Photo courtesy of Dr. Anand Kumar.
Nov. 18, 2013 - The use of biomass crops in agriculture has been steadily increasing, thanks to the focus on renewable energy and fuels from local and international governments, as well as the general public. One of the most widely explored is sorghum, a grass species primarily used as food and fodder.
Native to Africa, sorghum came to America through trade routes in the 1700s as a feed grain crop, says Dr. Anand Kumar, a researcher at Agriculture Environmental Renewal Canada (AERC), a bio-seed company that specializes in the development of sorghum and pearl millet varieties for grain and forage. Recently, food grain sorghums have received a boost, thanks to its drought and heat tolerance, as well as its smaller fertilizer requirements than other crops, such as corn.
"AERC Inc. introduced sorghum into Canada 20 years ago and initiated research on its adaptation and development of types suited to various end-uses," said Kumar. "As well, in North America, prevalence of celiac disease is leading to strong growth in the gluten-free market, of which sorghum is a an important grain."
Sorghum is generally classified into three types:
1. Grain sorghum – mainly used as a principal food in tropical areas and also as a raw material for alcoholic beverages, sweets and glucose.
2. Sweet sorghum – characterised by high sugar content in the form of sap (similar to sugar cane). It is used as a material for sweetener syrup, and also as an alternative feedstock for ethanol.
3. Forage sorghum, also known as Sudan grass, which is used for forage (green chop, grazing) and silage.
According to Kumar, sorghum has become a great example of a biomass crop because its yields are extremely high, anywhere from 50-70 tons per hectare of fresh biomass with 60-70 per cent moisture. "Currently, sorghums tailored to biomass production are being developed in the U.S. – they have enhanced photoperiod sensitivity and long growth duration, accumulating more than twice as much biomass as grain sorghum. Sorghum for biomass produces more leaves, longer stems (up to 14 feet) and has a higher stem-to-leaf biomass ratio."
Until recently, all sorghum and pearl millet grown in Canada was obtained from the U.S., which is grown in states where corn cannot be grown. In Canada, currently, only about 5,000-8,000 acres of sorghum is being grown in Eastern Canada, he adds. However, in 2013, 3,000 acres of production and demonstration plots were planted out west.
The problem with growing sorghum in Canada is one of maturity, as the plant need to dry and be ready to harvest in 95-115 days, says Kumar. "In years where there is not enough accumulation of hear (for example, if summer is cool), maturity of the grain is difficult. But, the issue of maturity is not a problem for forage and silage, only grian sorghum."
To address this, AERC started developing sorghum and pearl millet hybrids in 1994 specifically adapted to Canadian climates for Canadian and international growers. Currrent research on sorghum at AERC focuses on incorporating a gene to improve its digestibility, developing higer yielding grain-sorghum hybrids and developing superior quality silage sorghums.
The development of new hybrids at AERC is a continuous process, says Kumar, and new hybrids are constantly being developed and tester. "And when new hybrids are identified through multi-year and multi-locational testing, and their seed production within Canada is possible, we commercialize them."
AERC Inc. has five commercial sorghum hybrids currently available to the public in 2013 and 2014:
1. CFSH 30 Forage sorghum, multicut
2. CHMS 35 Silage sorghum (single cut)
3. CSSH 45 Sweet sorghum for silage (single cut)
4. CGSH 9 Grain sorghum hybrid with white grain
5. CGSH 28 Grain sorghum hybrid with red grain
Additional details of the different sorghum varieties, as well as pearl millet, can be found at www.aerc.ca.