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Sorghum grain ranks 5th in cereals for global production (see cereal statistics).
Sorghum is a genus with many species and subspecies, and there are several types of sorghum, including grain sorghums, grass sorghums (for pasture and hay), sweet sorghums (for syrups), and Broomcorn. The focus of this species page is on Sorghum bicolor ssp. bicolor, or grain sorghum.Grain sorghum and maize (corn) are comparable in costs of production and in nutrition, therefore the growing environment is the largest determining factor for choosing which to grow. Grain sorghum requires less water than corn, so is likely to be grown as a replacement to corn and produce better yields than corn in hotter and drier areas, such as the Southern US, Africa, Central America and South Asia (1, 2, 8, 10). One study showed that when corn required over 30 inches of water, sorghum required less than 23 inches (7). However, in cooler areas corn is probably a better option for production, based on yield.
US sorghum accounts for 70% to 80% of world sorghum exports (7).
Determining when and where sorghum was domesticated has been a quandary for historians. Whether it was domesticated in Africa, or transported from Africa and domesticated in India then returned to Africa, is not certain (3, 10). For discussions on the domestication of sorghum, see https://listhost.uchicago.edu/pipermail/ane/2005-December/021309.html and http://www.bioline.org.br/request?cs95020.
It is believed that African slaves brought sorghum seeds with them to the US, and that is how it was introduced to what is now the #1 sorghum growing country (10). And, although breeding has resulted in better nutritional value of sorghum and better flavor, earlier sorghums had higher tannin levels, which caused offensive flavor and was advantageously used as a deterrent to birds. These high-tannin sorghums are still grown where birds could cause significant losses (3).
Sorghum, like many grains, has a diversity of uses, including human consumption and animal feed.
Human food
Sorghum is used for human nutrition all over the world (2, 6, 7, 10). Globally, over half of all sorghum is used for human consumption (7). It is a major crop for many poor farmers, especially in Africa, Central America, and South Asia (10). Grain sorghum is used for flours, porridges and side dishes, malted and distilled beverages, and specialty foods such as popped grain (3, 10).
Feed
Sorghum is also considered to be a significant crop for animal feeds (3, 6, 7, 8, 10), and in the US this is the major use of the grain (2). Finely ground grains or high-tannin grains are less palatable to cattle. Due to its hard and waxy covering, the grains need to be processed by cracking, rolling, or grinding.(1, 2, 3). When processed the nutritional value of sorghum is comparable (but not equal) to maize (corn), so it requires supplementation of vitamin A(1, 2, 3, 8).
Grain sorghum is also used for silage, but it is not as commonly used as the sweet sorghum for this purpose (2). Sweet sorghums have higher silage yield, but grain sorghums have higher nutrition due to the grains, therefore sweet sorghum farmers may plant soybeans along with sorghum to raise the nutritional value of the silage (2).
Pasture - Cattle and sheep are freqently pastured on grain silage after harvest, but secondary growth produces prussic acid and may poison the animals, especially horses (2, 3).
Other
Sorghum fibers are used in wallboard (6, 7, 10), fences (3), biodegradable packaging materials (7), and solvents (3, 10). Dried stalks are used for cooking fuel, and dye can be extracted from the plant to color leather (3).
A more recent use of sorghum is for ethanol (7, 8). By-products from ethanol production, such as sorghum-DDGS (distillers dried grains with solubles), are also finding a place in the market (8).
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