Miscanthus: A future of energy
Author: Suraj Kar
The increasing scarcity and demand of fossil-fuel energy sources and climate change concerns lead to a search for an alternative sustainable energy source. Biomass energy is considered as a useful alternative for sustainable green energy production. Historically, humans have burnt plant materials like dry grass, wood and crop residues as cooking fuel and for heating. But with rising cheap and more convenient petroleum fuel, the use of plant-based energy sources decreased with time. Petroleum fuels were quick to replace almost all kinds of energy sources during the industrial revolution. The need for an alternative source of energy was obsolete until recently when a huge scarcity of petroleum in the market led to a peak price rise and recession and decades of excessive use of fossil energy led to Global warming as a result of a release of Green House Gases (GHGs) from their fossilized reserves. To combat these issues, research has started to find out better and alternative sources of energies that may partially and eventually permanently replace a majority of the fossil fuel demand. Energy from plant biomass is an effective alternative in this regard. Crop residues after harvesting are a good source of biomass. Also, anaerobic fermentation to produce alcohols from starchy grains like corn has also gained popularity in the past. Sugar alcohol from Sugarcane, Sorghum and Sugarbeet is also very popular in many countries. But with increasing population, shrinking and degrading agricultural land, there is an ethical concern regarding the use of food crops for energy production. We need dedicated biomass energy crops, that are resource-efficient and do not occupy valuable crop lands. This vision led to the adoption of perennial biomass crops that can grow on marginal lands without much resource investment.
Miscanthus is a native grass of eastern Asia that is highly adaptive to a variety of environments that range from tropical arid and semi-arid regions of Africa to 50 degrees north in Siberia or at an altitude from 6 m above mean sea level in northern Japan to as high as 4000 m on the eastern Himalayan mountains.
Miscanthus apart from its huge adaptation range has a plenty of special characteristics that give this crop an edge over other biomass energy species. Being a C4 perennial, it can produce a huge biomass for a fairly long period of time, that ranges from 7 to 15 years, depending on the region and species of the crop being cultivated. Its quick growth allows two to three cuts every year after the initial establishment phase. Its lignocellulosic biomass can be easily converted into ethanol or fed directly to the boilers to produce electricity. Its nutrient recycling ability spares the application of fertiliser every year that causes no eutrophication of water bodies. The ability of Miscanthus to withstand harsh environmental conditions allows it to grow in a range of environments including highly saline, extremely hot, cold or even barren erosion prone soils, low in nutrients. Though it is a tropical species, it can fairly adapt to a broad temperature range and can withstand a temperature as high as 45-degree centigrade in summer and -20 degrees in winters. Being rhizomatous in nature, it has an efficient overwintering ability and can germinate even after being under 6m of snow during winters in northern Japan. Its extraordinary cold tolerance and ability to cross with a range of species including maize, sorghum and sugarcane, inspired breeding research in recent times to induce more cold tolerance among these crops. A natural interspecific cross between diploid Miscanthus sinensis and tetraploid Miscanthus sacchariflorus, called as Miscanthus x giganteus, a sterile triploid, can produce a huge biomass and has high winter survival ability. Currently, this interspecific cross known as 'Illinois clone', is a matter of much comprehensive research to evaluate its winter survival, biomass production and relative invasiveness.
Recently, the breeding approach has been extended further to cross Miscanthus with sugarcane to develop an intergeneric hybrid 'Miscane' that shows a higher degree of cold tolerance and less susceptibility to disease than sugarcane itself. This may give us a greater scope to push the cultivation boundary of sugarcane into further north for both biomass and sugar-ethanol production. Hence, in the upcoming era of the alternative energy revolution and crop improvement, Miscanthus will be a key player.
1. Anzoua, Kossonou Guillaume, and Toshihiko Yamada. "11 Miscanthus Species." Biofuel Crops: Production, Physiology and Genetics (2013): 231.
2. Park, J. W., et al. "Development of new intergeneric cane hybrids, Miscanes, as a source of biomass feedstock for biofuel production." Plant and animal genomes XIX conference, San Diego. 2011.
About Author / Additional Info:
Currently I am doing my doctoral study at Hokkaido University, Japan
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