In these days of soaring food prices worldwide , imagine a crop that provides food, livestock feed and biofuel. It grows in dry conditions, tolerates heat, salt and waterlogging, and provides steady income for poor farmers.
Sweet sorghum, a plant that grows to a height of 8 to 12 feet and looks like corn but with the grain on top rather than on the side of the plant, has all these qualities.
“Sweet sorghum provides an opportunity for developing countries to re-direct oil money that used to go overseas back into their own rural economies,” says Dr. William Dar, Director General of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), one of the 15 allied centers supported by the Consultative Group on International Agricultural Research (CGIAR).
“We consider sweet sorghum an ideal ‘smart crop’ because it produces food as well as fuel,” Dr. Dar adds. “With proper management, smallholder farmers can improve their incomes by 20% compared to alternative crops in dry areas in India.”
In partnership with Rusni Distilleries and some 791 farmers in Andhra Pradesh, India, ICRISAT helped to build and operate the world’s first commercial bioethanol plant, which began operations in June 2007. Locally produced sweet sorghum is used as feedstock.
The process is simple. To produce ethanol, the sorghum stalks are crushed yielding sweet juice that is fermented and distilled to obtain bioethanol, a clean burning fuel with a high octane rating.
The grain can be used for food, chicken or cattle feed. Yet if it has been damaged by disease, no problem – it can also be used to make bioethanol, protecting farm incomes that would otherwise be lost.
The crushed stalks, called bagasse, can be burned to provide energy for the distillery. However research by ICRISAT’s sister center, the International Livestock Research Institute (ILRI), has found that the bagasse value can be doubled if it is compacted in nutritious blocks and fed to cattle.“
Similar public-private-farmer partnership projects with ICRISAT, local industries and farmers are also underway in the Philippines, Mexico, Mozambique and Kenya, as countries search for alternative fuels.
India intends to use a 10% ethanol blend to save an estimated 80 million liters (21 million gallons) of gasoline each year to ease the country’s growing need for gasoline and to reduce carbon emissions.
Sweet Sorghum’s Advantages
Sweet sorghum in India costs $1.74 to produce a gallon of ethanol, compared with $2.19 for sugarcane and $2.12 for corn.
It has high positive energy balance, producing about 8 units of energy for every unit of energy invested in its cultivation and production, roughly equivalent to sugarcane but four times more than for corn. Only 0.8 unit of energy is produced in fossil fuel production for every unit invested.
In the United States, the diversion of corn to bioethanol uses has contributed to increasing food prices. Since food-quality grain of sweet sorghum is not used in ethanol production, and is not in high demand in the global food market, it has little impact on food prices and food security. Sweet sorghum hybrids have almost equal yields of grain as from grain sorghum hybrids and significantly higher stalk yields, so “food production would not be forfeited by switching from regular sorghum to sweet sorghum,” says ICRISAT sorghum breeder Dr. BVS Reddy. Improved sweet sorghum technology could even raise sorghum grain production significantly.
It is also easier and cheaper to grow sweet sorghum than other biofuel crops in India. Sweet sorghum grows on “free” rainwater, whereas sugarcane requires costly irrigation. Sweet sorghum is also more water-efficient: sugarcane consumes two and a half units of water to produce one unit of ethanol, whereas sweet sorghum produces one unit of ethanol from one unit of water.
Some recent reports have raised concerns that the cultivation of certain biofuel crops produces more greenhouse gases than is being saved. This is less likely to be the case for sweet sorghum, although research is needed to assess this carefully. Sweet sorghum is grown on already-farmed drylands that are low in carbon storage capacity, so the issue of clearing rainforest, of great concern for oil palm and sugarcane, does not apply.
Sweet sorghum will not replace sugarcane in parts of the developing world where those crops are well established, emphasizes Dr. Reddy. However, the need for irrigation and high rainfall makes it difficult to expand sugarcane production without moving into ecologically sensitive areas like rainforests.
Fifth largest grain crop
Sorghum is the world’s fifth largest grain crop—behind rice, corn, wheat and barley. It is grown on more than 42 million hectares (107 million acres) in 99 countries. United States, Nigeria, India, China, Mexico, Sudan and Argentina are the leading producers.
According to ICRISAT scientists, an estimated 50% of the grain sorghum area -- 5.1 million hectares (12.9 million acres) in Asia and 12.64 million hectares (32.0 million acres) in sub-Saharan Africa, could be sown with sweet sorghum.
Improved varieties for greater yield
Scientists from ICRISAT and from India’s National Research Centre for Sorghum (NRCS) have developed varieties of sweet sorghum that would contribute to a reliable and steady supply of sweet juice for ethanol production.
Until recently, lack of steady sorghum feedstock throughout the year has constrained India’s efforts to expand ethanol production.
ICRISAT`s current efforts are to help provide a consistent supply by developing photoperiod and temperature-insensitive hybrids (flowering and maturity less influenced by day length and temperature changes) that can be planted any time during the year.
More Commercial Capability
The Rusni Distillery at the Mohammed Shahpur Village in the Medak district of Andhra Pradesh, India, now produces about 40 kiloliters (10,568 gallons) of ethanol every day from locally grown sweet sorghum and some other feedstocks.
Money that formerly went to overseas oil suppliers now stays at home to benefit the poor. Harvesting and processing the stalks provides about 40,000 person-days of labor per year at the distillery. Sweet sorghum was planted last year on about 1370 acres (540 ha) in the region with planned expansion to 2,000 acres to provide feedstock for the prototype distillery.
In addition to Rusni Distilleries, TATA Chemicals, a unit of one of India’s largest multinational enterprises joined the ICRISAT-Private Sector Sweet Sorghum Ethanol Research Consortium in late 2007. Under the agreement, ICRISAT will supply seeds for sweet sorghum varieties and hybrids along with technical support to farmers. TATA will contract local farmers to produce sweet sorghum on nearly 10,000 acres in Maharashtra State and will build a plant capable of producing up to 30 kiloliters (7,926 gallons) of ethanol per day. The Jade Grupo Cooperativo, Mexicano, Mexico, and Praj Industries, Pune, India have also joined the consortium.
The India experience is also serving as a model for other parts of the developing world. ICRISAT and five private companies in the Philippines have developed a memorandum of understanding to form a sweet sorghum consortium, and similar consortia are being formed in Uganda, Nigeria, Mozambique and South Africa.
In the public-private-farmer partnership model developed by ICRISAT, scientists develop sweet sorghum hybrids and test new cultivars with smallholder farmers. Distilleries provide farmers with improved seed and technical advice, offer a guaranteed price for the feedstock, and transport the harvested stalks for processing. Distilleries are developing decentralized stalk crushing stations to reduce transportation and handling costs, and to make it easier for farmers to retain the bagasse for animal feed. The goal is to develop a competitive biofuel industry that benefits the rural poor and is environmentally sustainable while not cutting into the food supply chain.
Interest in sweet sorghum’s ethanol potential is not confined to the developing world. With growing concern about the use of corn grain for bioethanol, the US Government is exploring the potential of sweet sorghum, as are several university and private sector groups. An International Conference on Sorghum for Biofuel, sponsored by the Office of International Research Programs of the U.S. Department of Agriculture and Texas A&M, will be held in Houston, Texas in August 2008.
Amidst today’s soaring food and oil prices, sweet sorghum is indeed a smart crop that contributes to household food security and helps livelihoods of the rural poor in the semi-arid tropics, now populated by about a billion people—the poorest of the poor.
The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) is a non-profit, non-political organization that does innovative agricultural research and capacity building for sustainable development with a wide array of partners across the globe. ICRISAT's mission is to help empower 600 million poor people to overcome hunger, poverty and a degraded environment in the dry tropics through better agriculture. ICRISAT belongs to the Alliance of Centers of the Consultative Group on International Agricultural Research (CGIAR).
Working in 55 countries, ICRISAT is headquartered in Patancheru ( Hyderabad), Andhra Pradesh, India and maintains regional hubs and country offices in sub-Saharan Africa.
Much of ICRISAT’s research focuses on “smart crops” and production systems that increase incomes of poor dry land farmers without compromising their need for food and feed or harming the environment.