By Jeri Stroade and Michael Boland, Kansas State University.

Reviewed September 2011 by Diane Huntrods, AgMRC, Iowa State University.
 

Overview
Sorghum (Sorghum bicolor), also known as milo, has a variety of uses including food for human consumption, feed grain for livestock and industrial applications such as ethanol production. The area planted to sorghum worldwide has increased by 66 percent over the past 50 years, while yield has increased by 244 percent. Around half of the sorghum produced is fed to livestock, and half is consumed by humans and used in other applications.

Currently, most human consumption of sorghum occurs in low-income countries, while high-income countries typically use sorghum as a component in livestock feed. Sorghum is a versatile plant because it can tolerate drought, soil toxicities, a wide range of temperatures and high altitudes. Since 25 percent of the population is expected to undergo severe water shortage by 2025, the crop’s adaptability suggests that it may soon play a larger role in supplying the world with grain.

Production
U.S. grain sorghum production in 2010 totaled 345.4 million bushels, down 10 percent from 2009, continuing a downward trend in production. With prices averaging $9.80 per cwt, however, the value of the grain sorghum crop that year reached $1.7 billion.  (NASS 2011)

Sorghum is grown in 14 states. Historically, Kansas and Texas have been the top two sorghum-producing states. In 2010 the two states retained their ranking as leading producers, harvesting 84 percent of the U.S. sorghum crop. Kansas produced 171.0 million bushels valued at $952.8 million, while Texas produced 119.0 million bushels valued at $516.5 million. Other states producing large quantities of grain sorghum include Oklahoma, Colorado, Louisiana and Nebraska.  (NASS 2011)

Leading producers around the world during 2010 included the United States (16.3%), Nigeria (19.3%), India (11.7%) and Mexico (10.5%) (U.S. Grains Council). 
 
Prices
Since sorghum is primarily used as a livestock feed in the United States, and it does not perform as well as corn (that is, higher feed/gain and lower average daily gain) in this capacity, its price will be lower. During 2010, the average price for sorghum in the United States jumped to $9.80 per cwt (NASS 2011).

Exports and Imports
The United States is the leading exporter of sorghum. In recent years, the country has accounted for more than 65 percent of world trade. In 2010 the United States exported grain sorghum valued at $720.8 million, a 13 percent  increase from 2009. The largest buyers for the grain sorghum were Mexico, Japan and Sudan.  (FAS 2010)

During 2010, U.S. imports of grain sorghum increased in quantity but not in value. The nation purchased sorghum valued at $41,000. Most of the imported sorghum originated in Haiti.  (FAS 2010)

Value-added Products
Globally, about 50 percent of sorghum is consumed by humans, but in the United States over 90 percent of the sorghum consumed is used as a component in livestock feed. Corn is the main substitute for sorghum in livestock feed. The starch and protein in sorghum are more difficult for animals to digest than those in corn, giving corn a distinct advantage for feed usage. However, research is being conducted to develop processing methods that allow animals to digest sorghum more readily. Processing breaks the seed coat, reduces particle size and increases surface area. Some methods of processing make the end-use value of sorghum comparable to that of corn because more starch and protein are able to be digested in sorghum.

While many new sorghum food products are currently being developed, the grain’s food use has been limited thus far. These limitations are mainly due to two characteristics of the plant. First, phenolic acid and tannins cause flour made from sorghum to have a bitter flavor. Second, the lack of gluten restricts sorghum’s usefulness in the food industry. Recently a food-grade sorghum was developed that does not contain phenolic acid or tannins, and thus, the resulting flour does not have a bitter taste. These varieties are being used in snack food applications in the United States and Japan, and can also be used to replace wheat flour in some baked products. The lack of gluten may be an advantage in a niche market, targeting people who are gluten intolerant.

Besides feed and food applications, sorghum is used in several other products. Archer Daniels Midland produces wallboard for the housing industry using sorghum. Due to its lack of conductivity, sorghum is becoming a popular material for biodegradable packaging materials.

Processing
Sorghum is increasingly being used in ethanol production. The crop is a good fit for different types of ethanol production including the traditional starch from grain, sugar from pressed juice and high biomass production. In fact, the entire sorghum plant can be used as biomass. Currently, around 12 percent of the U.S. sorghum crop is consumed by ethanol production.

Sweet sorghum is being pursued as a feedstock for half of the ethanol plants planned by Florida companies, including Southeast Renewable Fuels LLC in Fort Lauderdale. Southeast Renewable Fuels has three sweet-sorghum-fueled plants in the works, including one with Seminole Electric Cooperative in Tampa that reportedly will be online by 2011. New Planet Energy LLC, which has an office in Vero Beach, plans to use sorghum as part of the feedstock mix for a plant planned there. Louisiana Green Fuels, LLC, a project in Lacassine, Louisiana, will use an existing sugar cane facility to produce sweet sorghum ethanol. BioDimensions, a west Tennessee company, has assembled a group of farmers, equipment manufacturers and a local bottling company to produce ethanol from sorghum juice.

As of 2007, Kansas had eight dry mill plants that together produced more than 215 million gallons per year (MGPY) of ethanol, creating a market for 76 million bushels of sorghum and corn. Reeve Agri-Energy, another Kansas ethanol plant, produces 12 MGPY of ethanol. The 30 MGPY Abengoa Bionergy plant in Portales, New Mexico, has traditionally used all sorghum when the grain is available.

In 2008 China and India produced 1.3 billion gallons of ethanol from sorghum. In India, Rusni Distillery partnered with the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) to construct a distillery producing 10,000 gallons of ethanol a day using sweet sorghum (Agriculture Business Week 2008). Such efforts are being heavily supported in India because the grain portions of the crop can still be used for food production and animal feed. Note: For a list of other sweet sorghum renewable energy projects, see the AgriFuelsAustralia website.

Research and Development
While corn and sorghum have similar chemical makeups, corn is easier for livestock to digest and use than is sorghum. However, certain processing techniques can break down the sorghum seed enough so that it is as easy for livestock to use as corn is. Many studies have compared different processing techniques’ effect on various livestock’s ability to digest and use the feed. Studies on cattle show that steam-flaked sorghum was preferable to dry-rolled sorghum because it improved daily gain and feed efficiency. Research also suggested a complementary effect between corn and sorghum in cattle feeding. Sorghum was shown to be a slightly more efficient feed than corn for hogs when similar particle sizes and milling techniques were compared.


Sources
Crop Production Annual Summary, National Ag Statistical Service (NASS), USDA, 2011.

Crop Values Annual Summary, NASS, USDA, 2011.

Examples of Other Sweet Sorghum Renewable Energy Projects, AgriFuelsAustralia.

Global Agricultural Trade System (GATS), Foreign Ag Service (FAS), USDA, 2010.

Sorghum, U.S. Grains Council.

Sweet Sorghum: A New Smart Biofuel Crop, Agriculture Business Week, 2008.


Created September 2004 and reviewed September 2011.