Sorghum (Sorghum bicolour), also known as great millet, durra and jowar, originated in North-Eastern Africa. It is a significant crop in Sub-Saharan Africa and millions of people around the world depend on it for food.
It is the fifth major staple cereal after wheat, rice, maize, and barley, and is cultivated worldwide in warmer climates in semi-arid tropical areas of Africa, Asia, and Central America. It can be cultivated in areas that are prone to drought and on marginal land that is not suitable for other grain crops.
It is a vital food and fodder cereal crop with the same nutritional value as maize. The leaves and stalks are also used as green or dry fodder, hay, or silage for livestock.
Grains must be processed to break the waxy husk before being fed to cattle, otherwise most of the seeds will be swallowed whole, which may cause indigestion. It is also used to produce ethanol, grain alcohol, starch, adhesives, and paper.
Sorghum grains are richer in micro-nutrients than other grains. Half a cup provides 18% of the recommended daily dose of iron, 25% of vitamin B6, 37% of magnesium, and 30% of copper. It also contains significant amounts of phosphorus, potassium, zinc, and thiamine. Half a cup (96 g) of raw sorghum grains will provide one and a half cups of cooked sorghum. However, most people do not eat more than half a cup at one time, which will lower the calories and carbohydrates.
Half a cup of raw grains (1,5 cups cooked) contains 316 calories, 69 g of carbohydrates, 7,5 g of fibre, 10 g of protein, 3 g of fat, 2 mg of sodium and 2,5 g of sugars.
Although sorghum provides these dietary benefits, it lacks sufficient vitamin A that is essential for preventing the risk of blindness and even death in children with a vitamin A deficiency.
According to a recent study, new sorghum varieties developed by the United States Department of Agriculture (USDA) can help meet the nutritional needs of mothers and children in these mostly food insecure countries. In these countries, diets are dominated by cereal grains high in carbohydrates, which may lead to obesity and nutrient deficiencies, especially vitamin A, iron, and zinc, which are among the leading causes of death for children under five years.
Many chronic diseases are caused by underlying inflammation. The antioxidants in sorghum can help combat cell damage, thereby reducing inflammation. It also improves blood glucose responses, which is good for people living with diabetes or prediabetes, preventing the latter from developing into diabetes.
Gluten-free sorghum is suitable for people who are allergic to gluten and suffer from celiac disease.
The high fibre content may help reduce the body fat percentage. The low sodium content is suitable for people on a low-sodium diet to control blood pressure, while sorghum increases the intake of potassium.
It is, however, possible to be allergic to sorghum. Symptoms of an allergic reaction may include nausea, indigestion, vomiting, diarrhoea, and respiratory issues like coughing or wheezing. It is important to limit carbohydrate intake to prevent weight gain.
After harvesting, the grains are dried, which makes it shelf-stable so that it is available throughout the year.
Dried grains should be stored in are sealable container with a tight-fitting lid. After cooking, it can be stored in the refrigerator for up to a week.
The different varieties of sorghum grains are defined by colour, including white, orange, tan, pink, red, and black. It is processed into many formats, including flour for bread and pastries, liquefied as syrup, pearled sorghum as a hot grain and popped as a snack. Popped sorghum and sorghum syrup are ready to eat. Sorghum flour can be used along with wheat flour for baking.
Cooked sorghum grains make a nutritious, high-protein addition to porridges, grain bowls, or pilaf that is usually made with rice.
Typically, one cup of raw sorghum is cooked in four cups of liquid. Rinse the grains before adding boiling water. Bring back to boil and simmer uncovered on medium heat for about an hour.
Sorghum is drought tolerant because of its deep root system. Although it performs better than maize in semi-arid, drought-prone areas, it does not tolerate extended periods of drought. It grows best at temperatures between 25 and 32 °C at seeding, and in day temperatures of 30 °C during growth. It requires rainfall of about 400 to 750mm per year but is sensitive to frost and sustained flooding.
If the crop is sown in the rainy season, it may require one to three irrigations depending upon the rains. For summer crops, six to seven irrigations may be carried out due to high temperature. Winter crops may need irrigation at 30 to 45 days (seedling elongation stage), at 60 to 65 days (reproductive or heading stages), 70 to 75 days (panicle emergence), and 90 to 95 days (grain development stage).
Sorghum grows well in different soils, but best in sandy loam with good drainage. A soil pH range of 5,5 to 7,5is ideal. The soil should be ploughed and levelled with a fine tilth for weed-free sowing.
A seed rate of 35 to 40 kg per hectare is sufficient, and it should be carried out by drilling at a row-to-row distance of 25 cm and at a depth of no more than two to three cm. Seed broadcasting should be avoided.
Ten to fifteen tonnes of farmyard manure can be used on one hectare of land in preparation of sowing. Contact the agricultural extension officers in your area for more information on suitable weed, insect, and disease control.
The crop will be ready in single-cut varieties for harvesting at 65 to 75days after sowing (50%, flowering stage), and in multi-cut varieties, the first cut should be done at 45 to 50 days, and subsequent cuts should be carried out at one-month intervals. Sorghum is typically harvested in autumn, depending on the plant’s moisture content.
Depending on good farm management practices and a good variety, sorghum can yield up to 1 000kg/ha. Green matter yields are about 20 t/ha but may reach 75 t/ha under optimal growing conditions. Average yields of grain range from 0,5 to 0,9t/ha in Africa.
Sorghum can be used in conservation farming. Planted in rotation with a legume crop, it will benefit from the nitrogen provided by the legumes.
After harvest, the stubble can be ploughed in to improve the organic status of the soil while limiting erosion. Drought tolerant species improve water use efficiency.
Erramouspe, H.(2021) The Global significance of sorghum – Africa. National Sorghum Producers https://sorghumgrowers.com/magazine/the-global-signficance-of-sorghum-africa/
Heuzé, V. Tran, G. Lebas, F.(2015) Sorghum grain. Feedipedia, a programme by INRAE, CIRAD, AFZ and FAO https://www.feedipedia.org/node/224
Garone, S. (2021) Sorghum Nutrition Facts and Health Benefits. Verywell Fit https://www.verywellfit.com/sorghum-nutrition-facts-and-health-benefits-5093271
Paul, M. (2023) These new sorghum varieties might help sub-Saharan Africa’s nutritional needs. Down to Earth https://www.downtoearth.org.in/news/world/these-new-sor-ghum-varieties-might-help-sub-saharan-africa-meet-nutritional-needs-91013