Sweet Potato and Cassava More Efficient Than Corn In Ethanol Study

According to the US Department of Agriculture, recent experiments show that sweet potatoes and tropical cassava yield two to three times as much carbohydrate for ethanol production as field corn. Sweet potatoes and cassava also require significantly less fertilizer and pesticide than corn.
The experiments are unique in that all three crops were grown at the same time in two different areas of the country.
But sweet potatoes and cassava are not without disadvantages.
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The two crops have higher start-up costs than corn, so without big subsidies farmers may not see a reason to hop on the bandwagon. The study notes that sweet potato and cassava only have greater potential than corn if economical harvesting and processing techniques are developed.
And while cassava and sweet potato are not staple foods like corn, they still take up valuable land that could be used for much-needed food production.
Additionally, the two crops only reach the lower limits of sugarcane’s production ability. So while the discovery of their efficiency is a milestone in the search for better ethanol, we still have a long way to go.
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cassava and sweet potatoes are staple foods in Africa and the Caribbean.
Forgot the links:
http://en.wikipedia.org/wiki/Cassava
http://en.wikipedia.org/wiki/Sweet_potato#Uses
Growing up in the West Indies my grandmother made all kinds of foods (mostly a small fried cassava cake inherited from the native Arawak Indians) from cassava and sweet potatoes ( just called potato as opposed to “Irish potato” ).
These are not staple foods for mostly western countries with too much fuel needs.
Good point, Khurt. I guess I didn’t take that into account since the experiment was performed in the US.
Interesting, I hadn’t really given a lot of thought to alternatives before. One thing of note, though, is that the types of corn being grown for ethanol (as well as for livestock feed) aren’t the same varieties as the ones used primarily as a “food” source, so I’m not sure why either one would necessarily impact the amount of land available for food production since we really shouldn’t be considering corn grown for ethanol as a food crop.
Cchiovitti - The issue is that we only have a limited amount of land available for food production, and corn of all varieties requires the use of that land. In the case of ethanol from corn, land use requirements are very significant. See this paper for more info:
http://www.sciencemag.org/cgi/content/abstract/1152747
“Additionally, the two crops only reach the lower limits of sugarcane’s production ability. So while the discovery of their efficiency is a milestone in the search for better ethanol, we still have a long way to go.”
Yes, at this point in the technology, ethanol is not going to single-handedly solve our energy problems, but it is certainly a step in the right direction and a vast improvement over continuing to rely on foreign oil. Also consider that we are continually finding new sources of ethanol (a la sweet potato and cassava) and refining the extraction process to make it ever more efficient.
Nigeria is the largest producer of cassava. the government of Nigeria has not come to know the value to attach to the product; hence, they left the sector to rot away. But here and then, i want to use this avenue to ncourage the government of the country to invite investors to help them explore the product for better usage.
In Nigeria also, Gofta is a witness to the scheme put in place by the immediate past president, although his intentions was to assist the farmers and make food surplus and cheap for the people, most states governors and local government council head where not able to meet their requirement of supporting with their counterpart fund to complement the federal government effort, therefore many farmers in my state (Edo State) where not able to benefit from that scheme.
The original USDA article to which this article links says: “Overall, the data indicate it would be worthwhile to start pilot programs to study growing cassava and sweet potato for ethanol, especially on marginal lands.”
What marginal lands? I don’t recall seeing very many “marginal” lands in the south-east or mid-Atlantic states of America.
The article continues, “[A]dditional research could help develop new biofuel sources without diverting field corn supplies from food and feed use to fuel.”
Um, the issue is not so much whether corn or some other crop is used, but whether arable land is diverted to growing crops for fuel. The only positive point about cassava and sweet potato is that its starch yields are much greater than from corn. But, as the ethanol industry is always telling us, corn ethanol at least generates a high-protein co-product (in volume terms about 30% of the original grain). If farmers switch to cassava or sweet potato, they will produce more ethanol per acre, but less protein.