of high quality,” he says.
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